Daedalus2000 Posted October 28, 2015 Share #1 Posted October 28, 2015 Advertisement (gone after registration) The crop factor is 1.25. What do you mean the crop factor is 1.25? My understanding is that on the SL the 120mm S lens will give the field of view (fov) of a 120 lens on 35mm FF sensor, the 70 will give the fov of a 70mm etc etc. There is no crop factor. Link to post Share on other sites More sharing options...
Advertisement Posted October 28, 2015 Posted October 28, 2015 Hi Daedalus2000, Take a look here What's this "crop factor" (OT from Leica SL sensor). I'm sure you'll find what you were looking for!
psss Posted October 28, 2015 Share #2 Posted October 28, 2015 The crop factor is 1.25. ?? there is no crop factor, the S lenses cover a bigger sensor area then the SL sensor, so no crop....the 70 will be a 70....the SL is just using a part of what the lens covers.... like using a M lens on a T body.... Link to post Share on other sites More sharing options...
digitalfx Posted October 28, 2015 Share #3 Posted October 28, 2015 What do you mean the crop factor is 1.25? My understanding is that on the SL the 120mm S lens will give the field of view (fov) of a 120 lens on 35mm FF sensor, the 70 will give the fov of a 70mm etc etc. There is no crop factor. The S is not a 35mm sensor, so relative to the S camera you will see a 1.25 difference. Link to post Share on other sites More sharing options...
psss Posted October 28, 2015 Share #4 Posted October 28, 2015 The S is not a 35mm sensor, so relative to the S camera you will see a 1.25 difference. oh boy.... a 1.25 difference in what? the S sensor is LARGER then the SL sensor....so the Sl sensor simply "sees" a smaller area of what the lens throws at it..... the angle the 70 covers on the S if comparable to the angle a 50 covers on the SL.....but on the SL the (S) 70 will simply behave like a 70.... Link to post Share on other sites More sharing options...
Daedalus2000 Posted October 28, 2015 Author Share #5 Posted October 28, 2015 The S is not a 35mm sensor, so relative to the S camera you will see a 1.25 difference. The crop factor is not calculated in relation to another camera, it is done in relation to the lens focal length (assuming we all talk using the 35mm full frame sensor as the reference sensor). A 70mm S lens used on the SL will give the same field of view as any other 70mm lens will do, no crop factor needs to be applied. Link to post Share on other sites More sharing options...
lct Posted October 28, 2015 Share #6 Posted October 28, 2015 Focal length and field of view (FoV) are not the same thing of course. A 70mm lens has a 70 x 0.8 = 56mm FoV on the S and a 70 x 1.5 = 106mm FoV on the T. Link to post Share on other sites More sharing options...
IkarusJohn Posted October 29, 2015 Share #7 Posted October 29, 2015 Advertisement (gone after registration) Focal length and field of view (FoV) are not the same thing of course. A 70mm lens has a 70 x 0.8 = 56mm FoV on the S and a 70 x 1.5 = 106mm FoV on the T. Now I'm confused ... The 70mm S lens, is 70mm in terms of the size of the S sensor (if you get my rather lose language)? or is it the same regardless of the sensor size ... I thought the latter, in which case, effective field of view of the S 70mm lens on the 24x36mm sensor will be the same as an M 70mm lens (if one existed). Does that question even make sense? PS - "the focal length is the distance from the centre of the lens to the principal foci (or focal points) of the lens" Link to post Share on other sites More sharing options...
lct Posted October 29, 2015 Share #8 Posted October 29, 2015 On the SL the same 70mm lens will have a 70 x 1 = 70mm FoV Link to post Share on other sites More sharing options...
Daedalus2000 Posted October 29, 2015 Author Share #9 Posted October 29, 2015 Now I'm confused ... The 70mm S lens, is 70mm in terms of the size of the S sensor (if you get my rather lose language)? or is it the same regardless of the sensor size ... I thought the latter, in which case, effective field of view of the S 70mm lens on the 24x36mm sensor will be the same as an M 70mm lens (if one existed). Does that question even make sense? Focal length is a property of the lens, nothing to do with sensors. The field of view is affected by the size of the sensor though. Have a look at the section "In photography" here: https://en.wikipedia.org/wiki/Focal_length and this https://en.wikipedia.org/wiki/Crop_factor Link to post Share on other sites More sharing options...
digitalfx Posted October 29, 2015 Share #10 Posted October 29, 2015 oh boy.... a 1.25 difference in what? the S sensor is LARGER then the SL sensor....so the Sl sensor simply "sees" a smaller area of what the lens throws at it..... the angle the 70 covers on the S if comparable to the angle a 50 covers on the SL.....but on the SL the (S) 70 will simply behave like a 70.... oh boy... a 70mm lens is a 70mm lens. The difference is the crop factor of what the sensor sees. The difference between the S and the SL is a factor of 1.25 because the SL and S are different sized sensors. Link to post Share on other sites More sharing options...
