社長 寫:但為何用ISO3200?
Do u think my image is noisy? Not at all. That night is about 30 deg. Increase the ISO can shorten the exposure time and hence lesser the cumulated noise. This recalled a discussion 4 years ago in hkastroforum. Jerry Lodriguss said in his book, A Guide to Astrophotography with DSLR Cameras, that higher the ambient temp, the higher the ISO should be used.
http://www.hkastroforum.net/viewtopic.p ... so&start=0I guess Jerry Lodriguss wouldn't write his book without experimental fact. But whether people can find out explaination is another story. Fact is fact! Even no explaination provided, it is still a fact. In the link above, I tried to explain it in physics point of view, although people may not buy or understand. In fact only one guy with theoretical astrophysics background in the discussion agree with me. I tried it out and turn out that the image is ok.
發表於 : 2013-09-15, 11:01