pop Posted August 25, 2020 Share #141 Posted August 25, 2020 Advertisement (gone after registration) vor 46 Minuten schrieb jaapv: With the Q, using electronic framelines, the effect will be invisible, as any -if any- focus breathing by the lens will be compensated by software. The Q has no optical viewfinder. The electronic view finder shows the image exactly as projected by the lens onto the sensor. Hence, the variation of the angle of view is automatically accounted for. No assistance by any software is required. Link to post Share on other sites More sharing options...
Advertisement Posted August 25, 2020 Posted August 25, 2020 Hi pop, Take a look here Firmware version 4 available for CL. I'm sure you'll find what you were looking for!
jaapv Posted August 25, 2020 Share #142 Posted August 25, 2020 Oh yes, German has beautiful words for this corner of theory. Just think of the related Bildfeldschwund... 1 Link to post Share on other sites More sharing options...
lct Posted August 25, 2020 Share #143 Posted August 25, 2020 Where did you find that 52.5mm were typical for 50mm lenses? Any link? Just curious. Link to post Share on other sites More sharing options...
jaapv Posted August 25, 2020 Share #144 Posted August 25, 2020 5 minutes ago, pop said: The Q has no optical viewfinder. The electronic view finder shows the image exactly as projected by the lens onto the sensor. Hence, the variation of the angle of view is automatically accounted for. No assistance by any software is required. Not quite sure about that, although the Q has an EVF, it is a hybrid design with a digitally rendered field of view. ("crop") Link to post Share on other sites More sharing options...
pop Posted August 25, 2020 Share #145 Posted August 25, 2020 vor 2 Minuten schrieb jaapv: Not quite sure about that, although the Q has an EVF, it is a hybrid design with a digitally rendered field of view. ("crop") I think it would be quite over the top to compensate the shrinking field of view for closer distances. Anyway, you would see right away in the viewfinder whether the field of view becomes wider or not when changing the focusing distance from close up to infinity. Link to post Share on other sites More sharing options...
jaapv Posted August 25, 2020 Share #146 Posted August 25, 2020 As I said - I don't know, Leica goes over the top optically occasionally At any rate, it is not that easy to judge framing when focusing from full bokeh to sharp - unlike an optical viewfinder. Link to post Share on other sites More sharing options...
LocalHero1953 Posted August 25, 2020 Share #147 Posted August 25, 2020 Advertisement (gone after registration) 1 hour ago, jaapv said: I do suspect that we are talking at cross-purposes. Focal length is calculated and defined at infinity, which is the convention. Obviously that cannot change. But if you calculate focal length at any other focal distance it will be different which is what I am saying. It is quite relevant, as I mentioned, for rangefinder users because the change will affect the angle of view and thus the framing. With the Q, using electronic framelines, the effect will be invisible, as any -if any- focus breathing by the lens will be compensated by software. On an EVF camera,, with WYSIWYG viewing it is of no interest. I don't know whether the CL lenses are compensated (see the other article I linked to). I agree this may be a matter of terminology, though I'm puzzled that your english, which is so good, seems to use the words differently: in physics/optics, and excluding internal focusing and floating elements, focal length (in english) is a fixed property of a lens no matter where it is in relation to the subject and sensor. At close focus on a camera, the lens still has the same focal length as if it were focused at infinity. Focal length can be calculated and measured at any focus point - we all did this as school experiments on a lab bench, using Newton's formula to calculate focal length based on 'u' and 'v' - no need to do it at infinity - though of course you can. 1 Link to post Share on other sites More sharing options...
pop Posted August 25, 2020 Share #148 Posted August 25, 2020 vor 23 Minuten schrieb jaapv: As I said - I don't know, Leica goes over the top optically occasionally Well, I'll be - never mind. Apparently, they do just that, even on the lowly CL. I have taken the first pair with the 40mm Summicron-C (which is, of course, the proper lens to use on a CL). As it is a fully mechanical lens, the camera can not even guess at the distance it's set to. The first image was taken with the distance set to about 1m, the second with the distance set to infinity. I tried to keep the right edge of the picture constant. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! The second set was taken with the Sigma 45mm 1:2.8 at f/4 1 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! The second set was taken with the Sigma 45mm 1:2.8 at f/4 ' data-webShareUrl='https://www.l-camera-forum.com/topic/312494-firmware-version-4-available-for-cl/?do=findComment&comment=4032946'>More sharing options...
jaapv Posted August 25, 2020 Share #149 Posted August 25, 2020 17 minutes ago, LocalHero1953 said: I agree this may be a matter of terminology, though I'm puzzled that your english, which is so good, seems to use the words differently: in physics/optics, and excluding internal focusing and floating elements, focal length (in english) is a fixed property of a lens no matter where it is in relation to the subject and sensor. At close focus on a camera, the lens still has the same focal length as if it were focused at infinity. Focal length can be calculated and measured at any focus point - we all did this as school experiments on a lab bench, using Newton's formula to calculate focal length based on 'u' and 'v' - no need to do it at infinity - though of course you can. Maybe because I learnt my English in Oxford as a child and my technical terms in school and university in the Netherlands? Link to post Share on other sites More sharing options...
