RF accuracy chart - Page 2

BillBingham2 · 03-04-2008

Can you take the 135 up to 3.5 and 2.8 please?

Thanks.

B2 (;->

Anupam · 03-04-2008

I thought the rule of thumb was the EBL should be equal to or greater than the physical diaphragm opening for the aperture. Given that, one would need at least a 50mm EBL to focus the Noctilux. I wouldn't bet on reliably focusing the Noctilux consistently with the 25mm-ish EBLs of the R and R2. Anyone been doing that regularly?

ferider · 03-04-2008

Quote:

Originally Posted by BillBingham2

Can you take the 135 up to 3.5 and 2.8 please?

Thanks.

B2 (;->

Just updated the above picture and emailed you the sheet.

Cheers,

Roland.

digitalintrigue · 03-04-2008

Roland, for completeness you might want to add the 105/2.5.

ferider · 03-04-2008

Quote:

Originally Posted by Anupam Basu

I thought the rule of thumb was the EBL should be equal to or greater than the physical diaphragm opening for the aperture. Given that, one would need at least a 50mm EBL to focus the Noctilux. I wouldn't bet on reliably focusing the Noctilux consistently with the 25mm-ish EBLs of the R and R2. Anyone been doing that regularly?

Not the 50/1, but I have reliably used the 50/1.2 on the R2, Anupam.

Note that the above table does not account for minimum focus. For example, the 135/2.8 focuses down to 1.5m (? out of memory), the Leica 50/1 to 1m, and the newest Leica 50/1.4 to .7m, which makes the 50/1.4 practically as hard to focus as the 50/1. The worst lens to focus, IMO, is the 75/1.4 at .7m ....

Quote:

Originally Posted by digitalintrigue

Roland, for completeness you might want to add the 105/2.5.

I'll let it sit for a while, maybe we get some more requests ....
How is "my" 105 doing, BTW ?

John Noble · 03-04-2008

While we're having fun, here's a universal graph based on a .030 CoC. It's just a quick grab out of Apple's Grapher utility.

The Y axis is required EBL, and the X axis is aperture. The 35, 50, 75, 90, and 135 focal length curves are labeled.

No warranty express or implied.

BillBingham2 · 03-04-2008

Roland,

This would be a great tool for a Marketing person to use to figure out what is the right length for a particular mix of lenses. Not that there would ever be that big a market again, but it's very cool.

Thank you Sir!

B2 (;->

digitalintrigue · 03-04-2008

Quote:

Originally Posted by ferider

I'll let it sit for a while, maybe we get some more requests ....
How is "my" 105 doing, BTW ?

How 'bout a request for 43mm Pentax? Although any focal length under 50 is a not an issue...

*Your* 105 is doing great. Hey, come to think of it, I also bought one from Bill (F mount.)

Roberto · 03-04-2008

Quote:

Originally Posted by ampguy

...
Would be interesting to see if this table corresponds to other users experiences, I'd guess not, or who in their right mind would use a Bessa or CL??!!
...

Well..
I have a Bessa R and I have never been able to focus correctly the Jupiter 9 at f2, it start looking OK at f4.

I know it may be because it is Russian but in my opinion the J9 myth has born because of the short rangefinder base of many cameras out there like the Bessa..
R.

Roberto · 03-04-2008

Quote:

Originally Posted by ferider

Just updated the above picture and emailed you the sheet.

Cheers,

Roland.

Would you be so kind to post it somewhere on the net?

ferider · 03-04-2008

I can only post pictures on my smugmug account, but maybe somebody else
can host it ?

BillBingham2 · 03-04-2008

Quote:

Originally Posted by digitalintrigue

How 'bout a request for 43mm Pentax? Although any focal length under 50 is a not an issue...

*Your* 105 is doing great. Hey, come to think of it, I also bought one from Bill (F mount.)

It is an addictive lens. Beware.

I use to make fun of people having so many 50mm lenses, then I looked at the fact that I had four 105/2.5 (S, LTM, F and F AIs (ok the last one a lens I gave my wife years back that I now have)) and two CV 25/4 (S and LTM).

