Nikon F3 can't focus to infinty

[colker]

In Rennes, France. It's hard to find something like that here.

Yeah but how do I check this screen?

Remove the finder, then remove the screen and then place it back according to the instructions.

 

[TBsq]

I just ordered a new focusing screen. I'm going back to you as soon as I try it.

 

[Bille]

How do you know you are out of Focus? Does it Look blurry in the Finder? Do you have a Split prism?

What I would do: Turn the lenses to infinity, take pictures of a Building very far away and see how they Turn out.

Maybe find another Nikon Body for testing.

 

[E.M]

i had the same problem as view range with an F2 , the mirror was out of allignment , minor repair , but I brought it to dealer.

 

[TBsq]

I got the new screen. It's better, but it still slightly can't focus to infinity. I don't know where else to look.

How do you know you are out of Focus? Does it Look blurry in the Finder?

Yes

If I understand you correctly when you try to focus to infinity the infinity mark (∞) does a hard stop about 1mm from the 'distance index dot'.

No, it just can't focus to infinity.

i had the same problem as view range with an F2 , the mirror was out of allignment , minor repair , but I brought it to dealer.

What dealer? How much did it cost you?

 

[bmattock]

When one says that they cannot focus to infinity, it is important to understand what is actually being said.

These are some possible conditions:

1) The lenses appear not to be focused to infinity, but the images taken indicate that they are.

2) The lenses appear not to be focused to infinity, and the images confirm that they are not.

In the first condition, it is going to be something between the mirror and your eye. Possibilities include the mirror, the focusing screen, the pentaprism, the reticle you look through, and your eyes themselves.

In the second condition, it is going to be something in the path of the lens to the film. Possibilities include the lens(es) themselve, the mount, the camera body (dropped and damaged, etc) or even (although not likely) the film pressure plate in the back of the camera.

If it is the first condition, and the replacement focusing screen (including orientation if it is possible) and misplaced shims does not fix it, then a visit to the shop is in order.

I do not know the camera you have - does it have a diopter adjustment at the eyepiece? If so, can you adjust it?

Best of luck with it.

 

[nikon_sam]

Try checking something closer...
Camera on tripod, cereal box on table about 5 or 6 feet away...measure from front of box to the film plane mark on top of your camera...focus then look to see what the lens says, if the box is five feet away then the lens should confirm this...sounds like it the mirror rest is out of position...

 

[peterm1]

I got the new screen. It's better, but it still slightly can't focus to infinity. I don't know where else to look.

Yes

No, it just can't focus to infinity.

What dealer? How much did it cost you?

Look this may be a silly question but you say the finder looks blurry. Does the image in the finder look blurry even when you try to focus on something closer? If so then the problem is your eyes and you need a diopter lens on your eyepiece to correct your vision for the F3 finder - these finders have a slightly negative diopter built in. Could it be that does not work for you in its uncorrected state?

If the finder definitely is sharp when you try to focus on something closer then I suggest trying the following procedure. As another poster says set up a target - I like to use a tripod if possible to hold the camera steady in a fixed position, and find a lens with a set mark on it of say 3 metres. Then set up a target on the floor or table exactly a measured 3 meters to your camera's film plane (marked by a line on the top plate of the camera, using a tape measure exactly (not approximately) from focus subject to film plane) . Take some shots using the finder to focus and when the marked focus point on the rod (see below) looks in focus look at what the distance on marked on the lens says - it should say 3 meters. If the lens marking is different from this when you have correct focus according to the view finder then take some images to see if the lens is sharp when using the viewfinder to focus.

When I have done this I have used a wooden rod laid on the floor with the focus point clearly marked on the rod and a series of further marks in say 1 inch increments ahead of and behind the main focus point. That way if the lens is focusing ahead of or behind the point at which you think you are focusing according to the viewfinder then you will know how much when you check your test images.

If it is out of whack at 3 meters it will also suggest that something is wrong with the geometry of the camera - if not the focus screen then most likely the mirror (though its not clear to me how this could be out) or the lens mount. BTW have you checked that the lens mount ring on the camera is screwed down tight? Just a thought as if the lens mount is just a millimetre forward of where it should be this would cause focus problems which would culminate in the lenses not quite reaching infinity focus. It would focus at distances shorter than infinity though but the distance marking on the lens would not accord with the actual point of focus. The procedure I described above will help diagnose that.

To be frank I think most of us are a bit stumped as to why this is happening. Individual lenses not focusing at infinity are not all that uncommon but usually this is because someone has disassembled the lens for cleaning and not reassembled it correctly. Having several lenses all not focusing indicates a camera body problem - this is less common in my experience.

 

[peterm1]

I got a bit intrigued after making the post below and did a quick search on focus issues specific to the F3 camera and came up with the thread below from 2014. It sounds a little like the issue you are having. I have not studied it yet but you may like to read it.

https://www.rangefinderforum.com/forums/showthread.php?t=142668

It suggests there is an adjustment screw somewhere near the mirror to adjust its alignment.

