Honestly, I think Crystal Skull's main problem is regardless of the quality of the movie, the franchise already ended.
The Last Crusade wrapped up the series perfectly (in my opinion) and even the title implied it should be the end ("The Last Crusade" referring to the most recent attempt to obtain the Holy Great and also Indy's final adventure). I know nothing happens which technically prevents another movie; but it bookends the series well by bringing back Sallah and Nazis from Raiders and it even literally ends with him riding off into the sunset.
It was written in such a way because Lucas and Spielberg didn't have anything left to say with the franchise or character, and there was no fruit left on the vine (so to speak).
A lot of the issues people have with Crystal Skull come from it trying to do something new with the character and setting since the story was already completed in the previous installment.
All this to say I don't think it was a bad movie necessarily, just one which struggles to validate its own existence.
I thought about that, but since this is for a photo wall type situation (where there are props and things and you take your picture), I want the photo taking to be as automated as possible since people would be using the timer feature a lot. I'd be concerned that the autofocus wouldn't be correct, or something else that causes the photo to come out poorly if a real camera was used (without a dedicated operator).
If it wasn't for that, a standalone camera would be suitable (depending on the price).