Hi @slim,
In ODK Collect each form is independent from the others, so I don't think it would be possible to
while automatically increase the ID.
A possible solution would be to group photo sessions in a single form (1 or more photos), and use the repeat function to loop.
The functioning would be pretty similar to what you described; the photographer would:
i) launch the form for the session;
ii) enter the ID of the first photo
iii) a counter keeps track of the number of loops being added - e.g. calculate==(position (..))
iv) assuming the ID is alphanumeric, but the last digits are numbers, you could use substr() to get the numeric part and then add increase by 1 at each loop
v) the form would then recompose the ID using the appropriate calculate function.
Each form/submission would contain several records, one per repeat loop.
In case of dud shots, a new form should be used. It could be possible to include options to "skip" one or more numbers but they might be a bit convoluted.
This I think would be the simplest approach.
Alternatively you could look into ODK-X.
Btw, I assume that these photos are being taken with an external camera, and not with the phone in-built one. If this is case, I am wondering whether using an external application (e.g. ODK) would be more time consuming than just arranging and tagging the photos from a computer using dedicated software. If what you are interested was just the list of the photos saved in a folder (e.g. SD card), copying and pasting in a text/excel file should do the trick.
I hope this helps.
Best,
Andrea