Red Wavelength Choice

Ok guys, working on my projector build & currently sorting the red.

Which do you think would be better? Beam visibility is important more than graphics.

Straight 2.8W of 660 ( prob 2.4W after optics )
Straight 1.6W of 637 ( approx 1.4W )
Mix 2.2W of 660 & 637?

Some other mix....???? include 642???? I have 8 diodes to play with.

Cost is a factor so is it worth starting with 660 & upgrading as funds & experience allow or is it pointless? Would it be a good idea to get all working / built on 660 then upgrade?

Thanks

im sure lots of people will now post 660 is crap bla bla bla... heard it so many times.

but very cheaper, just as good beam as 640 and 637, but yes its a little darker than 640 and 637.


a few watts of 660 for low £££ or ££££ for 640 or 637

I love 660 for the deep red and larger color gambit; if you can build a 660 rig with enough power to match you other colors, I say go with 660.

I think the question is beams or graphics?

2.4W of 660 is going to be significantly dimmer than 1.6W of 637

I would go for a mix. That way you save money and still have allot of red. Also because of the broadband red you get beautiful colours;)

yes multiple lines is always nice :D

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Originally Posted by flecom

I think the question is beams or graphics?

2.4W of 660 is going to be significantly dimmer than 1.6W of 637

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indeed it would but 660 would cost you £££ where as 673 will cost you ££££

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Originally Posted by andy_con

indeed it would buy 660 would cost you £££ where as 673 will cost you ££££

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lol indeed, what a great summary of the whole dilemma... *retardo

you have do decide how many dollar (pound?) signs its worth to you! :D

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Originally Posted by flecom

lol indeed, what a great summary of the whole dilemma... *retardo

you have do decide how many dollar (pound?) signs its worth to you! :D

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indeed and until the price of a 640 or 637 diode comes down im sticking with 660 as i can get just as good a beam

My 2c...

It all depends on the size of your blue and green really, and of course how large a space you're intending to light.

I have a small projector with around 300mW of 660nm which is fine for a smallish room, pub etc. I have to pull the 150mW green and blue down to about 100mW each to get a good white balance.

I have a larger projector with 1W of 635nm and about 500mW of green and blue each and I have a little too much red without pulling that back to about 750 - 800 mW. But that's too big to use in a pub (without beam attenuation maps etc) and needs a larger club sized room.

If you're keen on beams and not graphics like me, there's no point in spanking up the power only to have to cut it back because the thing is just too damn retina burning bright! So think about where it will be used, choose your green and blue sizes accordingly and then x1 to 1.5 for 637 to 640nm or x3 for 660nm (or somewhere in between with a mix).

^^^ I agree with this.

How about telling us what power your other components are, and we might be able to advise. I've got a watt of 637 Kvant arriving soon to go in a 3.5W RGB projector (1W 532, 1.5W 445), so i may be able to give you some real world comparisons if yours is a similar sized build.

I agree also. Remember the less watts you run the safer it is, so more brightness for less watts = easier to keep within safe limits.

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Originally Posted by norty303

^^^ I agree with this.

How about telling us what power your other components are, and we might be able to advise. I've got a watt of 637 Kvant arriving soon to go in a 3.5W RGB projector (1W 532, 1.5W 445), so i may be able to give you some real world comparisons if yours is a similar sized build.

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yes I am eagerly awaiting seeing that come together and your thoughts on it...

I have a 2x 1W 650's and 1.2W 642nm KVant in my projector and I still feel it isnt enough O_o

Thanks guys for all your input so far, it helps.

Use is for beams rather than graphics & will be used in large club type events.

Other lasers confirmed so far are 2W 532 & 3.6W 445

with those kind of power levels you definitely need to be looking at 635/637

you would need a stupid amount of 660 to match your blue and green

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Originally Posted by flecom

with those kind of power levels you definitely need to be looking at 635/637

you would need a stupid amount of 660 to match your blue and green

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I agree; I was guessing you were going to use a watt or so of blue and green. I'd say you'll want 5 or 6 watts of 660 to go with 2 watts of green... Maybe more.

