flavio_egoavil

<p>Consider that an average medium format lens (of the well-known brands) on 6x6 or 6x7 format will give much greater quality (resolution, sharpness, tonality) than a fantastic 35mm lens on 35mm format. Now, regarding bokeh, saturation and contrast... yes there are some MF lenses that use a design that also exists on 35mm, and not necesarily on the same brand. For example a Zeiss 80/2.8 Planar uses the Planar design that exists on 35mm, on many brands. Another example: The 127mm f3.8C for the RB67 has the same design than the 90/2.8 Leitz Elmarit of the fifties.</p> <p>Most common telephoto lenses, in all formats, fall into one of a handful of common designs. <br> Not to mention the Tessar designs which are ubiquitous at all formats!</p>

<p>For what it's worth, the 50mm has an angle of view equivalent to about 25mm in 35mm format terms. Thus, it is not extremely wide. I bet the filter holder manual specifies the recommended maximum angle of view of the lens, perhaps in 35mm terms as well.</p>

<p>Size = very big and 100% full of quality and enjoyment.</p>

<p>The shutter on these lenses is usually the same on many of these series. You have a good chance to buy another junked mamiya lens of the same era and replace the shutter assembly. Or buy another junked 135mm (i.e. with lens elements problems but OK shutter)</p> <p> </p>

<p>Another Mamiya user on this forum told that a good idea is to get some junked filter, remove the glass, and glue it to the inside of the 65mm lens shade. That way, any filter can be fitted inside the lens shade. He mentioned using a 67mm filter thread with success. The choice of 67mm due only to having more of such filters available.</p>

<p>All mamiya TLR "chrome" lenses have apertures that are freely adjustable (1/3 stop increments if you wish, for example.) And i believe a camera technician could modify the later "black" lenses so the aperture click-stop is removed.</p> <p> </p>

<p>Why didn't your technician attempt to clean the lens element? That is the #1 thing to do.<br> You can swap freely the lens elements around, but with two warnings:<br> 1) Try not to mix lens components between the top and bottom lenses<br> 2) Do not lose any shims, and put them in exact order and place.</p>

<p>Replying to this old thread because it pops up frequently on search results.</p> <p>The above link is down. But let me summarize the lens formulas!! Which you can also see, along with Tim's test results, here:<br /> <a href="http://www.xpan.se/DailyPhotoDiary/2011-07/custom/0013.html">http://www.xpan.se/DailyPhotoDiary/2011-07/custom/0013.html</a></p> <p>Anyways, down to the lens formulas:<br /> 55mm -> it is a custom wideangle (retrofocus) lens, quite complex compared to the rest</p> <p>65mm -> The design is exactly as the old Angenieux retrofocus wideangle lenses, the first retrofocus lenses to be used commercially. It is also very similar to the early Nikkor 28/3.5 for SLR use.</p> <p>80mm f2.8 -> Identical to the Leitz "Elmarit" 90/2.8 of the fifties, 5 elements in 3 groups. Mamiya 127/3.8 lens for the RB uses exactly this design.</p> <p>80mm f3.7 -> Tessar design, according to Mamiya documentation (it's not a speculation)</p> <p>105mm f3.5 (chrome and black) -> Tessar, long focus design</p> <p>105mm f3.5 "D" and "DS" -> Heliar design, 5 elements in 3 groups.</p> <p>The case of the 105mm lens is very interesting. One gentleman on the old Robert Monaghan Medium Format forum told that, according to Mamiya engineers, the chrome lenses were "commercial formula lenses, engineered for maximum sharpness and contrast" and that "they were later recomputed to be less harsh at the request of wedding photographers". I believe they were referring specifically to the 105mm lens, since the Heliar design is world famous for smooth out-of-focus rendering, while the Tessar isn't it so. Also interesting is to note that a test of Mamiya TLR lenses (chrome lenses - 65,80,105,135,180) made in the mid-60s by Modern Photography rated the 105/3.5 (tessar) better than the 80/2.8 from f8 to f11, among the best results in the test, so we can't say that the 105/3.5 (tessar) wasn't sharp enough!<br> <br />The other lenses (65,80/2.8,135, 180 standard) did not change in optical formula when becoming "black", so it's not so obvious if they were "recomputed". They could have been recomputed still, but the basic lens design didn't change at all.</p> <p>BTW the best performing lens in that test was the 65/3.5, which doesn't surprise me.<br /> Link to the test (archived): <a href="http://web.archive.org/web/20060508231426/http://medfmt.8k.com/mf/mamiyatlrlens.html">http://web.archive.org/web/20060508231426/http://medfmt.8k.com/mf/mamiyatlrlens.html</a></p> <p>135mm -> Tessar design, long focus design. But in this case the diaphragm is on the rear of the lens. This is done to reduce the physical length of the lens itself. Alas, in theory this means performance will not improve too much when stopping down, and you can see this on the lens tests above by Tim.</p> <p>180mm, non "super" -> "Tele-tessar" design, telephoto lens. 4 elements in 3 groups.</p> <p>180mm Super -> Telephoto design not unlike some Canon/Nikon 135mm lenses for SLR.<br /> Please see this image for comparison between old and new 180mm, posted by myself elsewhere.<br /> <a href="http://static.photo.net/attachments/bboard/00b/00bWXd-530097584.jpg">http://static.photo.net/attachments/bboard/00b/00bWXd-530097584.jpg</a><br /> BTW the non-super 180mm is also a very sharp lens, at least about f8-11, with excellent bokeh. One of my best images was done with that lens. I also own the 180mm Super and it is as good as everyone else claims!</p> <p>250mm -> This is a telephoto design of 6 elements, not unlike other telephotos made by other manufacturers.</p>