638nm vs 637nm (single mode vs multimode)

[catalanjo]

Be interesting to hear your findings.............................they both looked to be exactly the same brightness, despite being double the power and having exactly the same beam properties.

Now that I do find curious !
Any explanation ? ...

...

Cheers

[norty303]

I expect it's all down to perspective. Also the fact that doubling of power is nowhere near double the brightness

[Humphry]

Perspective counts for a lot. Just last weekend I thought I was going crazy when 1W 532nm dwarfed 5W 532nm at a show until I moved to a more central position. There is definitely a sweet spot on the power vs visibility curve.

I expect it's all down to perspective. Also the fact that doubling of power is nowhere near double the brightness

I hope she takes divergence into account. Size isn't everything, or so they say

You've obviously never been to bed with an English woman!

[drm916]

Be interesting to hear your findings.

I've got some projectors here using a single P73 doing ~700mW and some other projectors using dual cubed P73 for ~1400mW and yet on a job over the bank holiday weekend they both looked to be exactly the same brightness, despite being double the power and having exactly the same beam properties.

At what distance? I compared 700mw 637 red to 1350mw 637 red a few months ago and saw almost no difference. But that was at about 60ft. I am guessing at 150ft it would have probably been more obvious.

[drm916]

Yeah for that price one could buy 4+ watts 637nm single mode. The build quality does look exceptional however. Just to be clear, the motivation for this thread is about optimising performance vs price ratio of laser projectors.

I am going to have the opportunity to test 2.8W 638nm vs 1.5W 637nm in a few weeks and I will be sure to let you guys know.

You can get 4+ watts of 637 for 1500 bucks?

[norty303]

It was about 30-40m I think.
Agreed that range counts and the bigger lasers need some space to 'stretch their legs'.
It could be that once something is very bright to our eyes, their ability to distinguish extra brightness is diminished. They're saturated essentially. Once things start to appear a bit dimmer at further range, we are able to see the difference more readily. Or a bit of all of the factors mentioned.

I still say a 3-4W projector with a bit over 1W of green is an incredibly versatile projector and will do a number of different roles and room sizes.

[drm916]

I agree. my 3-4 watt projectors work in just about every room.

[norty303]

It was about 30-40m I think.
Agreed that range counts and the bigger lasers need some space to 'stretch their legs'.
It could be that once something is very bright to our eyes, their ability to distinguish extra brightness is diminished. They're saturated essentially. Once things start to appear a bit dinner at further range, we are able to see the difference more readily. Or a bit of all of those.

I still say a 3-4W projector with a bit over 1W of green is an incredibly versatile projector and will do a number of different roles and room sizes.

Check out this vid, particularly from about halfway through with the hot beams. 2 of those are just over 3W, 2 are over double that (although one 2W 532 crapped out and down to 400mW and is now back in China)

[norty303]

Oops weird double post. Too much to sort out on my phone now, will see about tidying tomorrow

P.S. Do you like the mirror balls on steroids my mate built? Lit by 8 or 10 Robe Pointes.

[Humphry]

No I wish. Atenlaser 3W multimode red costs 4300 bucks (it is spatially filtered which is a biggie for me!). Lightspace 5W 637nm costs 4000. http://atenlaser.com/shop/index.php?...oller=category

You can get 4+ watts of 637 for 1500 bucks?