oysterboy Posted October 16, 2011 Share #1 Posted October 16, 2011 Advertisement (gone after registration) Do the hyperfocal scales on all manual lenses remain true when using a crop factor cameras like the M8? or do they only work for the full frame cameras (m9)? Quote Link to post Share on other sites More sharing options...
Advertisement Posted October 16, 2011 Posted October 16, 2011 Hi oysterboy, Take a look here Hyperfocal scales on Lenses and crop factor cameras (M8). I'm sure you'll find what you were looking for!
pico Posted October 16, 2011 Share #2 Posted October 16, 2011 (edited) Do the hyperfocal scales on all manual lenses remain true when using a crop factor cameras like the M8? or do they only work for the full frame cameras (m9)? Specifically, the DOF does not change, however degree of enlargement does, presuming you want the same horizontal presentation size one has with full-frame, therefore a more pessimistic reading of the scale is important. Someone smarter than I can give you the math. Essentially, you want a slightly small Circle of Confusion (CoC) factor. (What do folks think -- use the next stop physically larger on the scale?) My first real-life clue to this was using Hasselblad's SWC where the instructions suggest that for large print (say, 40" square) one should ignore the printed scale and use a CoC for a FF 35mm format camera, a nominal .0333 CoC. Edited October 16, 2011 by pico Quote Link to post Share on other sites More sharing options...
lct Posted October 16, 2011 Share #3 Posted October 16, 2011 Recurrent question. Do a search on the forum and you'll find many posts about this. In two words: - The M8 has about one *more* f/stop of DoF with *equivalent* lenses as M9's. 28mm on M8 vs 35mm on M9 for instance. - The M8 has about one *less* f/stop of DoF with *same* lenses as M9's. 35mm on both for instance. Hence the rule of thumb of choosing one less f/stop for zone focusing with M8 and other APS cameras. http://www.l-camera-forum.com/leica-forum/1728743-post104.html Quote Link to post Share on other sites More sharing options...
01af Posted October 16, 2011 Share #4 Posted October 16, 2011 Specifically, the DOF does not change ... Actually it does—becomes narrower with the smaller image format. What do folks think—use the next stop physically larger on the scale? Basically, yes. So when actually shooting at f/8, for example, then read the scale for 5.6. In other words, f/8 on the M8 will yield the same depth-of-field as f/5.6 on 35-mm full-frame format ... errr, approximately (with the same lens at the same distance). The math behind it is simple enough—to get the 'equivalent' aperture number, just divide the actual aperture number by the crop factor which for the M8 is 1.33. So using the next full f-stop instead (which would correspond to a factor of 1.41) is not perfectly accurate but close enough for any practical intents and purposes. Quote Link to post Share on other sites More sharing options...
oysterboy Posted October 16, 2011 Author Share #5 Posted October 16, 2011 Thanks guys. This explains a lot of things. I was using F8 and even sometimes F.5.6 on the M8 with a 28 Emarit asph and was still getting some shots not in focus. This really was F4 and F5.6 as you indicate. I realize I will have to go to F11 or F16 to really get a lot "territory in focus. and if I want to shoot at speeds of around 300 that means that I will have to crank up the ISO more than I perhaps would like to with the M8. Quote Link to post Share on other sites More sharing options...
lct Posted October 16, 2011 Share #6 Posted October 16, 2011 Yes but your 28 is equiv. to 35 as far as FoV is concerned. To compare what you used to do with a 28 on film you will have to use a 21mm on the M8 and you will gain one f/stop DoF from this viewpoint. Quote Link to post Share on other sites More sharing options...
DWatts Posted October 16, 2011 Share #7 Posted October 16, 2011 Advertisement (gone after registration) Do the hyperfocal scales on all manual lenses remain true when using a crop factor cameras like the M8? or do they only work for the full frame cameras (m9)? I asked Leica this very same question and posted their reply here about 10 months ago. Leica said thet the markings on their lenses were exactly the same whatever Leica camera was used - film or digital. Quote Link to post Share on other sites More sharing options...
ho_co Posted October 16, 2011 Share #8 Posted October 16, 2011 There's a 2006 LuLa article discussing the fact that depth of field with digital doesn't work the same as we were used to with film. See Digital Focusing Part One. A bit pedantic: Those are "depth of field" markings engraved on the lenses, not "hyperfocal" markings. The hyperfocal distance is the distance for which (for a given focal length and aperture) depth of field is its greatest. 2 Quote Link to post Share on other sites More sharing options...
