Muizen Posted January 8, 2012 Share #1 Posted January 8, 2012 Advertisement (gone after registration) My thread: "testing-possible-back-focus-m9" developed into a discussion about diopters. I feel therefore that it is best to continue this discussion in a new thread. On my M9 I use a MS-MAG x1,35 (Japan Exposures) but my focusing is still not precise enough. I wear glasses and my right eye needs the following correction: Sph. +2.50; Cyl. -1.00; AS 103°. I assume that AS 103° refers to a certain level of astigmatism? I have no idea whether 103° is serious? * What kind of diopter would I need to ensure the best possible focusing? * Should a diopter replace one's glasses or can be used while wearing glasses? (I would not like to not wear my glasses while shooting, but...) I contacted several Leica dealers asking whether they have Leica diopters in stock, but nobody has and I would have to order one! Thank you for advises and thoughts! Harry Link to post Share on other sites More sharing options...
Advertisement Posted January 8, 2012 Posted January 8, 2012 Hi Muizen, Take a look here Diopter choice for M9. I'm sure you'll find what you were looking for!
Double Negative Posted January 8, 2012 Share #2 Posted January 8, 2012 Since you have astigmatism (as I do) you might want to seriously consider the Walter RX Eyepiece (review). I used a 1.15x magnifier with variable diopter correction, and while it worked - didn't correct for it like the eyepiece does. I no longer use the magnifier and don't find it really necessary. All it did was magnify the blur whereas now, the low contrast images in the RF actually "pop" into focus for me. Link to post Share on other sites More sharing options...
stunsworth Posted January 8, 2012 Share #3 Posted January 8, 2012 The dioptre is used without glasses. Since you need a positive dioptre the easiest thing to do is to go to a supermarket where reading glasses are sold and try a selection of strengths while looking through the viewfinder. The dioptre of the ones that give you the clearest view will indicate which dioptre you need to buy. Link to post Share on other sites More sharing options...
ayewing Posted January 8, 2012 Share #4 Posted January 8, 2012 My thread: "testing-possible-back-focus-m9" developed into a discussion about diopters. I feel therefore that it is best to continue this discussion in a new thread.On my M9 I use a MS-MAG x1,35 (Japan Exposures) but my focusing is still not precise enough. I wear glasses and my right eye needs the following correction: Sph. +2.50; Cyl. -1.00; AS 103°. I assume that AS 103° refers to a certain level of astigmatism? I have no idea whether 103° is serious? The 103 degrees refers to the orientation of the cylindrical aberration which at -1.00 is fairly mild. For the best correction the suggestion by Double Negative of the Walter RX Eyepiece is a good one as you get a lens made to your prescription. However this is a rather expensive solution to the problem. __________________ Link to post Share on other sites More sharing options...
stunsworth Posted January 8, 2012 Share #5 Posted January 8, 2012 I should add that after losing my original Leica dioptre in a field I replaced it with a Chinese one bought on eBay. I've been more than satisfied with it, and it was a fraction of the cost of the Leica version. The only downside is that it's rather thicker than the one Leica sell, but I can live with that. Link to post Share on other sites More sharing options...
algrove Posted January 8, 2012 Share #6 Posted January 8, 2012 I should add that after losing my original Leica dioptre in a field I replaced it with a Chinese one bought on eBay. I've been more than satisfied with it, and it was a fraction of the cost of the Leica version. The only downside is that it's rather thicker than the one Leica sell, but I can live with that. Where can one find out about a "Chinese one"? Link to post Share on other sites More sharing options...
stunsworth Posted January 8, 2012 Share #7 Posted January 8, 2012 Advertisement (gone after registration) Where can one find out about a "Chinese one"? I've just done a search on eBay which came back with no results - that was using both dioptre and diopter as spellings. No idea why. Link to post Share on other sites More sharing options...
jaapv Posted January 8, 2012 Share #8 Posted January 8, 2012 Leica M9 FAQ Link to post Share on other sites More sharing options...
