JimBuchanan
New member
Transposed from another thread, this seeded my math exercise for the day, in light of all the hopla around Photokina . About the FF, 24x36 image circle and a possible new format size from Leica. And, as was replied to above, the FF image circle is 43.2mm.BTW, I mounted my 180mm APO summicron in front of a view camera and the image circle was 38-40mm. Certainly in MFDB territory and a bigger than 35mm sensor. There are probably other R lenses with large image circles too.
Robert
So, I grabbed my Summicron-R 50 and projected the horizon onto a white sheet of graph paper, and like robsteve, got an inverted image of almost 2 inches square or an image cirlce of over 60mm. But the image thru the viewfinder is way less, obviously cropped down to the sensor size.
At first, I thought this COULD support a larger format, but like the field stop of an eyepiece/telescope system, the frame or sensor size acts as a field stop because farther out than that is curvature of field, aberrations, etc. that need to be masked out.
UNLESS, the Leica designers had the forethought way back in the 90s or indeed this decade, to design into more current R lenses a larger image circle for some future larger format.
But, I doubt it.
Anyway, with a 43.2 image circle, it is possible to pull out a square format of almost 31mm, as shown below:
View attachment 7456
If Leica did design in a larger image circle as suggested above, by even just a few mm, 2:3 formats larger than 24x36 are easy to visualize. Wonder what CMOS or CCD formats larger than 35mm and smaller than medium format exist? Probably not much to choose from...