Colour Channels corrupted?

[AlanH]

It appears that Exiftool "may" be corrupting the blue and green channels of photos.

Points leading to this observation:
> started copying slide collection using a digital camera (Panasonic GM1 with legacy Minolta lense);
> other apps (Daminion, Fast Raw Viewer [FRV]), ON1 Raw 2017) can be use to change metadata except for camera make & model and lense model/type;
> thought of using Exiftool (only way?) to change camera & lens metadata and FRV to verify that changes display correctly in an actual application;
>using   -make="Minolta" listed a warning (Warning: [minor] Maker notes could not be parsed ) and erased all MakerNote tags;
> using  -make="_Minolta" appeared to work, BUT...;
> FRV displayed 'Camera: _Minolta' but nothing for 'Lens:';
> sent file copies to FRV developer thinking metadata was not displaying correctly and was told that the metadata was not the biggest problem: rather the blue and green channels had been corrupted/damaged on the raw files processed with Exiftool ;
> looking at FRV more closely, it was displaying only the internal JPG in place of the raw file;
> opening these files in ON1 Raw 2017 displayed the camera and lens metadata, the JPGs, but the raw files were only in shades of red and their histograms showed only the red channel (and a very tiny bit of blue and green);
> a fair bit of experimenting, and leaving camera make out of the processing, resulted in metadata (lens and camera model), JPGs and raw displaying correctly (on the 6 files tested).
> but... raw files opened with noticeably muted colours compared to original raw files.

>possibly this is because of my inexperience as new exiftool user - please let me know

>this command created the makernote warning, displayed the camera & lense metadata "correctly", but damaged the green & blue channels:
exiftool -P -overwrite_original_in_place -r -ext jpg -ext rw2 -lensmodel="MD 50mm/f1.4"  -model="XD-11" -make="Minolta"

> this command wrote the camera & lense metadata "correctly" but apparently damaged the green & blue channels:
exiftool -P -overwrite_original_in_place -r -ext jpg -ext rw2 -lensmodel="MD 50mm/f1.4"  -model="XD-11" -make="_Minolta"

> this command appears to have worked (except for muted colours in raw files & camera make unchanged, remaining "stylistically" incorrect):
exiftool -P -overwrite_original_in_place -r -ext jpg -ext rw2 -lensmodel="MD 50mm/f1.4" -model="XD-11"

Questions:
1) am I formatting the commands correctly?
2) why does  -make="Minolta" issue a warning and erase all MakerNote tags?
3) why does changing camera make from it's original value (Panasonic) to anything at all damage (in my case) the blue and green channels?
4) perhaps related to 3, are camera make & model, and lens model/type, used by raw processors to render a preliminary raw image?
5) before proceeding with a collection of thousands of slides/photos are there any other issues/cautions I should be aware of?

Thanks in advance for looking at this post. Your comments, suggestions would be greatly appreciated. I can provide a Google Drive link to a folder containing an original JPG and raw file and the outputs from the three commands listed above if interested.

Alan

[StarGeek]

See FAQ #8.