Another cult lens

[ferider]

Phil, where are you ?

For more details on the lens, have a look here, for instance: http://www.luminous-landscape.com/co...02-11-24.shtml.

Pictures say more than 1000 words ....











Here is how it was made: http://ferider.smugmug.com/Technical...0554962_2c5ht7

I'm confident that the SMC 50/1.4 will match the Leica RF calibration (measuring the lens physical length and correlating it to its focusing scale to predict focus error):



To be continued when my test film is back ....

Roland.

PS: The un-coupled Novoflex adapter is quite expensive. In the mean-time (after I got mine), other more affordable uncoupled Pentax/M adapters have become available, for example http://www.ebay.com/itm/250916389253.

[ChrisN]

I think the price of Pentax 50/1.2 lenses just climbed another notch!

Well done - do share the results please.

[mooge]

that is pretty awesome.

[flip]

cool

[RayPA]

Niiiiice work, Roland.


/

[CNNY]

Very nice job. You make it almost look easy.

[Phil_F_NM]

Holy cow!
I had not thought of that solution when measuring up my SMC 50/1.4 Takumar (the radioactive one) but I must have been correct in my measurements that the optimal focal length is within .05mm of 51.6mm if this lens does in fact focus accurately throughout the range. That is awesome.
Gonna inspire me to grab some pieces of old lens shroud and some M42 extension tubes to begin fabbing this up.
I'm wondering if I could achieve the same result using other brands. I'd love to find a Canon 50/1.2 L in FD mount and make it work.

Phil Forrest

Listening to that Dremel tool whine

[buzzardkid]

Here's hoping that Novoflex will be dropping the price on that adapter once the run on it starts


Nice job, I'm gonna think about what lens I would like to have with an approach like this.

Question: is the rear element diameter of the Nikkor 50/1.2 and Pentax 50/1.2 too large to make that cam line up with the RF arm?

[umcelinho]

sweet mod!

[Phil_F_NM]

The Canon 50mm f/.95 has a cutout notch in the rear element and it resolves images just fine, considering its vintage and speed. If you had one of these lenses and the focusing cam were in line with the rear element enough to touch it, you would want to paint the rear element black in the spot where your intermediate cam were to touch. It's far enough out though that you would be better off getting a fabbed up double L shaped bracket (like a Z) to interface with the rear element shroud instead of the glass itself. This little bracket has been the main stumbling block of my project to adapt fast Takumars to Leica M with RF coupling.

As for the K to Leica adapter, there are much cheaper versions available that you wouldn't have any problem cutting up. The Novoflex one is much more pricey.

Phil Forrest

[shadowfox]

Wow, I'm just imagining if I can do this with my Konica Hexanon AR 35/2.
Too bad no one sells a Konica AR to Leica M adapter

[rover]

Originally Posted by ChrisN

I think the price of Pentax 50/1.2 lenses just climbed another notch!

Well done - do share the results please.

I already have one

[kermaier]

Originally Posted by Phil_F_NM

I'd love to find a Canon 50/1.2 L in FD mount and make it work.

Amen, Phil -- if I could start using my FD 50/1.2 L again, I might cry.

Ari

[Phil_F_NM]

Ari, I'll let you know if I can get a 50/1.2 L to couple without hacking the mount itself. As long as the nominal focal length is close to the Leica standard, it should be possible. My housemate has one, so I have a design to play with in engineering this adapter.

Will, the reason it's even possible with some lenses (in this case, Pentax) is that their 50mm standard is actually ~51.6mm and the focusing rate is almost identical. It is the combination of these two factors that have everything to do with the ease of this adaptation.
If your 35/2 Konica AR has a rotating optical mass or rotating anything at the rear of the lens it would not be hard to transfer that motion to an angled cam surface calibrated to simulate the movement of the lens several millimeters as it were a 50mm. That's how all the lenses wider than 50mm do it, in a nutshell. Getting that cam ground at the right angle is the tough part.

Phil Forrest

[dave y]

Out of interest what is to be gained by doing this conversion?
A Leica with a Pentax lens is no different to using a Pentax Body with this lens.
I applaud you for the technical skills but photographically speaking it is a lot of work for no added benefit isn't it?
Surely the easiest thing to do is to buy a cheap slr body to use an slr lens with.

[Honus]

Originally Posted by dave y

Out of interest what is to be gained by doing this conversion?
A Leica with a Pentax lens is no different to using a Pentax Body with this lens.
I applaud you for the technical skills but photographically speaking it is a lot of work for no added benefit isn't it?
Surely the easiest thing to do is to buy a cheap slr body to use an slr lens with.

Maybe easier, but certainly not as much fun. Cool mod, Roland. You should bring it on Saturday to SFMOMA

[Phil_F_NM]

Some of us have favorite lenses for different reasons.
I like the way the Leica handles and prefer it to all other systems.
I like the way lenses such as the FD 50/1.2 L Canon, 50/1.2 Nikkor AIS, 50/1.4 Takumar, 50/1.2 Zuiko among others render subjects. The M42 Takumars have a look unique unto themselves and are amazing shooters. Plus all of these lenses are less expensive than super speed rangefinder lenses with very few exceptions. Plus, a lot of us already own some super fast SLR lenses but not the equivalent in the rangefinder line.

Nobody has stuck a FD 50/1.2 L on an M9 with full RF coupling yet. That lens and that camera would be a fantastic combination, far better than the old LTM Canon 50/1.2 which is more than a decade older.

And because we can.

Phil Forrest

[raid]

Nice job, Roland.
I use the 43mm 1.9 Pentax-L on RF cameras and the SMC 50/1.4 on Pentax SLR cameras.

[kzphoto]

Roland,

The conversion looks very nice! How much VF blockage are you seeing when using the lens? The 50/1.4, 1.2 and 1.8 have a very special place in my heart and this conversion brings back some fond memories of my Pentax K1000.

[f16sunshine]

That is pretty cool! I mean really cool!

[ferider]

Thanks guys.

I did it just for fun. Got the lens from a friend who didn't have a Pentax body, and neither do I. My wife wouldn't like me getting into another camera system, that usually requires a second body, more lenses, etc.

From the Leica viewpoint, you might like a 50/1.4, that has a great signature, is relatively compact, has a minimum focus of less than 0.7m (the above combo couples down to 0.65m), and sets you back less then US 200, if you use an adapter like http://www.ebay.com/itm/250916389253.

Kevin, the lens intrudes about 15-20% into the 50mm framelines of the M4P.

This mod only works for a couple of reasons:

1) the focal length of the Pentax lens is close to 51.6mm
2) the rear element is easily accessible (for example, with my OM Zuiko 50/1.4, it is not)
3) the separate ring of the last element really helps in doing the mod, and not distroying the glass.

You only need to disassemble the lens that far:



4a and 4b are baffles that are not needed any more. 1/2/3 are the rear element and its retaining ring (which is used for RF cam attachment).

BTW, the Novoflex adapter remained untouched.

Thanks again,

Roland.

[raid]

It is not RF coupled ... right?

[FrankS]

It looks to be, Raid.

[ferider]

It is, Raid, that's the only thing I did (pictures 3 and 4). This piece was the only thing done in my workshop (out of a brass pipe):

[f16sunshine]

So this is the M(K-Mount) version of the lens not the M42 version as I originally thought.
I have 2 of the M42 lenses here. I wonder if it is the same mod for the screw mount lens.