jaapv Posted January 19, 2012 Author Share #41  Posted January 19, 2012 Advertisement (gone after registration) Hello Everybody, W/ the range/viewfinder being -0.5 & the individual diopters -4 to +5 that means you could know the corrected net diopter necessary from -4.5 to + 4.5 in whole diopter increments measured @ the 1/2 diopter.  I wonder how we do the other increments for which they make specific lenses? I doubt Leitz would build such a precise whole diopter measuring system based on the 1/2 diopter & then leave the remaining net full diopters to interpolation. Very un-Leitz like.  What is Leitz like is some simple means to equally precisely measure the net whole diopters. Most likely either hidden or right in front of us & we don't see it.  Like a self timer release button on an M which can't be seen until you wind the self timer.  Best Regards,  Michael Michael, the 0.5 strength in the ocular is to compensate for the virtual 2m viewing distance of the framelines/RF patch, and this device dates back to 1955. The M3 viewfinder which had no such strength iirc. By your reasoning one would have to interpolate the whole strengths, as the one value gap does not change.  This wheel is a very simple WYSIWYG device that is not made to calculate theoretical values. Link to post Share on other sites More sharing options...
Advertisement Posted January 19, 2012 Posted January 19, 2012 Hi jaapv, Take a look here With a strange device. I'm sure you'll find what you were looking for!
Michael Geschlecht Posted January 20, 2012 Share #42  Posted January 20, 2012 Hello Jaap,  Interesting data from the 1968 Dealer Catalog:  Eyesight correction lenses:  Correction lenses LEICA M  spherical 14061 for astigmatism 14062  Correction for Visoflex 4X & Leicaflex  spherical 14118  Correction lenses all other magnifiers  spherical 14063 astigmatism 14059  IIIg  spherical 14064 astigmatism 14066  IIc, IIf, IIIb, IIIc, IIIf  spherical 14060 astigmatism 14065  I - IIIa rangefinder, universal viewfinder  spherical 14068 astigmatism 14069  Note:  I guess their putting "LEICA M" all in caps meant all M's since the catalog had M3's, M4's & MDa's.  Looks like the same -0.5 in all M's.  Astigmatism correction also available except Visoflex 4X & Leicaflex.  Visoflex 4X & Leicaflex both use the same 14118 for spherical correction.  Best Regards,  Michael Link to post Share on other sites More sharing options...
payasam Posted January 20, 2012 Share #43 Â Posted January 20, 2012 As I did not have access to such exotica, I made do with a device of ancient design -- my fingers -- to hold lenses of various powers over the finder eye-piece until I had found the right one. Then my optician shaped a lens of that power to be glued into the round holder that Don Goldberg had sent me. Total cost was about $2. As the glass lens is thick, the added on part sticks out a bit: but it works perfectly. Link to post Share on other sites More sharing options...
Michael Geschlecht Posted January 20, 2012 Share #44 Â Posted January 20, 2012 Hello payasam, Â Welcome to the Forum. Â Good idea. Â Best Regards, Â Michael Link to post Share on other sites More sharing options...
payasam Posted January 20, 2012 Share #45 Â Posted January 20, 2012 Thank you, Michael. Link to post Share on other sites More sharing options...
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