Another reference to focussing issues with F3

https://www.photo.net/discuss/threads/nikon-f3-body-focus-adjustment-question.267791/

Another thought occurs relevant to the F3. The F3 has a removable penta prism like many past Nikon pro bodies. Could it be that the penta prism is not properly mounted in place, thereby marginally throwing the body's geometry out and causing an apparent misfocus at infinity.

So this consideration begs a question - have you tried removing and refitting the penta prism or checking to see if the mounts are in good condition? Or if you can do so could you borrow another penta prism for an f3 and try focusing with a different prism on your camera body to see if that makes a difference. At least that would tell you if the problem is with the camera body or the prism.

One final thought before I leave this subject having run out of further ideas. Have you tried shooting photos at infinity to see how they actually look rather than just relying on how the finder looks - sorry if your posts cover this I cannot recall? When shooting at infinity - say for landscapes it is most usual for lenses to be stopped down and to rely on depth of field to do the rest. If the focus anomaly is small it is very likely that it will make little or no difference in practice as when shooting at say, f8 or f11 focused at infinity even with some focusing error the shot will be sharp due to the depth to field of the lens at such a small aperture. However where this may not help is with very long lenses shot wide open (say bird photography for example) where depth of field is limited.

 

[Phil_F_NM]

To check the physical adjustment of the camera body film plane to lens flange, take a known good lens and mount it on the camera. Mount the camera on a tripod. Remove the film door. Place a piece of frosted glass or plexiglass or even scotch tape vertically between the inner film rails on the body. Frosted side toward the lens. The inner rails are one film thickness closer to the lens flange than the outer rails. Lock up the mirror. Focus your lens on infinity at a very distant object and look at the film plane with a loupe. If it is in focus, then your problem is with the mirror/finder/groundglass. If not, your problem is with the camera body. Repeat this with a few lenses to ensure that it is not your lens. If you don't start with this, you'll go around in a circle of testing the focusing mechanism while not ensuring the camera itself it calibrated. Once you have the proper infinity focus at your actual film plane, you can begin to mess with the groundglass/finder/mirror.
As was mentioned, it could be your mirror, your eyepiece, your mounting of the groundglass condenser or even the prism itself.

Phil Forrest

 

[Godfrey]

Ok maybe I found the issue, it might be that the focusing screen is a one that goes on a Nikon F, not a F3.

If so, that's your problem. I had the same problem once when I accidentally dropped an F screen into my F3. Carelessness on my part...

G

 

[TBsq]

I checked the same lenses on another camera and they focus at infinity correctly. I have yet to test with the developped pictures.

Look this may be a silly question but you say the finder looks blurry. Does the image in the finder look blurry even when you try to focus on something closer? If so then the problem is your eyes and you need a diopter lens on your eyepiece to correct your vision for the F3 finder - these finders have a slightly negative diopter built in.

Interesting, but there's no blur when I focus on something closer. Do I need a diopter lens if I shoot with my glasses?

https://www.rangefinderforum.com/for...d.php?t=142668

It suggests there is an adjustment screw somewhere near the mirror to adjust its alignment.

I saw this post, but I don't see the screws they're mentionning. If the mirror is misaligned, how do I adjust it?

Another thought occurs relevant to the F3. The F3 has a removable penta prism like many past Nikon pro bodies. Could it be that the penta prism is not properly mounted in place, thereby marginally throwing the body's geometry out and causing an apparent misfocus at infinity.

I don't know, it seems properly mounted to me

So this consideration begs a question - have you tried removing and refitting the penta prism or checking to see if the mounts are in good condition? Or if you can do so could you borrow another penta prism for an f3 and try focusing with a different prism on your camera body to see if that makes a difference. At least that would tell you if the problem is with the camera body or the prism.

That could be it, but I have no way to borrow a prism.

To Phil Forrest, I will try to check that myself, but the focsuing screen and the lenses are out of the equation now

 

[E.M]

I don't remember the price for fixing my F2 ( which I bought new in 1972 ) , it was in the early eighties and I guess I brought it to the importer of Nikon ( Belgium ). Never had the problem again with my F2 and never had it with my other Nikons .

 

[Highway 61]

I got the new screen. It's better, but it still slightly can't focus to infinity. I don't know where else to look.

That is strange. If the focusing screen wasn't the culprit, both the two screens should produce the same out of focus visible result when you look at the image in the finder, lock the lens focusing ring at infinity and aim the finder at something really located at infinity. If the first focusing screen was out of alignment in its metal frame, or wrongly installed, installing the new screen would have solved this out. It's very unlikely that two screens are both defective, and in a different way.

What type of screens are they ?

 

[newsgrunt]

ok, can u post some photos of the screen you're using and also how it's placed in the body ? I've never had issues with focusing my F3 after years of use and abuse. Either the screen is incorrect, not seated properly or the lens mount is damaged. or something else, and there's no diopter in the finder right ?

