Nikon F100 issue - blurry viewfinder

mfohl · Mar 16, 2019

Hello Folks, I just purchased a used Nikon F100. Everything appears to be well except for one thing: when I look into the viewfinder, it is extremely blurry and distorted. It's like looking through a lensbaby or the bottom of a coke bottle. I put a newer Nikon zoom lens on it and set focus to S. When I pointed the camera at things and pressed the shutter button, I could see and hear the lens moving. I took a few shots, developed them, and they appear to be focused OK. Rotating the diopter knob doesn't help. I had planned to use the camera with some of my older non-auto prime lenses. And I tried one. I can barely compose, much less focus.

It seems to me that something is wrong in the pentaprism. Maybe the diopter knob had been moved too far in one direction or the other.

Does anyone have any wisdom on this issue? It would be much appreciated, as the camera seems to be an otherwise good choice.

Thanks!

-- Mark

jimjm · Mar 16, 2019

Is the viewfinder display readout also blurry, or just the image on the focusing screen?
The focusing screens are removable, so maybe it's not seated correctly.

Also, the previous owner may have installed an additional diopter lens on the eyepiece, which may not be compatible with your eyes. Try unscrewing that if one is installed. The default eyepiece is plain glass with no magnification factor.

mfohl · Mar 16, 2019

Thanks. The guy at the local camera store unscrewed the eyepiece and that apparently had no effect. Also, I can't even see the display stuff. It's supposed to be on the bottom, right?

jimjm · Mar 16, 2019

Yep, the green LED display readout is below the image, as you can see at the bottom of the page here.

Are the focus area brackets around the center of the image also blurry?

ic-racer · Mar 16, 2019

Get another one. Plenty of F100s around.

xtolsniffer · Mar 16, 2019

The dioptre adjustment mechanism could be damaged. It happened to my F100, its just a plastic frame that moves a lens inside the viewfinder and mine snapped and all I got was a blurry viewfinder. See if it changes as you crank the dioptre adjustment back and forth. If not, its likely broken. Its an easy repair if someone still has parts but its almost as cheap to get a new body.

PGillin · Mar 16, 2019

xtolsniffer said:
The dioptre adjustment mechanism could be damaged. It happened to my F100, its just a plastic frame that moves a lens inside the viewfinder and mine snapped and all I got was a blurry viewfinder. See if it changes as you crank the dioptre adjustment back and forth. If not, its likely broken. Its an easy repair if someone still has parts but its almost as cheap to get a new body.

I'm inclined to agree, my university's photo club owned one with this problem. The best bet is probably taking it to a repairman, if you're lucky nothing's actually broken and the diopter wheel has simply jumped a gear or become misaligned. Does the diopter appear to move or change at all when you adjust the dial?

FWIW I would personally get it repaired over buying a new body - better to put money into getting a camera into known-good condition than spend money on an unknown quantity. Just an opinion though. In any case hopefully you can get it working, they are nice shooters.

pentaxuser · Mar 16, 2019

Isn't the first and obvious answer to contact the seller and discuss it with that person or take it back to that person if he/she is not a distance seller. on the surface it sounds as if it arrived in a faulty condition.

pentaxuser

mfohl · Mar 17, 2019

pentaxuser said:
Isn't the first and obvious answer to contact the seller and discuss it with that person or take it back to that person if he/she is not a distance seller. on the surface it sounds as if it arrived in a faulty condition.

pentaxuser

I already did that. Seller says that it worked OK before he shipped it. Seller is engaged in this process, and I am keeping him informed of the developments.

tomkatf · Mar 17, 2019

xtolsniffer said:
The dioptre adjustment mechanism could be damaged. It happened to my F100, its just a plastic frame that moves a lens inside the viewfinder and mine snapped and all I got was a blurry viewfinder. See if it changes as you crank the dioptre adjustment back and forth. If not, its likely broken. Its an easy repair if someone still has parts but its almost as cheap to get a new body.

This is exactly what was wrong with my F100, apparently a fairly common problem... Needed diopter repair... as mentioned may be just as cheap to get a "new" body.

shutterfinger · Mar 17, 2019

Sounds like shipping damage. Shipping employee used it for a soccer ball, basketball, shipping truck rolled over in the snow and ice, plane hit a bit pot hole, or the seller packed it poorly.

MartinCrabtree · Mar 17, 2019

Plane hit a pot hole? OK.

shutterfinger · Mar 17, 2019

Isn't that what it is when you're flying along and the plane dropps 50 to 100 feet in a instant?

choiliefan · Mar 18, 2019

My F100 suffers from the same loose diopter lens.
I crammed/jammed some cushy foam rubber around this lens forcing it inward towards the prism.
A very cost effective repair... and works great.

John Koehrer · Mar 18, 2019

shutterfinger said:
Isn't that what it is when you're flying along and the plane dropps 50 to 100 feet in a instant?

737 Max 8?

mfohl · Mar 19, 2019

choiliefan said:
My F100 suffers from the same loose diopter lens.
I crammed/jammed some cushy foam rubber around this lens forcing it inward towards the prism.
A very cost effective repair... and works great.

I just might try this. Thanks!

PGillin · Mar 19, 2019

mfohl said:
I just might try this. Thanks!

This will give you trouble with manual focusing. Since the adjustment of the diopter won't be precise and could vary with time (as the foam compresses), temperature, humidity, etc, the sharpness of the image in the viewfinder won't be consistent. You may even have different levels of sharpness on different sides of the VF.
Which, if you want to use exclusively autofocus or focus-confirmation lights is fine, but simply won't do for manual especially where fast or long glass is involved.
Please, do yourself (and the repairers still working on 35mm gear, and us, by helping keep them in business) a favor and get a good tech to look it over.

choiliefan · Mar 19, 2019

Depending on the lens, I am using the camera both AF and manually with the confirmation light.
I bought a service manual last year and will eventually try my hand at opening the camera and assessing the problem but until then, it is what it is.

JWMster · Mar 23, 2019

I just bought a Nikon F100, too. Very sweet rig. I think you can find one on KEH ( https://www.keh.com/shop/nikon-f100-35mm-slr-camera.html ) or send it to them for repair.
Great camera.

Kino · Mar 23, 2019

I have a friend with a F100 body sitting in a closet unused. He's been trying to get me to buy it, but I am too busy buying old crappy cameras to repair and "have fun".

I could ask him for a price if anyone is interested. I think he was looking for around $150.

Nikon F100 issue - blurry viewfinder

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