Logic108 Posted January 16, 2010 Share #21 Posted January 16, 2010 Advertisement (gone after registration) o.k thanks. Not to hijack this thread. Just thought that the 50 summilux is acting like a 65 summilux which would then give shallower dof. In the same way that the 75 summilux gives shallower dof field than the 50 summilux. Link to post Share on other sites More sharing options...
Advertisement Posted January 16, 2010 Posted January 16, 2010 Hi Logic108, Take a look here Samples of the 50mm ASPH Summilux at 1.4 with M9 please?. I'm sure you'll find what you were looking for!
jaapv Posted January 16, 2010 Share #22 Posted January 16, 2010 The focal length does not change, just the crop. DOF is virtually independent of focal length, it has to do with enlargement. (and is thus indirectly associated with focal length, as a longer lens enlarges more) - but that is within the same sensor/film format. Just remember a P&S will have an extremely deep DOF - because of the very small sensor, even if you shoot at the equivalent of a tele lens. Link to post Share on other sites More sharing options...
digitalfx Posted January 16, 2010 Share #23 Posted January 16, 2010 I still don't understand the DOF issue with the 1.3 crop. It should be that the DOF is shallower on the M8 because the focal length is longer but some say that the DOF on the M9 is shallower. I'd love to hear which is true. The focal length is exactly the same on both cameras, as is the dof (assuming both were taken from the same position). The M8 is a 1.3 crop, meaning you are literally cropping the center of the sensor. This is no different than simply taking the M9 image into Photoshop and extracting the center of the frame...this has zero affect on the focal length of the lens or the depth of field. Link to post Share on other sites More sharing options...
jaapv Posted January 16, 2010 Share #24 Posted January 16, 2010 No - not true if you enlarge to the same size. The same way DOF gets shallower when you crop and enlarge in the darkroom. Link to post Share on other sites More sharing options...
digitalfx Posted January 16, 2010 Share #25 Posted January 16, 2010 No - not true if you enlarge to the same size. The same way DOF gets shallower when you crop and enlarge in the darkroom. I would challenge you to shoot a test with both cameras in the exact same position, then bring both images into photoshop and simply crop the M9 image...I think you will find that the lens properties are identical. Link to post Share on other sites More sharing options...
DeLosLindos Posted January 16, 2010 Share #26 Posted January 16, 2010 I would challenge you to shoot a test with both cameras in the exact same position, then bring both images into photoshop and simply crop the M9 image...I think you will find that the lens properties are identical. That is because the cropped M9 picture has the same pixel size and pixel count as the uncropped M8 has, so there's no need to enlarge in this case. To get Jaap's statement right an enlargement means also enlarging the CoC and therefor decreasing the DOF but in the M9 vs M8 comparising that is not the case? -DeLosLindos Link to post Share on other sites More sharing options...
digitalfx Posted January 16, 2010 Share #27 Posted January 16, 2010 Advertisement (gone after registration) not sure how zooming into the image (after the fact) could alter the dof. a 50mm is a 50mm on whatever format or chip you use. All of the lens properties, the distortion of the lens and the depth of field stay the same no matter what. The "field of view" is going to be what changes from your Full Frame sensor to a cropped sensor or s35 frame. There is a misconception that the 1.3 factor is a conversion for focal lengths. It's not. It's a conversion for field of views. A 50mm on the cropped sensor will have the field of view that a 66mm'ish lens would have on your Full Frame sensor... but it's still a 50mm lens and has the DOF and distortion characteristics of a 50mm lens. This is why, when I shoot 16mm film, I don't suddenly start calling a 25mm lens a 50mm lens, just because that's what it corresponds to on a S35 camera. It's still a 25mm lens. It has a "field of view conversion factor to S35" of 2X, but it's still a 25mm. Link to post Share on other sites More sharing options...
