I am looking for a cut film holder/ground glass back for a Linhoff Technika III 6x9 and I have a technical question about the back. I know these cameras were sold with either a 53/100/180 or 65/105/180 lens set (plus other combos as well). My specific camera is a "b" version and is equipped with the 100mm f/2.8 Planar and correct (matching) cam designed for use with the Zeiss 53 Biogon, 100 Planar and 180 Sonnar. My question is that in my search for the proper cut film back for this camera I find many with the DOF chart shown in the pic below. Was there also a DOF chart for the 53/100/180 lens set? Is it possible that if the DOF chart below is unscrewed that the DOF for the alternative lens set is printed on the back of the 65/90/105/180 chart?
yes! Thank you for posting. Perhaps they never made one for the III. I noticed that on the chart that I originally posted and is on your camera, they lump the 90mm and 105mm together. The DOF values for these lenses are very close. As a matter of fact on the chart, the values seem to have been calculated for a 90mm lens and then been assumed to be close enough for the 105mm. If you do the calculations, when focused at infinity, at f/11, the DOF for the 90mm lens is 30' to infinity and for the 105mm lens is 38' to infinity. The chart on the camera reads 30' to infinity. For a 100mm lens the DOF would be 35' to infinity. (calculations assumed 6x9 cm format and a 0.002756 circle of confusion.) I guess the table is just fine for all practical purposes. Thanks again for your help!