Archived posting to the Leica Users Group, 2006/03/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]yes. i think the most intuitive way of thinking about it is that the noctilux exhibits its pronounced depth of field characteristics at close- focust distances, say 5 feet, where at a DOF of about 2 inches you will need to be thinking in a portrait about which eye you want in focus. with a camera with a smaller format (or sensor), which would effectively make the lens a 75mm, you would need to move back to 7.5 feet to get the same portrait size image in the final print. at 7.5 feet, the DOF of the noctilux is about 5 imches, which renders most of the face in focus. the images therefore, would have a different look, becase of the increased depth of field in the second image, and the flatter perspective of the greater distance. moving in the opposite direction, consider the f2.8 150mm xenotar in 4x5. a 150mm is a "normal" focal length for 4x5, and f2.8 does not in an absolute sense sound like a "fast" aperture, though at focusing distances of 5 feet, the depth of field is 2 inches, just like the noctilux. here are some samples of my kids i took a couple of years ago with the xenotar, largely to reinforce in the intuition that the DOF tables say: http://www.shinozuka.org/20040914-xeno/ everyone is correct when saying that a 150mm f2.8 lens in 35mm mount focused at 5 feet would have that same 2" DOF, but you'd get such a tight crop of the subject you'd need to back up about 15 feet to get back to head-and-shoulders, at which point your DOF would be about 20 inches. -rei On Mar25 20:46, Eric wrote: > Adam: > > > will the depth of field be identical? > > Yes. Cropping doesn't change depth of field. > > The 50/1 on a 1.4x crop camera has the same look and depth of field as a > 70/1.4 on a "full frame" camera. > > You'd need a 35/0.7 on a cropped camera to get the same, razor-thin DOF as > the nocti on film. > > > > -- > Eric > http://canid.com/ > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information -- Rei Shinozuka shino@panix.com Ridgewood, New Jersey