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View Full Version : Shrinking lens for Leica M viewfinder?


Jonathan R
01-19-2019, 09:59
Possibly a foolish question, but I have to ask.

I have become a spectacle-wearer due to age, and like so many others before me, find this difficult with my beloved Leica M6. I'm aware of all the standard solutions (different viewfinders, correction lenses, accessory shoe finders, etc). All the screw-in correction lenses for my eye condition enlarge the image, which makes it difficult or impossible to see frame lines for wide-angle lenses. Blablabla, old complaint, much rehearsed in forums.

But ... is it optically impossible to design a screw-in device which makes the image seem smaller (so one can see it all) but also focus-able for long-sightedness? I just can't get my head around this.

mod2001
01-19-2019, 10:15
Possibly a foolish question, but I have to ask.

I have become a spectacle-wearer due to age, and like so many others before me, find this difficult with my beloved Leica M6. I'm aware of all the standard solutions (different viewfinders, correction lenses, accessory shoe finders, etc). All the screw-in correction lenses for my eye condition enlarge the image, which makes it difficult or impossible to see frame lines for wide-angle lenses. Blablabla, old complaint, much rehearsed in forums.

But ... is it optically impossible to design a screw-in device which makes the image seem smaller (so one can see it all) but also focus-able for long-sightedness? I just can't get my head around this.

Welcome in the club, same here :) I tried a 0.58 viewfinder once (Leica MP) and it works great for 35mm with glasses or the correction lens. with 28mm my eyes had to walkaround a bit in both cases, similar to the 35mm on my M6 with 0.72 VF.

Juergen

bayernfan
01-19-2019, 10:26
Yes, a demagnifying screw-in optical assembly is certainly possible, but to the best of my knowledge, I don't think it is a commercially available accessory. I wonder if a talented individual (MS Optics?) could insert custom lens elements into a Leica magnifier.

I believe rangefinder base-length is a function of the magnification power, so if you do demagnify, you will lose focusing accuracy.

Two easy options are available:

1. Use a screw-in diopter on your existing camera and lift or remove your glasses to shoot.

2. Find an M6/M7/MP with a 0.58x viewfinder.

pagpow
01-19-2019, 13:10
Something like this, Jonathan?
https://leicastoremiami.com/products/e-clypse-85x-viewfinder-magnifier-34mm?variant=345676233
Giorgio

peterm1
01-19-2019, 13:45
Yes, a demagnifying screw-in optical assembly is certainly possible, but to the best of my knowledge, I don't think it is a commercially available accessory. I wonder if a talented individual (MS Optics?) could insert custom lens elements into a Leica magnifier.

I believe rangefinder base-length is a function of the magnification power, so if you do demagnify, you will lose focusing accuracy.

Two easy options are available:

1. Use a screw-in diopter on your existing camera and lift or remove your glasses to shoot.

2. Find an M6/M7/MP with a 0.58x viewfinder.

Japan Exposures 0.85 magnifier / diopter for Leica M 16,900 yen

http://www.japanexposures.com/shop/accessories/ms-mag-x0.85w-magnifier-for-leica-m.html

The Japan exposures products have stepless variable diopter between -3.0 and +1.5 so should satisfy all the needs expressed by Johnathan.

I have not tried the 0.85 demagnifier but own one of the 1.35 magnifiers and mainly use it for its adjustable diopter. It works fine and I would expect the demagnifier to also work well.

But be aware of this - by reducing the size of the image in the finder it reduces the effective base length of the rangefinder by the same amount. Hence the rangefinder becomes marginally less easy to use accurately as Bayernfan suggests

Note also that the ad for the item says:" Reports on the effectiveness of this item are mixed. The minifier is not recommended while wearing glasses or for Leicas with 0.58 or 0.72 magnification as the minifying effect is minimal. Please contact us for details."

But also bear in mind that as this unit has diopter correction you should be able to use it without wearing your glasses which should help. I use mine in this manner as the glasses put my eye too far back to be comfortable - the exit pupil on Leica finders are just not up to the task of coping in that situation even with a demagnifier I would surmise. This solution is serviceable but not ideal - there is no ideal solution that I know of other than hopping into a time machine, taking 40 years off your age and developing 20/20 vision. But here's the thing - these units from Japan exposures work - subject to taking time to experiment to get the diopter setting right for your viewing eye.

Brian Legge
01-19-2019, 14:19
Keep in mind that some demagnifiers go on top of the existing glass, meaning you eye is further away, rendering them useless as a solution for glass wearers. I got lucky and found a deal on a .58 finder M6ttl. Not cheap but it was probably the best option.

bayernfan
01-19-2019, 15:06
a Hexar RF (0.6x) might also be a viable (and less costly) alternative. a few popped up for sale last month here on RFF.

Steve M.
01-19-2019, 16:24
I looked on eBay and there's been a number of M6 cameras that sold as low as $1000-$1200, while the cameras with 0.58 viewfinders were $1700 to $2200, and they were all the TTL model. So if you sell your M6 to buy a 0.58 M6 there is going to be quite a bit of money you would have to pay out to make that happen.

Or, as suggested here, buy a Hexar RF. I owned one for a while and it was more like an M7 with it's extra features. A Mr Zhou case with a bump where a grip would be made mine feel a lot better in my hands. Really neat camera.

rhl-oregon
01-19-2019, 16:35
What is your vision in dioptric / scuba-mask terms? (Minus, plus, -3, +3.25, etc.?)

I’m with the dioptric solution crowd (add a diopter, focus without glasses), though I also own a magnifier, which is best for 90mm plus.

Some of us may have extra M diopters that might work for you.

Rob-F
01-19-2019, 16:54
Japan Exposures 0.85 magnifier / diopter for Leica M 16,900 yen

http://www.japanexposures.com/shop/accessories/ms-mag-x0.85w-magnifier-for-leica-m.html

The Japan exposures products have stepless variable diopter between -3.0 and +1.5 so should satisfy all the needs expressed by Johnathan.

I have not tried the 0.85 demagnifier but own one of the 1.35 magnifiers and mainly use it for its adjustable diopter. It works fine and I would expect the demagnifier to also work well.

But be aware of this - by reducing the size of the image in the finder it reduces the effective base length of the rangefinder by the same amount. Hence the rangefinder becomes marginally less easy to use accurately as Bayernfan suggests

Note also that the ad for the item says:" Reports on the effectiveness of this item are mixed. The minifier is not recommended while wearing glasses or for Leicas with 0.58 or 0.72 magnification as the minifying effect is minimal. Please contact us for details."

But also bear in mind that as this unit has diopter correction you should be able to use it without wearing your glasses which should help. I use mine in this manner as the glasses put my eye too far back to be comfortable - the exit pupil on Leica finders are just not up to the task of coping in that situation even with a demagnifier I would surmise. This solution is serviceable but not ideal - there is no ideal solution that I know of other than hopping into a time machine, taking 40 years off your age and developing 20/20 vision. But here's the thing - these units from Japan exposures work - subject to taking time to experiment to get the diopter setting right for your viewing eye.

I'm wondering about the cautionary note for .72 or .58 finders. I did the math: .72 x .85 = .612, which ought to make the .72 finder very nice with 35mm lens. And .58 x .85 = .493, which seems handy for glasses wearers using a 28mm. But I guess peterm1's observation about this device putting the eye too far back must be the reason for the maker's cautionary note. Me, as a eye glass wearer, I use mostly .58 bodies. And (being a wide-angle lens user) I use a diopter correction lens with my ,72 bodies and with my M9.

peterm1
01-19-2019, 17:18
I'm wondering about the cautionary note for .72 or .58 finders. I did the math: .72 x .85 = .612, which ought to make the .72 finder very nice with 35mm lens. And .58 x .85 = .493, which seems handy for glasses wearers using a 28mm. But I guess peterm1's observation about this device putting the eye too far back must be the reason for the maker's cautionary note. Me, as a eye glass wearer, I use mostly .58 bodies. And (being a wide-angle lens user) I use a diopter correction lens with my ,72 bodies and with my M9.


I find that the diopter correction sort of fixes the problem for me more so than any magnification / demagnification. Because the diopter makes the image sharp enough for the finder to be usable without me using glasses then naturally I do not need to use my eye glasses when using the finder.

Johnathan approached it differently - he wants a demagnifer so he can use his glasses - and hence rely on the glasses to fix his vision problem Whereas I am saying with this device you do not really need glasses to view reasonably clearly though the finder. Eliminating the need for glasses means eliminating the problem in a different way.

Deardorff38
01-19-2019, 18:28
As an alternative, you could try using the external viewfinders....SBL00 et al