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Originally Posted by dilbert;

Other lasers confirmed so far are 2W 532 & 3.6W 445

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To me that means you have at least 1W too much blue or at least 1W less green than you need for balanced colour (before factoring in the red).

This is all good when going for full power beams of one colour or another but does mean you'd be significantly under powering the blue in balanced colour mode. This may affect your colour palette depth.

I agree with Tagalucci, it seems very blue heavy.

Running it through Chroma, at those wavelengths, you could achieve parity with the powers really and still should have a good white balance (albeit warm white balance).

ie. 2W 532, 2W 445, 2W 637

http://img688.imageshack.us/img688/7700/powerq.jpg

If you want it a little cooler, then you could actually add a little more green.

A better balance is achieved with 2.5W 532, 2W 445, 2W 637nm. I believe the balance point here is approaching that of Steve Milani's projector which has a very nice cool white (his plot from memory was slightly more on the edge of the white triangle ie to the left):

Here's the plot with 2W 445, 2w 637 and 2.5 W 532:

http://img90.imageshack.us/img90/7551/power2.jpg


You could even go 3W 532 as it just shifts the balance point upwards and to the left edge of the white triangle for a cool white:
http://img710.imageshack.us/img710/883/power3w.jpg


You have room in this last plot to increase blue once more if you wanted more blue as an individual colour. With green at 3W, 3.5W 445 would still work albeit the balance shifts below the centre point towards the blue spectrum. Nothing seen outside of Kvant style balance here though so should work.

Don't make the mistake looking at Chroma that most of us made early on by thinking that for perfect white it needs to be dead centre. From Steve Milani's results, the White balance area actually appears to be the feint white triangle in the centre which encompasses quite a large area so gives a very wide scope for many balance combinations based upon personal colour temp preferences for white.

Also remember, Chroma is predicting white. If you feel you need more strength in particular colour then you may of course want to forego your perfect white in pursuit of higher powers in one particular colour.

660nm BTW isn't the best choice. It's surprisingly dimmer than 642. 637 should give significant brightness gains.

Please not these are predictions only and no substitute for an on the ground test. Maybe you could hire a laser from Kvant that's over these powers, then turn down the colours in the software to suit until you have your perfect solution.

BTW according to Chroma on luminosity, just 850mw of 637 is the same brightness as 2.8W 660!!!

So that makes 637 around 3 times brighter.

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Originally Posted by White-Light

BTW according to Chroma on luminosity, just 850mw of 637 is the same brightness as 2.8W 660!!!

So that makes 637 around 3 times brighter.

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and 3 times the price, oh to be rich and could afford all these fancy modules.

why does the forum insist on only recommending 637 these days? if its not 637 yoour doing it wrong and the forum doesnt approve.

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Originally Posted by andy_con

and 3 times the price, oh to be rich and could afford all these fancy modules.

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I hear ya! However I think it's interesting that when you factor in the luminance vs cost, the difference narrows quite a bit.

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Originally Posted by andy_con

why does the forum insist on only recommending 637 these days? if its not 637 yoour doing it wrong and the forum doesnt approve.

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I like 660nm (especially with the 445nm blue for awesome deep violets and purples)

Thing is, if you wanted to get enough red to match about 2W of blue and 2W of green, you'd need around 6W of 660nm. So that's 24 x 660nm diodes, assuming you run them at 250mW. In fact you'd need to run them hotter than that to get 6W after combining. Now a 24 banger is a serious engineering feat, and I take my hat off to you Andy for your amazing effort in doing this.

You can get 2W of 637nm or 640nm which should match the 2W of blue and 2W of green in 12 diodes. Yes, more expensive diodes, but less diode mounts, lenses, flex mounts, mirrors, TECs, Lasorbs, drivers etc...

100% agree with you, but the original post says cheap, or there abouts.

so if someone is interested in cheap why we are recommending very expensive.

we would all like perfect projectors, with perfect colours and perfect scanners but thats not the real world. so why arent we saying this is the perfect module for you but if you are after cheap try this

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Originally Posted by White-Light

BTW according to Chroma...

