View Full Version : Focusing The Nokton 50/1.5 Down To 0.7m
P. Lynn Miller
08-09-2010, 04:05
I started a discussion about rangefinder 50/1.4 lenses that can focus down to 0.7 metres - Close Focusing 50/1.4 RF Lenses (http://www.rangefinderforum.com/forums/showthread.php?threadid=93468) - where the Master Lens Modifier aka Brian Sweeney posted this stroke of genius...
The 50/1.5 Nokton is a screw mount lens. You can back it off a turn in the LTM to M-Mount adapter for closer focus. The actual optics and the RF Cam will move in unison, the actual focus will agree with what the RF indicates. You could make an LTM adapter with a "shim" on it to set the stand-off, and essentially get a hacked dual-range lens.
To which I replied....
Brian,
You are a genius. I was looking at the Nokton 50/1.5 setting on my desk today thinking, if that focused to 0.7m, it would probably be good enough for me.
Just checked... a 3mm, maybe 3.5mm shim would provide enough extension to move the lens to the limit of the rangefinder linkage. I pulled the mount off the back and there seems like there could be enough helical there to modify the lens. Not sure how complicated the modification would be though.
I may fabricate a shim, which would not take long, to at least test performance of the Nokton 50/1.5 down to 0.7m. If the lens holds up at that distance then it may be worth looking at modifying it for 0.7m MFD.
Thanks!
Which brings us to the current state of affairs...
The thickness of a CD/DVD provides enough extension to just 'run-out of rangefinder'. I made a shim of an old DVD and will load the M5 with a roll of Efke 25 soon to check the performance of the Nokton 50/1.5 at distances less than 0.9m. With the shim installed, focus range is about 2.4m to 0.7m.
Since I do not have a digital RF, you will have to wait until I get the film developed and scanned for results. If someone with a digital RF wants to do this quick modification and post some images, that would be great.
Brian Sweeney
08-09-2010, 04:11
I will give this a try on my M8 later this evening with one of my lenses.
On the question of being parallel enough to the film plane after unscrewing- with the shim, it "should be". Only one way to find out.
This trick will not work with a wide-angle or telephoto lens. The only reason it works with a normal lens is that the RF Cam moves 1:1 with the optics.
"Genious"- I prefer the term "Mad Scientist". I even do the laugh, out loud and involuntarily.
P. Lynn Miller
08-09-2010, 04:20
Brian,
OK... Mad Scientist it is!
A DVD disc shim should be close to being the same thickness to keep the lens parallel for preliminary testing. It would be easy enough to spin off a spacer/shim of the right thickness from a piece of aluminium tubing if you had a lathe handy.
You should be able to quickly access the performance of the Nokton 50/1.5 with your M8 along with detecting any focus shift as well. Looking forward to seeing your results.
Brian Sweeney
08-09-2010, 11:36
I should also have realized that the threads will have to be filed down, as Roland did with his Nikkor 5cm F1.4 and I did with my Modified J-3. Early, before coffee. The RF follower of the camera can follow the lens cam only so far before hitting the threads of the lens. So in addition to shimming the adapter, the threads of the lens must be filed to the shape of the adapter's cut-out.
but what will the furthest focus range be after the mod?
I wonder - if it is so doable to make Nokton 50/1.5 focus closer - why didnt Cosina do it to begin with? I have a feeling that it is not as simple with this lens or it would already be done/"fixed" by Cosina. I believe they have to re-design it a lot to be able to focus down to 0.7m. Hope they do it too - as this was the main reason I sold it - otherwise it is a superb lens.
Probably the same reason Leica didn't adjust their cam and mounts on the 50 lux for 40+ years.
To work on the older cameras including M3s, they only focus to .8 or .9 meters.
Leica probably realized that by the '90s or whenever the E46 version came out, most of their users had moved on to M4s and up which supported .7m focusing.
I wonder - if it is so doable to make Nokton 50/1.5 focus closer - why didnt Cosina do it to begin with? I have a feeling that it is not as simple with this lens or it would already be done/"fixed" by Cosina. I believe they have to re-design it a lot to be able to focus down to 0.7m. Hope they do it too - as this was the main reason I sold it - otherwise it is a superb lens.
Probably the same reason Leica didn't adjust their cam and mounts on the 50 lux for 40+ years.
To work on the older cameras including M3s, they only focus to .8 or .9 meters.
Leica probably realized that by the '90s or whenever the E46 version came out, most of their users had moved on to M4s and up which supported .7m focusing.
Yes - but Nokton was made waaaaay after that time, when most/many people use Leicas, etc that do focus down to 0.7m - why didnt they learn from Leica?. Or did they think at Cosina that if you have a LTM lens one HAS to use it on old body that cant focus to less than 1m.? IMO if they could make it focus down to 0.7m and didnt - thats the stupidest thing they've done. Thats why I think there was another ( mechanical/optical design related) reason why it was not done. After all - LTM Nikkor 5cm/1.4 is an old lens yet can easiy be modified.
I agree, that it would have been much better for us if both Leica and CV allowed their lens to focus as close as possible, as soon as possible.
It would messy up their data sheets, they'd have to specify for min. focus capability *if your camera is capable but it sure would be nice to have the E43 luxes focus in a bit closer. Nokton too.
Yes - but Nokton was made waaaaay after that time, when most/many people use Leicas, etc that do focus down to 0.7m - why didnt they learn from Leica?. Or did they think at Cosina that if you have a LTM lens one HAS to use it on old body that cant focus to less than 1m.? IMO if they could make it focus down to 0.7m and didnt - thats the stupidest thing they've done. Thats why I think there was another ( mechanical/optical design related) reason why it was not done. After all - LTM Nikkor 5cm/1.4 is an old lens yet can easiy be modified.
P. Lynn Miller
08-09-2010, 13:19
I should also have realized that the threads will have to be filed down, as Roland did with his Nikkor 5cm F1.4 and I did with my Modified J-3. Early, before coffee. The RF follower of the camera can follow the lens cam only so far before hitting the threads of the lens. So in addition to shimming the adapter, the threads of the lens must be filed to the shape of the adapter's cut-out.
Brian,
I have disassembled the back of the Nokton 50/1.5 and there is a milled stop at 0.9m to prevent the lens from focusing closer. After I determine whether the lens will perform at 0.7m, I will work out if the lens is worth the aggravation to make the modification.
And yes, the mount will have to be filed to let the RF follower contact the cam past 0.9mm
As for why Cosina did not make the Nokton focus closer, my original thinking was they limited the Nokton to 0.9m because of being a LTM lens and the mount would need to have a notch cut in it to all the RF follower maintain contact with the cam and this is just not done on a factory lens. But the Color-Skopar 50/2.5 focuses to 0.75 and Cosina did cut a notch in the mount to ensure with would work with bodies the focus down to 0.75m.
