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View Full Version : Help, please!



royL
08-21-2003, 10:09 AM
I bought a CyberShot DSC-P52 camera and I need to know its camera respose curve to make hdri in HDRShop.

Please if someone knows this info or know where do I can find it, please help me.

I've already tried to contact sony but they just told me the same description that appear in the camera manual and that they dont know the camera response curve.:confused:

meshmaster
08-21-2003, 10:27 AM
What is a camera response curve? Does it have to do with the iso to shutter speed? If so, and if you are using windows xp, and if the camera is a digital one, it may be like my olympus... so you should be able to right click on the jpg that comes straight from the camera, go into properties->advanced... that gets you iso, etc... take a look at a couple of the photos that I have at turbosquid for some of the info that it gets you - I copied that stuff in from that properties place. It's listed in the technical notes on the individual images on ts - follow the link in my sig.

kevman3d
08-21-2003, 09:09 PM
Originally posted by royL
I bought a CyberShot DSC-P52 camera and I need to know its camera respose curve to make hdri in HDRShop.

I don't think most digital cameras actually have a response curve? Here's a snippet I found on a photography discussion forum:

Film has a sigmoidal logarithmitic response to light, so that very fast exposures (1/10000th second, sometimes happens with flash) and very long exposures (30 sec+, typically) require an extra fraction of a stop of light. I've encountered both cases of reciprocity failure. The one at the fast end took me a while to figure out what was happening, though, because it's not as commonly encountered.

Digital does not suffer from reciprocity, because CCDs have a straight linear response to light. This also explains why if you apply a sigmoidal lookup curve to a RAW digital image it helps to make it look more like film.

Digital does have problems with noise, however. Canon digital cameras (G2, G3, EOS1ds) have noise filters that can help with long exposures. In other circumstances you can overcome noise through cooling the ccd, but that's not exactly practical for a point and shoot

Not sure if that helps? But it was interesting anyway!