DNG compatibility for ACR (A720 vs SX1) - page 2 - RAW Shooting and Processing - CHDK Forum

DNG compatibility for ACR (A720 vs SX1)

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Re: DNG compatibility for ACR (A720 vs SX1)
« Reply #10 on: 14 / July / 2009, 19:00:57 »
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Crop area (defined by appropriate tag) can't fit into active area (defined by other tag). Active area should be enlarged by one pixel in x and y direction

try this

exiftool -activearea="24 344 2760 3992"   <dng_filename>

In my case, it did the trick

Someone correct these values in the code please

BTW: isn't it better to use cr2 file right from the camera ? It's compressed and smaller than uncompressed dng

Do you use this version of exiftool?:
http://www.sno.phy.queensu.ca/~phil/exiftool/

The cr2 file from the camera isn't recognized by ACR directly, and the DNG files can be read directly
in ACR (at least the DNG files produced by CHDK on my canon powershot a720), so it would speed up my workflow.
Also, DNG is a kind of generic format and CR2 is proprietary.
The camera can take CR2 Raw pictures much faster than DNG though, so it's a trade off. For action photography, CR2 is probably the way to go and then they can be converted to DNG later on optionally.
« Last Edit: 14 / July / 2009, 19:02:28 by dohduhdah »

Re: DNG compatibility for ACR (A720 vs SX1)
« Reply #11 on: 14 / July / 2009, 21:24:10 »
Indeed, dng_validate reports about you file:
Code: [Select]
ActiveArea: T = 24 L = 344 B = 2759 R = 3991

Maybe active area is too small.

Here is dng file produced from SX1's CR2 by Abode DNG converter:

Code: [Select]
ActiveArea: T = 12 L = 192 B = 2772 R = 4152

Maybe CHDK setting (active area) must be corrected.

With hexedit, when I punch in those other numbers (*), the thumbnail shows up.
Mysteriously enough, it only seems to work for one of the two DNG files I'm experimenting with (both shot with the same PS SX1):
http://www.ibbu.nl/~nsprakel/CRW_0880.DNG
http://www.ibbu.nl/~nsprakel/CRW_0881.DNG

So it seems to work for CRW_0881.DNG, but not for CRW_0880.DNG (the thumbnail is not displayed properly).

(*): storing the following 14 bytes (in hexadecimal notation) at offset 45E to offset 46B:
0C 00 00 00 C0 00 00 00 D4 0A 00 00 38 10


Re: DNG compatibility for ACR (A720 vs SX1)
« Reply #12 on: 23 / July / 2009, 20:01:14 »
Oh, I've noticed that the latest update for ACR (5.4) resolves problems with the sx1 raw files.
Hope to experiment more in the future to make up my mind whether to use DNG or the native CR2 format.
« Last Edit: 27 / July / 2009, 16:09:15 by dohduhdah »

 

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