520nm temperature effects & visibility & prices

[Lasermad]

i live in a damn COLD country :-)

following a comment in another thread can any confirm any real world
effets the cold has on 520nm v 532nm

I find 532nm definately fades markedly at below 5 degrees , a cold wind and
get below 5 towards 0 and i find its a struggle to keep units warm
to maintain brightness

Somene mentined this is not the case with 520nm ?

also 532nm is often described as "at the peak" of humans eyes perception , is there
a marked difference in visability at 520nm , any good photos going about
showing a colour difference

Basically im wondering if its worth changing to 520nm , also prices seem to
be pretty good , any thoughts

[stanwax]

Paul
520 wont fade like 532 as in 532 the issue is that the component parts of the system are temperature critical and in the cold may suffer from taking a longer than normal time to achieve the optimum temp.
520nm however is a diode, this will have a TEC (as per 532) but here its just used to remove the heat and the diode itself will heat up quite a lot as soon as its run. A 1W diode will need about 5V at about 1.6A (give or take) this equates to 8W of energy. Obvioulsy only 1W of this is light so the rest is heat, and though a 7W dont sound like a lot, when you are a little tiny laser diode that is a lot and so it will get toasty very quickly.
So though the visibility will be down on 532nm a 520nm will be more much more stable over temperature ranges.
555nm is the human peak of sensitivity and 532nm is close enough to be brightly seen, 520nm is just slightly less so. I do have a chart somewhere that I havent dug out since i moved that had all the figures on for vis wavelengths but Im sure you can google for it.
And I have 520nm in stock if you are interested - prices very comparable to similar 532
Rob

[edison]

Basically im wondering if its worth changing to 520nm , also prices seem to
be pretty good , any thoughts

Its worth changing but its still a compromise. The real nice yellow that you get with 532nm is missing when going 520nm. Comparing 520nm versus 532nm is like comparing apples and peaches. 520nm is a different wavelength, has on average twice the divergence of a good dpss (depending on wich brand of 520nm is being compared) and doesn,t have a round beamprofile. Bennefits are there also, perfect linear modulation (if a good driver is being used) , and also much faster in modulation.

When 520nm is being compared to 520nm and all the parameters are the same like divergence , beamsize at aperture , modulation speed etc then yes 520nm is a good choice. But the price of a 520nm with the same beamspecs that you can have with 532nm is allot higher. If your into graphics then low divergence is needed but otherwise you can go with something in the 1.3-1.6mrd range. That leaves 3 choices, laserwave, kvant or eightonlight.

[dave]

Hmm, only a little less yellow, but on the flip side the greens and blues are amazing with 520

[bridge]

I totally agree, 520nm is your best choose.
for 532nm, if you buy 10pcs RGB, you will got 10pcs different color balance, for 520nm, you buy 10pcs, you will got the same RGB
consider brightness, only compare 532 and 520nm, maybe different, but if you combine same power 520 and 532nm with same power red and blue, you even look RGB with 520nm is more brightness than with 532nm RGB.
Best regards!
Bridge