This is my biggest gripe with Cosina, we all know that they are capable of producing world-class optics, but sometimes they just seem to make illogical short-cuts. Why doesn't the Nokton 50/1.1 focus to 0.7m? JUst because Leica was too lazy to make the Noctilux f0.95 to focus to 0.7m was not a reason for Cosina to not make the effort.
Nikon/Nikkor has been making floating element lenses since 1970, long before the convenience of CAD/CAM. I would be happy to pay 50% or 100% more for the Nokton 50/1.1 if it focused to 0.7m.
Enough ranting... have a film to develop.
Brian Sweeney
08-09-2010, 14:19
The Leica M2 button rewind will focus to 0.7m.
My M3 will focus to ~0.7m.
I just tried the Summarit in LTM on the M8, and could unscrew it 1 full turn and have the RF pickup wheel of the M8 follow the Cam. The Summarit has thin threads. The images were in focus looing at the screen, pixel-peeping. I have a spare Summarit focus mount- I might go ahead and cut the threads.
This hack is for a pseudo Dual range lens. Put it on the shimmed adapter for close ups, will probably get out to at least 6ft. Put it on a normal adapter for 3ft to infinity.
Also: I know how to make the Jupiter-3 focus closer than my 0.8m hack. I could get it to 0.7m. Next time I pick up a cheap J-3, I'll try it.
My Canon P will get into ~0.8m with the modified J-3.
sounds like a lot of effort to get a lens to go from .7m to 6 feet, then need to switch adapters to go back to beyond 6 feet.
I can understand modding to increase min. focus and still get infinity, but I realize that will need some helical machining or more.
The Leica M2 button rewind will focus to 0.7m.
My M3 will focus to ~0.7m.
I just tried the Summarit in LTM on the M8, and could unscrew it 1 full turn and have the RF pickup wheel of the M8 follow the Cam. The Summarit has thin threads. The images were in focus looing at the screen, pixel-peeping. I have a spare Summarit focus mount- I might go ahead and cut the threads.
This hack is for a pseudo Dual range lens. Put it on the shimmed adapter for close ups, will probably get out to at least 6ft. Put it on a normal adapter for 3ft to infinity.
Also: I know how to make the Jupiter-3 focus closer than my 0.8m hack. I could get it to 0.7m. Next time I pick up a cheap J-3, I'll try it.
My Canon P will get into ~0.8m with the modified J-3.
Even with frame lines that move to compensate for parallax, the view from the finder is quite different from what the lens sees when you are that close. Frankly, if I am going to be shooting close I will use an slr that can go much closer than any RF lens. As a project, just to see if it can be done, I guess it's a challenge to do this modification. From the point of view of a photographer, I don't get it. But that's just me.
P. Lynn Miller
08-09-2010, 15:37
I just pulled the negatives from the tank and the results look promising. I will try to get some scans posted later today.
For the Nokton 50/1.5, making it a dual-range lens is very simple. Machine a shim the correct thickness, between 2.5 and 3mm(still not sure, the battery died in my digital micrometer), use the lens over its normal focusing range, infinity to 0.9, when you need to get up close and personal, spin the lens off the LTM adapter, pop on the shim, spin the lens back on, and you are good down to about 0.65m(at least that is about where the M5 is uncoupling) and out to about 2.5m, which perfect for a portrait shoot or close quarters such as a pub or dinner party. No modification needed to the lens or adapter.
I am going to have shim made up in the next day or two. If someone else wants one, let me know.
From one meter to .7 doesn't really stir my blood sorry and wouldn't be worth the effort from my angle!
A bit like teaching your cat to bark occasionally ... usefull for scaring off the odd intruder but it's still a cat!
:p
kinda like poppin' on some wheel spacers to pimp your ride, then poppin' them off for normal driving ... ;)
I just pulled the negatives from the tank and the results look promising. I will try to get some scans posted later today.
For the Nokton 50/1.5, making it a dual-range lens is very simple. Machine a shim the correct thickness, between 2.5 and 3mm(still not sure, the battery died in my digital micrometer), use the lens over its normal focusing range, infinity to 0.9, when you need to get up close and personal, spin the lens off the LTM adapter, pop on the shim, spin the lens back on, and you are good down to about 0.65m(at least that is about where the M5 is uncoupling) and out to about 2.5m, which perfect for a portrait shoot or close quarters such as a pub or dinner party. No modification needed to the lens or adapter.
I am going to have shim made up in the next day or two. If someone else wants one, let me know.
P. Lynn Miller
08-09-2010, 17:48
The thickness of the shim needed to take the Nokton 50/1.5 to 0.7m is 1.1mm. I am having one made today by a machinist friend.
Having a Nokton 50/1.5 that will focus to 0.7m will make for a very versatile, fast 50mm for general RF use. If I am planning for tight head and shoulder portraits, I will use an F with the Nikkor 105/2.5 or or the Micro-Nikkor 105/2.8 for macro work, or any of the other dozen or so Nikkor's that I have.
It seems that the only RF 50/1.4 lens that will focus to 0.7m is the Summilux or a modified LTM Nikkor 50/1.4, a modified Nokton would be an economical alternative.
Having abit of fun and why not?
I often mis-type Brian's name as Brain.
Mybe it is an omen?
is if you replaced the shim with a light proof inner baffle tube, then put 4 angled mini-hydraulic pumps around the lens base, triggered by sync'd stepper motors, then with a flick of a button or switch you could go from close focus mode to normal mode, maybe put a little bounce in the movement for effect !!
Take it down to E. LA and do some street shootin' !
The thickness of the shim needed to take the Nokton 50/1.5 to 0.7m is 1.1mm. I am having one made today by a machinist friend.
Having a Nokton 50/1.5 that will focus to 0.7m will make for a very versatile, fast 50mm for general RF use. If I am planning for tight head and shoulder portraits, I will use an F with the Nikkor 105/2.5 or or the Micro-Nikkor 105/2.8 for macro work, or any of the other dozen or so Nikkor's that I have.
It seems that the only RF 50/1.4 lens that will focus to 0.7m is the Summilux or a modified LTM Nikkor 50/1.4, a modified Nokton would be an economical alternative.
Having abit of fun and why not?
The thickness of the shim needed to take the Nokton 50/1.5 to 0.7m is 1.1mm. I am having one made today by a machinist friend.
Having a Nokton 50/1.5 that will focus to 0.7m will make for a very versatile, fast 50mm for general RF use. If I am planning for tight head and shoulder portraits, I will use an F with the Nikkor 105/2.5 or or the Micro-Nikkor 105/2.8 for macro work, or any of the other dozen or so Nikkor's that I have.
It seems that the only RF 50/1.4 lens that will focus to 0.7m is the Summilux or a modified LTM Nikkor 50/1.4, a modified Nokton would be an economical alternative.
Having abit of fun and why not?
Speaking of fun ... I'm off to play with the Norita! :D
edit ... and I meant to add ... I'm wondering if this mod would work on the Canon f1.2 ... Brian?