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http://danielbriggs.co.uk/laser/images/chromatronic.png
*retardo

well, something does not add up here... 2w of 532 + 3.6w of 445 and a cheap red with up to 8 diodes, is simply not going to happen.

- v1: forget the 8 diodes and go to a design with 16 diodes (or dual 8 bangers) were 14 is 660 2 is 637 (or 12 + 4 if you can afford it). still, i think that the red will be underpowered though...

- v2: forget cheap and go for 8 diodes 637

tough...

but what a beast this will be when finished!! easily into the 10w area :)

i bet you could count on one hand the number of people on this forum who own a 637 module, yet its the must have red module, as nothing else will do

Thanks for all your inputs, I've got my answer - I didnt say it 'had' to be cheap, was more interested in the results from mixing wavelengths & getting my head around the fact that 1.6W of 637 will be much more visible than multiple W of 660.

I've already got the design & build well underway on this projector so 8 red is the max - I've ordered a couple of the Opnext 637 to start. I will be building the module up with the cheap 660's though while I build & tinker to get it & drivers working etc - much rather kill one of these in testing so I will get a chance to compare.

It's a shame the better diodes do cost ££££, hopefully they will become cheaper in time or get used in some more mass produced consumer gear......

Anybody know of any developments on the horizon?

In my opinion, the 'best' is whatever achieves the required brightness with the required beam specs with the greatest simplicity (i.e. least chance of going wrong in the future/require constant fettling)

I think that 637/642 is the answer there.

I care not whether it makes 1W, 5W or 100W of power, what matters (to me) is the beam brightness, of course with the added advantage that lower powers overall are safer.

I really don't see the point in having a mixed diode head if you could have achieved the same brightness with less diodes, and hence less optics, less alignment, less correction optics, less cooling, etc Sometimes spending that little bit more brings a lot of benefits.

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Originally Posted by andy_con

i bet you could count on one hand the number of people on this forum who own a 637 module, yet its the must have red module, as nothing else will do

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Speaking for myself...

Having gone through the journey of discovery in all that is red when building my first RGB, 640nm was what everyone here was raving about. The logic was clear, nice tight bright red beams, more luminance than 660nm or 671nm. The cost for the power I required was more than I was willing to spend and I must say I'm still ok with my 635nm "torch" (even though there's a slight pink halo to my beams in that projector)!

I have since enjoyed building my own red from 660nm LOC diodes and observed the benefits of these diodes' beam specs. However, the lack of luminance mW for mW is painfully obvious.

Given this experience it seems more than reasonable to use something in the 635-640nm range (especially as I'd prefer to run my lasers at lower Watts with max luminance for audience scanning reasons).

635nm is a bit orange but not too orange. I'm not sure about 637nm. If I remember reading correctly, the new 637nm diodes can be run at higher currents than the 640nm diodes.

So unless my logic and research is flawed, why wouldn't my next 2W red be based on 637nm diodes and why wouldn't I promote this to others despite not yet having the moolah to actually own one!!!

I do get your point Andy, though I suspect the matter of ownership is just simply a matter of time before more of us get past our current projects and on to the next big red!

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Originally Posted by andy_con

100% agree with you, but the original post says cheap, or there abouts.

so if someone is interested in cheap why we are recommending very expensive.

we would all like perfect projectors, with perfect colours and perfect scanners but that's not the real world. so why arent we saying this is the perfect module for you but if you are after cheap try this

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Whereas I agree with what you're saying Andy, how do the economics work out?

If we're saying 2 Watts of 637nm is going to be the balance point for red, how much does more than 6W of 660nm cost - as that's the equivalent power vs luminosity point based on a figure of 3 times as bright.

Then there's also the safety implications of 6 watts of red.

I still haven't seen 637 so I'm taking Martin's word on it being as dark as 640. If not, there's very little brightness difference between 637 and 640 (approximately 15%) or 1/7th brighter according to Dan's favourite utility.