jneilt Posted January 9, 2012 Share #9 Posted January 9, 2012 I have seen your two posts, this one and the one regarding back focus. I have a pretty good astigmatism. It is 2.5 in left and 2.25 in right. I have to use diopters on telescope eyepieces with small exit pupils and VERY short eye relief so the stars will not look twisted and to the left. I also have a pretty mild correction for nearsightedness. Astigmatism is a pain. I would suggest you getting a recent eye exam before purchasing correction if you have not already. Mine with the measurements above is about 6 months old. I have no issues focusing my M9 while wearing glasses or contacts that are toric and weighted properly for my eyes. It is my understanding that the viewfinder of the M9 is at -.25 as is. If I can focus with glasses...I don't see why you need to focus without glasses. Is your glass script old? Are your glasses old? Can you not use your glasses? Maybe I am missing something, But if you are near/or far-sighted, why would you not shoot with your corrective lenses vs just a diopter lens? Also, any eyeglass maker worth their weight can grind a lens out for you to the size you need. I have one that cuts corrective lenses for my open sight rifles at ~ 5mm round. Link to post Share on other sites More sharing options...
thighslapper Posted January 10, 2012 Share #10 Posted January 10, 2012 I'm not sure that tinkering with any of this is going to improve focussing much -1 cyl is not a lot of astigmatism and is probably not significant from a focussing point of view....... I also use the 1.35x Japan Exposures with the variable dioptre correction and find this works fine for me (better than the 1.15 which is alignment critical) or the Leica offerings which cannot be fine tuned. Bear in mind with this mag you will need to alter the correction for close objects by quite a bit ..... the settings for infinity and 1m are a good way apart I spent several weeks trying to establish which of my 13 lenses were ok and trying to adjust the rangefinder to be ok with the majority before sending the worst offenders to Solms. The JE 1.35x was critical in establishing what was really going on and after a while I could check all the lenses hand-held and be confident MY focussing was ok and that the problem was the lenses/camera. The basic test is repeatability .... if you get consistent results than your focussing is not at fault Link to post Share on other sites More sharing options...
rafael_macia Posted January 10, 2012 Share #11 Posted January 10, 2012 My thread: "testing-possible-back-focus-m9" developed into a discussion about diopters. I feel therefore that it is best to continue this discussion in a new thread.On my M9 I use a MS-MAG x1,35 (Japan Exposures) but my focusing is still not precise enough. I wear glasses and my right eye needs the following correction: Sph. +2.50; Cyl. -1.00; AS 103°. I assume that AS 103° refers to a certain level of astigmatism? I have no idea whether 103° is serious? * What kind of diopter would I need to ensure the best possible focusing? * Should a diopter replace one's glasses or can be used while wearing glasses? (I would not like to not wear my glasses while shooting, but...) I contacted several Leica dealers asking whether they have Leica diopters in stock, but nobody has and I would have to order one! Thank you for advises and thoughts! Harry I use a -4 diopter on my M9. (Leica only makes up to -3 today) Using glasses on any Leica I have owned has never been an option for me. The view of the frame lines with a diopter is perfect. In 45 years of using nothing but diopters to focus, the only problems I have ever had, was finding a pair of glasses that could easily be taken off when I focus. My solution was always a leash (which I never liked the "look of"),........ until recently; I stumbled upon Tag Huer glasses which have rubber temples. (#3902) and they work perfect. I can flip the glasses up to focus, and they stay put. Most large Leica dealers have diopters, so they are not impossible to find. Leica diopters are expensive many, many, times more, ..... than say a Nikon diopter, of the same magnification. I have seen after market diopters, usually from Hong Kong on eBay I have sometimes taped non Leica diopters on Leica cameras, and Visoflexes. Hold a diopter up to the eyepiece, see if it's sharp. then order what you think will work. also, I have heard of opticians who have made up prescription diopters, which were fitted into Leica diopters, replacing the stock Leica glass with an exact Rx glass. Ken Hansen, the Leica dealer, told me there was once an optician across the street from where he had his shop on Madison Avenue, who made up custom diopters. ..... But that the shop is no longer there. Good luck! Again, a diopter will be much, much better to use than glasses with a leica. I don't have an astigmatism, so I cannot comment on that aspect of your situation. Link to post Share on other sites More sharing options...
esophoria Posted January 12, 2012 Share #12 Posted January 12, 2012 As an eye doctor, I feel I can answer the below question with certainty: I wear glasses and my right eye needs the following correction: Sph. +2.50; Cyl. -1.00; AS 103°. I assume that AS 103° refers to a certain level of astigmatism? I have no idea whether 103° is serious? * What kind of diopter would I need to ensure the best possible focusing? The 103 refers to the axis of astigmatism. Nothing unusual about it. Having 1.00D of astigmatism based on your eyeglass Rx is fairly common. The magnitude is small-- nothing to write home about. As people age, many do benefit (increase in visual acuity....this is good) from correcting of their astigmatism. What is certain: for very precise focusing, a spectacle correction of would be a good thing. This can be achieved with spectacle lenses or with a special Rx made for your Leica M9 camera. Link to post Share on other sites More sharing options...
