Re: [darktable-dev] Lens correction with FF lenses used on APS-C
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: This allows you to know how the lens was calibrated. J-L Le sam. 23 févr. 2019 à 19:31, David Vincent-Jones 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
Re: [darktable-dev] Lens correction with FF lenses used on APS-C
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
Re: [darktable-dev] Lens correction with FF lenses used on APS-C
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
Re: [darktable-dev] Lens correction with FF lenses used on APS-C
* Florian W [02-23-19 10:37]: > Thanks for your answers guys. > > Simon, I'm curious to know why to you it's not the best idea ? > > > Le sam. 23 févr. 2019 16:19, Sturm Flut a écrit : > > > Hi, > > > > it does, as long as lensfun can find the lens in its database. I've been > > using full-frame-only lenses on both my Nikon D750 (full-frame) and > > D7100 (APS-C) for years. > > > > (It's not the best idea, though, so I'm about to replace the D7100 with > > a second full-frame body). > > > > cheers, > > Simon > > > > > > > > Am 23.02.19 um 14:42 schrieb Florian W: > > > Hi, > > > I happen to use on my Canon 750D (APC-C) 2 lenses designed for full > > > frame (Canon EF 50mm f/1.8 STM and Canon EF 28mm f/2.8 IS USM) > > > I wondered if the lens correction module takes into account that the > > > camera is full frame or APS-C to apply the proper correction ? > > > > > > Can someone tell me ? also curious as I have for years used both full-frame and aps lenses on my present D850, D7200 and D500 and previously D70, D3, D200 and D7100 and not noticed any abnormality. but adding a 1.3x extension on my v1 70-200 f/2.4 does lack clarity and more so on the D850. -- (paka)Patrick Shanahan Plainfield, Indiana, USA @ptilopteri http://en.opensuse.orgopenSUSE Community Memberfacebook/ptilopteri Registered Linux User #207535@ http://linuxcounter.net Photos: http://wahoo.no-ip.org/piwigo paka @ IRCnet freenode ___ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org
Re: [darktable-dev] Lens correction with FF lenses used on APS-C
Thanks for your answers guys. Simon, I'm curious to know why to you it's not the best idea ? Le sam. 23 févr. 2019 16:19, Sturm Flut a écrit : > Hi, > > it does, as long as lensfun can find the lens in its database. I've been > using full-frame-only lenses on both my Nikon D750 (full-frame) and > D7100 (APS-C) for years. > > (It's not the best idea, though, so I'm about to replace the D7100 with > a second full-frame body). > > cheers, > Simon > > > > Am 23.02.19 um 14:42 schrieb Florian W: > > Hi, > > I happen to use on my Canon 750D (APC-C) 2 lenses designed for full > > frame (Canon EF 50mm f/1.8 STM and Canon EF 28mm f/2.8 IS USM) > > I wondered if the lens correction module takes into account that the > > camera is full frame or APS-C to apply the proper correction ? > > > > Can someone tell me ? > > Thanks > > > > > ___ > > 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
Re: [darktable-dev] Lens correction with FF lenses used on APS-C
Hi, it does, as long as lensfun can find the lens in its database. I've been using full-frame-only lenses on both my Nikon D750 (full-frame) and D7100 (APS-C) for years. (It's not the best idea, though, so I'm about to replace the D7100 with a second full-frame body). cheers, Simon Am 23.02.19 um 14:42 schrieb Florian W: > Hi, > I happen to use on my Canon 750D (APC-C) 2 lenses designed for full > frame (Canon EF 50mm f/1.8 STM and Canon EF 28mm f/2.8 IS USM) > I wondered if the lens correction module takes into account that the > camera is full frame or APS-C to apply the proper correction ? > > Can someone tell me ? > Thanks > > ___ > 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
Re: [darktable-dev] Lens correction with FF lenses used on APS-C
I believe it does. Changing body type (full-frame instead of aps-c) changes geometry. Body type description is nothing more than just a file in /usr/share/lensfun/version_1 with cropfactor parameter being the only meaningful information used for geometry calculaton. Timur. On Sat, 2019-02-23 at 14:42 +0100, Florian W wrote: > Hi, > I happen to use on my Canon 750D (APC-C) 2 lenses designed for full > frame (Canon EF 50mm f/1.8 STM and Canon EF 28mm f/2.8 IS USM) > I wondered if the lens correction module takes into account that the > camera is full frame or APS-C to apply the proper correction ? > > Can someone tell me ? > Thanks > > _ > __ 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-dev] Lens correction with FF lenses used on APS-C
Hi, I happen to use on my Canon 750D (APC-C) 2 lenses designed for full frame (Canon EF 50mm f/1.8 STM and Canon EF 28mm f/2.8 IS USM) I wondered if the lens correction module takes into account that the camera is full frame or APS-C to apply the proper correction ? Can someone tell me ? Thanks ___ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org
