Marshal
Oct 26 2002, 10:48 PM
FWIW, the pics from Rob with the 1Ds are no worse in chromatic aberration then with my D1X. It can be somewhat time consuming to fix in PS. Depending on how bad it is from one shot to the next, 15-20 minutes per image. At least with architecture.
The way I work with it is to Select the areas with Chromatic Aberration, Feather by 1-2 pixels at most and either use Fred Miranda's Moire Reduction Action, OR, individually reduce the blue, green and red saturation, whichever color the CA is showing for that area. I rarely if ever use that MR action for the entire image, because while it may fix the problem in those former problem areas, it often messes up the color in other areas of the image.
Someone else created an action or program for dealing with color fringing, but it didn't work for me and I've since deleted it. I read about it on Rob's site in the forums. May work for you, but not for me. Much more complicated then Fred's action too.
Marshal
Oct 28 2002, 02:11 AM
The 15-20 minute estimate was with architecture, where it seems to show up more than with other shots, such as nature type shots. Go figure. I spent closer to 30 minutes I think on a couple of interior architecture shots of the inside of a church recently with a lot of detail on the ceiling. It was with a Nikon 14mm ED lens if that means anything, other than exquisite sharpness of course.
Think about it this way, most of us, including probably you spend a lot of time in PS anyway tweaking images. The digital cameras, be they Nikon D1 series or Canon D60 & 1Ds already substantially reduce the time it would take to clean film, often twice before the scanning process, which includes pre-scan and then the scan, then the inevitable extra cleanup and adjustments afterwards. Ideally, I would never have to remove the color fringing, but I've accepted it as an occasional part of the workflow.
Howard
Oct 28 2002, 11:32 AM
"Chromatic aberration. Certain wide angle photos show massive amounts of it, enough that it could limit the use of at least the EF 16-35mm f/2.8L lens at its wider settings. Chromatic aberration, where colours appear out of register along the edges of high contrast areas, manifests itself primarily as red and/or green borders, though one cityscape photo also shows some intense colour bleeding in an area of particularly high contrast (the latter problem may not be accurately described as chromatic aberration - at this point I'm not sure). This phenomenon is apparent only in photos taken with two different 16-35mm f/2.8 zooms, not with other, longer Canon lenses. While it's possible that the sheer volume of chromatic aberration is a quirk limited to the preproduction EOS-1Ds that captured the photos, it's more likely that this will be typical of what EOS-1Ds users can expect, at least with some extreme wide angle lenses and certain high contrast scenes."
:cool:
Stefan Klocke
Oct 30 2002, 03:32 AM
Panarama tools are very good and reliable. However the learning curve is steep and if only used once in a blue moon not very pratical.
A better choice might be Picture window, unfortunately not a Photoshop plugin. M Reichman used it for the 600mm Pentax? lens that showed Chromatic abberation as well. Check out Michaels arcticle:
http://www.luminous-landscape.com/reviews/chromatic.shtml
Stefan
Howard
Oct 26 2002, 07:57 AM
Howard
Oct 27 2002, 08:53 AM
Dear Marshall,
Thanks for the reply.
That seems to be an INORDINATE amount of time required. I'm NOT doutbting what you say....but it is a LOT of time to waste.
For now, I'll continue to shoot with my 6X7 and scan film.
If they can fix the Chroma Aberr., I will be thrilled to go digital all the way!
Best.....Howard
Tim Gray
Oct 28 2002, 11:26 AM
see: http://www.caldwellphotographic.com/Tutoria....ng.html
panorama tools can fix this - setting up the profile seems a bit time consuming, but you can easily reuse the settings.
Isn't the concensus that CA is a property of the lens, not the camera?
Marshal
Oct 29 2002, 08:45 PM
"see...caldwellphotographic.com..."
That's the one I couldn't get to work well. Complicated at best, but unreliable and more of a hassle than anything.
Pekka Potka
Oct 31 2002, 08:02 AM
Chromatic aberration is NOT a problem with EOS 1Ds. If there is any problems itīs not from the chip. Hey guys, donīt jump into correcting something that doesnīt exist yet
Even 14mm wide angle (Canon) behaves very, very well, as does TS lenses, certain wide angle zooms may show chromatic aberration, thou. But thatīs a lens problem only, the price we are paying now because the chipīs resolving power is so much better than what film can ever record...
Cheers
pekka
Cliff LeSergent
Oct 31 2002, 09:41 AM
For what it's worth, the EF 16-35mm f2.8L used in Rob Galbraith's tests was defective and has since been sent to Canon for repair. This might explain some of the results (chromatic abberation, blurred spot) he observed.
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