Nikon rangefinder out of focus?

[Imakebadphotos]

Hi, I think my Nikon helicoid is out of alignment, I have my rangefinder set to infinity and the two images are in perfect alignment, but yesterday I notice my 28mm lens was showing signs of decementing in the rear element. I deside to open the back and check with a focusing screen and I noticed that the image I focused on in the viewfinder was not in sharp focus when viewd through the focusing screen. I switched out the 28mm and used my 50mm and the same thing happens, the image is out of focus until I turn the lens past the focused point in the viewfinder. A simple fix would be to turn the vertical screw to line up the image but my infinitely view will be substantially off. I did have this camera sent out for a CLA a months back, so could this be that the helicoid was put in at the wrong point, is that how these rangefinders operate? Or does the the focusing screen im using not match that will be seen on film?

 

[Highway 61]

If the helicoid male and female parts had been reassembled with a wrong starting point (it can happen, those are three starting points designed), everything would be a mess and by no means could you reach the infinity lock with the inf. symbol aligned with the distance index. So I would exclude that.
The Nikon RF has a very long throw. To check the infinity coincidence of the RF patch when looking through the viewfinder, you must find a target really located at what matches infinity the best. The target should be at least 1,000 m far away from you. Otherwise, use the moon if you can see it...

Checking a lens collimation or a RF calibration at home works better for infinity checking, with the home infinity method than with a lone focusing screen and a lupe.

See this :

http://elekm.net/zeiss-ikon/repair/collimate/

 

[Sonnar Brian]

Have you used the camera with film since getting it CLA'd?

I use a strip of exposed negative film taped across the back of the camera, with a Loupe with flat glass that sits across the film rails to test focus. I get good agreement with film.

 

[Imakebadphotos]

Have you used the camera with film since getting it CLA'd?

I use a strip of exposed negative film taped across the back of the camera, with a Loupe with flat glass that sits across the film rails to test focus. I get good agreement with film.

I have ran some film through but only developed one roll and it looks good but that was because I was using it around f16-f11. The exposed film is a great idea and has helped. This problem seems to happen when I focus at close distance with the apature wide open. Could this be a sign of focus shift with these lenses?

 

[Imakebadphotos]

If the helicoid male and female parts had been reassembled with a wrong starting point (it can happen, those are three starting points designed), everything would be a mess and by no means could you reach the infinity lock with the inf. symbol aligned with the distance index. So I would exclude that.
The Nikon RF has a very long throw. To check the infinity coincidence of the RF patch when looking through the viewfinder, you must find a target really located at what matches infinity the best. The target should be at least 1,000 m far away from you. Otherwise, use the moon if you can see it...

Checking a lens collimation or a RF calibration at home works better for infinity checking, with the home infinity method than with a lone focusing screen and a lupe.

See this :

http://elekm.net/zeiss-ikon/repair/collimate/

Thanks, im glad I can rule out helicoid. I focused the rangefinder patch on the mountains and everything lines up perfectly. Im beginning to wonder if its because of focus shift. This problem occurs when I'm using a 50 prime and telephoto lenses when the appature is wide open and focusing is at 0.9 meters. If so, then I guess it would be best to just focus slightly past the focused image in the viewfinder?

 

[Highway 61]

First : by construction, the Nikon RF has a big main advantage over the Leica RF : if it's bang-on at infinity, then you don't have RF calibration problems at close distance. Explanation : the RF pitch throw from infinity to close-up depends on the mounted lens focal length. With the Contax-Nikon system, the double lens mount system allows the lenses themselves to drive the RF accordingly to their focal length, this doesn't rely on the correct resting position of an eccentric RF arm in the camera lens chamber, as it's the case with the Leica system. So : accurately adjust your RF with the calibrating srcew located under the camera front plate so that the RF patch in the viewfinder is dead-on while aiming the camera towards a target located at a "real" infinity (using a lupe to look at the RF patch is advised), and you're done.

Second : focus shift does exist, especially with Sonnar-designed lenses. That said, in the real life, we seldom suffer from it. What is the percentage of pictures we take which are shot wide-open at the closest focusing distance ever ? Low. Very low. Almost nil.

Third : at the closest focusing distance, with, say, a 50mm lens, the out of focus areas, below your subject, will be identical and as nice at f/2.8 as what they would be at f/1.4. Some odd esoteric concepts which are quite fashionable today, like "creamy bokeh", didn't even exist when the Nikon rangefinder cameras and lenses were made. Apertures like f/1.4 and f/2 on such a lens (Nikon even made a f/1.1) weren't designed for bokeh, they were designed for shooting in available light with the slow speeds films which were marketed back then.

Fourth : with a telephoto lens, the Nikon RF baselength is too short anyway to allow critical focusing at close-up and wide-open. The least forth and back movement of your subject will make your focus off. Want to shoot portraits with a 105mm or a 135mm lens wide open at close-up, focusing on your subject eyes ? Use something else than a rangefinder camera. Want to shoot bricks walls to look at distorsion, focus shift, vignetting, sharpness corner-to-corner ? Stop taking photos and go and listen to some music or have a nice bike ride instead.

