miles_s.

<p>Raid, is the "eye" a prism or lens or both?</p>

<p>Tom, that is not normal. Sadly you have bought a non-functional lens. No repair seems obvious. As for replacement be very patient. The cost of Geiss modified lenses on Ebay is highly variable. I have purchased 100mm for less than $10 and more than $40. Sadly I don't have a 35mm for sale right now.</p>

<p>Re reference try Sidney F Ray, 2002, _Applied Photographic Optics_, Focal Press, ISBN 0240515404 and references therein.</p>

<p>The rangefinder may be off at of near infinity and depth of field will cover the error. However, the lens needs to be able to focus at infinity. If you want the far off background in focus you have to focus at infinity and use depth of field for closer objects. So you infinity focus can be a hair off in the rangefinder and it does not matter so long as the focus is good.</p>

<p> </p>

<p>The rangefinder may be off at of near infinity and depth of field will cover the error. However, the lens needs to be able to focus at infinity. If you want the far off background in focus you have to focus at infinity and use depth of field for closer objects. So you infinity focus can be a hair off in the rangefinder and it does not matter so long as the focus is good.</p>

<p> </p>

<p>What is a "Screw tab" in this context?</p>

<p>1/6 is close enough considering this is a reflected-light meter. Indeed, 1/6 is within the acceptable tolerance of a calibrated reflective meters.</p>

<p>As discussed previously the framelines on a Leica are set up to aid with the imperfect coverage. <br />Variously one needs to use the inside, outside, and outside plus then some of the framelines. <br />For a 50mm lens at its closest focus of about 0.7 metres use the inside edge of the framelines <br />and you get the actual film area minus a 0.5 mm border. At 2 metres the same area coresponds <br />to the outside of the frameline. At infinity use the outside plus 3 times the thickness of the<br />framelines. On the CLE you may want to invest in a test roll and a digital camera through the<br />viewfinder. </p>

<p>Dale, if you are running out of space that is a problem. Assuming you can't sell or part with your entire colelction here are a few solutions: sell or give away some stuff you don't need to people who need it, catalogue your collections (including condition) to better understand what you have and its value, organize it so you can find stuff faster, put effort into using it more or doing restoration work, focus your collecting so you know what you are looking for and not buying what ever comes up, ...</p>

<p>"In the 1960s there was a guy around the US Canada border ..." What a precise description of the liocation. More to the point, you think the brass in classic cameras will make you a millionaire?</p>

<p>"Well it's nice to know that he is aware of Leica and their design beauty." I have been told by Apple employees he is quite the student of design. They were mum on who schooled him but regardless he is likely aware of the Leica and many other triumph in design.</p>

<p>Dan,<br>

I am sorry to hear you have lots a friend. Specific question, did Charlie Barringer have a large document collection on photography unwanted by his estate, unsuitable for sale etc but good for an archive? General question, what in general is to be done with material our experts hold that isn't in books as they pass on?</p>

 

<p>I think vintage Nikon filters have a 0.50 pitch or one thread ever 0.50 millimetres.</p>

<p>Heh, not bad. With 7 groups at .5% to 1% loss per surface that is a T stop of .98 to 1.01.</p>

<p>Kelly, I would be grateful if you could elaborate more.</p>

<p>I think the two rules "Should be the same as the diagonal of the print, not more than twice the diagonal of the print" and "Take the enlargement factor from the negative to the print and multiply by the focal length of the lens used" don't hit on the real issue which is visual accuity. Estimate the smallest details in the print that need to be resolved. Assume 20/20 vision and divide this by one minute of an arc (0.0003) to a constant of order 1 you have your distance. (20/10 would be two minutes of an arc.) Strictly speaking this isn't the way to do it. There are books on exhibiting photgraphs. However, using this approach you can create your own rules of thumb. You can extend this practice to handle panos. Crop largely does not matter until it affects the the smallest details in the print or places part of the print well off the center of the viewers perspective.</p>

