Pentax custom settings in metadata?

[Beholder3]

Hi,
I wonder if you'd be willing to use your forensic skills on trying to identify if/where Pentax custom settings might be coded into the makernotes similarly to how you dug out the place where the teleconverter is documented.

One interesting custom setting would be the "auto focus hold" setting C-18 which has four possible values (off/short/medium/long).

I could provide a bunch of test files shot with all four settings.

[Phil Harvey]

I didn't do this for my K10D and K-5, so I'm not sure they are available, but I can give it a try.

Let's start with the AutoFocusHold setting.  Send me 8 samples (lens cap on, manual exposure, small JPEG) taken in this order and I'll see what I can find:  m,o,l,s,l,s,m,o (o=off, s=short, m=medium, l=long).

- Phil

[Beholder3]

Thanks. I just mailed you the requested 8 files.

[Phil Harvey]

OK, here is how to extract the AutoFocusHold information for the K-3 II:

exiftool -U -Pentax_AFInfo_0x01fd DIR

It could be that the other custom settings are located in and around this section of the metadata.  If you shoot some test images and systematically grep the above ExifTool -U -s output for tags around this, you may be able to decode the settings.  If you send me your discoveries I will add them to ExifTool.  You can report them in this format:

AFInfo_0x01fd: AutoFocusHold 0=Off, 1=Short, 2=Medium, 3=Long

Hopefully all of the settings are in independent bytes, but it could be that a single byte stores multiple settings.  I can deal with this too if it happens -- just report the byte values and I'll sort it out.

Of if you want, just send me the EXIF (exiftool -o %d%f.exif DIR) and a description of each file and I'll do the grepping.

Thanks.

- Phil

[Beholder3]

Great that you were able to identify the tag!

I actually don't really understand what you mean by this "grepping" thing. But I did shoot more sample shots for each of the remaining 25 custom settings of the Pentax K-3 II and mailed you the metadata extracts generated as you described.

Maybe you are able to identify more tags from them. 

I can provide more test data, but I fear I am unable to help with the actual tag identification. That is beyond my skills.

[Phil Harvey]

Thanks.  I'll analyze these as soon as I get a chance, and post back here if I need anything else.

- Phil

[Beholder3]

Did you have a first look by any chance?

[Phil Harvey]

Yes, but it wasn't as easy as I was hoping.  The rest of the settings are not stored in the same area of the metadata.  I haven't yet managed to locate where they are.

- Phil

[Phil Harvey]

I spent some time on this and it looks like the settings are embedded deep in a binary data block.  It will be difficult to decode, and the format of these blocks often changes with firmware version.  I plan to do more work on this when I can, and to compare with sample images from other K-3 II firmware versions, but this is more of a long term project for me I think.

- Phil