MTC Photography Posted July 15, 2006 Share Posted July 15, 2006 Minox and Tessina are two of the better known subminiature cameras. Minox has a frame format of 8x11, Tessina has a frame format of 14x21mm. The size of Tessina frame is 3.3 times that of Minox.<P> However the optical performance of Tessina is not on par with Minox; inspite of the much small size of negative, Minox lens is much sharper then Tessina. <P> Tessina uses two reflection mirrors in its optical systems, one for the viewing lens, like Rolleiflex TLR and othe twin lens reflex camera; however, in Rolleiflex, there is no reflection mirror in the light path of taking lens. With Tessina, a reflection is directly in the light path of its taking lens.<P> In this sens, "twin lens reflex" is not a proper term for Tessina, it should be called more precisely twin lens twin mirror reflex" camera.<P> Twin mirror although contributes to the compactness of Tessina, however the reflection mirror in the light path hurts the optical performance.<P> It is impossible to make perfectly flat mirror surface, any eveness in the reflection surface will be magnified two times, being half way in the light path. Secondly a 1 sec deviation of the mirror from exact 45 degree will cause a 2 sec deviation in the light rays; thirdly, it is hard to perfectly center the reflection mirror. An optical system with a reflection mirror in light path can never match the performance of a mirrorless optical system<P> Tessina lens also exhibit another shortcomings: severe vignetting. Minox lens at f/3.5 shows no sign of vignette; Tessina lens at f/5.6 still exhibit substantial vignetting.<P> I have two samples of Tessina camera, one Tessina's lens is way way out of alignment, when the focusing scale is at infinity, object in the viewfinder is very blurry, because the lens is actually focus at about 6 feet !! Never seen any camera with such gross misalignment.<P> I have a dozen of Minox 8x11, every one of them is perfectly collimated, never got one with such Tessina style gross out of focus.<P> Perhaps my other Tessina's lens is also misaligned ?? I don't know. Or perhaps a newly out of factory Tessina will perform better ? <P> Any one has sharp full size Tessina picture to show that Tessina is actually very sharp and no vignette ? <P> One clear advantage of Tessina over Minox is in close up photography, Minox depends on copy stand and focus dial at preset focus distances. With Tessina using a pentaprism, the Tessina does not need to be a preset distances and can be focused thru pentaprism or 8x magnifier directly. The 8x magnifier is sharper, but the 6x pentaprism is more convenient.<P><div></div> Link to comment Share on other sites More sharing options...
MTC Photography Posted July 15, 2006 Author Share Posted July 15, 2006 Another picture showing general softness from Tessina<div></div> Link to comment Share on other sites More sharing options...
MTC Photography Posted July 15, 2006 Author Share Posted July 15, 2006 Tessina picture does not look as sharp as from Minox Leica M3 3.1MP digital. The follow picture is taken with Minox Leica M3 3.1MP a focusless camera !, yet it looks sharper than from Tessina. The M3 3.1MP picture has being decolored for comparison<div></div> Link to comment Share on other sites More sharing options...
john lehman, college alask Posted July 15, 2006 Share Posted July 15, 2006 <p> Tessinas seem to get out of alignment when dropped or otherwise mistreated. I had Carl Heitz overhaul mine (altho they did not replace the mirror as I asked). My experience is that with the same film and print size, both cameras produce fairly close results (meaning the Minox negative is a bit sharper). I have never enlarged either beyond 5x7 (but then I don't enloarge 35mm beyond 8x11 or A4). More Tessina comments at <a href="http://johnandlisa.us/john/tessina-notes.html">http://johnandlisa.us/john/tessina-notes.html</a></p> Link to comment Share on other sites More sharing options...
MTC Photography Posted July 16, 2006 Author Share Posted July 16, 2006 Upload a picture from Minox<P> The picture taken with Minox B is far sharper than Tessina/Edixa/M3 3.1MP.<div></div> Link to comment Share on other sites More sharing options...
MTC Photography Posted July 16, 2006 Author Share Posted July 16, 2006 "TD Bank" taken with Minox B, also sharper than Tessina<div></div> Link to comment Share on other sites More sharing options...
h._p. Posted July 18, 2006 Share Posted July 18, 2006 You're absolutely right about the Tessina's lack of definition, Martin. I have the original Amateur Photographer test report from January 1968 and their test pictures show just how 'muzzy' the lens is. On the other hand, as your own test pictures show, you get 1/3rd of the grain with the larger negative so, for some people, the Tessina may have its uses. Link to comment Share on other sites More sharing options...
Troll Posted July 21, 2006 Share Posted July 21, 2006 Thanks, Martin. I've always sort of wanted a Tessina (on a wrist band), but believe that you've finally cured my lust. Link to comment Share on other sites More sharing options...
martin_pistor Posted July 25, 2006 Share Posted July 25, 2006 Hi Martin, so, whats your point? The tessina is a pita if you strictly look for perfect pics and ease of use, at least compared to a Minox B or later (EC's not counting). It's just a curiosity, and great fun to use still. Stopping it down two stops gives nearly vignetting free pics at mine, compared to the minox it allows 1 Stop for faster Film, the third stop to compare 4 at the tessina to 3,5 at the B is neglectable. Sharpness is hard to judge, I'd have to take pics with a solid stand to compare. Do you really own the pentaprism? Congrats. BtW, I did 8x11 to 8x10(inches) enlargements, and they went out fine. Have fun. Martin Link to comment Share on other sites More sharing options...
MTC Photography Posted July 25, 2006 Author Share Posted July 25, 2006 Martin, what Tessina model you are using ? I suspect that later Tessina models such as Tessina 35 or Tessina L has improved lens. Link to comment Share on other sites More sharing options...
MTC Photography Posted July 25, 2006 Author Share Posted July 25, 2006 I usually enlarge Minox 8x11 on Ilford multigrade RC paper to 8x10". The best results were from Kodak Technical Pan negatives developed with diluted Agfa Rodinal Special-- no noticable grain -- followed by Agfa Copex Rapid developed with SPUR NANOSPEED, Agfa APX 100 prints are also quite good. The amazing thing about Minox is that in a Minox 8x10" enlargement, there are hidden details which can only be revealed by using a loup to examine the 8x10" enlargement. Link to comment Share on other sites More sharing options...
MTC Photography Posted July 26, 2006 Author Share Posted July 26, 2006 Bill, the Tessina is different, although it has some shortcomings, but it has some advantages over Minox, particularly in the close up department, you may still have to find out for yourself whether you like Tessina or not. I have two of Tessinas, one automatic 35mm, the other Tessina 35 ( in repair). Link to comment Share on other sites More sharing options...
MTC Photography Posted August 13, 2006 Author Share Posted August 13, 2006 As expected, "Tessina 35" has an improved lens over "Tessina automatic 35mm".<P> The Tessinon 25mm/2.8 lens on Tessina 35 has no visible vignetting, and appears to be sharper than the lens on Tessina automatic 35mm<p><div></div> Link to comment Share on other sites More sharing options...
MTC Photography Posted August 13, 2006 Author Share Posted August 13, 2006 The sharpness of Tessina 35 is comparable to that of Minox<div></div> Link to comment Share on other sites More sharing options...
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