D810 Focus Issue

[Hue]

Hello to everyone. This is my first post. I joined after reading a lengthy thread by ?D200 who is seems hasn't been active in a while.
I have a focus problem that my D810 has been to a Nikon service center for 3 times and they state they cannot reproduce... even though the problem is visible every single use.
In any autofocus mode the camera focuses and returns a sharp image. However, the image in the optical viewfinder is not in focus. It is not a diopter issue. If I'm using a lens that allows manual focus tuning while in autofocus mode I can autofocus and then fine tune to achieve a sharp image in the viewfinder. If I shoot then my resulting image is well out of focus. Again, though, if I simply allow the camera to focus and I shoot then I get a great image. If I change completely to manual focus I get the same. Sharp image in the viewfinder but out of focus results. I have found that I can manually focus to a sharp image and then move the focus ring between maybe 1/8" and 1/4" toward closer and I get a sharp image... out of focus now in the viewfinder.
I have read about adjusting the focus using the screws under the bottom plate but I hesitate to do that since it seems to be focusing fine.
I'm sure there is an adjustment to fix this but I'm not sure where to find it. Can anyone help?
Also... it's the same with any lens I use.
Thanks

 

[Needa]

Hue, Welcome!
To me it sounds like the focus is working correctly and you do not want to adjust the focus sensor. If you take a picture in manual focus mode using the confirmation dot and not what is looks like in the view finder is it in focus? The OVF ( optical view finder) relies on several mirrors to to produce the image you see, if one of those mirrors is not were it should be this could cause this. The only adjustment I am aware of is the diopter.

 

[BF Hammer]

Camera can find focus fine, so it must be either your eye(s) or the diopter. Diopter is for fixing human eyesight problems.

FYI: 20/20 is not perfect eyesight. It's a reference for normal eyes. When you get fitted for glasses at an optometrist they typically try to get your vision corrected to better than 20/20. Ironically the guys wearing glasses likely see much better than those who don't.E

EDIT: tested premise, this information is incorrect.

 

[Hue]

Camera can find focus fine, so it must be either your eye(s) or the diopter. Diopter is for fixing human eyesight problems.

FYI: 20/20 is not perfect eyesight. It's a reference for normal eyes. When you get fitted for glasses at an optometrist they typically try to get your vision corrected to better than 20/20. Ironically the guys wearing glasses likely see much better than those who don't.

Thanks, BF Hammer, I appreciate your input. However, if it was either my eyes or a diopter issue then I wouldn't be able to make a small focus adjustment and achieve sharp focus in the viewfinder. If the image in the viewfinder was actually sharp and I saw it as blurry then I should also see the finished image as blurry. I have 3 other Nikons that all work perfectly and I've been photographing for over half a century - it's definitely a camera issue.

 

[Hue]

Camera can find focus fine, so it must be either your eye(s) or the diopter. Diopter is for fixing human eyesight problems.

FYI: 20/20 is not perfect eyesight. It's a reference for normal eyes. When you get fitted for glasses at an optometrist they typically try to get your vision corrected to better than 20/20. Ironically the guys wearing glasses likely see much better than those who don't.

By the way, in Live View the preview is fine. The problem is only in the optical viewfinder. I think it almost has to be a mirror adjustment issue of some sort. I'm very technical and mechanical BUT I have never been inside a SLR or DSLR.

 

[Hue]

Camera can find focus fine, so it must be either your eye(s) or the diopter. Diopter is for fixing human eyesight problems.

FYI: 20/20 is not perfect eyesight. It's a reference for normal eyes. When you get fitted for glasses at an optometrist they typically try to get your vision corrected to better than 20/20. Ironically the guys wearing glasses likely see much better than those who don't.

Here ( https://www.fredmiranda.com/forum/topic/1371020/ ) I've just found someone who had the same issue and I've read about others with this exact issue.

 

[BF Hammer]

For all future readers, just let the autofocus do it's thing, then without touching the focus ring on the lens, move the diopter adjustment wheel until your image is focused in the viewfinder.

@Hue certainly your D810 diopter wheel is out of spec. What's a person gonna do?

 

[Hue]

For all future readers, just let the autofocus do it's thing, then without touching the focus ring on the lens, move the diopter adjustment wheel until your image is focused in the viewfinder.

@Hue certainly your D810 diopter wheel is out of spec. What's a person gonna do?

Certainly the diopter is NOT the issue. Did you actually read my complete initial comment... the part where I explained that I can manually focus and obtain a SHARP image in the viewfinder? That would not be possible if the diopter was out of adjustment.
I have around 81 cameras. It's a pretty good bet that I understand how to adjust an eyepiece. I believe I learned that somewhere around 1973.
As I'm always learning I would love to hear, though, how the diopter can be in sharp adjustment but then be out of focus when the camera is actually in focus.

 

[Needa]

Is it possible the focus screen was removed and not reinstalled correctly?

 

[BF Hammer]

Certainly the diopter is NOT the issue. Did you actually read my complete initial comment... the part where I explained that I can manually focus and obtain a SHARP image in the viewfinder? That would not be possible if the diopter was out of adjustment.
I have around 81 cameras. It's a pretty good bet that I understand how to adjust an eyepiece. I believe I learned that somewhere around 1973.
As I'm always learning I would love to hear, though, how the diopter can be in sharp adjustment but then be out of focus when the camera is actually in focus.

I disagree about it being impossible to manually focus to a sharp image in the viewfinder with the diopter off adjustment.

My understanding is the diopter is a focus adjustment for the viewfinder image, broken to the simplest concept. Each time I had blur from manual focus, it was from unintentionally moving that diopter wheel. The focus indicator dot would always work, since that uses the AF sensor. But my eye said not there.

Ps: I will test that tonight when I get home from work on my D750. (tested and I am wrong)

 

[BF Hammer]

OK, I am wrong on this.

 

[Hue]

Is it possible the focus screen was removed and not reinstalled correctly?

It hasn't been removed unless it was done at the service center... as far I know. I have read that shimming it can correct this issue, though. It's really odd and even more odd that the Nikon service center said they can't reproduce the problem when it actually happens 100% of the time.
I think I might contact them again tomorrow and find out if there is a different service center I can send it to. It is very frustrating.
Thanks.

 

[Hue]

It hasn't been removed unless it was done at the service center... as far I know. I have read that shimming it can correct this issue, though. It's really odd and even more odd that the Nikon service center said they can't reproduce the problem when it actually happens 100% of the time.
I think I might contact them again tomorrow and find out if there is a different service center I can send it to. It is very frustrating.
Thanks.

Thank you for your time and thoughts on it. I think I'll call Nikon and see if there is a different service center I can send it to. If I had a local camera shop I would gladly go pay someone to fix it.