Jet Posted January 17, 2010 Share #28 Posted January 17, 2010 Just shot with a newly acquired 50 lux... I love this lens. Great subject, great lense too! 50 lux shines with portrait like this one. Jet Link to post Share on other sites More sharing options...
digitalfx Posted January 17, 2010 Share #29 Posted January 17, 2010 Link to post Share on other sites More sharing options...
digitalfx Posted January 17, 2010 Share #30 Posted January 17, 2010 sorry, previous images are on M8...I didnt realize I was in the M9 forum when I posted them. Link to post Share on other sites More sharing options...
horosu Posted January 17, 2010 Share #31 Posted January 17, 2010 Here are two samples at 1.4 on the M9. The first was ISO 1250, the second ISO1600. Link to post Share on other sites More sharing options...
adli Posted January 17, 2010 Share #32 Posted January 17, 2010 not sure how zooming into the image (after the fact) could alter the dof. a 50mm is a 50mm on whatever format or chip you use. All of the lens properties, the distortion of the lens and the depth of field stay the same no matter what. The "field of view" is going to be what changes from your Full Frame sensor to a cropped sensor or s35 frame. There is a misconception that the 1.3 factor is a conversion for focal lengths. It's not. It's a conversion for field of views. A 50mm on the cropped sensor will have the field of view that a 66mm'ish lens would have on your Full Frame sensor... but it's still a 50mm lens and has the DOF and distortion characteristics of a 50mm lens. This is why, when I shoot 16mm film, I don't suddenly start calling a 25mm lens a 50mm lens, just because that's what it corresponds to on a S35 camera. It's still a 25mm lens. It has a "field of view conversion factor to S35" of 2X, but it's still a 25mm. DOF is not a characteristic of the lens but a print of a certain size produced with a camera/lens combo. You can't actually tell what DOF a picture has before you have taken enlargement of the print into consideration. That is why the sensor size matter when using the same FL on different sensor sized cameras. But then you typically change FL when you change sensor size or else you will get different pictures (FoV) Link to post Share on other sites More sharing options...
lars_bergquist Posted January 17, 2010 Share #33 Posted January 17, 2010 Depth of field ON THE FILM OR SENSOR depends only on two factors: Aperture, and reproduction ratio. Obviously, from the same camera position, a longer lens produces a greater repro ratio, say, 1:10 instead of 1:20, so this is where focal length comes in -- indirectly. But if you also change position so that on-sensor reproduction is the same, d.o.f. is also the same (but the position change changes the perspective, of course). But we don't look at 24x36mm pictures. We enlarge them, on paper or on a monitor. As we increase enlargement, detail that looked sharp will look first slighty unsharp, then outright fuzzy. Clearly, in order to obtain a A4 size print, we must print out the file from the cropped sensor at a greater ratio of enlargement than that from a full format one. So on-sensor depth of field has to be a bit greater in order to produce the same visual expression of spatial 'sharpness' with the cropped-sensor camera. Now, with the M8 and a 50mm lens, we would probably not take the picture from the same distance as with a M9, and that change would change reproduction ratio ... damn. It is a complicated matter, but understandable as long as we do not conflate different factors. In practice, we should understand d.o.f. well enogh to relegate the whole subject to our unconscious. If we constantly had to think about gravity, force parallellograms and all that, we would never learn to ride a bicycle. The old man from the Bicycle Age Link to post Share on other sites More sharing options...
digitalfx Posted January 17, 2010 Share #34 Posted January 17, 2010 In practice, we should understand d.o.f. well enogh to relegate the whole subject to our unconscious. If we constantly had to think about gravity, force parallellograms and all that, we would never learn to ride a bicycle. The old man from the Bicycle Age crap, now i'm confused...im switching to the X1 so I dont have to think about this Link to post Share on other sites More sharing options...
diogenis Posted January 17, 2010 Share #35 Posted January 17, 2010 Actually it is not a very difficult lens to focus. I prefer to have the largest part of DOF in front of the subject, as that promotes plasticity. Lovely shot Jaap, and those from the other guys, but I also liked how you nailed that 3D aspect! Superb! Link to post Share on other sites More sharing options...
Chipkahn Posted January 18, 2010 Share #36 Posted January 18, 2010 Picture attached was taken with the 50mm ASPH Summilux at 1.4 with M9. Takes great pictures. 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/109674-samples-of-the-50mm-asph-summilux-at-14-with-m9-please/?do=findComment&comment=1190737'>More sharing options...
previlo Posted January 19, 2010 Author Share #37 Posted January 19, 2010 Thanks a lot for the samples so far and for the additonal information around DOF, point ov view, etc.! Keep the samples going, please! Thanks! Link to post Share on other sites More sharing options...
Mauribix Posted January 20, 2010 Share #38 Posted January 20, 2010 If we constantly had to think about gravity, force parallellograms and all that, we would never learn to ride a bicycle. Lars, you made my day! Link to post Share on other sites More sharing options...
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