alundeb wrote:
I think it is in how we map the Rayleigh criterion into lines or line pairs.
When two airy disks intersect as the Rayleigh criterion, the maiximum of one coincides with the first null of the second. The distance between the maxima is then equal to the radius of the airy disc. The point is, these two maxima represent a line pair when they represent two bright lines with a dark line between them. So the Rayleigh criterion maps directly into line pairs per mm, not lines per mm.
Edit:
Yes, that is how it is.
Rayleigh for green at F2.95 is 500 lp/mm not 250 lp/mm.
Of course. My error, and THAT'S why you shouldn't write stuff like this when getting home at three o'clock in the morning while still slightly drunk. A factor fo two it is, Rayleigh = lp
*hangs head in shame*
philip_pj wrote:
Lee, I would not be too fussed on the multiple sample front, if your aim is not purely a 'sharpness' derby. Though admittedly the thread is bending off in that general direction. I am much more interested in the overall perceivable photographic quality of images of the sort that regular photographers take, which looks to place me in the small niche of photographers down at the end of the distribution.
I'm definitely with you on real world testing and visual examples. There will be a mixture of normal field shooting and deliberate, Lloyd-Chambers-esque A-B comparisons. I'm just going to do an Imatest "sharpness derby" also
The multiple samples aren't really about maximizing the "sharpness derby" results, though. Roger Cicala's blogs make it clear 2-3 samples isn't nearly enough for that. It's more about screening for actual bad samples. For example, the Zeiss Jena 180/2.8 is supposedly the same optical design as the very first 180mm from 1936. My expectations for that lens aren't very high; I could get a bad sample and not realize it.
About to order a Leitax adapter for my Leica as R 180/2.8 APO lens as I am giving up hope for a Canon D800 equiv MP camera. Use to use it on my 1ds3 with and without 2x APO TC. Wish I could convert both ends of TC to Nikon mount so I could use it .
Look forward to IQ from D800E and this super sharp lens .
FM member worldinlens can convert the 2x APO converter to Nikon on both ends. He has already done at least one. He lives in Russia however, so I don't know the cost of shipping and import.
carstenw wrote:
FM member worldinlens can convert the 2x APO converter to Nikon on both ends. He has already done at least one. He lives in Russia however, so I don't know the cost of shipping and import.
Thanks Carsten!
I could not remember the name of the FM'r who had mentioned he had done that. I will PM him to see if he wants to covert it for me. Have you sold your R180/2 APO? I remember you were thinking of selling it awhile back.
Did you ever shoot comparison shots against the Nikon 200/2 VR version 2?
I didn't sell it yet, this will be a long process I did shoot a comparison with the VR 1, but I can't find it here on FM. Here is a copy I posted on getdpi:
