Hello Nick, Thursday, April 1, 2004, 9:14:18 AM, you wrote:
> Hi List, > Last year I was comparing the grain at high ISOs on a couple of DSLRs ( > whilst we waited for some wildlife, in a forest). > In an idle moment at the weekend, I tried the same experiments, but > figured that the way to do it would be to use a lens cap and compare > pure noise from different cameras. The results are quite interesting, > but of course hard to quantify. I confess that I do not know in detail how a digital camera works, so please forgive my possible dumbness, but..... Is what you're doing Nick, not the same as simply turning up an audio amplifier until you hear the hiss? There is always noise associated with all linear amplifiers, for a number of reasons. What is important in audio amplfiers is whether the noise floor is 100 dB or 40 dB below the full output level. What I am saying is that in the digital camera noise measurements are only of value when measured against the presence of some sort of signal, e.g. light. Just a thought. Don Lodge Bejazzled, York =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
