Originally posted by GUB f4.5 is an approximation coz I am using my super technical technique(
) of a black ringbinder reinforcing ring over the back lens to stop it down.
Saved in camera as jpeg and not pped.
Uploaded the sharpest of taken images which interestingly was the one taken at ISO 250 compared to ISO125 for the others. Is that because of shutter speed/ camera shake on my crappy tripod or does the higher iso grain make for a visually sharper image?
I think I have done it correctly-- my 4x6 print doesn't resolve 5 or higher like you said but 4 is the relevant number anyway with your viewing distance(magnification). I distanced the camera so it just viewed the 12x9 square.
Sorry about the colour cast -- doing it at night.
Looks like the 5 lp is just resolved - 250 lp/mm. Backs up why you are getting those great shots on the main Adapted thread. Your dog is famous
'So many lenses, so little time...'
PS - your 12 x 9 framing matches mine. Our results should be comparable.
---------- Post added 04-08-14 at 01:50 AM ----------
Originally posted by GUB I think viewing distance/magnification could be quite a variable in results after shuffling the camera to fit the image. Wouldn't it be simpler to say 2inches of distance for every mm of focal length. That would be 100 inches for the 50mms which is about right. The smart thing about this is it would work for all focal lengths so long as you accurately know the focal length (ie zooms would be a problem)
Interesting point. I started all this using Canon guy Atkins 'fit the frame' approach. But I find I generally under-fill the frame. I've been accepting that, as doing so conservatively shows the lp resolution... But now that I see the 06 from Hans....
---------- Post added 04-08-14 at 02:08 AM ----------
Originally posted by barondla On 28mm lens comparisons for FF or APS-c, I would also want to know how rectilinear each lens is. Straight lines that curve can ruin some shots. It can be fixed in post, but there is resolution loss.
Now that I think about it, using a FF 28mm on the Q makes no sense at all. Using the Q to assess a 28's resolution and contrast (for use on APS-C/FF), maybe.
Otherwise, we are dealing with all the complexities of a retrofocus design, without the need to do so - as Baz' 110 shots show...