ramosa
B&W
My eye check today indicates my right eye is at -1.0 diopters. I know M8s are (without diopter correction) set at -.5. Thus, I need to purchase a -.5 diopter correction lens, right? (Thus, -.5 + -.5 = -1.0 ...)
Thanks for any help/confirmation.
Thanks for any help/confirmation.
leica M2 fan
Veteran
Sounds perfect to me but I've never seen 1/2 diopters so you might have to go with the -1D which you won't even notice. Good luck.
ramosa
B&W
Leica has them in .5 increments (plus and minus) up to 2.0 ... then 3.0 without a 2.5.
ramosa
B&W
in some posts online, some folks are saying my explained approach makes sense, but that they'd actually recommend getting a -1.0 diopter and find that it works better. any experience with these things?
peterm1
Veteran
No - be careful. I struggled with this for some time till I got the correct answer.
Apart from the inbuilt diopter adjustment, the M8 (in fact all Leica M cameras) are set up so that when you look through the finder the apparent (or I suppose you could say optical) distance to the subject is (I think) 2 meters. If as I am you are long sighted, this means you will need less adjustment than that specified by the optometrist before even allowing for any inbuilt adjustment in the Leica finder.
If the eye examination revealed that a -1.0 diopter correction is required, the chances are that the optometrist is referring to the correction required at reading distance - which is certainly not 2 meters, more like 450mm.
Ring your optometrist and ask this question... What correction would I require for correct adjustment at a distance of 2 meters? They can calculate this - or should be able to from your eye test and should not need you to re-attend. This is what I did basically. And the optometrist scribbled a few notes made a few calculations and then told me the figure that I had already arrived at by trial and error ....see below. But of course I still had to make the further adjustment for the fact that M eyepieces have the -0.5 inbuilt adjustment.
This is what I did to double check this.
Go to your local pharmacist and look for the stand where they sell cheap non-prescription reading glasses. These usually cost between $5 and $20 depening on quality of the frames. Try them on, one after another by looking through the viewfinder of your camera with different glasses on till you find the one that gives clearest vision. Of course you will need to focus on some suitable object each time. This will give you pretty close idea of what diopter is required in practice. (In a pinch, until your diopter lens arrives you can even just by a pair and use them as your shooting glasses, but its not ideal as it puts your eye further away from where it should be for best view through the finder.) This is the strength diopter you buy-the same as the glasses that give the best result. And if you check it against what the optometrist tells you, you should find its -0.5 from the strength he / she specified.
A final option. Go to this e store and buy their viewfinder magnifier for the Leica M. It comes in two magnification strengths ........1.35 and 1.15. The link below says one is out of stock but when you click on it it says that have now restocked.
http://www.japanexposures.com/shop/product_info.php?products_id=109
http://www.japanexposures.com/2009/02/02/ms-mag-x115-magnifier-for-leica-m-sold-out/
The beauty of this option is that the magnifier also has infinite diopter adjustment between -3.0 and +1.5 diopters (assuming your requirement is in this range.) It works well, although it is said to give a slightly less bright image than the Leica single diopter lens - which is to be expected as there are more elements. The upside is that the increase in magnification also helps with focusing as well by increasing the apparent rangefinder length and making the rnagefinder more accurate. It costs about double what you would pay for a Leica single diopter adjustment. But I think its worth it as if your eyes change over time - you just manually change the setting on the magnifier to compensate - no need to buy new dioper lenses.
cheers and good luck.
Apart from the inbuilt diopter adjustment, the M8 (in fact all Leica M cameras) are set up so that when you look through the finder the apparent (or I suppose you could say optical) distance to the subject is (I think) 2 meters. If as I am you are long sighted, this means you will need less adjustment than that specified by the optometrist before even allowing for any inbuilt adjustment in the Leica finder.
If the eye examination revealed that a -1.0 diopter correction is required, the chances are that the optometrist is referring to the correction required at reading distance - which is certainly not 2 meters, more like 450mm.
Ring your optometrist and ask this question... What correction would I require for correct adjustment at a distance of 2 meters? They can calculate this - or should be able to from your eye test and should not need you to re-attend. This is what I did basically. And the optometrist scribbled a few notes made a few calculations and then told me the figure that I had already arrived at by trial and error ....see below. But of course I still had to make the further adjustment for the fact that M eyepieces have the -0.5 inbuilt adjustment.
This is what I did to double check this.
Go to your local pharmacist and look for the stand where they sell cheap non-prescription reading glasses. These usually cost between $5 and $20 depening on quality of the frames. Try them on, one after another by looking through the viewfinder of your camera with different glasses on till you find the one that gives clearest vision. Of course you will need to focus on some suitable object each time. This will give you pretty close idea of what diopter is required in practice. (In a pinch, until your diopter lens arrives you can even just by a pair and use them as your shooting glasses, but its not ideal as it puts your eye further away from where it should be for best view through the finder.) This is the strength diopter you buy-the same as the glasses that give the best result. And if you check it against what the optometrist tells you, you should find its -0.5 from the strength he / she specified.
A final option. Go to this e store and buy their viewfinder magnifier for the Leica M. It comes in two magnification strengths ........1.35 and 1.15. The link below says one is out of stock but when you click on it it says that have now restocked.
http://www.japanexposures.com/shop/product_info.php?products_id=109
http://www.japanexposures.com/2009/02/02/ms-mag-x115-magnifier-for-leica-m-sold-out/
The beauty of this option is that the magnifier also has infinite diopter adjustment between -3.0 and +1.5 diopters (assuming your requirement is in this range.) It works well, although it is said to give a slightly less bright image than the Leica single diopter lens - which is to be expected as there are more elements. The upside is that the increase in magnification also helps with focusing as well by increasing the apparent rangefinder length and making the rnagefinder more accurate. It costs about double what you would pay for a Leica single diopter adjustment. But I think its worth it as if your eyes change over time - you just manually change the setting on the magnifier to compensate - no need to buy new dioper lenses.
cheers and good luck.
john_s
Well-known
Are you saying that your prescription is for glasses with -1 lenses for distance vision? In other words, you are a bit shortsighted? If so, read on, otherwise ignore.
