Mike Chaney's Tech Corner

In reading the Comprehensive Raw Photo Support link http://www.ddisoftware.com/qimage-u/tech-raw.htm (http://www.ddisoftware.com/qimage-u/tech-raw.htm), I see three variations of lens distortion correction. dcraw (none), manufacturer correction, and Qimage Ultimate correction. This looks good for Qimage Ultimate. However, that is followed by a rather short list of Canon, Olympus, and Panasonic cameras for which it appears this customized lens correction is applied. Following is a very long list of cameras which includes the one I have, Sony RX100.

Does this mean the lens correction applied in Qimage Ultimate for cameras like mine is the same as dcraw, or essentially none? Or, is Qimage using the manufacturer correction?

Hi Ron,
The ability to convert camera raw file and also make lens corrections are two different things. For raw QU uses David Coffin's dcraw but the lens correction feature is something that Mike does from "calibration" images supplied by users or from a  camera he owns.
I suggest you email Mike at mchaney@ddisoftware.com and ask what is required to get you camera/lens calibrated for QU raw. I recall that another user did that a few months ago for a Panasonic camera/lens.
Terry

Imaging Resource did a review and test of the RX100 where they measured JPEG vs uncorrected RAW lens distortion. The images are located about 1/3 the way down the page at the link below. The distorted image at 28 mm was produced by using dcraw which provides no distortion correction. They rated the uncorrected distortion at 3.8% or extremely high. It seems to me that it has to be corrected to provide an acceptable image.

http://www.imaging-resource.com/PRODS/sony-rx100/sony-rx100A4.HTM (http://www.imaging-resource.com/PRODS/sony-rx100/sony-rx100A4.HTM)

I will e-mail Mike with my concern. If it is simply a matter of me doing a test with my camera that is not a problem.

Many modern cameras like yours have lenses with a correction element missing in the lens and software correction to the image is used, either in-camera for the jpeg's or in  the raw software.
The correction software needs sample images of a grid or similar, to set the software parameters for that camera/lens. Obviously the camera maker can do that easily, but a little more difficult for independent software developers.
Terry

In the case of the RX100, I suspect they don't do it to save costs, but to increase performance while reducing size. I don't know the ins and outs of dealing with camera manufacturers, but it surprises me that they would be anything less than accommodating on providing the needed data to correct for their lens. They provide conversion software (Sony Image Data Converter) as a free download and make no money selling software. They make their money on the camera, and the more compatible it is with the software suppliers, the better it is for them.

Terry, just to be clear, I am not talking about a custom camera/lens color profile. I've looked at Profile Prism, and it appears to be limited to color correction. I am only talking about geometric lens distortion correction. Also, not concerned about individual straightening of buildings which will tilt in or out. I just want the equivalent of what the camera does automatically for JPEG shots. Improving on the manufacturer correction would be nice, but is not necessary. If Qimage Ultimate already matches the default Sony correction that is fine for me. If it doesn't provide any geometric correction at all, that is an unacceptable dead stop. For the RX100 lens geometric distortion correction is essential.

I've e-mailed Mike, but not heard back from him yet.

Yes, I understand that.
It does not at present but it does not have to be a dead stop. As I said, contact Mike Chaney (program developer). He'll tell you what is needed so that the Sony lens correction can be incorporated into QU.
Terry

I wrote Mike an e-mail over a week ago and have not heard back from him. I've decided that at least as an interim solution, to upgrade my PS Elements to version 11 which includes RAW support for the RX100, and continue to use Qimage Pro just for printing. I had hoped to get down to using one software package like Qimage Ultimate, but that does not seem possible at least for now.

Off-topic: I emailed Mike a while ago too about providing a RAW image for the Fuji S9000 profile, but never heard back either.  Maybe he's on a well-earned vacation?

I wonder if Mike has taken on too much by not using the manufacturer supplied lens correction data in the RAW file, and attempting to develop custom lens corrections for each camera/lens combination on the market. As I read the RAW support list, there are only three Canon Powershot cameras, one Olympus lens, and 12 Panasonic cameras that have lens correction. There is a very long list of cameras supported with just dcraw, which provides no lens correction. But, even if your camera is on that list, it is not really supported if you need lens correction. On many cameras like the one I have it is essential. It is part of the way the camera was designed to work. Without it you have a grossly distorted image.

You are implying that anyone can just "use" the "data" in the raw file to do the correction.  Such is not the case because there is no standard for that data, which is why DCRAW does not offer lens distortion correction.  Each manufacturer does their own thing WRT lens distortion data in raw files so I'm left with doing it myself for each camera and each lens.  I can do it better than the manufacturer (because I'm not limited to "simple" correction algorithms), but I need sample photos that contain straight lines (like shower or floor tiles) that show all the way to the edge of the frame at a minimum of about 8 focal lengths for that lens throughout it's range.  That's what has to be done until/if DCRAW starts supporting lens distortion corrections.

I'm sure I could reverse engineer it for each manufacturer if I had enough time... or maybe buy a few programmers from each manufacturer to do it for me, but then I'd probably have to do something stupid like RENT you the software for $30/mo.  ;)

Mike

I wish!  I don't take vacations.  I searched back through the past 18 months and I have not a single incoming mail from you at the MSU email address where you are registered.  Not even in my spam folder (which I never delete: just archive).  So try emailing again and I'll reply with the instructions on how to take the raw shot.

Regards,
Mike

I sent you an email last Saturday regarding images for the S9000 camera profile but haven't heard back yet.

Mike, I upgraded my Qimage Pro to Qimage Ultimate, and I finally got around to taking the RAW shots with the Sony RX100 needed for the geometric distortion correction. They are currently sending by WeTransfer. 230 MB or so, and it is taking a while with my upload transfer limit, but I presume it will get there. I believe these corrections will be suitable for the Sony RX100II camera as well. It uses the same size sensor and same lens.

Ron