Digital BW, The Print

I can't speak for hi output very broad spectrum led lighting but I can
say a bit for generic LEDs.
I have an ongoing project of a diy XYspectro utilizing LEDs(silly I
know but interesting and educational). In any event, in the course of
designing this, I've had reason to measure and evaluate a fair number
of off the shelf LEDs. In general I found that it would be very
difficult to come up with a set that could be reasonably considered to
approximate any normal lighting's full spectral curve. I was able to
construct full spectrum coverage(roughly 340-750nm) but it has a lot
of spikes in output. That isn't a major issue for my use as it can be
accounted for in calculations but I suspect(as you have mentioned
Ernst) that it would be very expensive to individually control gangs
of relatively narrow peak LEDs in a manner that emulates something
like a continuous spectrum incandescent for large scale viewing
purposes. It took 13 LED bands for me to be comfortable with what I
considered adequate output for reasonable precision of results. 

Regards,
Duane





--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Ernst Dinkla
<edinkla@...> wrote:
>
> pr_roark wrote:

> > I think the LEDs are clearly the future, but I'm not sure what the 
> > light quality (CRI) is or whether there are appropriate sizes/lumens 
> > for our replacement project.  Actually, there is a program in 
> > California that is going to end up giving our gallery free lights.  
> > So we have to pick from what they have, which seems to be simply a 
> > selection of CF floods and 'spots' (more like floods than a halogen 
> > spot).
> > 
> > I, too, would like to hear if anyone has experience with the LEDs.
> > 
> > Paul
> > www.PaulRoark.com 
> > 
> > 
> 
> Paul,
> 
> Video and camcorder users need small floods and spots with 
> continuous output. It looks like they embrace LED lighting 
> faster, armatures that have all LED types included like Red, 
> Green, Blue, Amber, White, etc to get more full spectrum. I 
> have not seen a spectral curve yet nor a decent CRI quote 
> for them. I suspect still an (expensive) compromise on color 
> quality.
> 
> http://www.s131567196.onlinehome.us/
> 
> http://www.elementlabs.com/KelvinTILE.html
> 
> -- 
> Met vriendelijke groeten, Ernst
> 
> 
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