Canon 100mm f2 on RD1

jeff laitila

jeff laitila

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I picked up a great condition copy of the Canon 100mm f2 ltm lens and have tried it on my RD1. The color, sharpness, contrast and bokeh of this lens are all spectacular, but a problem I am having is that the focus cam seesm to be not 100% compatible with my RD-1.

Closer focus works great, but on medium to longer focus ranges it backfocuses.

Does anyone have any experience with this lens?

I love the output from this lens, and hope there is a way to get its pfcusing calibrated to the RD1.

Thanks for looking.
 
I don't know this lens sorry but due to the short base length of the R-D1's rangefinder it will be difficult to focus at wider apertures than f/4 (or f/3.5 if you use a 1.3x magnifier) anyway.
 
Hi there

Hi there

Thanks for the reply.

I've been shooting with fast glass recently (50mm f1.2) and have not had any trouble focusing. (Not to say that things aren't different when shooting telephoto though...)

Could I be having a problem because I am shooting a 100mm lens, but using a 90mm ltm to M mount adapter ring?

I hope this is an operator error problem. That's an easy fix.
 
jeff laitila said:
...Not to say that things aren't different when shooting telephoto though...
Click to expand...
Yes things are different indeed due to the focal length. If you get accurate results at f/4 no problem. If you get inaccurate results at f/2 no problem either, its normal given the short base length of the RF as i said earlier.
 
Thanks

Thanks

I'll work on it some more, adjusting apertures to see if I can work my way through this.

I appreciate the replies.
 
Every lens might have it's own collimation tolerances, but shooting with focal lengths over 75mm and f2 or faster is a anyway hit&miss thing a R-D1 or any Bessa R-R4. A viewfinder magnifier could be a help for more accurate focusing.
Didier
 
jeff laitila said:
I've been shooting with fast glass recently (50mm f1.2) and have not had any trouble focusing. (Not to say that things aren't different when shooting telephoto though...)

Could I be having a problem because I am shooting a 100mm lens, but using a 90mm ltm to M mount adapter ring?
Click to expand...

Welcome to the club! I use a 100/2 Canon on my R-D 1 and agree its performance is sensational, but also concede that getting correct focus can be a challenge.

A few responses to your points:

-- The focal length marked on the adapter ring doesn't make any difference. It only designates what frameline will be activated when you use the adapter on a camera with automatic frameline selection, such as a M Leica or a Zeiss Ikon. The framelines are selected manually with the R-D 1, so the marking on the adapter ring doesn't matter.

On the other hand, particularly if your adapter ring is a third-party brand, it's possible that its thickness is slightly off. I've encountered this on lots of third-party adapters. Usually they're slightly too thick by a couple of hundredths of a millimeter, making the lens focus closer than it should. The only way to be sure is to measure the adapter's flange thickness with a caliper or micrometer -- it should be 0.98 or 0.99mm . If you don't have a caliper and do have several adapters, you might try switching them around and seeing if there's one that gives you better focusing results than the others when used on this lens with this camera body.

-- The fact that you get good focusing with your 50/1.2 suggests your focusing technique is basically okay, but as someone else pointed out, a 100/2 lens is more demanding in terms of focusing accuracy than a 50/1.2. I find that using an eyepiece magnifier helps a lot. If you can't find or don't want to use a magnifier, you might want to try using "split-image" focusing. This means that instead of lining up the rangefinder by merging the two images in the center of the patch, find a vertical line in the subject and use the sharply-defined edge of the patch to join the "split" in the vertical line. The eye's ability to do this accurately (which actually has a name: "vernier acuity") is considerably higher than its ability to merge two overlapping images, so this can help you focus more accurately under difficult conditions.

Your results may be a little hit-or-miss until you really get the hang of it, but I'm sure you'll agree that the optical results this lens produces are worth the effort!
 
There has been talk as well of Canon LTM lenses not focussing accurately across the board on the R-D1. Personally I haven't seen it and I shoot the slower version of the 100mm, the 50mm f/1.2, and the 35mm f/2,8 fairly regularly...
 
Let`s see some samples of the f2.0 100mm on this camera....we very rarely see examples of photos made with this lens on here
......pictures please!!


Tom
 
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