2019-10-24 update note: diglloydTools has been 64-bit for years, and runs on macOS through macOS Mojave. Not yet tested on the not-recommended macOS Catalina, and the notarization requirement is a weeklong headache to solve. As well, Apple may have removed crucial APIs. All IntegrityChecker users should migrate to the cross-platform java version.
Pete O writes:
Quick question regarding the purchase tiers for Diglloyd Tools.
I recently encountered a couple corrupt files following a big import. Fortunately they were identified in Capture One, but I'd like to have more confidence in these transfers in the future.
It looks like Integrity Checker is just what I need, but I'm trying to decide which tier to purchase (i.e., 1 month, 1 year, etc.). Do the the different tiers just ensure I can upgrade to the latest version during the period purchased? Just want to confirm I'm interpreting this correctly.
MPG: corrupt files can occur at any stage (bit flips in the originals, bad copies, etc) but the key thing is once downloaded from the camera, using IntegrityChecker can flag any changes on any drive, any time, original or backups. The only prerequisite is to do an 'update' on any new or changed files once.
The hashes live in the folder with the files and thus can be checked any time on any drive. For example, checking a 23rd-generation copy of the original proves that all prior 22 copies were identical to the original (when copied).
As a pro photographer myself, I strongly recommend NOT converting to DNG format as the files get changed by Photoshop during editing for simple changes like exposure or white balance. In other words, Photoshop changes the DNG for simple metadata, which properly belongs in an XMP sidecar file. Other raw file formats do not suffer from this headache. Changing the DNG causes hugely increased backup times, and no ability to discern unwanted changes from those caused by editing. The workaround is to lock DNG files, forcing Photoshop to use XMP sidecar files. I have reported this workflow absurdity to Adobe and I hope to see a change made, at least an option to never modify DNG files, using XMP sidecar files always, just as with all other raw file types.
Purchase options for diglloydTools
The diglloydTools "tiers" are just a download privilege period—you can use the downloaded version forever once downloaded.
However, as a serious tool for long-term data integrity checking, most professionals purchase the 5 year option so they can download for five years including any updates any time, since they rely on it as part of workflow. Teams must purchase more than one license, but individual users may use it on all of their own machines.