Archived posting to the Leica Users Group, 2003/04/23
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]For a long time, I wondered what looked to different to me about many digital pictures, then it hit me - depth of field. With the exception of the new Canon, Kodak (and the lamentable Contax N) full frame DSLR bodies, most of the digicam images we see were made with cameras using sensors smaller than 24x36mm. The reasonably priced DSLRs all have frame sizes that capture some fraction of that, such as as the 15.1x22.7mm Canon 10D, and require a lens of shorter focal length to achieve the same field of view as a 35mm film camera. For example, a Canon 10D would require a 31mm lens to get the same FOV as a Canon EOS1v film SLR with a 50mm lens. Correct me if I'm wrong, but I believe depth of field is related to focal length and aperture size alone. The depth of field of a 25mm lens is the same regardless of the size of the film or digital sensor. Consider the example above and let's assume that the film shooter is using a 50mm set to f1.4. To acheive the same FOV, the DSLR user will need a 31mm lens. But lenses around this focal length with maximum apertures of f1.4 are few and far between, not to mention that a 31mm lens at f1.4 will still have more DOF than a 50mm at 1.4. The DSLR shooter could use the same 50mm f1.4 lens, and back off from the subject, but then again, the increased distance to subject will result in increased DOF. The differences in aesthetic are even more pronounced if you throw a Leica M into the film camera role, with lenses like the Summilux ASPH 35, Noctilux, etc. As a practical matter, you simply cannot reproduce the Leica M aesthetic with most digital cameras today without photoshop tricks. Back in the 50s, my Dad took alot of beautiful photos with an old Contax SLR with a 58mm f2.0 lens. I always loved the "look" of those pictures which was largely the result of the current technology at the time. He shot color slides, and Kodachrome 25 was the best available at the time. In addition, the Contax had no auto aperture, so you would normally have the lens wide open to focus, then stop down to shoot. This was a hassle, so as a result he would leave the aperture at f2 and adjust the shutter speed. Hence, they often had the shallow DOF of a 58mm lens at f2. I could tell when he got his first auto exposure P&S and started using faster film, because everything in his pictures was in focus. Gone was that beautifl shallow DOF I'd seen in his earlier photos. What's the point? I guess it's the obvious one, that imaging technology tends to create a dominant aesthetic. Also, it's that many of us love the Leica for its fast lenses and the shallow DOF aesthetic we so prize can be difficult to achieve with DSLRs and certainly with all compact digicams. It will be even harder to achieve if the new Olympus "four thirds" system becomes a standard, with it's smaller chips and smaller (and shorter focal length) lenses. And as fewer and fewer people take the trouble to shoot film, this look will become increasingly rare. Shallow depth of field with short focal length lenses will become a thing of the past. - --Jim - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html