No problem, Frantisek. I enjoy the debates and never take any of it personally. I don't know enough about the way white balance is controlled to answer intelligently. But my 200W bulbs are conventional tungsten floodlights, not photofloods. Other low-light tungsten efforts have pleased me. I can't be certain that they are optimum, but I don't see any excessive noise.
> pcn> *ist D, tungsten WB setting, ISO 800, f1.4 @ 1/45th: > pcn> http://www.photo.net/photodb/photo?photo_id=3145171&size=lg > > Oh I know, Paul, it almost looks like I am clashing into your opinions > ;-) > > Perhaps I wrote it confusingly. I was hinting at that the WB > feature of digital is not miraculous, like still many people think. It > just boosts the _digital_ gain of the B or R channels (AFAIK only D2X > does the boost of gain still before AD conversion, which might be > beneficial). Add to it that tungsten light (normal household bulbs of > 2700K, not your 200W floodlights <g>) are defficient in blue (just > look at their spectra), and I see that the blue pixels are quite > underexposed. Especially at higher ISOs where we are boosting the gain > even more just for the speed. The result? All these blotches of blue > channel noise all over the shadows and maybe even skintones. Yes I am > talking about iso 800-1600. > > The outcome? Simply that complete white balancing under defficient > light source has its drawbacks. > > But it was the same with C41 negatives. You could tell the lab to > balance it if it was shot under tungsten, but still, because of > defficient blue part of spectra, the blue sensitive layer would get > underexposed. And we would get more grain and sometimes strange > colours as the lab tweaked it. > > When I shoot under such lighting, either with film or digital, I > usually just let it be golden yellow, adjusting the WB only very > slightly. > > Whew, all this words to just tell that there is no free lunch! > > Now what ;-) > > Frantisek >