• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Nikon F100 issue - blurry viewfinder

between takes

H
between takes

  • Tel
  • Mar 21, 2026
  • 0
  • 0
  • 0
Tompkins Square Park

A
Tompkins Square Park

  • 8
  • 1
  • 87

Recent Classifieds

Forum statistics

Threads
202,862
Messages
2,846,719
Members
101,574
Latest member
JRSCollection
Recent bookmarks
0

mfohl

Subscriber
Allowing Ads
Joined
Jan 10, 2007
Messages
1,246
Location
Westerville,
Format
Multi Format
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
 
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.
 
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?
 
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.
 
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.
 
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
 
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.
 
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.
 
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.
 
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!
 
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.
 
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.
 
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.
 
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab Blue Moon Camera & Machine
Top Bottom