P. Lynn Miller
08-09-2010, 21:43
I never knew that the Nokton 50/1.5 was so freakin' sharp! The negatives are scorching at f1.5 and 0.7m! Wow! I can only hope that my mediocre flatbed scanner will be able to the lens some justice.
Just picked up a set of alloy shims... 0.8mm, 0.9mm, 1.0mm, 1.1mm.
Scans and photos to come soon...
P. Lynn Miller
08-09-2010, 23:32
Here as some 'test' scans as promised.
Here are the technical details -
Leica M5
Nokton 50mm f1.5
Efke KB100
Rodinal 1:25
Epson V500 scanner
All images were shot hand-held at 1/60th of sec at f1.5 at minimum focus distance, that is just before the lens decoupled from the rangefinder, which is about 0.65m.
The Efke 100 was rated at box speed and developed in Rodinal 1:25 at 19°C for 6:30 minutes with vigorous agitation.
The negatives were scanned on my Epson V500 at 3200dpi as transparencies in .tif format. The .tif files were imported into Photoshop CS4, inverted with CF Systems ColorNeg filter. The files were converted to Black & White with Photoshop B&W command with no filters. All files were adjusted with the same contrast curve. The files were resized to 900 x 600 images with Bicubic Sharper and saved as Highest Quality .jpeg files.
Here are the scans...
http://plynnmiller.com/rff/2010_08_003_005_900.jpg
http://plynnmiller.com/rff/2010_08_003_006_900.jpg
http://plynnmiller.com/rff/2010_08_003_007_900.jpg
http://plynnmiller.com/rff/2010_08_003_010_900.jpg
http://plynnmiller.com/rff/2010_08_003_012_900.jpg
The scanner simply does not come close to capturing the resolution that is on the negative. With a loupe I can easily read the newspapers. And unexpected bonus was the M5 rangefinder is spot-on.
I am already hearing grumblings about not having full-resolution scans and the small web images. Well, I am happy with the negatives and this is as technical as I am going to get. I am stunned at the resolution the Nokton 50/1.5 is putting on the negative, not unlike my Collapsible Heliar 50/3.5 negatives.
There is no reason that the Nokton 50/1.5 cannot be used with confidence down to 0.7m and that was the only reason for these test shots. I am more than happy with the performance wide-open and close-up.
Now I am waiting for someone to complain about the bokeh!
Does that mean if you used a collaspible lens, you could push back in the shim thickness and get both near and standard.
Brian Sweeney
08-10-2010, 01:34
For a collapsible lens: you would have two detente's in the tube, one for use close-up and the second to undo the shim. The tube would not hold flat enough without being locked into place.
This should work on the Canon 50/1.2 as well, in fact just about any 50mm thread mount lens.
As for the trouble of using a dual-range lens, Leica and Nikon made dual-range lenses. People use extension tubes. This is essentially an RF coupled extension tube.
Is it worth it? 0.7m gives an edge. That is why Leica moved to it.
If you have spare shims... sending PM.
wombatjuice
08-10-2010, 02:47
Kudos to OP for sharing his finds...
Now if there's an easier/idiot-proof way I would like to try this out too! :P
oh, come on. Why go to all this trouble when all you need is another $3400 to trade in for a new lux asph!
P. Lynn Miller
08-10-2010, 06:12
oh, come on. Why go to all this trouble when all you need is another $3400 to trade in for a new lux asph!
For only $3400 it is hardly worth the bother... :bang:
P. Lynn Miller
08-10-2010, 14:48
First things first... let's give credit where credit is due... while I was banging on about getting a Nokton to focus down to 0.7m... it was Brian's idea to make a simple shim to allow an LTM lens to close focus... not mine. I am just the mechanic, while Brian is the engineer.
This has to be the simplest lens hack ever, only using a filter is simpler only if you do not have to remove the lens hood to install the filter.
Absolutely no modification is needed to the lens, M-adapter or camera.
Here is the set-up... camera, the Nokton 50/1.5, LTM to M-mount adapter, and a shim. Here are the 4 shims that I had made to different thicknesses to determine how much extension was needed to allow the lens to focus to 0.7m. The shims are 0.8mm, 0.9mm, 1.0mm, and 1.1mm thick.
http://plynnmiller.com/nokton5015_07shim/nokton5015_07shim_101.jpg
50-75 M-mount adapter, 0.9mm shim, and Nokton 50/1.5
http://plynnmiller.com/nokton5015_07shim/nokton5015_07shim_102.jpg
Showing shim on lens...
http://plynnmiller.com/nokton5015_07shim/nokton5015_07shim_103.jpg
So here is how simple this modification is... here is the lens mounted without the shim...
http://plynnmiller.com/nokton5015_07shim/nokton5015_07shim_104.jpg
Here is the 0.9mm alloy shim... lightweight, virtually indestructible, easily carried in a shirt-pocket...
http://plynnmiller.com/nokton5015_07shim/nokton5015_07shim_105.jpg
To deploy the shim and convert the Nokton 50/1.5 to a close-focus lens... unscrew the lens from the M-mount adapter... leaving the adapter mounted on the camera... put the shim on the lens mount...
http://plynnmiller.com/nokton5015_07shim/nokton5015_07shim_106.jpg
And screw the lens back onto the camera... the shim is almost undetectable...
http://plynnmiller.com/nokton5015_07shim/nokton5015_07shim_107.jpg
I have settled on using the 0.9mm shim, this will let the Nokton focus to just under 0.7m without letting the lens uncouple from the rangefinder. I do not like having a decoupled lens, especially when shooting quickly at close-focus, you can forget the lens decouples and end up with lots of out-of-focus negatives.
Since there must be a standard helical twist for all 50mm LTM lenses, I am thinking that any 50mm LTM lens that focuses to 0.9m will focus to 0.7m. The same will go with a lens the will only focus to 1m, 1.1m and etc, once the shim thickness has been established for that MFD(minimum focus distance), it should apply to all lens of the MFD regardless of brand or aperture. Am I right about this Brian?
Thanks!
P. Lynn Miller
08-10-2010, 15:20
...if you cut the shim so it makes a elongated C shape, you will be able to take it on and off without screwing the lens all the way off. As long as the shim extends past the midway point there should be no problems with the lens remaining parallel to the mount.
Patrick,
Sorry I did not address your idea yet, got busy with scans, photos and etc.
An elongated C-shaped shim should work, although that thread interface between an LTM lens and adapter is pretty loose and provides no support for the lens.
Good idea... I will see if I can get one made. I am running on the good-will of my machinist friend at the moment, so this may start to cost me!
I guess the question is... how much is one willing to pay for a this adapter. Cost to manufacture in quantities of 20 should be very reasonable. You would need to have a few thicknesses on hand to cater for different lenses.
Thanks!
Maybe the Japanese gods will in their wisdom produce an M-Mount version of this lens. I've always found this lens to be sharp, even wide open. Really an amazing lens for the price. A great value.
