diopters for the M9

[stump4545]

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is it safe to say since i don't use glasses then i don't need any diopters for the M9?

 

my vision is not perfect 20/20 for sure though.

 

just trying to improve my focusing accuracy.

 

 

thanks a lot.

[andybarton]

If your distance vision is good, you won't need a dioptre adjustment lens.

[vk2109]

is it safe to say since i don't use glasses then i don't need any diopters for the M9?

 

my vision is not perfect 20/20 for sure though.

 

just trying to improve my focusing accuracy.

 

 

thanks a lot.

it's really up to you and how you see thru the viewfinder. I wear contact lens and I use a slight -1 diopter. really helps when your eye get a bit tired. I also feel it adds more contrast and helps thus the focus. just my personal opinion

[jaapv]

Just try at your local optician.

[dorman]

If your distance vision is good, you won't need a dioptre adjustment lens.

 

I think the M9 viewfinder is set at -0.5 dioptre, which means that a distant object will appear to be 2 metres away.

Therefore if you can see clearly at 2 metres you don't need a dioptre attachment.

If you need glasses to see at 2 metres then you need a dioptre the same as those glasses.

[hoppyman]

You may find the information in this thread of interest.

http://www.l-camera-forum.com/leica-forum/customer-forum/171589-leica-camera-faqs-frequently-asked-questions.html

[pico]

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is it safe to say since i don't use glasses then i don't need any diopters for the M9.

 

I don't know, but there is a continuous variable diopter at japan exposures | films and more (formerly Megaperls Japan Webshop).

 

At your own risk.

[lars_bergquist]

I think the M9 viewfinder is set at -0.5 dioptre, which means that a distant object will appear to be 2 metres away.

Therefore if you can see clearly at 2 metres you don't need a dioptre attachment.

If you need glasses to see at 2 metres then you need a dioptre the same as those glasses.

 

This is not quite true. The framelines and the edge of the rangefinder patch are at virtual 2 meters, but not the finder image – including what's inside the patch. Just like in the case of binoculars, the image you see is at a virtual distance that varies, at some ratio, with the subject distance. This is why we have to focus the glasses. The M can do without finder image focusing (i.e. have a fix-focus finder) because of the negative magnification, which increases visual d.o.f. But when the Leica III was given a 1.5X rangefinder, in order to focus the 135mm lens accurately, it had to have a focusing ocular. This was the technical reason for it. It did of course also correct for errors in eyesight, on the side, but this was basically taken care of by screw-in compensation lenses for both the finder and the rangefinder eyepieces (remember, the RF focus lever did not compensate for eyesight problems in the finder!)

 

Remember, this is is totally different from the finder screen of a SLR camera. In that case, you have a matte screen at an invariable distance from the ocular, and the image you see on that screen is an optical real image focused slam on that screen. So it's all very simple. With the M, what you have is two virtual images, one from the finder and one from the rangefinder. My distinct impression is that in most cases, the finder furniture (framelines etc.) is at a distance slightly closer than the actual finder image(s). And the two overlapping images in the RF patch are a good deal more critical than the framelines.

 

The old man with the rheumy eyes

[Jeff S]

my vision is not perfect 20/20 for sure though.

 

I prefer to first correct my daily vision as best as possible (still not perfect due to astigmatism). Sometimes I'm not looking through a finder.

 

I agree with Jaap and others that the best way to determine if a diopter will help is to try some at your local optician, with the camera. All the theory and underlying science is fine, but eyes are tricky and individual preferences and needs vary; it's best to experiment. Same with magnifiers.

 

Jeff

[stunsworth]

Possibly the simplest thing to do is to go to a supermarket that sells reading glasses, try a few on see what strength of diopter gives you the clearest view, and then order a correction lens of that strength.

[Jeff S]

Possibly the simplest thing to do is to go to a supermarket that sells reading glasses, try a few on see what strength of diopter gives you the clearest view, and then order a correction lens of that strength.

 

Steve, I still think it's best to try different diopters while looking through the camera finder. This is easy to do, and is the only way to eliminate all the variables and correction factors already involved with the VF.

 

Jeff

[stunsworth]

Steve, I still think it's best to try different diopters while looking through the camera finder.

 

Sorry, that's what I meant - apologies for not explaining myself correctly. Put on a pair of glasses, look through the viewfinder, and pick the diopter that gives you the clearest view.

[andybarton]

That idea won't work if you're shortsighted.

[dorman]

That idea won't work if you're shortsighted.

 

No, but my suggestion will.

[jaapv]

In theory - yes. In practice - real eyes sometimes defy theory.

[Jeff S]

In theory - yes. In practice - real eyes sometimes defy theory.

 

Agreed...exactly my point. I've seen many posts from people who meticulously calculate and anticipate a solution, only to find a different one suits.

 

Jeff

[hoppyman]

And astigmatism if present, cannot be corrected by the standard (spherical) correction lenses.

You may be able to get some improvement and this is all down to individual's eyes of course. As suggested there is just no substitute for trying actual corrections with your eyes and your camera and preferably with a knowledgeable optician/opthamologist to assist..

 

I just went through this whole thing again and now have found that my left (shooting) eye has deteriorated further and in fact the standard corrective lenses (nor the magnifiers) do not solve my problem there.

[pico]

And astigmatism if present, cannot be corrected by the standard (spherical) correction lenses.

 

I have profound astigmatism. My wife's old Leica III has an adjustment at the eyepiece that acts like a variable diopter and helps me focus much better.

 

So what is happening there. Is that adjustment a variable diopter or black magic, and if it ain't magic, why cannot Leica add it to it's current line?

[jaapv]

Because the adjustment is a focussing lever for the rangefinder only. The viewfinder is separate. When combining the two like in the M the system does not work. See post #8 above.

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[andybarton]

My dealer has an arrangement with an optician across the mall, so that customers looking to buy a dioptre adjustment lens can have their eyes tested to ensure that the adjustment lens is correct, taking into account the -0.5 built-in correction in the viewfinder.

 

Sounds like a good idea, to me.