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Thread: Mixed single and multimode

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    Default Mixed single and multimode

    Ok so I have a question...

    I haven't seen the difference between multi mode and single mode diodes in a projector in person. I know single mode give you a much better beam spec but are also considerably lower power. Everyone says I should have one.

    I'm looking at the the Lightspace LS-RGB-700 which has the following: Red637nm 170mw, G520nm 120mw, B445nm 500mw, PT-30K

    Omar said the red and green are both single mode but, the blue is multimode. So... from an uneducated perspective, I'm wondering what that ultimately means in this projector. Am I going to have a nice fine tight white line with blue fringe around it every time I'm projecting a white cue? Is this a decent "bedroom programming unit" for (I think) $980?

    I'm going to tackle the kit from DTR at some point and I already bought the mounts but, the way my life goes, that might be a 2019 project. It's just easier and faster to buy something.

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    I say you take the kit from DTR as I'm planning to do!
    In my current projector I use a 445nm diode for blue, around, max 700mW powered by a flexmod p3. For green I have a nice small CNI unit installed, which has a very tight beam and tiny dot. the beam profile of the multimode blue diode is bad. i get a lot of scattering and unwanted reflections everywhere. that might be my not perfect alignment though. For indoor use, you do not want to exceed a total power of lets say, total 500 mW. my eyes start to hurt if I exceed 40% of the total power output my projector can deliver. Besides, the 500 mW in the projector you mentioned does not quite make sense for the blue, since the red is only 170mW. Or does the ratio differ if you are using a 520nm diode instead of a 532nm source ? I don't know. I only heard the best things about that DTR kit. that's gonna be my next project for 2015.

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    That unit is going to be red light and blue heavy, of course, Brad. The price is good and LS quality is good as well. 120mw of 520nm means a multimode though unless it is pair of the 50mw. That means the blue will be the largest followed by green and finally red, but my guess won't be that bad. I would ask LS for some pics and see if they will tune it for quality beams instead of max power.

    I just built 3 pjs with paired single mode reds and blues along with the 120mw green and was very happy with the results. That green corrects really well with a G2 lens to work great with single mode red and blues until at least 80 feet. The cost of materials alone on those builds with 506's in them was closer to double the cost of that LS unit albeit with better beam quality (I assume) and a significantly better white.

    Have you enquired about the shipping cost yet? That became the Achilles heel for Goldenstar IMO but hopefully LS still has those costs kept down.

    David
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    If it has the real 500mw 445 diode then the emitter is about half as wide as the ca$io I think. That might be acceptable mixed with SM R and G. If it the standard 1 watt 445 turned down with a 8mm lens you wont be happy.

    I have a complete SM projector with the DTR kit doing around 120R 70G and 180B (I think) Its tiny. I can ship it to you to play with for a few weeks if you want.

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    Humm...

    Maybe I'll see if they can get me some more photos or video of the output. And I'll think about your generous offer of a trial for a week or two. That might just seal the deal.

    Believe it or not, with all the gear I have, I have no laser at home. I'm really thinking about the whole small, single mode bedroom type decent projector for show creation at home. I sometimes take home a Kvant Spectrum 1.6 but, that's still like lugging around a car battery and a pain to drag back and forth and set up. I'll take it home and it will sit on the bedroom floor for a few days, get in the way and then, I'l just drag it back to work.

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    Quote Originally Posted by logsquared View Post
    If it has the real 500mw 445 diode then the emitter is about half as wide as the ca$io I think. That might be acceptable mixed with SM R and G. If it the standard 1 watt 445 turned down with a 8mm lens you wont be happy.
    Even at that emmiter size, I am curious why they don't just use a SM blue. Unless it is for total power advert. Some people might be turned off at the prospect of a 0.3W projector vs "1W".

    Quote Originally Posted by Bradfo69 View Post
    Believe it or not, with all the gear I have, I have no laser at home. I'm really thinking about the whole small, single mode bedroom type decent projector for show creation at home. I sometimes take home a Kvant Spectrum 1.6 but, that's still like lugging around a car battery and a pain to drag back and forth and set up. I'll take it home and it will sit on the bedroom floor for a few days, get in the way and then, I'l just drag it back to work.
    They are great for the living room. I switched to all single mode and haven't looked back. Sure, the yellows and oranges aren't fantastic but I think they do well enough.

    I would honestly stick with all SM diodes. You would have to attenuate a 500mW blue for balance so again, I don't know why they would use one outside of total power specs.
    Those who fail to grasp art are the ones who criticize it.

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    Quote Originally Posted by logsquared View Post
    ...... If it the standard 1 watt 445 turned down with a 8mm lens you wont be happy.
    But if they used a <4mm collimator and correction optics (prism or Cylindrical), the beam diameter will be acceptable compared to the red and green

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    Quote Originally Posted by mccarrot View Post
    But if they used a <4mm collimator and correction optics (prism or Cylindrical), the beam diameter will be acceptable compared to the red and green
    That is the big *IF*

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    I haven't seen the difference between multi mode and single mode diodes in a projector in person. I know single mode give you a much better beam spec but are also considerably lower power. Everyone says I should have one.
    I believe strongly in single mode because of the beamquallity and whenever i see a superthight beam i get excited. The downside with single mode is that to get higher power you just need to stack allot of them. Your not only get better graphics but you also gain in brightness. Why going with 2 multimode reds if you can stack 6 single mode reds and have the perfect beam? Of course it also makes a big difference who is stacking them.

    Most people make the mistake by buying the most of mw/usd but it would be better to go with a quallity beam. Lower divergence means higher brightness and better graphics. It amazes me still that people choose for the higher power instead of going for the quallity beam. With a good quallity beam projector you can do both graphics and have more brightness so it can be used always. With all the info arround here you should think by now that people get it..........

    My experiance is that up till 2 multimodes they are good for doing beamshows and a compact RGB setup can be adchieved.

    Its funny this discussion goes on forever it seem. In a nutshell : want the perfect beam you have to pay.......


    Interested in 6-12W RGB projectors with low divergence? Contact me by PM!

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    The 462nm 1.4W is cleaner than the 445nm diodes and a nicer color. Plus you can clip a lot of beam off and still have plenty of power to mix with the other lower power single mode diodes. I run it all through a 2x telescope and let it clip the beam and then let the edge of the large beam fall off the mirrors. Result is a nice clean beam. Spatial would work better.

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