Google| Subject | Re: converting raw images from Canon EOS 600D |
| From | bd |
| Date | 12/02/2013 01:09 (12/02/2013 00:09) |
| Message-ID | <l7gj2v$s13$2@usenet.pasdenom.info> |
| Client | |
| Newsgroups | rec.photo.digital |
| Follows | Floyd L. Davidson |
| Followups | Floyd L. Davidson (1h & 40m) > bd |
Le Fri, 29 Nov 2013 17:30:23 -0900, Floyd L. Davidson a écrit :
Floyd L. DavidsonThanks a lot for this useful input. I will comment inside your text, according to what results I got from my first tests
bd <bdebreil@teaser.fr>wrote:
Le Fri, 29 Nov 2013 17:30:23 -0900, Floyd L. Davidson a écrit :
the first thing is to check the configuration of UFRAW. Here are
my defaults, from top to bottom:
---- Pre-Configuration ----
At the top: Enable Raw histogram
2nd line: Set Exposure to 0.0 (see Note) Set Restore Details for Negative EV to "HSV space for sharp detail" Set Clip Highlights for Positive EV to "digital linear" Set Auto Adjust Exposure to disabled (see Note) Note: Clicking the last icon will set exposure to 0 and disable Auto Adjust.
3rd line: White Balance -- set to either "auto" or "camera" Grayscale Mode -- None (which means color) Lens correction (optional, may not exist) -- None Base Curve -- Straight Line (use reset button on right)
Color Management -- A. Input ICC Profile: No profile B. Gamma: 0.45 C. Linearity: 0.10 D.Output
ICC Profile: sRGB E. Output intent: Perceptual F. Output Depth: 8 (16 sometimes) G. Display ICC Profile: sRGB H. Display intent: Perceptual Correct Luminosity, Saturation -- A. Contrast (Optional, may not exist): 1.00 B. Saturation: 1.30 C. Manual curve D.Click
on both left and right bottom reset buttons Lightness Adjustments -- Does nothing on mine (if it exists, set everything to 0)it does nothing here either
Crop and Rotate -- Click on two reset buttons, and "lock" icon. Note that there are bugs associated with the functions in this menu, and on occasion odd crops may show up that require these resets to be reset to get a normal view.This is not appropriate here. I like the TIFF format and use it a lot, but the raw data from my new camera do not seem to agree with what is expected in the tiff format. Whenever I select TIFF as output format for ufraw, I do get tiff images indeed, but I can't open them using GIMP ! The message I get is something like: GIMP message: the opening of .....tif has failed: Le greffon Image TIFF n'a pas pu ouvrir l'image (the tiff image plugin has been unable to open the image).
Save -- THIS IS IMPORTANT! A. The "path" should be your current working directory. B. Select the output file format (I would recommend only TIFF).
So, untill I get to know how to solve this, I have to settle with the ppm format, which seems to work fine.
NEW: I just tested ufraw with the tiff output format on an old raw image from my old Canon Powershot G2 ==>Same results ! Gimp refuses to open the sort of tiff I obtain... It worked with the tiff that I obtained using straight dcraw (dcraw -T), it does not with those I get through ufraw
C. Set JPEG compression level as desired(less
than 92) C. Enable JPEG progressive encoding D.Enable
TIFF lossless compression E.I tried to disable TIFF compression, but the uncompressed tiff images that I got wouldn't open either.
Enable Embed EXIF
F. ** Set Create ID file to ONLY ** G. Set save image defaults to Always H. Disable remembering output path I. Enable overwriting files without askingyour
Bottom of page: Enable Live Histogram Check the indicate box for Overexposure Uncheck the indicate box for Underexposure
---- End of Pre-Configuration ----
The effect of setting UFRAW to only write an "ID" file is important. I start UFRAW like this:bdFloyd L. Davidson
ufraw *.nef
You will want to change *.nef to whatever suffix is appropriate for
raw files.with CANON it is *.CR2
this works perfectlybd
ufraw-batch *.ufraw
Floyd L. Davidsonany
The next step will be processing with an editor. If you use GIMP or
other 8 bit editor you'll want to get the gamma and brightness very close to perfect with UFRAW, because changing either in GIMP can cause posterization.It is good to know this
But GIMP is fine for cropping and most other edits. You can do minor adjustments to contrast and brightness, in particular to local area selections. Local sharpening and blurring is also done with GIMP, and then before writing the final output file to disk it should be 1) saved as an XCF formatted intermediate file, 2) scaled to the appropriate size, 3) apply Sharpen and Unsharp Mask, and finally 4) saved to disk (perhaps as a JPEG format).I am not sure that I always went though these steps in the right order, and, so far I had never used the XCF format, which I will do from now on.
I had a few times used a gimp filter: Filters =>Improve =>Sharpen. It sometimes gave good results, although not as good as what you get with the jpeg images delivered by the camera. For this filter, I used the defaults settings and, each times I had tried to change these settings I got worse results.
I just discovered something - but I surely need to investigate this a lot more :
Correct luminosity, saturation... "Click on both left and right bottom reset buttons"
If, instead of doing this above, I click to both right and left buttons that are just above the reset buttons, that is:
Black spot automatic adjustment
and
automatic adjustment of the curve (flatening the histogram)
I get a non linear curve, and the image looks a lot sharper and better, at least for this particular image which is the photo of an old handwritten document more than 200 years old and faded.
I would have tested the curve from "Fotogenetics" as suggested in the online ufraw manual... but it seems that it is a proprietary Adobe tool which is a "Windows Only" software.
11/30/2013-
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