I think that's why people tend to use the brightest colours as a starting point unless like 445, there's such a price difference as to make the brighter colour unthinkable for most people's budgets.

well, 637 is unthinkable for me at the moment. all i can do is put all the spare change from my trousers to a little box.. and when this little box gets heavy enough, i'll buy myself a brand new shiny 637. there are stills lots of parts to be bought before i start to get picky about red wavelentghs

to me, if there is a dilemma between 637 and 640, i say go for the 637. case isolation just by itself is a winner.

if the dilemma is between 660 and 637, i say stick with the 660 and enjoy the deep purples etc.

the only cheap way out of this is get a 660 and extreme cool it to some "undiodly" level of the celcius scale to get closer to 645nm. but this carries its own world of different problems (heat dissipaton, condensation etc etc etc)

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Originally Posted by andy_con

100% agree with you, but the original post says cheap, or there abouts.

so if someone is interested in cheap why we are recommending very expensive.

we would all like perfect projectors, with perfect colours and perfect scanners but thats not the real world. so why arent we saying this is the perfect module for you but if you are after cheap try this

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thing is if you have 2W of green and 3+W of blue theres almost no reason to put in something like 1W of 660... (which would be "cheap", at least compared to the other lasers) its simply not going to suffice...

you want a red that can match those power levels? you got to pay to play, sorry *retardo

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Originally Posted by taggalucci

Speaking for myself...

Having gone through the journey of discovery in all that is red when building my first RGB, 640nm was what everyone here was raving about. The logic was clear, nice tight bright red beams, more luminance than 660nm or 671nm. The cost for the power I required was more than I was willing to spend and I must say I'm still ok with my 635nm "torch" (even though there's a slight pink halo to my beams in that projector)!

I have since enjoyed building my own red from 660nm LOC diodes and observed the benefits of these diodes' beam specs. However, the lack of luminance mW for mW is painfully obvious.

Given this experience it seems more than reasonable to use something in the 635-640nm range (especially as I'd prefer to run my lasers at lower Watts with max luminance for audience scanning reasons).

635nm is a bit orange but not too orange. I'm not sure about 637nm. If I remember reading correctly, the new 637nm diodes can be run at higher currents than the 640nm diodes.

So unless my logic and research is flawed, why wouldn't my next 2W red be based on 637nm diodes and why wouldn't I promote this to others despite not yet having the moolah to actually own one!!!

I do get your point Andy, though I suspect the matter of ownership is just simply a matter of time before more of us get past our current projects and on to the next big red!

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theres nothing wrong with 635 besides the giant beams, but its also very expensive... for the price of a higher power 635 you might as well buy a 637/642

Andy, yer just going to have to infrindge on a patent or two and start mass building that 24 banger. >:)

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Originally Posted by dilbert

Thanks for all your inputs, I've got my answer - I didnt say it 'had' to be cheap, was more interested in the results from mixing wavelengths & getting my head around the fact that 1.6W of 637 will be much more visible than multiple W of 660.

I've already got the design & build well underway on this projector so 8 red is the max - I've ordered a couple of the Opnext 637 to start. I will be building the module up with the cheap 660's though while I build & tinker to get it & drivers working etc - much rather kill one of these in testing so I will get a chance to compare.

It's a shame the better diodes do cost ££££, hopefully they will become cheaper in time or get used in some more mass produced consumer gear......

Anybody know of any developments on the horizon?

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sorry i took "Cost is a factor so is it worth starting with 660 & upgrading as funds & experience allow or is it pointless?" as meaning cheap, my bad.

637 it is then

No worries - could have probably phrased it better. I meant cost is obviously a factor but now looking at all the other factors such as visibility, safety, heat, complexity, alignment, cost of extra optics / hardware, size, ability to use my own custom series driver as diodes isolated, match to my other kit I have already etc its no longer such a clear cut issue as I first thought.

Very useful thread for me.:D

For me, even cost-wise... I went 660 for a while and I was constantly dissapointed in the lack of brightness. I now have a 642 and I wish I would not have wasted my money on a 660. So, in essence, it would have been cheaper to go with 642 outright. I would have just had to save for an extra month.