P. Lynn Miller
08-10-2010, 15:53
The shim could also have a protrusion to facilitate it being removed, perhaps with either a thumbnail slot similar to a pocket knife, or a bent up edge that would be far away enough not to interfere with the lens being mounted.
Patrick,
Been speaking the Brian and I am going to make a rudimentary C-shaped shim for him to test with his M8 for 'parallelness' and etc. If you want to test one as well, send me a PM with the thickness you want or the lens that you are going to be testing.
Making a circular shim is straight-forward and quite simple with a metal lathe. But when you start making shapes, you start looking at needing to use ground flat-stock or making over-size circulars and then machining or hand-cutting the shape into the shim.
It can certainly be done, but as you know, each step adds time and cost.
Give me an hour or two...
P. Lynn Miller
08-10-2010, 15:55
Maybe the Japanese gods will in their wisdom produce an M-Mount version of this lens. I've always found this lens to be sharp, even wide open. Really an amazing lens for the price. A great value.
I hope that they choose to make it a real f1.4 lens as well. A close focusing M-mount version of the Nokton 50/1.5 would be very nice. The only off-shelf close-focusing 50/1.4 is the Summilux, which is simply unaffordable for me at this time. And I am sure I am not alone.
P. Lynn Miller
08-10-2010, 16:22
Here are a few candid portraits with the Nokton 50/1.5... focused to 0.7m and wide-open. Remember these negatives were taken while I was still using the CD plastic spacer.
http://plynnmiller.com/nokton5015_07shim/2010_08_003_014_900.jpg
Leica M5 | Voigtländer Nokton 50mm f1.5 | Efke KB100 | Rodinal 1:25 | 6:30 minutes | 19ºC
http://plynnmiller.com/nokton5015_07shim/2010_08_003_020_900.jpg
Leica M5 | Voigtländer Nokton 50mm f1.5 | Efke KB100 | Rodinal 1:25 | 6:30 minutes | 19ºC
http://plynnmiller.com/nokton5015_07shim/2010_08_003_027_800.jpg
Leica M5 | Voigtländer Nokton 50mm f1.5 | Efke KB100 | Rodinal 1:25 | 6:30 minutes | 19ºC
There is no sharpening on these scans. Rodinal at 1:25 can make the grain pop on this emulsion.
P. Lynn Miller
08-11-2010, 01:20
Notice anything strange about this photo...
http://plynnmiller.com/nokton5015_07/nokton5015_07_101.jpg
No shims... but racked out to 0.7m! The Nokton 50/1.5 has been modified internally to allow it focus all the way down to just under 0.7m. Mission accomplished!
The modification was relatively straight-forward without compromising the integrity of the lens in any way. While I did leave a few tracks internally, there is no evidence of the modification externally except for the small notch filed in the LTM mount as shown below.
http://plynnmiller.com/nokton5015_07/nokton5015_07_102.jpg
With a fabrication of a few tools, I can modify these lens without any trace of the lens ever being tampered with except the notch on the mount. All I need now is to be able to engrave the '0.7' on the meter scale and '2.5' on the feet scale. If the ZM 50/1.5 is made in the same way, this modification could be done to that lens as well.
Having the Nokton 50/1.5 being able to focus as a full range lens from infinity to 0.7m has filled my need/want for a versatile 50/1.4 RF lens and my need/want for a Summilux 50. Instead I am looking for a silver Nokton 50/1.5 to modify as well to go with my new, yet to be bought silver M5.
Roland (ferider) knows the procedure for doing the same on the Canon f1.2 ... I must get around to it one day.
Notice anything strange about this photo...
Seems to be extrermely underexposed! :angel:
Brian Sweeney
08-11-2010, 01:33
If you took any pictures of the lens while apart, or do one again- please post it here!
A number of these lenses have internal stops, some even external stops, that can be removed or changed. That is the trick used for the close-focus J-3.
Filing the threads down allows the RF wheel of the camera to follow the cam inside the lens. ~3ft focus is where the Cam and edge of the threads lines up. When the threads are filed, many LTM cameras can also focus closer. My Canon P keeps up with the modified J-3.
Close focus lenses on a Leica- now everyone will want one.
Vincent.G
08-11-2010, 01:47
OMG Miller, you should send your resume to Cosina.
P. Lynn Miller
08-11-2010, 01:49
If you took any pictures of the lens while apart, or do one again- please post it here!
A number of these lenses have internal stops, some even external stops, that can be removed or changed. That is the trick used for the close-focus J-3.
Filing the threads down allows the RF wheel of the camera to follow the cam inside the lens. ~3ft focus is where the Cam and edge of the threads lines up. When the threads are filed, many LTM cameras can also focus closer. My Canon P keeps up with the modified J-3.
Close focus lenses on a Leica- now everyone will want one.
Brian,
No photos... I got stuck into it and forgot. The construction of the Nokton is odd compared to any lens I worked on before.
The modification requires complete disassembly of the focus helical and some serious filing since the stops are machined into the lens mountings. And, of course, the actual lens mount had to filed to allow the RF arm to follow the cam, but that was a few light touches of the file as you can see.
Keith,
I am sure there are many lenses that can be modified to focus to 0.7m. I wanted a modern lens without 'character issues', so that is why I picked the Nokton 50/1.5. It has a reputation of good resolution, good contrast, well-controlled flare, and lack of focus-shift. I am pleased with the end result.
Very cool, Lynn. You must have had patience at assembly end to get infinity aligned again.
With a fabrication of a few tools, I can modify these lens without any trace of the lens ever being tampered with except the notch on the mount. All I need now is to be able to engrave the '0.7' on the meter scale and '2.5' on the feet scale. If the ZM 50/1.5 is made in the same way, this modification could be done to that lens as well.
Oh my goodness. That would make my favorite lens (ZM Sonnar 50/f1.5) so much more incredible. I wonder what would happen to the focus shift.
With your modification to the Nokton, you can still focus to infinity, correct?
How about with the shims? My understanding is that you cannot, but that DOF would cover the error.
Brian Sweeney
08-11-2010, 10:32
The new solution of removing the internal stop allows the lens to be used full-range, 0.7m to infinity. This is also true of my modified J-3, done much the same way- internal stop removed, threads files down.
The "mini-Extension-Tube" shim allows the lens to be used 0.7m to ~ 3m. Remove the shim for 0.9m to infinity. No change to the lens is required. That trick will work on a lot of LTM lenses.
I love the ingenuity of this forum.
P. Lynn Miller
08-11-2010, 14:31
Lynn--
Wow, now you really have my attention. A serious bravo is in order here.
Please keep the forum updated on your efforts with the CV 50/1.5. And if you get those tools, absolutely let us know.
Should I consider posting my own lens to you now?
--JSU
Thanks!
I have reached my goal with the Nokton 50/1.5, I have a fast 50mm lens that can focus continuously from infinity to 0.7m, no rings, no shims, opertates just like the Summilux 50 ASPH.
