400mW 640nm vs 1.1 watt 650nm - Pics and videos! ;)

[-bart-]

@Stoney

If you call 488nm blue, you'd probably call 612nm red...

[buffo]

100mW+ argon heads are becoming cheaper since everyone wants a DPSS, guess what I'm going to use for my blue.

By the time you factor in the cost of an AOM to modulate your argon, plus the power loss across the crystal, and the extra electricity (and cooling) you'll need, the DPSS blue solution doesn't seem quite so expensive.

True, for power levels above 200 mw, Argon is definitely cheaper even with all the added costs above, but I think for anything below 150 mw, you're really better off with a DPSS blue. The added complexity of an air-cooled argon isn't worth it at low power levels, in my opinion.

Adam

[flecom]

Hm, I think part of the problem is the non-linear nature of our perception. It requires something like a 4-fold increase in power to appear twice as bright. 2x the power level will not appear twice as bright.

huh? I was talking about lumens not mW...

"The lumen (symbol: lm) is the SI unit of luminous flux, a measure of the power of light perceived by the human eye."

[Xytrell]

But the lumen to power ratio is linear. green light is ~600lm/W, so 2W of green is ~1200lm, 3W of green is ~1800lm etc.

1600 lumens do not appear twice as bright as 800 lm, but perhaps closer to 1.5 times.

[flecom]

But the lumen to power ratio is linear. green light is ~600lm/W, so 2W of green is ~1200lm, 3W of green is ~1800lm etc.

1600 lumens do not appear twice as bright as 800 lm, but perhaps closer to 1.5 times.

so then what would you suggest we measure perceived brightness in?

[Xytrell]

Good question. Is there a scale analogous to the sound decibel? Maybe we can have light decibels with base 2 instead of 10

[flecom]

take your pick

Quantity		Symbol	SI unit			Abbr.	Notes
Luminous energy		Qv	lumen second		lm·s	units are sometimes called talbots
Luminous flux		F	lumen (= cd·sr)		lm	also called luminous power
Luminous intensity	Iv	candela (= lm/sr)	cd	an SI base unit
Luminance		Lv	candela per square m	cd/m2	units are sometimes called "nits"
Illuminance		Ev	lux (= lm/m2)		lx	Used for light incident on a surface
Luminous emittance	Mv	lux (= lm/m2)		lx	Used for light emitted from a surface
Luminous efficacy	 	lumen per watt		lm/W	ratio of luminous flux to radiant flux

[whitephantom]

on the LEFT is 640, as it appears slightly more orange than the RIGHT