Quote:
Originally Posted by postcardcv
Well I ordered a screw in filter to have a go on the cheap, unfortunately the 30D clearly has a very strong internal IR filter - without the filter I was getting 1/400th at f8, with the filter on I needed to push the shutter speed out to a ridiculous 25 seconds to anything. Even then the files don't have that IR feel, I think with the long shutter speed I'm also getting some visable light contamination. I think I now have two choices, get the camera converted or forget about IR for now...
|
What filter did you get then Peter.
Looking back at the 30D test with a Hoya R72, that chap was getting 4 secs at f2.8 at ISO800. So say 16 secs at f5.6 ISO800 puts you in the same ballpark as my D2X with polariser. Stronger IR filters than the R72, example the B+W 093 that cuts at 800nm, would probably require far longer exposure times.
My tests show that the only possible source of IR contamination if you use a screw in IR filter, is stray light through the viewfinder. Eliminate that, and exposure duration is not a prob until sensor heat creates its own set of problems.
Don