Back & Front focus with certain lens on R-D1

[RFNewbie]

This may sound a little crazy but I am experiencing focusing issues with certain lens on the R-D1. After taking 60 pictures of my friends using the CV 40mm, only 3 are focused correctly when viewed on my computer at home. The other 57 shots were backfocused on their clothes. The lens was set at between f/1.4 - f/2 on the various shots. At first I thought it was the R-D1 until I tried another lens. My Zeiss ZM 50mm is dead on perfect. So I used a ruler at a 30 degree angle about 4 feet away. Same conclusion, the ZM 50mm, when focused at f/2 was perfect in both of the shots that I took. The other 2 lens are off. I took one picture and then refocused to infinity and back before taking the next. Same results repeatedly. :bang: The CV Nokton 40mm f/1.4 is backfocusing about 1.5 - 2 inch at 4 feet away (f/1.4 - f/2.8), repeated 10 times. The Zeiss ZM 21mm is focusing forward about 3 inch at 4 feet (f/2.8), repeated 5 times. Any ideas on how to fix this? This is my first rangefinder so I don't know if there is suppose to be a shift depending on each lens. I would assume no. All the lens are new and were bought within the last month.

I have enclosed cropped samples for a comparison.

Thanks for your input ahead of time.
Leo

 

[barjohn]

I don't know the answer to your question but have you tested each lens at infinity? Take your camera and lens and point at a bright star and see if it focuses at infinity with each lens. I find stars work well because the distance is definitely infinite and you have a pinpoint source that is easy to tell whether it is coming together or not. Post your results and you will probably get more advice.

 

[pfogle]

If the focus is out, either the rangefinder or the lens itself can be the culprit.

Since you have two lenses that work OK, and the other two are not consistent (one in front, one behind) then it's probably going to be better to get the lenses adjusted, and leave the rangefinder alone.

It's a job for a professional, IMO.

On the other hand, you could probably get a way with just doing the 40mm, as the error in the 21 is not likely to be much trouble (smaller aperture, more DOF)

edit - just noticed in your post that the lenses are new... try to exchange and check out another copy.

 

[RFNewbie]

I don't know the answer to your question but have you tested each lens at infinity? Take your camera and lens and point at a bright star and see if it focuses at infinity with each lens. I find stars work well because the distance is definitely infinite and you have a pinpoint source that is easy to tell whether it is coming together or not. Post your results and you will probably get more advice.

Thanks I'll try taking pictures of the stars and see what happens. Then I'll post the sample pics along with the ruler test. Thanks again.

 

[Jim Watts]

If you have confirmed by checking both at infinity and closeup with the ZM 50mm that rangefinder alingement is OK and also that there is no backlash in the mechanisim, then it is your lenses that need adjusting. It is possible to collimate (by adding or removing shims) your lenses, but as Phil says it is really a professional job, IMHO also. It really needs the correct equipment to get the close focus consistantly correct while retaining infinity focus, but others in this forum have managed to do it themselves.

There is though a further problem in that if you collimate the lenses to be correct on one body they will probably be incorrect on another. This is exactly my own problem. I have a 35mm Cron that front focusses on my R-D1 by about 3 inches at 4 feet, but it focusses perfectly on my M4. I do not want to risk downgrading its focus on the M4 so I just allow a bit if using this lens on the R-D1.

My 21mm Avenon also front focuses by about 3 inches, but again as Phil says because of the DOF its not a problem.

To try to exchange your lens for another example as they are new is good advice. I have the 40mm Nokton and my sample is better than yours with regard to focus on my R-D1. I at first I thought it was perfect, but if I'm hyper-critical I would say there is a slight back focus. That is that the point of focus (even at f1.4) is sharp subject to repeatability within my own and the rangefinder base length, but DOF is all behind the plain of focus with none in front. Its not really a problem that has too much effect on results though unlike your own.

I now tend to use this lens for wide aperture and closeup instead of my Cron, although I still prefer the 'drawing' of the Cron overall.

 

[mwooten]

I've noticed that how I focus has an effect on whether or not the focus point is sharp. With my 40mm rokkor, I have found that if I approach the point of focus from the near (rather than from infinity) then I get sharp focus, and to the contrary if the point of focus is made from infinity then the image is off. I hope this makes sense.

If you have already tried using this technique, and your lenses still are off -- then I agree with the others that you should send them back under warranty.

Take care,
Michael

 

[barjohn]

I wasn't suggesting you shoot pictures of the stars but merely check infinity alignment with each lens. If some are on and others are off, it is most likely the lenses. If all are off it is most likely the R-D1. If it is the R-D1, the infinity alignment is the easiest one to fix yourself, just follow the directions posted here on one of the threads on RF alignment.

 

[ZorkiKat]

I've noticed that how I focus has an effect on whether or not the focus point is sharp. With my 40mm rokkor, I have found that if I approach the point of focus from the near (rather than from infinity) then I get sharp focus, and to the contrary if the point of focus is made from infinity then the image is off. I hope this makes sense.

If you have already tried using this technique, and your lenses still are off -- then I agree with the others that you should send them back under warranty.

Take care,
Michael

My R-D1s does the same too. I get correctly focused pics when lens focusing movement starts from minimum focus setting. When focusing lens from the infinity side of the scale, the focus is always off. This consistently happens with all my Jupiters. Same happens with my Summitar, the only other lens which I've tried in this regard with the camera.

Jay

 

[jvr]

My R-D1s does the same too. I get correctly focused pics when lens focusing movement starts from minimum focus setting. When focusing lens from the infinity side of the scale, the focus is always off. This consistently happens with all my Jupiters. Same happens with my Summitar, the only other lens which I've tried in this regard with the camera.

Jay

ZorkiKat, since I aligned my R-D1s RF properly, every lens I own is focusing ok, except for the Jupiter 9! I'll try your suggestion on the direction of focus and see if it helps!