I am -1.5 prescription for my right (camera) eye for distance vision and I find -1 to be good with Leica M6. If one is shortsighted I have come to the conclusion that for a rangefinder, it's best to go slightly weaker than distance eyeglass prescription. My conclusion is based on trial and error with different values, not on optical theory.
EDIT: I've been doing some experiments to help advise the OP and I've noticed that my original post contained a mistake: my Leica diopter is -1.5, same as my eye prescription. My previous diopters were -2.0 (which used to be fine). My confusion came from my other camera, a Mamiya 6, for which the diopters are available only in whole diopter increments. I recently went from -2.0 which had been ok to -1.0 which is better for me.
So, I would now advise the OP to choose a -1.0.
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ramosa
B&W
Great thanks! I will get to a local Walgreens to see if they have -diopter glasses for quick trial. Yes, my prescription for normal distance is -1.0 diopters for my right eye.
John Lawrence
Well-known
I have the same prescription, and this has been my experience too. I currently use a -1 with my MP and find it works very well.
John
ampguy
Veteran
drugstores don't carry neg diopter glasses
drugstores don't carry neg diopter glasses
reading glasses are always positive mag.
neg. diopters are for myopia or short sightedness where you need the negative correction for distance, but can see close up (reading range) without correction.
Throughout my myopia (-1 to -2.5) I've always used what my rx was for, with both Leica's, and SLRs. But being within .5 (pref less negative) has also been fine, but less optimal than exact as my driving rx.
Has also been the recommendation of my eye doctor.
Looking through an optical VF at infinity, your eye is at infinity (with .72 and 1:1 mag, at least), not 2m, so if you want infinity sharp, and use these mag VF's, use what your rx for infinity (e.g. driving range) is.
If in doubt, talk to your eye doctor.
drugstores don't carry neg diopter glasses
reading glasses are always positive mag.
neg. diopters are for myopia or short sightedness where you need the negative correction for distance, but can see close up (reading range) without correction.
Throughout my myopia (-1 to -2.5) I've always used what my rx was for, with both Leica's, and SLRs. But being within .5 (pref less negative) has also been fine, but less optimal than exact as my driving rx.
Has also been the recommendation of my eye doctor.
Looking through an optical VF at infinity, your eye is at infinity (with .72 and 1:1 mag, at least), not 2m, so if you want infinity sharp, and use these mag VF's, use what your rx for infinity (e.g. driving range) is.
If in doubt, talk to your eye doctor.
ramosa
B&W
OK, I guess the Walgreens approach won't work. I have a call into my optician. It seems like most would recommend that I go with a -.5 diopter, but some suggest a -1.0 diopter.
john_s
Well-known
ramosa, please see the correction I made to my original advice. I had made a mistake which is now corrected.
ramosa
B&W
john: thank you ... for your initial input and the clarification.
andephotographic
Established
I am short sighted, if I always use my camera with either contacts or glasses on then is a diopter lens going to do me any good?
My optician does not give me a copy of my prescription but I have contacts and the ones I use in my right eye are marked as +2.25.
john_s
Well-known
The eyepiece diopter is an alternative to eyeglasses or contacts. Maybe it's more suitable to those of us who are short sighted (minus prescriptions) because we manage reasonably well without glasses except for driving, viewing blackboards etc. I prefer to not wear my glasses most of the time, so the diopter is helpful in focusing and also enjoying the view through the camera's viewfinder.
andephotographic
Established
Ok, I always wear glasses or contacts.
I had noticed that focusing on distant objects with the likes of a 50mm on I was struggling but I think that's just the different between SLR type camera and rangefinder.
I had noticed that focusing on distant objects with the likes of a 50mm on I was struggling but I think that's just the different between SLR type camera and rangefinder.
Steve M.
Veteran
I was just at the eye doc about this very issue, and called around a lot to ck on how it works. From what I gathered, unless I have the camera I'm going to use in front of me, there's no way to get it exactly right. Having an astigmatism in my focusing eye doesn't help either, as diopters do not adjust for that. On one camera I see better by using the bottom of my bifocals, on another it works better at the top!
I did go to the local dollar store a couple of years ago and brought my camera w/ me, then peered into all of the different reading glasses w/ the camera held up to my eye. A couple of them were "close enough", but now that I sold that camera, the glasses I bought don't work w/ the cameras I now have. An adjustable diopter is a good answer, but that will surely pull your eye back from the viewfinder and you won't be able to see the whole frame in all likelihood.
I did go to the local dollar store a couple of years ago and brought my camera w/ me, then peered into all of the different reading glasses w/ the camera held up to my eye. A couple of them were "close enough", but now that I sold that camera, the glasses I bought don't work w/ the cameras I now have. An adjustable diopter is a good answer, but that will surely pull your eye back from the viewfinder and you won't be able to see the whole frame in all likelihood.
ramosa
B&W
A conclusion. After getting advice, I contacted my optometrist. A few days passed, however, so I went ahead and order two diopters: -.05 and -.1. Before they arrived, my optometrist got back to me and recommended that I would need overall -.05 at two meters. That would mean I wouldn't need an additional diopter at all. When the diopters arrived, however, I tried the -.05 one and think it offered a small improvement, so I kept this one. As others have said, there's nothing better than being able to try out a diopter to see what works best. Thanks for your input.