In the database (in liblensfun-data package, file slr-canon.xml for Canon), you will find the various bodies / lenses. For each lens, there is a comment like: <!-- Taken with Canon 5D Mark III --> This allows you to know how the lens was calibrated.
J-L Le sam. 23 févr. 2019 à 19:31, David Vincent-Jones <david...@gmail.com> a écrit : > On my system the camera and correct lens is found by default .... which is > what I want! > > David > On 2019-02-23 9:12 a.m., Sturm Flut wrote: > > Hi, > > Am 23.02.19 um 16:34 schrieb Florian W: > > Thanks for your answers guys. > > Simon, I'm curious to know why to you it's not the best idea ? > > (oversimplifying it a bit) > > Full-frame lenses are designed to deliver their full sharpness across > the whole full-frame image circle. If I put a full-frame lens on my > APS-C D7100, I am basically expecting it to deliver 24 megapixels within > the smaller APS-C image circle the sensor is cropping out. That means I > expect the lens to deliver about 24*2,25 = 54 megapixels over the whole > full-frame image circle. Which not that many standard lenses will do. > > If put my standard 24-70/2.8 on a Nikon D850 and (let's say) it only > delivers 40 megapixels of actual resolution instead of the ~46 the > sensor wants, that's not going to be a catastrophe. If I put it on a > camera with a lower resolution sensor, e.g. the 24 megapixel sensor in > the D750, there is zero problem. But if I put the same lens on the > D7100, the cropped area will only get around 40 / 2,25 = 17 megapixels. > That's suddenly 30% less than what the sensor needs. And not every lens > will even deliver these 40 megapixels. Good APS-C and especially > Micro-Four-Thirds lenses are expensive and hard to make because they > have to be very sharp within the smaller image circle. > > Prime lenses are usually sharper to begin with, so with your 50/1.8 and > 28/2.8 it might not be that much of an issue. But I can clearly see the > problem with my 24-70/2.8, and especially with the good old 70-300/4.5-5.6. > > cheers, > Simon > ___________________________________________________________________________ > darktable developer mailing list > to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org > > > ___________________________________________________________________________ > darktable developer mailing list to unsubscribe send a mail to > darktable-dev+unsubscr...@lists.darktable.org > ___________________________________________________________________________ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org
