Thank you guys! First of all thanks for the link, AS that is really helpful! The only problem would be some of my shots were done a while ago on film so I don't have the specs, the other problem would be if I am combining it with lets say a stock photo of a place I have not visited. I am worried a bit to use the transform tool or other perpective adjusting tool because of the degradation of pixels. So distorting the 2d images would have to be done very carefully. I was thing if I am using on of my photos as a plate it would be eaiser to manipulate the 3d render based on that photo. If I had a photo of the Amazon jungle and I want to insert the sci-fi building it would be easier to mamipulate that 3d building that the plate of the Amazon jungle. If the photo is stock or film then I would not have the specs of the lens etc.