Just don't ever debunk the Brown Lady of Raynham Hall. I think that one is so interesting so I probably won't listen.
Seriously, much can be explained but in many cases those explanations are thrown up as just possibilities. It's much harder to prove that any of these photos are real than to explain what they might be. I'm not saying that debunking isn't important but I still believe that some that are debunked are possibly real.
While that is true, I am of the frame of mind that debunking is step number one. The reason being is because when you finally come up with something that can not be debunked, then you might actually have found something.
So we debunk, and we debunk, and we debunk... so that when something comes around that leaves us scratching our heads, it's a big deal. It's like the scientific method... minimize the variables so that the outcome is based off of what is being tested. If other things can cause the outcome, then your data hasn't been collected well and your experiment wasn't set up right.
At this point, we can not prove that ghosts exist for sure. Like you said, it is much harder to prove the pics are real then to explain what they might be, However, if the "evidence" CAN be explained is it really evidence?
And some of it isn't really just to explain things for the heck of it. A lot of the debunking is based on historical or scientific knowledge. Lord Combermere is actually a pretty well known example of the concept of "ghost photography" which was extremely popular and historically documented. The idea of matrixing is scientifically proven, that the mind will create images of things that are not there by using light and shadow or differences in color or random shapes. When looking at these photographs it is actually pretty easy to see exactly how this is happening and when we debunk photos of matrixing, we point out exactly what is causing an image.
In case anyone cares, here are some things I look for:
1) EXIF data (if the photo is digital). This will give me information like exposure, if the flash fired, what type of camera it was, or if the image has been manipulated in some way.
2) Does the photo make sense? Why was this picture taken of some random field of nothingness in the middle of the night?
3) Comparison photos and information. Is there anything in the area that could possibly be an explanation?
4) Were there other people there? Can you account 100% for all of them? Was it a private tour or investigation or was the place open to the public?
5) Is the photo of something reflective? These sorts of photos can cause all sorts of issues because reflections in glass or a mirror can easily lead to matrixing.
6) The quality of the photo. Can anything really be made out or is it too grainy/pixilated/dark/ect? Really, this should be number 1, but I am too lazy to change my numbering atm.
I can honestly say I have seen less "possible" photos then I have fingers on my hands.