Dioptre correction lenses

[seany65]

Hello all,

Recently, the numbers in the viewfinder of my nikon f301 became a bit blurred, so I got a +1 dioptre correction lens and the numbers are now as clear as they used to be.

Unfortunately, the image in the viewfinder is marginally less sharp. This is not too easy to see with my tamron 17a standard zoom lens, which was on the camera when I was in the shop testing the correction lens, but when I put my tamron 103a tele zoom on, the problem became easier to see. I also tried with my tamorn 20a tele zoom and had the same problem, so it's not the 103a lens at fault. I've compared the view (using all 3 lenses) with the correction lens in place and slid up out of the way.

So has anyone got any idea what I can do about it?

Any help would be much appreciated.

 

[john_s]

The only thing I can think of is that the image to be focused and the numbers are at a slightly different distance optically and would need slightly different corrections for you to see both clearly. That would be impossible I suppose. I would tend to favour seeing the focusing image as a priority and put up with the numbers being not quite as sharp. Diopters are mostly available in increments of one whole unit (Leica has some 0.5 increments) but if a +0.5 were available it might just about be the best compromise. Have your eyes changed a bit lately? At my age (70+) they are changing from year to year. I have changed diopters more than once as a result.

 

[Kai-san]

If you are not already using one, maybe an eye cup could improve things by removing disturbing side light.

 

[seany65]

Thanks for the replies.

@john S, Yes, I think my eyes have changed recently, and I think it's slightly possible that having had covid twice (the 2nd time more severe but not too bad) may have had an effect. I also now have more milk in my tea since then, lol.

After making the original post, it did finally occur to me that a different correction lens my be what's needed.

Don't ask me why it didn't occur to me before making that post, but I've deecided to blame that on covid as well, lol.

@Kai-san, As far as I can tell, side light isn't usually bothering me but very occasionally when it's really bright in comparison to what the camera is aimed at it can make it harder to see the screen well enough to focus. This is usually when indoors and a bulb is pretty close.

 

[hap]

The only thing I can think of is that the image to be focused and the numbers are at a slightly different distance optically and would need slightly different corrections for you to see both clearly. That would be impossible I suppose. I would tend to favour seeing the focusing image as a priority and put up with the numbers being not quite as sharp. Diopters are mostly available in increments of one whole unit (Leica has some 0.5 increments) but if a +0.5 were available it might just about be the best compromise. Have your eyes changed a bit lately? At my age (70+) they are changing from year to year. I have changed diopters more than once as a result.

Far better for your health to change diopters liberally, than change wives.

 

[retinax]

Far better for your health to change diopters liberally, than change wives.

I disagree. In both cases, it's crucial to recognise if the present one is bad for you.