Muizen Posted January 12, 2012 Author Share #13 Posted January 12, 2012 [quote name= What is certain: for very precise focusing, a spectacle correction of would be a good thing. [/quote] esophoria, In the above sentence something seems to be missing after the word "of"? Harry Link to post Share on other sites More sharing options...
Muizen Posted January 12, 2012 Author Share #14 Posted January 12, 2012 From the many appreciated responses to my question regarding diopters I learned that: 1) it is better not to use a magnifier because of the reduction of the visibility of the outer frame lines in the view finder and the loss of contrast which is vital to successful focusing; 2) focusing is easier when a diopter is used than just with glasses; 3) astigmatism is not a serious problem as long as the level isn't over AS 1,03 (?) Here I can only hesitate whether this is a correct conclusion? I am sure this will be corrected. I also got the impression that shooting while wearing glasses reduces the field that the view finder covers, because the eye is further away from the VF. Thank you for correcting the above observations! Harry Link to post Share on other sites More sharing options...
esophoria Posted January 12, 2012 Share #15 Posted January 12, 2012 Sorry for the small confusion. It is difficult to tell you the magntiude of cylindrical power you should be prescribed. Many factors enter that decision, e.g, your previous prescription, the magnitude of change from the previous description. As I was taught many years ago....prescribing cylinder is a difficult art and science....use it sparingly like perfume. Again, don't worry about the 103....is it just the axis of your astigmatism-- which normally can vary between 0-179 degrees. Hope that clears up the confusion. Link to post Share on other sites More sharing options...
Muizen Posted January 13, 2012 Author Share #16 Posted January 13, 2012 I had a second more precise test to determine the level of astigmatism of my right eye. My right eye has the following conditions: SPH + 2.00; Cyl -1,25; AS 112° My optician is of the opinion that correcting the astigmatism as can be done by the Walter RX Viewfinder, will undoubtedly improve my vision when focusing my M9 without glasses. What is the experience of members of this forum? Link to post Share on other sites More sharing options...
Muizen Posted January 13, 2012 Author Share #17 Posted January 13, 2012 To focus my M9 without wearing glasses I have two options: - at my SPH +2.0 use a +2.0 Leica diopter, or since the Leica VF already is -0,5 should I select +2.5? - use the Walter RX that will also correct astigmatism. Is this necessary/useful at my rather low level of astigmatism (CYL -1,25; AS 112°)? Link to post Share on other sites More sharing options...
jaapv Posted January 14, 2012 Share #18 Posted January 14, 2012 You should try it out with the tryout lenses of your eyedoctor first. These Leica diopters cost over 100 $.... Link to post Share on other sites More sharing options...
suchislife Posted August 29, 2014 Share #19 Posted August 29, 2014 The best way to choose the right dioptre setting is probably to ask your optometrist at your next check-up. He/she might need to know the native setting of the camera (I think I read somewhere that the M9 starts at -0.5; not sure about that.) Or just take the camera with you and explain what you want. (My optometrist talks about my 'prescription' and says it should be the same for glasses and dioptre. I don't remember the more technical details of my own eyesight.) Link to post Share on other sites More sharing options...
sblutter Posted August 29, 2014 Share #20 Posted August 29, 2014 My vision Rx is similar, minus the AS. Am a 90% 50mm shooter. I brought in every diopter avail. and settled one question: I prefer to focus with glasses on. With trial, error and eye strain headaches, I've learned to recognize when its in focus - and I shoot a lot at f:2.0 and print every keeper to 22 x 17. I suggest you shoot extra frames just in case (bracketing for focus) When I'm shooting longer (75, 90, 135) I use a 1.25 diopter. The variable Chinese one caused fits and is rather dark. Good idea, disappointing results. Shooting wider - less critical, not an issue. Deciding to shoot with glasses on narrowed the experimentation by half. Link to post Share on other sites More sharing options...
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