<p> </p>

<p>Alex, seeing as how you want a precise finder that allows you to move you eye position then I recommend you do the following. Learn how an Albada viewfinder works. Buy a Cosina 40mm viewfinder. Take it apart and remove the glass disk in the center noting which way it faces. Using a white paint add 50mm framelines. If you must replace the disk with a new piece of glass. Reassemble.</p>

<p>105mm compared to 56x70 is the same diagonal angle of view as 51mm to 24x36. So the cheap solution is a 50mm finder for 35mm. However, if framing accuracy is paramount I would buy a Cosina 40mm finder mask it.</p>

<p>I find the CV 35mm meters differently on my CL than on my M6. In contrast a 50mm Summicron gives the same meter reading on both. I thought this had something to do with non-retrofocus design. However, since I only use incident light metering I never looked deep into this. CV 21mm works on the CL too.</p>

<p>Not JC Penny but Adorama, Avenon, Bower, Kobalux and Pasoptik. Here is a cache of the manufacturer's website. Slow to load.<br>

<a href="http://web.archive.org/web/20020405224906/www.kobalux.com/k28-2.html">http://web.archive.org/web/20020405224906/www.kobalux.com/k28-2.html</a><br>

You may want to dig a bit deeper on this one. This is an M-Series Kobalux, which means it is shipped with an adapter. However, I thought these had eight blades like this lens.<br>

<a href="http://static.photo.net/attachments/bboard/00D/00DbeD-25722984.JPG">http://static.photo.net/attachments/bboard/00D/00DbeD-25722984.JPG</a><br>

Yours has six blades. Anyways, nice to get as a gift.</p>

<p >Thank you for posting pictures of these products, their prices and discussing the merits of both. This is not done enough. </p>

<p >Can you explain how light hitting the back of the adapters will arrive at the sensor (or film) such that your statement "back of Rayqual adapter is painted black, the PIXCO adapter is no treated, may cause more flare" is relevant?</p>

<p >Your statement "I took a set of 5 measurements of the thickness of these two reos adapter flange with a digital caliper Here are the results: ... Obviously the Rayqual REOS adapter is slightly thinner then the PIXCO, and thus has higher precision and less film plane error." is hard to follow. The deviation of the PIXCO is less than the RAYQUAL but "Rayqual ... has higher precision" per your conclusion. </p>

<p >Perhaps, there is no error in your statement and you are reporting a series of measurements of the thickness of the same place and providing the error in the measurement. In which case why burden the reader with the details of the result and obfuscate the method? For example, did you measure the same spot or different spots. </p>

<p >However, most importantly what does precision have to do with anything? The adapter should be at the correct thickness. That is a question of accuracy not precision. Of course, perhaps you are measuring a non-functional distance. That is, this measured distance is not the adapter "thickness" – extension of the register distance. You appear to be ascribing quality based on what is design choice to a non-essential element of a functional object. If the measurement is non functional, then why bother measuring it? Why not test it with various lenses and describe it aesthetic properties? </p>

<p >Elaboration would help improve your post. Perhaps you could do so when the third adapter arrives. </p>

<p>"'A few years of storage should not make a lens stiff. Several years might.' What's the difference?"<br>

Time.</p>

<p>Peter, one lens is to stiff. The other is too smooth. You goldilocks or one one of the bears? A few years of storage should not make a lens stiff. Several years might. Your local camera repair person can help you without a need to send the lens to Leica. If you are DIY inclined I would remove the optical groups, heat the helical, work the focus to distribute the now viscous grease, reassemble, check collimation and adjust. This involves no major disassembly but don't do it if you have never worked on lenses before. However, I recommend sending it to you local camera repair person and if need be check the collimation yourself when you get it back.<br>

@jody, I think I am misreading your post. Why does one have to be be in "an isolated room"? Many leicaphile like being alone with their lenses but not sure that is essential to your advice.</p>

<p>What is CSC an abbreviation of? "CSC interference filter" does not seem to be a term used much.</p>

<p>Winfried, agreed. And I would add that if one must use a filter check the effect of it at different apertures. This is because many of these compact RFs have some means to have an aperature between the meter cell and window to adjust for different aperture settings. Therefore, the effective area of the cell changes.</p>