Archived posting to the Leica Users Group, 2013/05/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Adam, Though primarily developed for tech camera users (Alpa, Cambo, Horseman, Arca) because you are moving the back to the far limits of the image circle, it is useful in all formats, especially with wide angle lenses. You can use this CaptureOne LCC correction process for any raw file that can be managed by CaptureOne. I think "Cornerfix" does the same thing specifically for Leica (DNG files?). https://sites.google.com/site/cornerfix/ Also, I got my physics mixed up on my response. Forgot my Roy G Biv. The reds and blues separate the most... Best, Bob On Sun, May 19, 2013 at 3:33 PM, Adam Bridge <abridge at mac.com> wrote: > Very clear, Bob, thank you! > > I've seen the translucent white covers but only thought of them for white > balance and not for lens cast. > > I didn't know it applied to the Alpa. Is it also the case for say medium > format cameras or is this a technical camera domain issue? > > Adam > > On May 19, 2013, at 1:37 PM, Robert Adler <rgacpa at gmail.com> wrote: > > > Hi Adam, > > As I understand it, as you go out further towards the edges of an image > > circle, the reds, greens and blues hit the pixel sights at ever > increasing > > (in nano seconds no doubt!) increments. Thus the colors begin to > separate. > > You start to to get more red and less green as you go further out. I > > actually have to address this quite significantly on my Alpa because I > move > > the digital back from right, to middle to left across the image circle > for > > a pano It is known that "lens cast" is a problem for MFDB on tech cameras > > where shifting is used quite often. CaptureOne has a Lens Cast Correction > > feature just for this. > > > > At some point in shooting a venue, I put an opaque white piece of plastic > > in front of the lens. I then take an exposure, usually two stops more > open > > than the exposure that I'm using for the image; and using the shutter > speed > > to open up, not the aperture). These LCC shots are then used in > CaptureOne > > to even out both the vignetting and the color cast. I also use the middle > > of the shot that is taken through this opaque device as a white balance > and > > it works pretty well. > > > > Seems Fuji has somehow allowed a user to adjust in the camera for third > > party lenses that aren't already corrected by them and that are using > their > > X mount to M mount adapter. > > Clear as mud? :-) > > Bob > > > > > > On Sun, May 19, 2013 at 8:51 AM, Adam Bridge <abridge at mac.com> wrote: > > > >> On May 18, 2013, at 8:12 AM, Robert Adler <rgacpa at gmail.com> wrote: > >> > >>> If it a Fuji adapter supported lens, there are built in adjustments for > >>> distortion (barrel/pincushion), color separation and light falloff. > This > >>> information is passed in the metadata with the RAW file and can be read > >> by > >>> ACR/CaptureOne/Aperture (all accept the color separation unfortunately, > >> but > >>> this can be corrected in various 3rd party software if needed). > >> > >> Bob, I don't understand "color separation" in this list of items. > >> > >> Is that like color temperature? > >> > >> Adam > >> > >> > >> _______________________________________________ > >> Leica Users Group. > >> See http://leica-users.org/mailman/listinfo/lug for more information > >> > > > > > > > > -- > > Bob Adler > > > > _______________________________________________ > > Leica Users Group. > > See http://leica-users.org/mailman/listinfo/lug for more information > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > -- Bob Adler