Fifth : hope this helps. 😉

 

[Imakebadphotos]

First : by construction, the Nikon RF has a big main advantage over the Leica RF : if it's bang-on at infinity, then you don't have RF calibration problems at close distance. Explanation : the RF pitch throw from infinity to close-up depends on the mounted lens focal length. With the Contax-Nikon system, the double lens mount system allows the lenses themselves to drive the RF accordingly to their focal length, this doesn't rely on the correct resting position of an eccentric RF arm in the camera lens chamber, as it's the case with the Leica system. So : accurately adjust your RF with the calibrating srcew located under the camera front plate so that the RF patch in the viewfinder is dead-on while aiming the camera towards a target located at a "real" infinity (using a lupe to look at the RF patch is advised), and you're done.

Second : focus shift does exist, especially with Sonnar-designed lenses. That said, in the real life, we seldom suffer from it. What is the percentage of pictures we take which are shot wide-open at the closest focusing distance ever ? Low. Very low. Almost nil.

Third : at the closest focusing distance, with, say, a 50mm lens, the out of focus areas, below your subject, will be identical and as nice at f/2.8 as what they would be at f/1.4. Some odd esoteric concepts which are quite fashionable today, like "creamy bokeh", didn't even exist when the Nikon rangefinder cameras and lenses were made. Apertures like f/1.4 and f/2 on such a lens (Nikon even made a f/1.1) weren't designed for bokeh, they were designed for shooting in available light with the slow speeds films which were marketed back then.

Fourth : with a telephoto lens, the Nikon RF baselength is too short anyway to allow critical focusing at close-up and wide-open. The least forth and back movement of your subject will make your focus off. Want to shoot portraits with a 105mm or a 135mm lens wide open at close-up, focusing on your subject eyes ? Use something else than a rangefinder camera. Want to shoot bricks walls to look at distorsion, focus shift, vignetting, sharpness corner-to-corner ? Stop taking photos and go and listen to some music or have a nice bike ride instead.

Fifth : hope this helps. 😉

I know its been two weeks since you responded to my question. Here is my update. I focused the viewfinder to infinity and adjusted it and everything in sharp focus. Now I know that the true problem is. the rangefinder patch close up focus is at 2.5 feet not the 3 feet base length. I guess at one point in this cameras life, someone messed with the prism. Any idea how to fix that.

 

[Sarcophilus Harrisii]

I know its been two weeks since you responded to my question. Here is my update. I focused the viewfinder to infinity and adjusted it and everything in sharp focus. Now I know that the true problem is. the rangefinder patch close up focus is at 2.5 feet not the 3 feet base length. I guess at one point in this cameras life, someone messed with the prism. Any idea how to fix that.

I am having trouble following you. Before you said: "...I have my rangefinder set to infinity and the two images are in perfect alignment..."

Now you've said: "I focused the viewfinder to infinity and adjusted it and everything in sharp focus."

What do you mean by "adjusted it"? According to your first post the RF was aligning correctly to begin with. Why, then, would it need adjusting?

How, precisely, did you check it? Naked eye? Apropos your remark about the patch being out at close range, if infinity calibration is marginally out that wouldn't help. Many owners can adjust infinity close—few get it spot on.

"the rangefinder patch close up focus is at 2.5 feet not the 3 feet base length."
I have no idea what you're trying to say. Unless you're using a naval targeting instrument—your rangefinder does not have a 3 foot base length.

I suggest checking through the lens at infinity. Use the most powerful loupe you can find, and be particular. Spend five minutes looking at the glass. Check the RF patch alignment. A small 2–3 times scope through the finder will show up deviations impossible to spot with the naked eye. Such deviations are not acceptable for ideal calibration. Your subject should be minimum of 1 kilometre distant.

If the camera passes these tests—then you can think about checking calibration at close range. Otherwise you're only going to be chasing your own tail.

 

[Imakebadphotos]

First of all, forgive me if what I say sounds confusing, its difficult for me to explain it. I set the lens at infinity, I checked the viewfinder with my eye, the two images match as close as I am able to get it, they line up perfectly to me. I currently don't have any magnifiers that I look through the viewfinder. I checked the film plane with the waist level magnifier, and at infinity it all looks good. The problem was when I'm focusing closer. Through the viewfinder im still able to focus as close as two and a half feet while the indicatior on the lens stops at three feet. I just got my S3 back from a CLA and both lens and viewfinder stop at three feet, but I can still move closer with the SP. I set the two cameras side by side, sitting on separate tripods focusing at the furthest mountain and while looking through at each viewfinder, both double images were one to one. I could not see any difference between the two of them. But I am looking through them with a naked eye.

 

[Highway 61]

II guess at one point in this cameras life, someone messed with the prism. Any idea how to fix that.

I think that I have understood your explanations and, yes, unfortunately, they may sound like the small prism located behind the front plate secondary RF window got a bit out of alignment. That prism is attached to the camera casting with a small bracket and two screws. Removing the top cover may tell you something : the screws in question are factory covered with black shellac. You will probably see evidences of the screws having got touched in the past, if this is the case.

If the prism has to be re-aligned, it can be done, but then the camera has to be sent to someone having a professional collimator, like DAG etc.

 

[Imakebadphotos]

If the prism has to be re-aligned, it can be done, but then the camera has to be sent to someone having a professional collimator, like DAG etc.

Yeah I may have to send it in to DAG. But that's fine, I still have a S3 to use in the meantime so I won't be down a camera. I love using this type of camera. Thanks again.