Hello Gary,
Opanda wasn't updated since months, and isn't very complete - I'm sure they doesn't decode the data themself - there are many sources in the web, with tag descriptions. There is no need (and it's not possible) that every software author decode all tags themself.
Big Red wrote that PhotoME is able to show the shutter count of the Pentax DSLRs.
This is possible since a few months. It wasn't possible before, because the shutter count of newer Pentax
models is encrypted too, and noone thought about an encryption before.
Using hundreds of sample images, I've figured out that the shutter count of the Pentax DSLRs is encrypted.
Thanks to the help of Phil Harvey (
ExifTool) it was possible to find the algorithm and to decode the shutter count. We've analysed the images, found that it use the date of the camera to encrypt the shutter count and Phil was able to find a formula to decode it.
Just because noone found it before, doesn't mean that it isn't there - maybe they just havn't looked close enough.
The Pentax shutter count is encrypted using the date and time. If you just search for values which increase by one for each photo, you have no luck - because as soon as the second of the time change, the encrypted value could look totally different.
Canon seems to use a similar system - they are mixing the shutter count with the date and time and most likely some other informations too. That's why it isn't easily possible to identify the value as counter.
What, from your point of view, might it take (apart from time) to accomplish this? some sample images from some of the cameras?
For the Pentax shutter count, a user has sent me 650 shots in a row - which helped to decode the value.
I already took 600 shots in a row with my A710IS, to see how the values change. I'm in contact with Phil Harvey, he has a PowerShot too and will also try to figure out how the encryption works.
I have the hope that Canon use the same algorithm for their DSLR
models, which they use for the PowerShot. In that case, it should be easily possible to decode the value for the DSLRs too.
Otherwise we'll need hundreds of samples too, depending on the complexity of the algorithm.
To check if the shutter count is there or not, I assume 30 or 50 images taken in a row should be enough - but even if you don't find anything by comparing 50 images you can't be sure that it isn't there, maybe the algorithm is just very complex.
After the shutter count of the PowerShots is decoded, I'll try find one for Canon DSLRs too.
Cu, Jens