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
> 

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