I replaced my Nikon FM focusing screen and now it misfocus

MFstooges · Jun 4, 2021

Like the subject says, I followed the camera repair diagram to the 'T' except for one thing that is not shown clearly in the diagram and in youtube videos : matte side direction. I did not make note on the original screen orientation and I am not 100% sure which side facing up but the screen has a recess that is align to the metering LED so logically the notch should face upside in order to give room for the LED.

Now the screen is blurry when the lens focus is set at infinity. What could be wrong?

ic-racer · Jun 4, 2021

I did not make note on the original screen orientation...What could be wrong?

Very wild guess...screen orientation.

Kino · Jun 4, 2021

http://www.mir.com.my/rb/photograph...ikonfeseries/fefmshared/html/screenchange.htm

MFstooges · Jun 4, 2021

Kino said:
http://www.mir.com.my/rb/photograph...ikonfeseries/fefmshared/html/screenchange.htm

No Sir. Older Nikon FM is different.

MFstooges · Jun 4, 2021

ic-racer said:
Very wild guess...screen orientation.

MFstooges said:
the screen has a recess that is align to the metering LED so logically the notch should face upside in order to give room for the LED.

wiltw · Jun 5, 2021

The instructions put the tab on the right (as you look into the camera)...if it is NOT on the right, it has to be upside-down!

I have never seen a focusing screen with matte (focus) side away from the lens...the only controversy is the placement of the fresnel lens on large format cameras, on the lens side or on the photographer side of the focusing screen.

Down Under · Jun 5, 2021

There is a quick and easy solution to this problem.

Take the camera to your nearest repair center and have them do it for you. Often as not it can be fixed while you wait. WIth any luck at all, it will not be (too) expensive for you to have it done properly.

Then never, ever try to do this sort of thing again. there is an old saying about "false economy". And some even harsher words for those who tinker too much at home with their own cameras.

YouTube can be fun to watch, but very dangerous for those addicted to home repairs. One of (several) good reasons why I will no longer buy quality cameras on Ebay, too many amateur fix-its...

Chan Tran · Jun 5, 2021

ozmoose said:
There is a quick and easy solution to this problem.

Take the camera to your nearest repair center and have them do it for you. Often as not it can be fixed while you wait. WIth any luck at all, it will not be (too) expensive for you to have it done properly.

Then never, ever try to do this sort of thing again. there is an old saying about "false economy". And some even harsher words for those who tinker too much at home with their own cameras.

YouTube can be fun to watch, but very dangerous for those addicted to home repairs. One of (several) good reasons why I will no longer buy quality cameras on Ebay, too many amateur fix-its...

Your suggestion is neither quick nor easy. Where is the the nearest repair center?

ruilourosa · Jun 5, 2021

mamiya 645 pro tl had the matt surface facing the prism, not the mirror...

MFstooges · Jun 9, 2021

I think I found the problem. I replaced the mirror box original brass shims with aluminum shims from donor body. I remembered the aluminum shims are thicker than the brass. Now if I can find the original brass shim....sigh.

BobD · Jun 10, 2021

Just go to your nearest Nikon brass shim store and buy some more.

gone · Jun 10, 2021

Unless you have the patience of Job, it would probably be best to send it to a repair person. There's at least 2 I've seen on google searches that had prices well under $100 for a CLA. Normally I can fix most basic stuff on old SLR's, but shimming and re-shimming, and then checking focus each time, might put you around the bend.

MFstooges · Jun 12, 2021

momus said:
Unless you have the patience of Job, it would probably be best to send it to a repair person. There's at least 2 I've seen on google searches that had prices well under $100 for a CLA. Normally I can fix most basic stuff on old SLR's, but shimming and re-shimming, and then checking focus each time, might put you around the bend.

Yeah it will be nice if CLA includes other extra stuff outside of 'clean, lube & adjustment'. Besides this is my beater body and sort of a fun DIY project.

I replaced my Nikon FM focusing screen and now it misfocus

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