vielhilftviel Posted March 31, 2021 Share #1  Posted March 31, 2021 (edited) Advertisement (gone after registration) Is there a website or a simple calculation I can do to calculate for example what the 18-56 would be on full frame?  I googled it a bunch before posting but to be honest now I’m more confused then before. Edited March 31, 2021 by vielhilftviel Link to post Share on other sites More sharing options...
Advertisement Posted March 31, 2021 Posted March 31, 2021 Hi vielhilftviel, Take a look here How to simply calculate CL vocal lengths on SL cameras?. I'm sure you'll find what you were looking for!
Jeff S Posted March 31, 2021 Share #2  Posted March 31, 2021 Focal length remains unchanged camera to camera, but the equivalent field of view is reduced when when using a full frame lens on a ‘cropped’ sensor.  Most people will not put a ‘cropped’ APS-c lens on a full frame camera, as it will merely waste a bunch of pixels by using only part of the larger sensor. However, putting a full frame SL lens on a CL will result in a cropped field of view equivalent to a lens with 1.5x focal length (an Sl 50 on a CL will have an equivalent field of view of a 75mm lens). Jeff Link to post Share on other sites More sharing options...
lct Posted March 31, 2021 Share #3  Posted March 31, 2021 There is no calculation to do as far as focal lengths are concerned. The lens is a 18-56 on any camera. SL cameras will just "crop" their sensor to the APS-C format when using TL lenses. Link to post Share on other sites More sharing options...
vielhilftviel Posted March 31, 2021 Author Share #4  Posted March 31, 2021 vor 4 Minuten schrieb Jeff S: Focal length remains unchanged camera to camera, but the equivalent field of view is reduced when when using a full frame lens on a ‘cropped’ sensor.  Most people will not put a ‘cropped’ APS-c lens on a full frame camera, as it will merely waste a bunch of pixels by using only part of the larger sensor. However, putting a full frame SL lens on a CL will result in a cropped field of view equivalent to a lens with 1.5x focal length (an Sl 50 on a CL will have an equivalent field of view of a 75mm lens). Jeff Ok then my question ist how to I calculate the equivalent point of view? And yes I do want to use CL lenses on full frame because they are tiny and it’s just for video so I don’t care about loosing megapixels it will still be 4K if that makes sense. Link to post Share on other sites More sharing options...
Jeff S Posted March 31, 2021 Share #5  Posted March 31, 2021 The field of view is whatever the manufacturer specifies for a given lens.  The larger sensor will not crop anything away; that’s only an issue when putting a lens with a larger image circle on a smaller sensor. Jeff Link to post Share on other sites More sharing options...
vielhilftviel Posted March 31, 2021 Author Share #6  Posted March 31, 2021 (edited) vor 6 Minuten schrieb Jeff S: The field of view is whatever the manufacturer specifies for a given lens.  The larger sensor will not crop anything away; that’s only an issue when putting a lens with a larger image circle on a smaller sensor. Jeff In this thread you yourself even comment that the 18mm would have the field of view of a 27mm so all I’m trying to figure out is how people like you figure that out and how I can then figure out what 56mm and so on would be   Edited March 31, 2021 by vielhilftviel Link to post Share on other sites More sharing options...
lct Posted March 31, 2021 Share #7  Posted March 31, 2021 Advertisement (gone after registration) 18 minutes ago, vielhilftviel said: Ok then my question ist how to I calculate the equivalent point of view? And yes I do want to use CL lenses on full frame because they are tiny and it’s just for video so I don’t care about loosing megapixels it will still be 4K if that makes sense. Just multiply by 1.5x then. Your 18x56 lens will have an equivalent FoV of 27x84 this way. Same as on the CL but with less pixels of course. 1 Link to post Share on other sites More sharing options...