As for sending me your lens... I would make that a cautious... yes.
Oh my goodness. That would make my favorite lens (ZM Sonnar 50/f1.5) so much more incredible. I wonder what would happen to the focus shift.
With your modification to the Nokton, you can still focus to infinity, correct?
How about with the shims? My understanding is that you cannot, but that DOF would cover the error.
Have no idea how the ZM Sonnar will perform closer than 0.9m. I suppose that it is one of those try it and see.
Yes, the Nokton can now focus from infinity to 0.7m. You will not be able to use shims on the ZM Sonnar as it is not an LTM lens.
The new solution of removing the internal stop allows the lens to be used full-range, 0.7m to infinity. This is also true of my modified J-3, done much the same way- internal stop removed, threads files down.
Brian,
The modification of the Nokton 50/1.5 is more about moving the stops than removing them. The original infinity stop is not altered and the lens will not focus past 0.7m.
I am sure that there will be plenty of Nokton 50/1.5 owners who want to know if I will do this modification to their lens. I will consider it on a case by case basis, I am not a professional lens repairer nor the 'Mad Gearhead Scientist'.
The modification takes about 3 hours from start to finish, with some custom tools and practice, that time should be about halved. It does require the focusing helical to be disassembled, so it can become a tedious reassembly. I do not have a convenient method of ensuring that the lens is calibrated for correct focus except by using my M5. I will try to get a more standardised method of be able to collimate the lens after modification. Send me a PM if you want to discuss your lens further.
I will be starting a new thread over in the Voigtländer Bessa forum to exhibit photographs taken with the 0.7m Nokton 50/1.5.
Thanks!
Brian Sweeney
08-11-2010, 15:43
I know a lot of people want you to document that next lens that you do.
As for "Mad gearhead Scientist"- if the laugh comes involuntarily as you focus to 0.7m, you are most definitely a "Mad Scientist".
The question I have to ask is if the manufacturer of the lens restricts the minimum focusing distance to one meter with a design that can be altered relatively easily to get it to .7 mtr ... what was their purpose in doing so in the first instance?
P. Lynn Miller
08-11-2010, 15:50
Brian,
Not sure about the involuntary laugh, but when you consider that this modification requires putting a big file into a small lens and then filing like a madman... I have to be abit deranged.
I am worried about documentation as there is a huge amount that can go wrong and I do not want to be held responsible for the write-off of someone's Nokton. I will take photos of the next one I modify though with all the disclaimers.
I think the 50/1.5 and 35/1.7 were made for the Bessa R, Keith, and limited because of the camera, not the optics.
Roland.
I think the 50/1.5 and 35/1.7 were made for the Bessa R, Keith, and limited because of the camera, not the optics.
Roland.
Ahh ... that makes sense!
Thanks Roland ... I need to know these things! :p
P. Lynn Miller
08-11-2010, 16:28
The question I have to ask is if the manufacturer of the lens restricts the minimum focusing distance to one meter with a design that can be altered relatively easily to get it to .7 mtr ... what was their purpose in doing so in the first instance?
Keith,
I have asked this question myself, because it seems that Cosina could have used this as marketing point. I think there are 2 reasons...
1. The Nokton 50/1.5 was released very early in the production of the Bessa bodies and Voigtländer lenses in 1999. The rangefinders of the the Bessa T, R, and R2 only coupled to 0.9m. So there was no in-house incentive to make the Nokton focus closer.
2. The Nokton 50/1.5 is an LTM lens, so that meant that the mount of the lens would have to be modified to allow coupling down to 0.7m.
Now oddly, when the Color-Skopar 50/2.5 was released in 2002, it had a modified LTM mount and the lens does focus to 0.75m
So go figure...
There should be a Nobel price for lens hacking, and I know a few here that should receive it :):cool:
Now, Lynn, would you do yourself a favor and post a detailed DIY manual?
Unless you do want to see your mailbox full of Noktons from all over the world waiting for your magic ;)
Thanks guys, great job!
Roundtable at Cosina headquarters:
"They found out! They found out! I told you some genius would find out eventually! Next thing they will find out how to open up the Color Skopars to f1.2, and then what?"
;-)
ethics_gradient
08-12-2010, 12:12
I do not have a convenient method of ensuring that the lens is calibrated for correct focus except by using my M5. I will try to get a more standardised method of be able to collimate the lens after modification.
Just tape a small piece of ground glass on the film plane of your M6. I use a similar trick when checking the accuracy of my lenses. I think this is what repairpeople do as well.
P. Lynn Miller
08-15-2010, 14:18
...unless you do want to see your mailbox full of Noktons from all over the world waiting for your magic ;)
With the current status of my employment, I would not be opposed to a mailbox full of Nokton's to modify especially if they were accompanied by a donation. ;):angel:
I wonder - since there is more involved in making Nokton focus closer than Nikkor 5cm/1.4 - how sure are you that lens (Nokton) still focuses correctly at ALL focus distances? Could you also give a more detailed explanation as to what you did to make it focus closer? Cause if it works as you say it does - you just put Cosina to SHAME! Great work - regardless, though. Hope to see more samples from your "fixed" Nokton.
Brian Sweeney
08-15-2010, 15:00
The Nokton should be just fine across the full focus range, the RF Cam moves 1:1 with the optics, and the RF of the camera is calibrated to 0.7m. Same with the Nikkor, filing down the threads is required to allow the RF follower to not get blocked as the cam moves inside the mount of the lens.
NOW- the Jupiter-3 and Jupiter-8 modified for close focus does have the problem of focus not being accurate across the entire range. But, that is for a different thread.
P. Lynn Miller
08-15-2010, 15:12
I wonder - since there is more involved in making Nokton focus closer than Nikkor 5cm/1.4 - how sure are you that lens (Nokton) still focuses correctly at ALL focus distances? Could you also give a more detailed explanation as to what you did to make it focus closer? Cause if it works as you say it does - you just put Cosina to SHAME! Great work - regardless, though. Hope to see more samples from your "fixed" Nokton.
My modified Nokton focuses correctly at all distances, right down to 0.7m. The reason being that I actually re-machined(by hand) the close-focus stop. This modification only allows that lens to be extended further along the focus helical by 0.9mm. The tricky part of this modification is the machining involved. Cosina could have done the 'mod' on the lens in less than 1 sec with their CNC mills while manufacturing the lens. But modifying the lens after the fact is more tedious and complicated.
If you are a willing to disassemble your Nokton 50/1.5, you will find that the focus stop is milled into the main lens housing. So the lens has to be disassembled entirely, leaving only the main housing, which then has to be reworked so the close focus stop is moved further along. Care has to be take not touch the bearing surfaces of the focusing ring and helicals on the housing. Nick those with the file and you will have a rough focusing lens forever, not to mention possible wobble.
The modification makes no changes to helical pitch, infinity stop, focusing cam shims, or infinity focus indexing. So the lens is unaffected except that is now focuses to 0.7m instead of 0.9m.