LocalHero1953 Posted August 25, 2020 Share #150 Posted August 25, 2020 😁 I think the misunderstanding is in the use of 'determined' and 'defined' . Focal length is defined as the property at infinity, but it can be determined at any focus point. 1 1 Link to post Share on other sites More sharing options...
lct Posted August 25, 2020 Share #151 Posted August 25, 2020 4 hours ago, nicci78 said: Leica M lenses have tiny numbers engraved on the side of focusing scale. Add them to the marketing name of the lens to get the real focal length. So 50mm M lenses got 25 engraved on the side. So add 2.5 to 50, you got 52.5mm [...] Must have learned this one or two centuries ago but my 50/2 apo has not those numbers so it must count as a 50mm lens i guess whilst my 50/1.4 asph has "14" and my 50/2 v4 "19". Makes an average of 51,1mm IINW. I have not all my 50mm lenses with me here but wouldn't it be more simple to round off at 50mm? Link to post Share on other sites More sharing options...
jaapv Posted August 25, 2020 Share #152 Posted August 25, 2020 23 minutes ago, lct said: but wouldn't it be more simple to round off at 50mm? That is exactly what most, if not all, users do ; ignore those little numbers except for exceptional situations, of which there are few. Link to post Share on other sites More sharing options...
lct Posted August 25, 2020 Share #153 Posted August 25, 2020 1 minute ago, jaapv said: That is exactly what most, if not all, users do ; Hardly surprising but what's the point of those "53" or "52.5" so-called average numbers then? Link to post Share on other sites More sharing options...
pop Posted August 25, 2020 Share #154 Posted August 25, 2020 In some (rare) cases, for instance when doing macro work, you need to know the exact focal length of your lens. I just had a look at the wiki here in the forum and at the technical data sheets for several modern 50mm Leica M lenses. An actual focal length is not given for all lenses, but for all lenses where it is given it's more than 50mm. Link to post Share on other sites More sharing options...
nicci78 Posted August 25, 2020 Share #155 Posted August 25, 2020 For newest 50mm lenses, Leica did not provide exact focal lengths. But for current Summicron-M, Summilux-M and Noctilux-M. We got either 52.3mm or 51.6mm. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/312494-firmware-version-4-available-for-cl/?do=findComment&comment=4033012'>More sharing options...
lct Posted August 25, 2020 Share #156 Posted August 25, 2020 53 minutes ago, nicci78 said: For newest 50mm lenses, Leica did not provide exact focal lengths. But for current Summicron-M, Summilux-M and Noctilux-M. We got either 52.3mm or 51.6mm. Depend on lenses, the Summarit 50/2.5 is 50.1mm. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/312494-firmware-version-4-available-for-cl/?do=findComment&comment=4033047'>More sharing options...
nicci78 Posted August 25, 2020 Share #157 Posted August 25, 2020 Of course, it is kind of a mess. I dit not check everyone of them. APO-Summicron M or SL did not reveal this information anymore. Now let's go back to FW 4.0 So for clarity there are other charts Sigma new DC DN lenses are nicely spaced. Ideal for CL new crop mode. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 1 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/312494-firmware-version-4-available-for-cl/?do=findComment&comment=4033056'>More sharing options...
ramarren Posted August 25, 2020 Share #158 Posted August 25, 2020 (edited) Wow. A topic about a firmware update that's talking about the difference between nominal focal length and actual focal length. "Thread drift..." Nominal marked focal length is usually within +/-5% of the actual focal length, measured at infinity. Far as I'm aware, it's always been that way. If you can actually see the difference between a 48.9 and a 52.4 mm lens, you have better eyes than I do or are just being a mite OCD. LOL! G Edited August 25, 2020 by ramarren 2 1 Link to post Share on other sites More sharing options...
gteague Posted August 25, 2020 Share #159 Posted August 25, 2020 well, i honor the math and have no argument about the 'rounding'. but my question when i saw the 53mm figure in the chart i responded to was why the exif reports the rounded and not the actual figure. i get that the body firmware controls this i guess, so it's the manufacturer who decides what gets into the exif. and the editors i have which also show equivalent focal length again don't use an actual figure, but a figure extrapolated from what the manufacturer provides. that makes sense, but i was just caught by surprise when the op used the actual and not the rounded focal length. /guy Link to post Share on other sites More sharing options...
nicci78 Posted August 25, 2020 Share #160 Posted August 25, 2020 Exif it totally dependant of camera manufacturers. Whatever is written in it, will be passed to you. It is quite logical to use the marketing name in the Exif. Otherwise you will be confused. I use the "real" focal length, because it will impact the multiplication. The more you multiply, the bigger the gap will be. 1 Link to post Share on other sites More sharing options...
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