Jeff S Posted March 31, 2021 Share #8  Posted March 31, 2021 (edited) 10 minutes ago, vielhilftviel said: In this thread you yourself even comment that the 18mm would have the field of view of a 27mm so all I’m trying to figure out is how people like you figure that out and how I can then figure out what 56mm and so on would be No I didn’t.  IF the 18-56 were a FULL FRAME lens, then putting it on a cropped CL sensor would narrow its field of view equivalent to that of a 27- 84 lens. But an 18-56 APS-c lens will not be cropped on a larger sensor.  It will retain whatever field of view it has (in APS-C terms); it just won’t fill up the whole sensor (hence wasted pixels).  Jeff Edited March 31, 2021 by Jeff S Link to post Share on other sites More sharing options...
beewee Posted March 31, 2021 Share #9  Posted March 31, 2021 (edited) Full frame equiv. focal length = 1.5 x <APS-C focal length> Example: 27 mm = 1.5 x 18mm APS-C equiv. focal length = <Full frame focal length> / 1.5 Example: 18mm = 27 mm / 1.5  Things to note: This formula only gives you the equivalent angular field of view and does not account for differences in depth of field APS-C will have more depth of field for the same field of view as full frame As a rough rule of thumb, you gain about 1-stop equivalent in depth of field when going from full frame to APS-C for the same field of view For example: A 18mm f/2.8 APS-C lens will give the equivalent field of view as a 27mm f/2.8 full frame lens But the depth of field of the 18mm f/2.8 APS-C lens shot at f/2.8 will have an apparent depth of field that is similar to a 27mm full frame lens stopped down to f/4 Edited March 31, 2021 by beewee Link to post Share on other sites More sharing options...
vielhilftviel Posted March 31, 2021 Author Share #10  Posted March 31, 2021 vor 9 Minuten schrieb Jeff S: No I didn’t.  IF the 18-56 were a FULL FRAME lens, then putting it on a cropped CL sensor would narrow its field of view equivalent to that of a 27- 84 lens. But an 18-56 APS-c lens will not be cropped on a larger sensor.  It will retain whatever field of view it has; it just won’t fill up the whole sensor (hence wasted pixels). Jeff I think I finally get what you mean but why does it sound like Ict is saying something different vor 11 Minuten schrieb lct: Just multiply by 1.5x then. Your 18x56 lens will have an equivalent FoV of 27x84 this way. Same as on the CL but with less pixels of course. Is my language barrier stopping me from understanding that both of you say the same thing or is one of you wrong??  Link to post Share on other sites More sharing options...
Jeff S Posted March 31, 2021 Share #11  Posted March 31, 2021 It’s mostly a matter of defining your frame of reference, so to speak ... full frame or different size sensor.  Once one starts comparing formats (let alone aspect ratios), it gets confusing. For some people, 4x5 or larger is their ‘full frame’. I therefore don’t waste much time comparing or doing the math. I just get used to how a given lens renders on a given format. And that just requires practical experience.   Jeff Link to post Share on other sites More sharing options...
lct Posted March 31, 2021 Share #12  Posted March 31, 2021 11 minutes ago, vielhilftviel said: I think I finally get what you mean but why does it sound like Ict is saying something different Is my language barrier stopping me from understanding that both of you say the same thing or is one of you wrong?? Haha it's when Jeff said "But an 18-56 APS-c lens will not be cropped on a larger sensor" i guess. He has an advantage over me as an SL user so you should believe him in the first place. Now, in my understanding, the SL does "crop" its sensor to the APS-C format when using TL lenses. Other colleagues here will tell you more on that. Link to post Share on other sites More sharing options...
motard Posted March 31, 2021 Share #13 Â Posted March 31, 2021 vor 32 Minuten schrieb vielhilftviel: Â but why does it sound like Ict is saying something different because ICT is right and Jeff S is wrong. Link to post Share on other sites More sharing options...