I could say shame on Cosina as well... but I do not want to sound ungrateful for the huge contribution they have made to the rangefinder community. Without Cosina we would be much poorer in RF lens variety and choice, and I never want to take their efforts and work for granted. I just wish that Cosina would stop operating in the shadow of Leica and show us the world-class optics producer that they are. Time for Cosina to set its own rules of play.
Thanks, Brian... I do not know much about the J-3 or J-8.
That's what I content myself with doing Fred. Or using a tele instead of a 50.
Still from 1m to 0.7m corresponds to a crop factor of 1.4, or half the film real estate.
Roland.
Brian Sweeney
08-16-2010, 11:29
OK, this is not a flame...
But why not just crop a bit? All of this work is totally aimed at producing an un-cropped image which is a bit closer. We are talking 11 inches here?
Why not crop?
Too Easy.
And besides... It does not give the same perspective as moving in closer....
P. Lynn Miller
08-16-2010, 13:43
OK, this is not a flame...
But why not just crop a bit? All of this work is totally aimed at producing an un-cropped image which is a bit closer. We are talking 11 inches here?
Fred,
I have asked myself this question... since the answer could save me a lot of headaches and grief.
I am not a cropper... it is simply something I do not do unless there is no other choice. I want to compose in the viewfinder what I am going to see on the print. I know that RF frame-lines are representative, but when I look at my negatives, I am seeing what I saw in the frame. Maybe a hang-over from my years of using a Nikon F with 100% viewfinder. Who knows...
When using 35mm film, I particularly do not crop as the negative is already very small. As Roland stated above, moving from 1.0m to 0.7m increases the amount of emulsion that you can use for printing by 50% or so. And the is significant in my opinion.
The driving motivation for modifying the Nokton 50/1.5 to focus to 0.7m was increase the versatility of the lens. Yes, I could use a telephoto to get closer, but then I have to carry a second lens. This allows me to carry one lens that is fast, not too long, not too short, and allows me to get close enough for tight portraits and etc. without spending a months wages on the Summilux 50. This lets me hit the streets with a pocket full of film and the M5 with the Nokton 50/1.5 thrown over my shoulder.
That is why I modified my Nokton 50/1.5 to focus to 0.7m.
I wonder if there is any progress on this - I mean - did you have a chance to do any more lenses and take pics of this procedure? I am very tempted to get Nokton and try this modification on it - so I wish I have a bit more info/pics for that.
P. Lynn Miller
08-22-2010, 02:42
I am hoping to have a silver Nokton 50/1.5 in a few days and I will document the modifying of this lens. Just need to find a chrome M5 now...
Lynn, I wonder if such a modification would be possible on the ZM C-Sonnar...
P. Lynn Miller
08-23-2010, 02:13
Lynn, I wonder if such a modification would be possible on the ZM C-Sonnar...
If it is built like the Nokton 50/1.5, yes, it should be able to be modified. Since I do not have a ZM C-Sonnar to dissect I have no idea.
Now if someone want to donate a C-Sonnar for the greater good, I am happy to investigate.
SimonSawSunlight
08-23-2010, 02:34
aye as hell.
While I didnt take either of them apart, to me it looks like focusing action seems same/similar with both Nokton 50/1.5 and Heliar 75/2.5, which makes me wonder if Heliar 75/2.5 is another lens that can be "fixed" to focus closer too?
kermaier
08-26-2010, 15:47
OK, this is not a flame...
But why not just crop a bit? All of this work is totally aimed at producing an un-cropped image which is a bit closer. We are talking 11 inches here?
I guess for those times when backing up a foot would send you tumbling down the stairs or over your chair backwards or cause you to miss the moment. :)
Ari
I am hoping to have a silver Nokton 50/1.5 in a few days and I will document the modifying of this lens. Just need to find a chrome M5 now...
I was wondering if there is any progress on this? I'm itching to take something apart. ;)
Why not just get a J3, and cut out a shim? This gives you .7m to infinity, and trust me, the lens is as good or better than the CV 50/1.5 (or at least my sample), and about 1/2 the size.
Not to hijack this thread but....
Has anyone tried this with the UC-Hex 35/2? (is it possible?) Because the biggest draw back of the 35 is the .9m focus.... if it went .7, they'd jump in value.
Well, having felt ADVENTUROUS today, I thought I'd have some fun. Here is a result :) :
http://i647.photobucket.com/albums/uu192/krosya/Camera%20Repair/IMG_0033.jpg
Notice anything different? ;)
http://i647.photobucket.com/albums/uu192/krosya/Camera%20Repair/IMG_0032.jpg
And here is a quick test shot on RD1s at NEW min focus - 0.7m or even less (didnt measure , but its pretty close, hehe):
http://i647.photobucket.com/albums/uu192/krosya/Camera%20Repair/EPSN6508.jpg
shim? how thick, how far out can you focus now? nice!
P. Lynn Miller
09-25-2010, 17:06
No shim... he did some metalwork!
I would be curious if you worked out the same modification is I did.
I have not have time to modify and document the silver Nokton 50/1.5 yet... so many other things on the burner. Probably will not happen for another few weeks.
No shims. Lens focuses throughout the whole range. Just some metal work - took me a few hours - lens had to be taken apart completely and some metal had to be filed down. I did take some pics, which I can post later. Not an easy modification, but can be done if you are handy. Funny thing is - now that I have done it, I'm mystified as to why Cosina didnt do it to begin with, as it wouldnt cost them a penny. Oh well, - I'm happy I did it and didnt screw it up. ;)
P. Lynn Miller
09-25-2010, 17:23
Team that close focusing Nokton 50/1.5 with your M5... makes a great al-rounder. Well done on the modification.
It's an LTM lens, so do most ltm cameras couple down below 1m? without mods?
I sure wish the makers of my J3 also supported it.
However, one of the CVs, can't remember if it's the 50/1.5 or 50/1.1 is quite distorted at .7m, much more so than my J3, so keep that in mind if you were the manufacturer of the lens ...
No shims. Lens focuses throughout the whole range. Just some metal work - took me a few hours - lens had to be taken apart completely and some metal had to be filed down. I did take some pics, which I can post later. Not an easy modification, but can be done if you are handy. Funny thing is - now that I have done it, I'm mystified as to why Cosina didnt do it to begin with, as it wouldnt cost them a penny. Oh well, - I'm happy I did it and didnt screw it up. ;)
I had a little scare - when I put it back together it didnt focus right:
http://i647.photobucket.com/albums/uu192/krosya/Camera%20Repair/EPSN6470.jpg
Took it apart again, found the problem - put it back and here we are:
http://i647.photobucket.com/albums/uu192/krosya/Camera%20Repair/EPSN6473.jpg
http://i647.photobucket.com/albums/uu192/krosya/Camera%20Repair/EPSN6497.jpg
http://i647.photobucket.com/albums/uu192/krosya/Camera%20Repair/EPSN6504.jpg
Great, sharp, close focusing lens with a beautiful bokeh - just what it is supposed to be!
