Some issues to keep in mind when attempting to authenticate by screen caps I have found to be:

1 Often things appear to be a different color on screen than in person. Especially true for wardrobe. Lighting or camera lens filters could often be a reason.

2 Often you can't see the item in question clearly enough up close in a screen cap to be certain what it really looks like.

3 Often stunt items and hero items are not just cast in different materials but have a different look with extra stuff visible on the hero item.

4 For items on ebay that end in three days or less its often hard to get access to a DVD in time to even get any screen captures.

5 Items from TV shows are very hard to figure out whcih episode they are from and often hard to get DVD/VCD or even VHS copies of.

6 Over time a prop can get damaged lose its coloration, physically be stripped and repainted or altered for another production in a way that makes it appear differently than it originally did on screen.


Anyone have any more issues to keep in mind. Or comments on these?

Are props often altered so theys can be used in other movies or Television shows? Is this a common problem?

Why woudl it be hard to get access to a DVD for screen caps?

Things are altered for use in other productions more often than you would think.
For example one of the rifles used in Star Trek Enteprise is basically a repainted Jem H'dar rifle from an earlier Trek production.
And often series of productions such as a tv show or movie series will attempt to reuse all of their props and costumes from before as possible by repainting, adding decoration or something else to spruce them up, make them less recognizeable and more able to use as new in a current production.

And by it might be hard to get access to a DVD in certain instances I meant if your local video store doesen't have it and you don't have it, and you don't know a friend that does it might be hard to order and get it in time to gather screencaps to compare to the item being sold. Plus it might be costly to do this for every item you were even slightly considering buying.

Now with a service like Netflix or some other DVD rental by mail service one might have an advantage in being able to capture screencaps in response to interesting items they see for sale.

Guess that makes sense about sometimes not being able to get screen cap pics in time. Thanks for explaining.

I agree with your assessment 100%. Even screen-caps can be deceiving. Certain items, I am highly confident that I have matched. Other items, it's just too difficult to tell.

-HorrorPropKing

Some items also can't be matched because they were in cut scenes.
All of the Charmed and Sabrina the Teenage Witch items which are available in seemingly endless quantity suffer from this problem if they are in fact even used by actors.

Great point!!

-HPK

Is it better to try to match up props via what one sees on a tv screen or to try to print out image captures and work with that? Any thoughts on this?