01af Posted October 17, 2011 Share #9 Posted October 17, 2011 [schmal]... but your 28 mm lens is equivalent to 35 mm as far as field-of-view is concerned. To compare what you used to do with a 28 mm on film you will have to use a 21 mm on the M8 and you will gain one f-stop depth-of-field from this viewpoint.[/schmal} Yes ... except he is using a 28 mm lens on his M8. Okay? If he was using a 21 mm lens then he would look at a 21 mm lens' depth-of-field scale—and from there, lose a stop, not gain one. I asked Leica this very same question and posted their reply here about 10 months ago. Leica said thet the markings on their lenses were exactly the same whatever Leica camera was used—film or digital. Yes, I remember them saying so. But they are wrong. Quote Link to post Share on other sites More sharing options...
DWatts Posted October 17, 2011 Share #10 Posted October 17, 2011 Quite suprisingly I prefer to believe Leica ! ! Quote Link to post Share on other sites More sharing options...
lct Posted October 17, 2011 Share #11 Posted October 17, 2011 DoF markings of lenses are what they are. They just can't be used the same way if you mount the same lens on full frame or crop cameras. Easy to check with M or R lenses on APS-H, APS-C and Four Third or Micro Four Third cameras. Quote Link to post Share on other sites More sharing options...
01af Posted October 17, 2011 Share #12 Posted October 17, 2011 Quite suprisingly I prefer to believe Leica! Yeah ... I guess believing is easier than thinking. Quote Link to post Share on other sites More sharing options...
pico Posted October 17, 2011 Share #13 Posted October 17, 2011 Thanks for not toasting me, Olaf. Quote Link to post Share on other sites More sharing options...
SJP Posted October 18, 2011 Share #14 Posted October 18, 2011 Quite suprisingly I prefer to believe Leica ! ! Not everything Leica says is correct. This topic has been discussed to death multiple times, some would argue way too many times, and always ultimately boils down to the result Olaf mentions. If you crop the sensor then you need to adjust the DoF accordingly. More crop => larger depth of field, for the M8 typically about 1 stop. Quote Link to post Share on other sites More sharing options...
01af Posted October 18, 2011 Share #15 Posted October 18, 2011 More crop => larger depth of field ... Except it's more crop => less depth-of-field Quote Link to post Share on other sites More sharing options...
SJP Posted October 18, 2011 Share #16 Posted October 18, 2011 At 10 meters nominal focus point we get at f/2: 35mm FF sensor 6.59 - 20.84 meters 28mm M8 sensor 6.45 - 22.35 meters (larger DoF than the 35 mm equivalent) 35mm M8 sensor 7.40 - 15.46 meters (less than on FF) So it depends on what you are comparing, the same lens 35 mm on FF and M8, or the 35mm on FF and the "equivalent focal length ca. 28 mm" on the M8. I am using 31 micron for FF CoC and 21 micron for the M8 sensor in these calculations and am convoluting with the diffraction limited Airy disk. I prefer comparing equivalent focal length i.e. keeping the angular field of view constant. Anyway, I think we agree that a cell phone has a larger depth of field than a full frame of MF camera. A smaller sensor gives less 3D isolation. Quote Link to post Share on other sites More sharing options...
Jeff S Posted October 18, 2011 Share #17 Posted October 18, 2011 The last section of this article addresses the OP's question. Jeff 1 Quote Link to post Share on other sites More sharing options...
DWatts Posted October 18, 2011 Share #18 Posted October 18, 2011 Yeah ... I guess believing is easier than thinking. Depends who is doing the 'thinking' Quote Link to post Share on other sites More sharing options...
01af Posted October 18, 2011 Share #19 Posted October 18, 2011 I think we agree that a cell phone has a larger depth-of-field than a 35-mm full-frame or medium-format camera. Yes. A smaller sensor gives less 3D isolation. No. Quote Link to post Share on other sites More sharing options...
SJP Posted October 19, 2011 Share #20 Posted October 19, 2011 No.Can you elucidate? Quote Link to post Share on other sites More sharing options...
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