Can this modification be done with other lenses?
I would love to make my CZJ 5cm 1.5 focus closer.
The same applies to the Canon 50/1.2 and the Heliar 50/2.
Maybe at Christmas time some people here will be Santas ... ?
P. Lynn Miller
09-25-2010, 17:31
The 50/1.1 shows a lot of barrel distortion at .7m... but only if you are shooting newspapers or brick-walls. In real use, the distortion is not evident. The 50/1.5 is is very well corrected right down to 0.5m.
P. Lynn Miller
09-25-2010, 17:36
Any thread mount 50mm can be very easily made to focus to 0.7m with a simple shim inserted between the lens and camera just I did with the Nokton 50/1.5 earlier in this thread. The lens will not focus to infinity, but will focus from about 4m(12')or so down to 0.7m. It is a very quick and easy way get abit closer, takes as long as mounting and unmounting the lens.
As for actual modifications to the lens helical, each lens is unique. I know Brian has modified a couple of various lens to be full-range focusing from infinity to 0.7m.
So maybe having a few shims handy would take care of most close-up sitiations. As long as the RF is still coupled, it is a great finding, Lynn and Brian.
I dont know about most- but a while back , after I did modify my LTM Nikkor 5cm/1.4 t focus closer, It did so on Canon 7 camera having full RF coupling.
Nokton 50/1.5 is a modern lens, even though LTM, should have still been made by Cosina with 0.7m. After all, they did make CV 21/4 that is LTM and focuses close.
Other lenses - dont know. As I said - Nikkor 5cm/1.4 -I've done that one. I also took apart CV 75/2.5 today and tried to make it focus close. It's a whole diffent design inside and I did make it focus a LITTLE closer,but it's really not possible to modify it to go to 0.7m, as far as I could tell.
I wish I was brave enough to take some more expensive lenses apart, like my M-Hexanon 50/1.2 t make it focus closer too - it's 0.9m now. But it's too nice of lens as well as rare to experiment with. Same goes for UC-Hex 35/2 -I dont have it any more, but I wouldnt risk it.
Brian Sweeney
09-25-2010, 17:42
Krosya- well done. I and others would appreciate it if you posted the pictures and instructions for the tear-down.
Brian Sweeney
09-25-2010, 17:45
My Canon P holds coupling with the modified J-3. A quick test is to take the lens off of the camera and check the close-focus of the RF without the lens. If it is much closer than 0.9m, and chances are the threads of the lens are blocking it from achieving close-focus. File the threads down.
Krosya- well done. I and others would appreciate it if you posted the pictures and instructions for the tear-down.
I'll have to get them sorted out - I took some photos as I wa doing it, but not every step, so some things I'll have to write out, while they are fresh in my head.
Brian Sweeney
09-25-2010, 17:57
The second time that I worked on a J-3 I decided to photograph everything and write it down. Like how not to spend an hour getting the helical back together.
It's scary how fast the "data" gets lost without writing it down.
Notice anything strange about this photo...
http://plynnmiller.com/nokton5015_07/nokton5015_07_101.jpg
No shims... but racked out to 0.7m! The Nokton 50/1.5 has been modified internally to allow it focus all the way down to just under 0.7m. Mission accomplished!
The modification was relatively straight-forward without compromising the integrity of the lens in any way. While I did leave a few tracks internally, there is no evidence of the modification externally except for the small notch filed in the LTM mount as shown below.
http://plynnmiller.com/nokton5015_07/nokton5015_07_102.jpg
With a fabrication of a few tools, I can modify these lens without any trace of the lens ever being tampered with except the notch on the mount. All I need now is to be able to engrave the '0.7' on the meter scale and '2.5' on the feet scale. If the ZM 50/1.5 is made in the same way, this modification could be done to that lens as well.
Having the Nokton 50/1.5 being able to focus as a full range lens from infinity to 0.7m has filled my need/want for a versatile 50/1.4 RF lens and my need/want for a Summilux 50. Instead I am looking for a silver Nokton 50/1.5 to modify as well to go with my new, yet to be bought silver M5.
BTW, I didnt have to make a notch in the mount - at least not yet. I only tried it on RD1S, but no coupling issues at all so far. I'll have to check other bodies though.
Still too much work for .2 / .3m IMHO. I can get .7m to infinity with a super thin shim on my J3 (tip - rei width membership card ~.2mm or so).
Why can't the Noktons just use a shim, or a fat adapter, as they apparently do vary in thickness?? Infinity - 10 feet is still infinity.
Still too much work for .2 / .3m IMHO. I can get .7m to infinity with a super thin shim on my J3 (tip - rei width membership card ~.2mm or so).
Why can't the Noktons just use a shim, or a fat adapter, as they apparently do vary in thickness?? Infinity - 10 feet is still infinity.
I suppose - it's different from person to person - it took me about 3-4 hours to make this modification, but to me it's worth it. Afterall - people pay a huge $$ difference from E43 to E46 Summilux pre-asph just to be able to focus closer, since they say that optical formula is the same.
So, YMMV. I'm loving the new "upgraded" Nokton and no shims or other things to mess with. :p
semordnilap
09-25-2010, 18:55
Mmmmmm.... Please post pictures...! I'm getting more and more interested in this...
P. Lynn Miller
09-25-2010, 18:58
Still too much work for .2 / .3m IMHO. I can get .7m to infinity with a super thin shim on my J3 (tip - rei width membership card ~.2mm or so).
Why can't the Noktons just use a shim, or a fat adapter, as they apparently do vary in thickness?? Infinity - 10 feet is still infinity.
I am not sure what you are trying to promote here...
I have said numerous times, that the simplest and easiest, non-destructive, easily reversible method to get the Nokton 50/1.5 to focus to 0.7m is with a shim/extension ring between the lens and camera/M-mount adapter as illustrated here...
http://plynnmiller.com/nokton5015_07shim/nokton5015_07shim_102.jpg
With the correct shim thickness, any LTM 50mm can be made to focus to 0.7m with rangefinder coupling. The shim thickness will vary depending on the close focus distance built into the lens. The Nokton 50/1.5 requires a 0.9mm while the Rigid Heliar 50/2 requires a 1.1mm to get down to 0.7m. While I have been making my shims from aluminium, they can be made from an old membership, steel, old DVD/CD, etc.
While you have the shim/extension ring installed, you will not be able to focus the lens to infinity, the focus range will be limited from 0.7m to about 4m. Remove the shim/extension ring and the lens operates as normal.
Brian is the authority on J-3 construction and modification and I am sure he will be happy to contribute to a new thread about modifications that allow the J-3 to focus to 0.7m.
With some metal work, the focus range of the Nokton 50/1.5 be extended to 0.7m without the use of a shim/extension ring. The lens will focus continuously from infinity to 0.7m with a turn of the focus ring. The extra 0.2m was worth taking the time to permanently modify my Nokton 50/1.5.