BTW, John asked me for your address so I think this is a fast turn around from him. A good sign.

B2 (;->

BillBingham2 · 03-04-2008

Quote:

Originally Posted by Roberto

I know it may be because it is Russian but in my opinion the J9 myth has born because of the short rangefinder base of many cameras out there like the Bessa..
R.

No, there's a lot of truth to it. I had a J9 on my Bessa T, my Leica M6 and M4-P testing it and it was off. Have a number of folks around the world with similar issues (the focus being off of dead on a couple to four inches). Went to a Nikkor 85/2, SPOT ON with every camera.

B2 (;->

digitalintrigue · 03-04-2008

Yes, this will be my third (F, S, LTM)

I emailed John...thanks for the heads up.

Roland, I can host...

ferider · 03-04-2008

Quote:

Originally Posted by digitalintrigue

Roland, I can host...

Sent you a PM.

John Noble · 03-04-2008

OK, here's a new chart with limit lines for common bodies.

[edit: updated the chart for better readability]

ferider · 03-04-2008

Quote:

Originally Posted by BillBingham2

No, there's a lot of truth to it. I had a J9 on my Bessa T, my Leica M6 and M4-P testing it and it was off. Have a number of folks around the world with similar issues (the focus being off of dead on a couple to four inches). Went to a Nikkor 85/2, SPOT ON with every camera.

B2 (;->

This is me focusing an N 85/2 on a friend's RD1 (no magnifier) -- and failing miserably. I've tried on R3 and R2 with no success.

Photo by Robert

Roland.

BillBingham2 · 03-04-2008

The RD1 and R2 does not surprise me, the R3 does, but everyone has off days.

B2 (;->

digitalintrigue · 03-04-2008

Spreadsheet is here

ferider · 03-04-2008

Quote:

Originally Posted by John Noble

OK, here's a new chart with limit lines for common bodies.

Tres cool, John !

Roberto · 03-04-2008

Quote:

Originally Posted by digitalintrigue

Excel spreadsheet is downloadable here.

Thanks a lot..

Roberto · 03-04-2008

Quote:

Originally Posted by digitalintrigue

Excel spreadsheet is downloadable here.

Now.. we need to add all of the FSU cameras...

ampguy · 03-04-2008

CL and lens were CLA'd at the same time. Close focus at f2 hit rate was maybe 80-90%, partially IMHO due to smaller patch RF than larger M's and trying to use it indoors. Worked perfect at F2 on later larger M's and 2 RD1s.

I don't know what to say about the RD1 and 75/1.4, it's not 100%, but you can see for yourself here:

http://matsumura.smugmug.com/gallery...xbjR#255483561

Quote:

Originally Posted by LCT

Indeed it is not normal at all. At f/1.4 your 75 is way out of the accuracy range of the Epson. It is even very difficult to focus on the M8. Also, the .72x M6 has a longer EBL than the R-D1 (w/o magnifier) and the 40/2 should not have any problem with your CL at any aperture IMHO. Did you have the 40/2 cla'd as well?

ampguy · 03-04-2008

I specifically went around shooting objects close up and wide open:

http://matsumura.smugmug.com/gallery...xbjR#255483561

You do need some kind of contrasting patch, but I find that is necessary with most lens.

The M6 focuses it easier, but by no means is it not possible to focus close up and wide open on an RD1, in my experience.

Next beer get together, I'll give a master class in "Focusing the 75/1.4 Lux"

http://matsumura.smugmug.com/gallery...xbjR#255483561

Quote:

Originally Posted by MikeL

Ted, are you framing your subjects for the 75mm like you would with the 50mm? (i.e. farther away from your subjects with the 75mm)

ferider · 03-04-2008

Quote:

Originally Posted by ampguy

Next beer get together, I'll give a master class in "Focusing the 75/1.4 Lux"

Well, it might be the cigarettes, coffee, beer and other vices, but I have even
difficulties on the M6. The M3 is the right base for bertha