 

[leicapixie]

When my daughter went Nikon digital, My old pro kit was returned..
Off I went to the beach and lo and behold, my focus was wrong on infinity!
All the 5 lenses,,would not reach infinity.
If I removed my glasses, it was perfect.
I used my Leica M mostly with N-F half world away.
I discovered my eyes had changed!
I was no longer near sighted, but arms too short.
So! Check your sight, focus screen.
What other cameras are you using?

 

[Sarcophilus Harrisii]

To be frank I think most of us are a bit stumped as to why this is happening. Individual lenses not focusing at infinity are not all that uncommon but usually this is because someone has disassembled the lens for cleaning and not reassembled it correctly. Having several lenses all not focusing indicates a camera body problem - this is less common in my experience.

There's no great mystery involved, because establishing the cause of the focusing problem just entails a basic understanding of how a single lens reflex works, and making a competent inspection of the focus accuracy in the correct order at the necessary locations—note that is locations, plural. The reason we are all still none the wiser is, quite simply, because the thread starter has tendered evidence that they lack this basic understanding, and has not taken the good advice previously offered, on board.

In the fourth post, I suggested the following:

First of all you need to establish what needs adjusting.
Check the focus screen installation.
Work out what the film plane focus looks like. You will have a better idea of where the fault lies once you have verified the register of the body is correct.

The thread starter's response to my (bold) comment above, was:

What do yo mean?

In the thirtieth post, Phil was kind enough to, essentially, expand my advice in some detail. His entire post is most helpful however I have highlighted below one vital point he mentions which I also told the thread starter myself (in not so many words):

To check the physical adjustment of the camera body film plane to lens flange, take a known good lens and mount it on the camera. Mount the camera on a tripod. Remove the film door. Place a piece of frosted glass or plexiglass or even scotch tape vertically between the inner film rails on the body. Frosted side toward the lens. The inner rails are one film thickness closer to the lens flange than the outer rails. Lock up the mirror. Focus your lens on infinity at a very distant object and look at the film plane with a loupe. If it is in focus, then your problem is with the mirror/finder/groundglass. If not, your problem is with the camera body. Repeat this with a few lenses to ensure that it is not your lens. If you don't start with this, you'll go around in a circle of testing the focusing mechanism while not ensuring the camera itself it calibrated. Once you have the proper infinity focus at your actual film plane, you can begin to mess with the groundglass/finder/mirror.
As was mentioned, it could be your mirror, your eyepiece, your mounting of the groundglass condenser or even the prism itself.
Phil Forrest

The *lenses* of the thread starters camera may well be focusing to infinity just fine. We don't know, though, and neither does the owner because eight posts later there's still absolutely no indication the film focus has been checked!

The lens of a single lens reflex projects an image (hopefully) into focus at or about the film rails of the camera.

The reflex mirror, focus screen, eyepiece, play absolutely *no* direct part in creating this image. They are however calibrated (or, ought to be) to return a viewfinder focus that is (nominally) exactly the same as the film rails.

Note I said that the viewing components are calibrated to the film rails. Not vice-versa.

Apart from the most cursory of checks (screen installation; eyepiece diopter; prism fitment if interchangeable) it's inappropriate to contemplate adjustments to mirror, installed screen height etc, until the status of the lens focus at the film has been verified good, because otherwise, you have no idea what the hell you're calibrating the viewfinder focus *to*.

Incidentally I quite agree with Peter's (quoted) comment above that the body adjustment is less likely to be off than the viewfinder calibration. Generally, unless a camera has been poorly worked on or had some impact damage the film focus is less likely to be out in a quality SLR that was, presumably, properly adjusted once, when manufactured. But that's not the bloody point, because the film focus is your target for the viewfinder calibration. Without establishing that first, you're merely hoping that when the finder looks right, the images will be. Phil has already summed up the perils of this methodology quite nicely.

Personally, I think it's time to stop flogging this horse. It's dead. The thread starter may be well advised to pass the camera onto a repairer who actually possesses the requisite basic understanding of camera design for inspection and repair. God knows I've spent countless hours doing my best over the years to help members with their camera problems if I could—but if someone won't, or, can't, recognise good advice and run with it, then, there are limits to how much I can assist, and, I suggest others, also...

 

[p.giannakis]

My advice is this:

The F3 is a fantastic camera and if you have it serviced it will provide you with years of trouble free service. It is also quite expensive camera too, so if none of the above advice has resolved the problem, i think it is a good idea to hand it to an experienced repair man before more damage is done to it.

 

[Highway 61]

One problem, many friendly explanation attempts, and still nobody knows what is really wrong with this F3, because the OP didn't explain it clearly from the beginning and didn't answer the questions asked so that the problem became more clear as for how it was showing up.

End of this thread for me.

 

[jszokoli]

God knows I've spent countless hours doing my best over the years to help members with their camera problems if I could—but if someone won't, or, can't, recognise good advice and run with it, then, there are limits to how much I can assist, and, I suggest others, also...

Don't dispair, there are other people reading these posts and your explanations are helping them better understanding the mechanics of what could be happening...

Joe