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Thread: mRad calculation

  1. #31
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    The longer FL collimator requires less precision in the spacing and alignment of the cylinder pairs.

  2. #32
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    Quote Originally Posted by planters View Post
    The longer FL collimator requires less precision in the spacing and alignment of the cylinder pairs.
    where are you sourcing your cylinder pairs and what fl's are you using?

    i set up a quick and dirty spatial filter test last night and was quite amazed at the results.
    suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.

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    I'm getting most of my lenses from Edmond Optics with a "Vis 0-degree" coating. They have a better selection, but cost more than Thorlabs who produce equality quality, but have a more limited supply. I'm pretty sure the blue lens pair is a rectangular -25mm followed by a round +50mm (I need to confirm this second FL). This gives a 1/4mrad divergence from a 5mm beam.

  4. #34
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    a 5mm beam is pretty big unless you're using large mirrors. i forget, are you using ems and hoping to switch the saturns when the dsp amps are out?

    Quote Originally Posted by planters View Post
    I'm getting most of my lenses from Edmond Optics with a "Vis 0-degree" coating. They have a better selection, but cost more than Thorlabs who produce equality quality, but have a more limited supply. I'm pretty sure the blue lens pair is a rectangular -25mm followed by a round +50mm (I need to confirm this second FL). This gives a 1/4mrad divergence from a 5mm beam.
    suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.

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    a 5mm beam is pretty big unless you're using large mirrors. i forget, are you using ems and hoping to switch the saturns when the dsp amps are out?
    Yes, I am using the EMS 8000 scanners and I am waiting to try the DSP amps. I am kinda like you regarding quality, if I have your posts correctly. I am able to tolerate the multimode beam quality, but only by aggressively correcting the beams and adding spatial filtering. Then, at these power levels, the beams are better than the Pluto projector or a Kavant or frankly anything else I have seen out there (I can say this because I haven't actually seen an OPSL based projector, yet). The downside is the scanners ARE slower.

  6. #36
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    Sorry I'm so late to this thread...

    Brad, there is DEFINITELY something wrong with your green. I have the same projector (a pair of them, actually) and my green is much tighter. It's not scanner mirrors, it's not dichros, and it's not a fundamental problem with the green diode. It is either miss-aligned optics in the green module, or a failure on the green diode that is causing the beam to spread.

    I'm sure the replacement unit will be much better. As you saw in Alexandria, my direct Pluto's have great beam specs (almost as good as the DPSS Pluto's), even over a 70 ft throw.

    Adam

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    My replacement 520 with the improved optics will arrive from DHL this morning. I should know tonight and be able to report back.

  8. #38
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    Brad, if you ever want to cheat, try McCarrots calculator:

    http://mpe.laserextreme.nl/

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    Ok, new green installed and it seems to be 100% better. The O in TOP is a circle as it's supposed to be and is not wider on one axis versus the other. Everything else is appearing cripser as well. I haven't tried it side by side with an original Pluto yet but, I am doing that shortly. The image of the ape as pictured on page one now has sharp definition and no more fuzziness.

    I really dislike the new touchscreen boards they're using in the Pluto's now. They are a novelty but, not that helpful for the serious laser person. You can no longer flip the X and Y axis at the projector. Well.... you CAN but, it's just overridden by the insertion of an ILDA cable.

  10. #40
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    can you shows us the fair field projection now? both while scanning the orientation test pattern and the just a green spot.

    Quote Originally Posted by Bradfo69 View Post
    Ok, new green installed and it seems to be 100% better. The O in TOP is a circle as it's supposed to be and is not wider on one axis versus the other. Everything else is appearing cripser as well. I haven't tried it side by side with an original Pluto yet but, I am doing that shortly. The image of the ape as pictured on page one now has sharp definition and no more fuzziness.

    I really dislike the new touchscreen boards they're using in the Pluto's now. They are a novelty but, not that helpful for the serious laser person. You can no longer flip the X and Y axis at the projector. Well.... you CAN but, it's just overridden by the insertion of an ILDA cable.
    suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.

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