Found a post several weeks ago by Xiaofeng.
In dng4ps2
1.select a650 is
2.copy
3.In camera Properties set the BitsPerUnit=12
4. Rename Copy of a650is as A1100is (just cosmetic)
5. In camera menu select A1100
6. Select Hit convert.
Now dng4ps2 (the latest beta release) converts the PS2 files to .dng files.
I always save a 5 Mpixel jpg file (5Mp.jpg) with the raw file. But all is not well.
If
dng4ps2 can find the matching 5Mp.jpg file (i.e. they are both in the same directory),
and the user has selected to include a preview file,
then
dng4ps2 includes the 5Mp.jpg file in the dng file
When the .png file is opened in IrfanView, then only the 5Mp jpg file is displayed
end;
If
dng4ps2 can't find the matching 5Mp.jpg file (i.e. the user hides it in another directory),
and the user has not selected to include a preview file,
then
dng4ps2 creates a dng file
When the .png file is opened in IrfanView, then the displayed 12 Mp image is extremely color shifted
end;
If
dng4ps2 can't find the matching 5Mp.jpg file (i.e. the user hides it in another directory),
and the user has selected to include a preview file,
then
dng4ps2 stops with an error message and no .png file is created
end;
It looks like CHDK uses some parameters for the A1100 (other than the 12 bit change) which are not the same as the A650is. When dng4ps2 realizes this parameter error, and there was no request to create a preview file, then dng4ps2 does the best it can and creates a severely color shifted image.
This explains why in there is sometimes no difference between the 5Mp.jpg and the alleged raw conversion.
If your method works, please post the procedure.
If you have similar problems, please describe what you are doing, and maybe we can figure out what is going on.
hha