Ok, this is weird.
I'm working on the latest DF version on a site recently updated to 6.2.6 (was 6.1.3).
I have two forms, both with image fields. On 6.1.3 they were both working well. I have disabled save to database on both, and fields would pass data to an event calling a stored procedure and writing to custom tables.
After the DNN upgrade to 6.2.6, the image field on ONLY one of those two forms doesn't seem to retain any value - checked it in debug mode and it wouldn't pass the value to the SP call at all, it just gave an empty value.
I checked configuration of both forms, and it was identical regarding general settings, initial javascripts, and settings of the field itself. I happened to read that sometimes modules can interfere with DF so i checked and the only difference was an Open Web Studio module sitting below the problematic form. I deleted it, retried and still nothing.
I'm out of ideas - how can an image field not pass its value to an event, while there's a similar image field on another form with identical settings, which does? I'm missing something here but I'm not sure what. Any ideas?