Daedalus2000 Posted October 29, 2015 Author Share #11 Posted October 29, 2015 oh boy... a 70mm lens is a 70mm lens. The difference is the crop factor of what the sensor sees. The difference between the S and the SL is a factor of 1.25 because the SL and S are different sized sensors. I think it is better if you use the same definition of a crop factor like the rest of us: https://en.wikipedia...iki/Crop_factor According to this definition the 70mm gives you a 70mm field of view on the SL and a 56mm equivalent field of view on the S camera. Yes the ratio is 1.25 but this is not a crop factor. Link to post Share on other sites More sharing options...
digitalfx Posted October 29, 2015 Share #12 Posted October 29, 2015 The crop factor is not calculated in relation to another camera, it is done in relation to the lens focal length (assuming we all talk using the 35mm full frame sensor as the reference sensor). A 70mm S lens used on the SL will give the same field of view as any other 70mm lens will do, no crop factor needs to be applied. In plain english...the image recorded in the SL will not look the same as the image recorded in the S using the exact same S lens. The S Sensor is 56% larger than 35mm full frame = 0.8x crop factor compared with 35mm Link to post Share on other sites More sharing options...
Daedalus2000 Posted October 29, 2015 Author Share #13 Posted October 29, 2015 In plain english...the image recorded in the SL will not look the same as the image recorded in the S using the exact same S lens. That is a correct statement, but not the answer to what was asked initially. I can see you will not accept our answers, so let's finish this by agreeing that a 70mm S lens will give an equivalent field of view on the SL as a 70mm M lens. Can we agree on this? Link to post Share on other sites More sharing options...
digitalfx Posted October 29, 2015 Share #14 Posted October 29, 2015 That is a correct statement, but not the answer to what was asked initially. I can see you will not accept our answers, so let's finish this by agreeing that a 70mm S lens will give an equivalent field of view on the SL as a 70mm M lens. Can we agree on this? As I stated a 70mm lens is always a 70mm lens. The original question was: What happens (crop ratio) when you attach a S lens to the SL body?...to this question the answer is that a crop factor of 1.25 is the mathematical difference of the image the same lens would see as compared to using it on the S, which IMO is what the OP was asking. Link to post Share on other sites More sharing options...
CheshireCat Posted October 29, 2015 Share #15 Posted October 29, 2015 What happens (crop ratio) when you attach a S lens to the SL body? The crop ratio with respect to a full-frame sensor is 1. The crop ratio with respect to the S sensor is 1.25. Link to post Share on other sites More sharing options...
lct Posted October 29, 2015 Share #16 Posted October 29, 2015 Suffice it to know the diagonal values of the sensors involved, for instance 28.34mm for the T, 43.27mm for the SL and 54.08mm for the S2. The respective FoVs of a 70mm lens are then: - on the T: 43.27 : 28.34 x 70 = 106.85mm (1.53x crop factor) - on the SL: 43.27 : 43.27 x 70 = 70mm (1.00x crop factor) - on the S2: 43.27 : 54.08 x 70 = 56mm (0.80x crop factor) Link to post Share on other sites More sharing options...
psss Posted October 29, 2015 Share #17 Posted October 29, 2015 is this a joke? Link to post Share on other sites More sharing options...
Willy ͡° ͜ʖ ͡° Posted October 29, 2015 Share #18 Posted October 29, 2015 What do you mean by joke? Does that mean the question is a joke? Does that mean the answer is a joke? I sure hope not. I'd suggest you offer an answer-if you have one that is. Link to post Share on other sites More sharing options...
psss Posted October 29, 2015 Share #19 Posted October 29, 2015 What do you mean by joke? Does that mean the question is a joke? Does that mean the answer is a joke? I sure hope not. I'd suggest you offer an answer-if you have one that is. the question has been answered several times in several different threads.... i am assuming that there is some joking going on here by the way this is being "discussed" if the technical terms invite discussion i will make it easy: the 70mm S lens will be a 70mm lens on the SL.... Link to post Share on other sites More sharing options...
Willy ͡° ͜ʖ ͡° Posted October 29, 2015 Share #20 Posted October 29, 2015 Thank you. THAT is an answer, and I do apologize for the inconvenience that may cause this forum to reply -again- to an obviously dealt with topic. Link to post Share on other sites More sharing options...
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