I've been doing some testing and am confused, hopefully someone can explain this to me.
I noticed when using a GG looking through the back of a 35mm film camera, at any given f/stop it has much less of a hot spot and is overall much brighter and covers edge to edge of frame than when I look at my medium density GG through my 4x5 Graflex.
Having the same f/stop means the same amount of light relative to the size of the image plane should be let in. I understand the inverse square law of light and the fact that the 4x5 is further away from the GG, but f/stop should account for this. If I stop down to a f/8 on my 35mm camera without the GG the aperture is small and yet when I place a GG over where the film will be the image still covers the GG edge to edge and is fairly brighter than when looking through the same GG on my 4x5 at that f/stop--and in this case the hot spot is severe and vignetting makes it very hard to see the edges when looking straight on.
The only thing I'm not accounting for that I can think of is grain size. With the same GG in 35mm the grains will be relatively bigger. But I would assume the fact it's brighter is opposite that of what I would expect.
I'm trying to find a way to capture images digitally from the back of my 4x5 without the hot spot. I can easily do this with a 35mm camera because the image on the GG is very good, of course I don't want to do that. I'm trying to figure out why I can't do it with a 4x5 camera.
Is it lens design? If so why? (Since both end images look correct at the film plane -- once you develop the negative). Hope this makes sense. thanks!
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