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Thread: Question about anamorphic prisms

  1. #1
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    Default Question about anamorphic prisms

    I have seen a bunch of threads talking about how the anamorphic prisms can clean up the beam a little for 445's. What kind of "clean" are we talking here? I am using one of the aixiz collimators right now, and that has helped a little. Basically, will a pair of prisms get me an "adequate" beam profile for graphics? I understand that, at best, I will be getting a square beam, but how tight will the dot be? Right now, anything has got to be better than the "|" shape I am getting.
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    The prisms, when correctly aligned, will "squeeze" the line " | " into a smaller line " | " and appear more dot-like at close range. There will be some losses incurred, of course.

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    Lightbulb

    If you want a "square"; the best way is to stack 4 "||||" and use a prism afterwards. Using one will only get you a | at longer distances.
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    allthat... aka: aaron@pangolin

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    I am mainly looking for a decent beam profile that will work for graphics.
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    Uh, Simon... Andy... I'd prefer someone with experience break his heart.

    The 445 beam is not too bad for graphics but I don't think you can get its beam to what you are really wanting.

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    I guess it all depends on the distance at which you want to project your graphics. If this is a constant you can just focus the lens for a tight(ish) 'dot' at that particular distance. I have a 445 with anamorphics and to be honest it's not that bad at all for graphics. If you're being picky there are better blues for graphics work (473nm DPSS), however, there's nothing to beat the price of the 445's

    Jem
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    Thanks everyone for your input. I am not talking long distances no more than 50 feet and even then, probably not that much. I am using a 445 right now for graphics and it isn't horribly bad, it just isn't good. I am just looking for something a little more adequate. I am not doing commercial shows or anything like that so, it is really coming down to personal preference rather than professional results. I own a 473nm but unfortunately, it is TTL and only 100mW. Besides that, I like the look of the purples I get from 445nm in combination with my 640nm. The perfect solution for me is a 457nm, but there is about a $3000 difference between that and 445nm at the power level I require .

    I ordered a set of prisms to experiment. That is the good thing about these diodes, cheap enough to play around with. I am hoping a diode manufacturer will come up with a blue that has a beam profile close to the 640nm reds!
    Those who fail to grasp art are the ones who criticize it.

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    If you set the angle between the prisms bigger then normal you get a very thight beam. Kvant and RGB do the same And their projectors have a tight beam. You have more losses but not to much so you can end up with a 800mw thight beam. That is when you use a 405g2 lens with a FL of 4.

    allthatwhichis:

    If you want a "square"; the best way is to stack 4 "||||" and use a prism afterwards. Using one will only get you a | at longer distances.
    Sorry but that won,t work. When stacking 4 next to eachother like this IIII and shoot it throug a prism you will end up with this I I I I after the prisms

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    edison is spot on about combining 4 beam using prisms, it just dont work

    no prisms -




    with prism pair -

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    Quote Originally Posted by andy_con View Post
    edison is spot on about combining 4 beam using prisms, it just dont work

    no prisms -
    ...
    with prism pair -
    ...
    Do you mind sharing how far away from the prisms that was measured, and with what collimating lens?

    Thanks

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