BernardC Posted March 31, 2021 Share #14  Posted March 31, 2021 1 hour ago, vielhilftviel said: it’s just for video so I don’t care about loosing megapixels it will still be 4K if that makes sense. It makes perfect sense. As others have mentioned, you can multiply the focal length by 1.5 to get the equivalent full-frame POV. There's another way to think about it. You will be cropping to the traditional motion picture field of view, so cinema rules apply: 18mm is the Touch of Evil (Orson Welles) focal length 24mm is Paris, Texas 28 and 32 are your "standard" lengths 40mm is The Godfather 50mm is Psycho Anything longer or shorter is just a gimmick, to distract you from a bad script 🙂 In other words, an 18-56 is all you need to create several masterpieces. Focal lengths are perceived differently in motion vs. stills. Motion pictures are shot a bit wider than stills because people watch them on bigger screens, from farther away. That holds true in the age of smartphones: the relative size of a smartphone, 30cm from your eyes, is similar to a cinema screen. 1 Link to post Share on other sites More sharing options...
Jeff S Posted March 31, 2021 Share #15  Posted March 31, 2021 (edited) 44 minutes ago, motard said: because ICT is right and Jeff S is wrong. It crops in reference to the SL format size, but not in APS-c terms (same as on the CL), which is what I later specified.  It retains the FOV as on the CL. An SL lens FOV is, however, truly cropped on a CL. That’s why I don’t like format comparisons. Jeff Edited March 31, 2021 by Jeff S Link to post Share on other sites More sharing options...
Ingo Posted March 31, 2021 Share #16  Posted March 31, 2021 https://us.leica-camera.com/content/download/173173/4674745/version/7/file/EN_SL2.pdf  On page 86 there is a short explanation. Link to post Share on other sites More sharing options...
beewee Posted March 31, 2021 Share #17  Posted March 31, 2021 1 hour ago, Jeff S said: It crops in reference to the SL format size, but not in APS-c terms (same as on the CL), which is what I later specified.  It retains the FOV as on the CL. An SL lens FOV is, however, truly cropped on a CL. That’s why I don’t like format comparisons. Jeff Perhaps a more concise way to say it is that, if you used the same APS-C lens on the CL and on the SL/SL2/SL2-S, you’ll get the exact same field of view, and exact same depth of field. The only difference is the difference in sensor resolution because the SL/SL2/SL2-S will discard the sensor data that is outside of the APS-C equivalent sensor area. Conversely, if you put a full frame lens (for example a 18mm) onto the SL/SL2/SL2-S, you have two options. You can take advantage of the entire sensor area which will give you a 18mm field of view and depth of field. Or you can use the SL/SL2/SL2-S in APS-C crop mode and get a 27mm equivalent field of view but with the same original depth of field. Now if you put that same 18mm lens on the CL, you’ll get the exact same image (with some differences in resolution due to pixel density on the sensor) as the SL/SL2/SL2-S in APS-C crop mode. Meaning that you get a 27mm equivalent field of view and the same depth of field that you see on the SL/SL2/SL2-S. 2 Link to post Share on other sites More sharing options...
Jeff S Posted March 31, 2021 Share #18  Posted March 31, 2021 46 minutes ago, beewee said: Perhaps a more concise way to say it is that, if you used the same APS-C lens on the CL and on the SL/SL2/SL2-S, you’ll get the exact same field of view, and exact same depth of field. The only difference is the difference in sensor resolution because the SL/SL2/SL2-S will discard the sensor data that is outside of the APS-C equivalent sensor area.  I wrote this earlier...  “But an 18-56 APS-c lens will not be cropped on a larger sensor.  It will retain whatever field of view it has (in APS-C terms); it just won’t fill up the whole sensor (hence wasted pixels). “ Too wordy? Jeff Link to post Share on other sites More sharing options...
FlashGordonPhotography Posted March 31, 2021 Share #19 Â Posted March 31, 2021 I know this stuff but after reading this thread, even I'm not so sure now. No wonder the OP is confused....... Maybe you guys can help him with DoF next...... Gordon 4 Link to post Share on other sites More sharing options...
lct Posted March 31, 2021 Share #20 Â Posted March 31, 2021 1 hour ago, FlashGordonPhotography said: I know this stuff but after reading this thread, even I'm not so sure now. No wonder the OP is confused....... Maybe you guys can help him with DoF next...... Gordon Why simplify things when they can be so complicated An SL with a TL lens is simply a big CL with less pixels. Same APS-C format + same lens + same aperture = same DoF 1 Link to post Share on other sites More sharing options...
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