Diopters

ColColt · Aug 18, 2015

These things still confuse me. I know Nikon is set at -1 prism and Leica rangefinders are set at -.5. I ordered a +.5 for the Nikons and it was spot on-I lucked out. With the Leica I don't know. You'd think a +1would work with the Leica seeing that the +.5 worked so well with the Nikon.

Not willing to blow $100 for a diopter I may have to send back I stopped by myi optometrist today to see what my last prescription was just about 4 months ago. They gave me a copy and from what I can tell the OD(for my right eye distance seeing) is -2.50(Spherical they call it). The Cylinder is +0.25. The gal at the optometry section who fits and fixes glasses told me for the Leica rangefinder I would need a +.5 since the camera is set for a -.5. That didn't make any sense. Can anyone shed light on this intriguing subject who may be in the know about diopters?

ic-racer · Aug 19, 2015

Please note that the Leica M-Viewfinder is preset by default to -0.5 diopters, so anyone wearing glasses of 1 diopter strength would require a +1.5 diopters correction lens.--LEICA

-2.5 minus -0.5 equal -2.0 (part #14358)

Gerald C Koch · Aug 19, 2015

Thanks to attending a grammar school and not a grade school OD is Latin for oculus dexter (right eye), and OS for oculus sinister (left eye).

ColColt · Aug 19, 2015

ic-racer said:
-2.5 minus -0.5 equal -2.0 (part #14358)

That can't be right. I have a +0.5 diopter on the Nikon F2 and can see great with it. Nikon's prism is -1. My right eye is -2.50 from what they told me yesterday.

ic-racer · Aug 19, 2015

ColColt said:
That can't be right. I have a +0.5 diopter on the Nikon F2 and can see great with it. Nikon's prism is -1. My right eye is -2.50 from what they told me yesterday.

If you are throwing the optemetry data out the window and using your own test, then the Leica should be fine as it is.

Nikon: -1 minus 0.5 = -0.5 (your prescription determined by you)
Leica: -0.5 minus 0 = -0.5 Therefore no correction needed. Therefore when you get the Leica, see how it works with no additional diopter.

Also, you can just wear your glasses, when using either camera.

ColColt · Aug 19, 2015

I got the information about the Nikon prism being -1 from Sover Wong. That's how I knew what I needed was a +0.5 diopter and as I stated twice it works.

https://www.flickr.com/groups/nikonf2/discuss/72157633240457394/

I already have the Leica M2 and can't see well with the standard diopter built into the camera of -.5. I assumed from having the Nikon +0.5 diopter I'd need a +1 for the Leica. I always wear glasses as I'm near sighted a bit and can't see distance well without them. That's why there's a minus in my prescription of -2.50.

Prof_Pixel · Aug 19, 2015

ColColt said:
I always wear glasses as I'm near sighted a bit and can't see distance well without them. That's why there's a minus in my prescription of -2.50.

Yes, -2.50 is quite nearsighted (been there, done that), Since you will be wearing your glasses (with that -2.50 correction), that -2.50 value doesn't enter into the calculations. What you need, in effect, is the correction that would be used in making bi-focal lenses - this will be a PLUS value lens and a +0.5 correction doesn't sound too unreasonable.

Prof_Pixel · Aug 19, 2015

>>Please note that the Leica M-Viewfinder is preset by default to -0.5 diopters, so anyone wearing glasses of 1 diopter strength would require a +1.5 diopters correction lens.--LEICA<<

That would be true if the person was NOT wearing their glasses when using the camera.

ColColt · Aug 19, 2015

The bifocal part is +2.50(I think). That's in the "Add" section of the prescription. I apparently have an astigmatism as there's a Cylinder value of+.25 for the right eye.

Prof_Pixel · Aug 19, 2015

ColColt said:
The bifocal part is +2.50(I think). That's in the "Add" section of the prescription. I apparently have an astigmatism as there's a Cylinder value of+.25 for the right eye.

That would mean your bi-focal lens would be 'just plain glass' (which I guess isn't all that unreasonable for a nearsighted person).

How well does the Leica work for you right now with your glasses on?

ColColt · Aug 19, 2015

Without a diopter I can't focus good with the Leica with the glasses. I tried putting the Nikon diopter over it and it appears too strong.

Peter Simpson · Aug 19, 2015

Nikon works the other way, according to the fourth bullet on this chart: http://www.nikonusa.com/fileuploads/pdfs/EP_CompChart.pdf

If you want +2.0 correction, you order the +2.0 part. The -1 of the prism is already taken into account.

(Hint: search with the Nikon 4-digit part number on Google to find sellers)

Prof_Pixel · Aug 19, 2015

ColColt said:
Without a diopter I can't focus good with the Leica with the glasses. I tried putting the Nikon diopter over it and it appears too strong.

So you are saying that the +0.5D Nikon lens is too strong and no lens is too weak?

BTW, are you using the distance part of your glasses or the reading part?

ColColt · Aug 19, 2015

As I ponder over all this, I think the +1 diopter for the Leica would be the ticket-you agree?

The +.5 for the Nikon IS great. I am using the top part of the glasses(distance) for focusing, not the bifocal area below. I actually take the glasses off at the computer as I don't need them for that distance viewing of the monitor.

Sirius Glass · Aug 19, 2015

ic-racer said:
-2.5 minus -0.5 equal -2.0 (part #14358)

OR wear contact lens and the problem goes away.

Diopters

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