I have small kids, who I like to shoot relatively close up, and who like to come straight towards the camera :D
One reason I keep coming back to SLRs is that I can focus to .5m with a 50mm lens. If rangefinders only went to 1m, I wouldn't be using a rangefinder camera at all. The difference between 1m and 0.7m is huge for me. I'm watching this thread with great interest, although I am not in the slightest bit handy...
P. Lynn Miller
09-26-2010, 00:08
Nokton 50/1.5 is a modern lens, even though LTM, should have still been made by Cosina with 0.7m. After all, they did make CV 21/4 that is LTM and focuses close.
Agreed... Cosina has no real reason as to why they did not make the 50/1.5 focus to 0.7m from the factory, especially when the 50/1.5 is made to focus to 0.75m.
I also took apart CV 75/2.5 today and tried to make it focus close. It's a whole diffent design inside and I did make it focus a LITTLE closer,but it's really not possible to modify it to go to 0.7m, as far as I could tell.
Did you take any photos of the 75/2.5 apart? If so, would you be kind enough to start a new thread on the 75/2.5, which is rapidly becoming one of my most used lenses. I actually prefer the 75/2.5 to the new 75/1.8. Would be great to get the 75/2.5 down to even 0.9m.
Thanks!
Thanks guys for all the info and insight into the experimentation. I have 2 left hands as we say in Holland, but I always enjoy seeing others hacking lenses. As the Nokton has been sold out for a while I wonder whether Mr K. will produce a Nokton 50/1.5 in M mount and at the same time with closer focus. Wouldn't that be nice ?
Thanks guys for all the info and insight into the experimentation. I have 2 left hands as we say in Holland, but I always enjoy seeing others hacking lenses. As the Nokton has been sold out for a while I wonder whether Mr K. will produce a Nokton 50/1.5 in M mount and at the same time with closer focus. Wouldn't that be nice ?
That would be nice, but if they follow the same trend - a "new" Nokton 50/1.5-M/close focus would cost extra $200 or so. Based on latest price on Nokton at CmeraQuest - $599 it would make it $800 lens!
Did you take any photos of the 75/2.5 apart? If so, would you be kind enough to start a new thread on the 75/2.5, which is rapidly becoming one of my most used lenses. I actually prefer the 75/2.5 to the new 75/1.8. Would be great to get the 75/2.5 down to even 0.9m.
Thanks!
I did take pics and I will post them with some explanations as well. HOWEVER, I wouldnt get too excited yet - the way 75/2.5 is made - there is no way (or at least easy way) to make it focus closer, other than just a very bit. But I'll show what best I could do. Maybe someone handier than me will figure a way to do more?
I'm certainly not trying to take away anything from your or Brian's idea of using the shim. I am excited by what you've found with the shims and spent many hours on my own with both the 50, and a 35 based on your first postings.
I guess what you're not seeing, or believeing from me is that with the J3, it is possible to have a very usable lens that focuses from about .8m to near infnity, and I am assuming (based on the very small shim width compared to yours on the Nokton 50/1.5) that maybe this could translate to the Nokton, all it would take is someone to try a thinner shim, or a certain model of LTM/M adapter from CV).
In fact, I'm saying you can buy a brand new CV adapter from CameraQuest today, and possibly get what I'm getting with my J3, which is about .8m to just before infinity.
One could call that adapter out of spec, or for purposes of this thread, a benefit.
Thanks again Lynn for the awesome idea of using shims. It was fun for a couple of days with the 35, but the real usefulness for me is having a 2nd '50 that I'll know I can use if I don't plan on heavy infinity work, but lots of close work. That's what my J3 is dedicated for right now.
I've owned the Nokton before, and it's a big big lens, next biggest 50 I've owned was the Noctilux 50/1. The J3 is about 1/2 the size, so it's my choice for modding/shimming/using.
I am not sure what you are trying to promote here...
I have said numerous times, that the simplest and easiest, non-destructive, easily reversible method to get the Nokton 50/1.5 to focus to 0.7m is with a shim/extension ring between the lens and camera/M-mount adapter as illustrated here...
...
With the correct shim thickness, any LTM 50mm can be made to focus to 0.7m with rangefinder coupling. The shim thickness will vary depending on the close focus distance built into the lens. The Nokton 50/1.5 requires a 0.9mm while the Rigid Heliar 50/2 requires a 1.1mm to get down to 0.7m. While I have been making my shims from aluminium, they can be made from an old membership, steel, old DVD/CD, etc.
While you have the shim/extension ring installed, you will not be able to focus the lens to infinity, the focus range will be limited from 0.7m to about 4m. Remove the shim/extension ring and the lens operates as normal.
Brian is the authority on J-3 construction and modification and I am sure he will be happy to contribute to a new thread about modifications that allow the J-3 to focus to 0.7m.
With some metal work, the focus range of the Nokton 50/1.5 be extended to 0.7m without the use of a shim/extension ring. The lens will focus continuously from infinity to 0.7m with a turn of the focus ring. The extra 0.2m was worth taking the time to permanently modify my Nokton 50/1.5.
P. Lynn Miller
09-26-2010, 14:04
Ted,
The modification that you are proposing is that with a thinner shim, about .04mm, the Nokton 50/1.5 would focus from 'near' infinity to about 0.8m, thus making a more versatile solution than a 0.9mm shim which limits the usability of the lens from 4m to 0.7m. So nice compromise that would allow you to use the lens in 95% of situations without removing the shim. Good idea!
I am concentrating on the Nokton 50/1.5 and you are promoting the J-3. What we need to agree on is that this 'shim' solution will work on any LTM 50mm, Jupiter, Canon, Nikkor, Leitz, Voigtlander, etc.
The lightbulb moment for me was when Brian wrote this -
"The 50/1.5 Nokton is a screw mount lens. You can back it off a turn in the LTM to M-Mount adapter for closer focus. The actual optics and the RF Cam will move in unison, the actual focus will agree with what the RF indicates. You could make an LTM adapter with a "shim" on it to set the stand-off, and essentially get a hacked dual-range lens."
The common denominator the Nokton 50/1.5 and J-3 share is they are both 'screw-mount' 50's.
I chose the Nokton 50/1.5 because I wanted a modern, fast 50mm with multi-coating and etc. I particularly wanted to be able to modify the Nokton to focus to 0.7m. I wanted the Nokton to be a full range lens from infinity to 0.7m without shims, adapters, etc. So I was very happy to spend a few hours to permanently modify the Nokton.
You like the J-3 for all the right reasons and are happy to have the lens focus from near infinity to 0.8m. And have found a very quick and easy solution to modify the J-3.
The real important information to take away is that if you have a LTM 50mm, with use of a shim, you can make the lens focus closer. And the credit for this brilliant idea goes the Dr. Brian Sweeney.
It would be great if you would start a new thread about your modified J-3 with some pictures and information, would be useful for anyone else using a J-3.
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