Help please! ...finding the right diopter correction value!

[David H. Hartman]

I can read red digital alarm clocks at night without my glasses but I had to return one that was blue because it fuzzed out and was totally useless for me. As I remember my mother could read a blue alarm clock but not a red one, just the reverse. I'm not sure of the reason but I think it's something specific to one's eyes.

Dave

[Frank Fremerey]

Dave. I guess the click-correction in my other cameras do not correct for astignatism.

The information in the VF is displayed in white for the D500 and green for the D3 and D600.

my current guess is that I am 0.5 dioptrien off from -1, the base setting.

which could it be?

+0.5 or -0.5???

[Frank Fremerey]

Dave. I guess the click-correction in my other cameras do not correct for astignatism.

The information in the VF is displayed in white for the D500 and green for the D3 and D600.

my current guess is that I am 0.5 dioptrien off from -1, the base setting.

which could it be?

+0.5 or -0.5???

[pluton]

I can read red digital alarm clocks at night without my glasses but I had to return one that was blue because it fuzzed out and was totally useless for me. As I remember my mother could read a blue alarm clock but not a red one, just the reverse. I'm not sure of the reason but I think it's something specific to one's eyes.

Dave

I noticed the same phenomenon with the "blacklights" (long wave UV lights) we played with way back in the 1960's.
Deep red or deep blue come to focus at different distances from the same lens.  Yellow/green or white light should sit in the middle.  I was/am farsighted(shorter lens-to-retina distance), so I could focus on the deep blue light, but it didn't happen with deep red.

[pluton]

Dave. I guess the click-correction in my other cameras do not correct for astignatism.

The information in the VF is displayed in white for the D500 and green for the D3 and D600.

my current guess is that I am 0.5 dioptrien off from -1, the base setting.

which could it be?

+0.5 or -0.5???

I advise against guesswork, and for empirical discovery.   
Find an optician that has small hand lenses in 0.25 diopter values, or order some cheap plastic lenses from a science supply house. 
The optician is better because they can deal with astigmatism and intelligently advise you.  Your 1.00 astigmatic value(as I recall) is serious enough to annoyingly blur your vision if it isn't brought into the calculations.

[Frank Fremerey]

I have been to and mortar optician today. We measured and tested.

Result: focussing on objects less tan 2 meter from the camera +0.5 helps. But: focussing on anything beyond
the correction disturbs my focussing.

So: for near objects I should get a chepo +0.5. For far object I do not need anything.

Diagnosis: The ability of my eye to compensate the light trouble in the near field is limited. A static diopter cannot work.

[Hugh_3170]

Frank, commiserations my friend.

Does the issue just apply to your preferred eye, or to both?

[Frank Fremerey]

My preferred eye is kaputt.

I had to switch to the left a while ago.

There is not problem with DSLRs so no trouble at work.

The VF and esp the ground glass of the FM2 are not up to the task.

Best MF camera I own is the D500. Good diopter adjustment and
a great ground glass.

I guess that if I get the F6 ground glass to work in my FM2 or
D600 that focussing might be just as precise and snappy.