Herb,
For some reason, the PEF files you uploaded doesn't load correctly in PhaseOne C1 RAW. The lower 15% of the image is just black. Never seen this with my own PEFs... Any ideas?
Jostein
----- Original Message ----- From: "Herb Chong" <[EMAIL PROTECTED]>
To: <pentax-discuss@pdml.net>
Sent: Monday, January 31, 2005 5:04 AM
Subject: IMATEST comparison of Pentax Photo Laboratory and Adobe Photoshop CS RAW converter
i've been playing a little bit with IMATEST, Norm Koren's program to analyze color, resolution, noise, and linearity of digital cameras. you can read more about it at www.normankoren.com. i've posted a set of results from doing the color test at various ISO settings and looking at color fidelity, noise, and linearity. you can read about the test and how to interpret the graphs at http://www.imatest.com/docs/colorcheck.html. the details are pretty technical so i posted all of the output graphs instead of trying to explain too much. here are the results http://users.bestweb.net/~hchong/IMATEST_Results/ as output by IMATEST. all of the EXIF details for my six test images are contained in http://users.bestweb.net/~hchong/IMATEST_Results/PentaxPhotoLaboratoryImageData.csv. i shot all of these outdoor with direct sun on the color chart. this reduces contrast by having the darker zones coming out light. all images were defocused a fair bit to remove surface texture noise from the chart itself.
i always shoot in RAW. i used IMATEST to do a comparison of the output from Pentax Photo Laboratory TIFF16 to Adobe Photoshop CS RAW TIFF16 from the same set of RAW files. both conversions were done with with automatic white balance and exposure. Photo Laboratory conversion used all default settings. i have the Sharpening slider in Photoshop RAW set to 50 and otherwise everything else was default. white balance was left at As Shot.
the conclusions i draw from doing this comparison, which mainly shows the difference between the Pentax and Photoshop converters is that the Pentax converter is significantly worse at color accuracy and noise reduction. the Photo Laboratory conversion rates as very good for color fidelity while Photoshop CS RAW rates as excellent or better. the noise from Photo Laboratory at high ISO shows significant chroma noise while the noise from Photoshop CS RAW is mostly luminance noise. the noise spectrum of both converters is really different too. it suggests that Photo Laboratory does little or no noise reduction and that the noise grows rapidly with underexposure. Photoshop CS RAW seems to do the same types of noise reduction that most digital cameras do.
i didn't shoot enough images to be sure, but the sequence of images using ISO 200, 400, 800, 1600, 3200, and 200 was interesting enough to make me want to try something. the second ISO 200 exposure tested worse than the first one. i wonder if i shoot a full burst of 6 images at ISO 200 whether there will be a progression of decreasing quality from the first image to the last.
i need to do this test with the Thumbs+ Digicam RAW 1.5 plugin to see how it fares. i wonder how other converters will do.
Herb....
