CheshireCat Posted January 11, 2014 Share #1 Posted January 11, 2014 Advertisement (gone after registration) So yesterday I bought a nice used Elmarit 90 f/2.8 not coded. - I mount it on the M240, set to Auto detection. No lens info in image. - I set the M240 to Manual, selecting the lens profile. Info in image is 90 f/2.8. - I set the M240 to Auto again. Info in image is 90 f/2 Another firmware bug ? How is Auto detection supposed to work with uncoded lenses ? Link to post Share on other sites More sharing options...
Advertisement Posted January 11, 2014 Posted January 11, 2014 Hi CheshireCat, Take a look here Lens detection mysteries. I'm sure you'll find what you were looking for!
farnz Posted January 11, 2014 Share #2 Posted January 11, 2014 This was the same with all of the M8 and M9 variants and is caused by one of the Elmarit's flange screws being in just the right place with respect to the coding LEDs to make it happen. So, no, not another firmware bug. Pete. Link to post Share on other sites More sharing options...
george + Posted January 11, 2014 Share #3 Posted January 11, 2014 This was the same with all of the M8 and M9 variants and is caused by one of the Elmarit's flange screws being in just the right place with respect to the coding LEDs to make it happen. So, no, not another firmware bug. Pete. Yes, this is the way it works. Well set screw. Or Leica foresight? Link to post Share on other sites More sharing options...
CheshireCat Posted January 11, 2014 Author Share #4 Posted January 11, 2014 If so, why didn't it work the first time I mounted the lens ? Link to post Share on other sites More sharing options...
jaapv Posted January 11, 2014 Share #5 Posted January 11, 2014 The M240 is fairly picky with coding. I suppose it just picked it up the second time and just not the first. Link to post Share on other sites More sharing options...
george + Posted January 11, 2014 Share #6 Posted January 11, 2014 If so, why didn't it work the first time I mounted the lens ? Could be a loose or ill aligned (!) screw. Link to post Share on other sites More sharing options...
CheshireCat Posted January 11, 2014 Author Share #7 Posted January 11, 2014 Advertisement (gone after registration) It cannot be the screw for the following reasons: 1) There is no screw where the lens coding is supposed to be. 2) Even if there was a screw, 90 f/2.0 (two point zero) lenses have three bits set to one. Now, can't the M240 guess the lens is a 90mm by means of the frame lines selector ? Link to post Share on other sites More sharing options...
george + Posted January 11, 2014 Share #8 Posted January 11, 2014 My 90mm Canadian Elmarit has six screws. One of them is in the detection area. And, lucky for me, the M, and the M8, recognizes it as "2.8/90mm" Link to post Share on other sites More sharing options...
jaapv Posted January 11, 2014 Share #9 Posted January 11, 2014 It cannot be the screw for the following reasons:1) There is no screw where the lens coding is supposed to be. 2) Even if there was a screw, 90 f/2.0 (two point zero) lenses have three bits set to one. Now, can't the M240 guess the lens is a 90mm by means of the frame lines selector ? No it cannot. You said it was a 2.8 Elmarit? That is one black bit. Link to post Share on other sites More sharing options...
farnz Posted January 11, 2014 Share #10 Posted January 11, 2014 My 90mm Canadian Elmarit has six screws. One of them is in the detection area. ... Ditto for mine that I no longer have. Pete. Link to post Share on other sites More sharing options...
CheshireCat Posted January 11, 2014 Author Share #11 Posted January 11, 2014 No it cannot. You said it was a 2.8 Elmarit? That is one black bit. The 2.8 Tele-Elmarit is one black bit, but mine is the 11807 2.8 Elmarit newest version (the one discontinued in 2008). Link to post Share on other sites More sharing options...
CheshireCat Posted January 11, 2014 Author Share #12 Posted January 11, 2014 No it cannot. It can, according to this: Leica Lens Codes | La Vida Leica! Link to post Share on other sites More sharing options...
ModernMan Posted January 11, 2014 Share #13 Posted January 11, 2014 It can, according to this:Leica Lens Codes | La Vida Leica! In the case of your 90/2.8, the M240 knows from the frame lines (selected by 3 o'clock bayonet lug on the lens flange) that your lens has a focal length of 28 or 90 mm. From the frame line selection alone it cannot tell which focal length (28 or 90), or lens model. So, in the absence of the 6-bit code it reports the lens as uncoded and applies no image corrections. However, in the presence of a 6-bit code (or what the camera code sensor perceives as one e.g. screw heads) it makes a determination as to what model the particular lens is. So, you get the correct frame-line pair in the viewfinder from the frame-line selector (purely mechanical linkage), and the lens selection in firmware (and resulting corrections) from the 6-bit code. A "quirk" in this is that the M240 requires that the frame lines selected agree with the lens code, or else the camera concludes that the lens is "uncoded". That should never happen unless a code is being read incorrectly, frame line selection is not working correctly, or the lens is miscoded. As noted in the article you linked, the MATE selects one of 3 different frame line pairs depending on focal length setting, although it of course has only one code. Contrary to what is sometimes reported, the WATE has a fixed frame line selection, and the camera has no sensor input from which it can determine which focal length the WATE is set to. Link to post Share on other sites More sharing options...
jaapv Posted January 11, 2014 Share #14 Posted January 11, 2014 It can, according to this:Leica Lens Codes | La Vida Leica! The article is incorrect. It lumps the MATE and WATE together. They are different; The MATE selects framelines, the WATE does not. Link to post Share on other sites More sharing options...
jdlaing Posted January 11, 2014 Share #15 Posted January 11, 2014 My WATE pulls up 28/90 frame lines on the M240 no matter which focal length is used. Link to post Share on other sites More sharing options...
jaapv Posted January 12, 2014 Share #16 Posted January 12, 2014 That is correct, however, the MATE will adjust the framelines according to the focal length chosen. Provided the mechanism works properly:rolleyes:. Link to post Share on other sites More sharing options...
jdlaing Posted January 12, 2014 Share #17 Posted January 12, 2014 That is correct, however, the MATE will adjust the framelines according to the focal length chosen. Provided the mechanism works properly:rolleyes:. I know that. Link to post Share on other sites More sharing options...
CheshireCat Posted January 12, 2014 Author Share #18 Posted January 12, 2014 Today I forgot to restore the autodetection setting from Manual to Automatic. All the shots I took with a coded 24/3.8 have been tagged and processed in camera as Elmarit-M 90/2.8, i.e. proper lens correction not applied. Again, the firmware is clueless nonsense. Camera must use manual setting only for uncoded lenses. There must be one different manual setting for each framelines pair. Camera must show the currently detected framelines pair in a different color, but still allow me to configure the other pairs. Only lenses compatible with that pair must be listed. At power on, or whenever a lens is mounted, if the lens is uncoded then the current manual setting must be shown on screen for 2 seconds together with the message "Press SET to change lens model". If user presses anything else, then the message goes away. Link to post Share on other sites More sharing options...
farnz Posted January 12, 2014 Share #19 Posted January 12, 2014 So the firmware's to blame for something you forgot to do? Pete. Link to post Share on other sites More sharing options...
CheshireCat Posted January 12, 2014 Author Share #20 Posted January 12, 2014 So the firmware's to blame for something you forgot to do? Yes. This is what computers are for. I am a human and should not care about trivial things an algorithm is perfectly able to do for me. Link to post Share on other sites More sharing options...
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