I dont normally like to cross thread but i thought this one was worth a look at.
Personally, i cant think of anything simpler than taking a quick couple of snaps during projections. The only reply on the other channel was something like, "With digital photos as screenshots you can alter the colours a lot before posting", i cant see anyone bothering to doctor screenshots just to list a film, especially when its fading or scratched.
I'm sure most of us can spot a poor listing, they either have no images as at all, they may show a bit of film with a bit of light shinning through, or just as bad as no screenshots is those who copy perfect stills from the web and use them as images from the film, only an idiot would even bother looking at those listings UNLESS, the film is listed at a ridiculously low price and you happen to be one of the few bidders and get it for next to nothing, sometimes thats worth a gamble.
I think we can all safely say that large amounts of decent feedback tends to be a sign of a good seller.
Straightforward images taken direct during projection through the film are the easiest and best way.
Anyone in this hobby who has an ounce of a clue will know that the images are always no more than a guide, the projected image will always be better. For those collectors who purchase from ebay, surly by now they can spot a genuine screenshot and those who have used a filter to make the pictures look better?