Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 35

Thread: Ok, all you smart people...

  1. #11
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    Ok, you cannot measure output using an FB3. So your power drop is entirely consistent with what I would expect to see when using an FB3 to test power.

    The BEST way to test power if you must us an FB3 is to display the LaserMedia test pattern with a size of zero in both axis. This pattern has the most 'on' time.

    Doing it this way, you can get to within about 5% of max power compared to using an actual 5vdc mod signal. If you know the difference before you start then you can factor this in. But the FB3 is incapable of providing a constant 5V so is not really suitable for power testing. I believe the QM can do this somehow, although I seem to recall its a special mode or switch or something.

    That aside, buy an ILDA Gem. I got one recently and it's made checking stuff just SOOOO straightforward, and I don't have to set up all my kit in order to work on a projector.


    P.S. This is laser 101
    P.P.S. This is the Help section for forum issues, bugs, etc....
    P.P.S. I had an all nighter on Saturday and didn't get home til 11am Sunday, so this is my cranky day, expect it to get worse as the hours pass....
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  2. #12
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Default

    We were using an LD-2000 on a .net to test the power, not an FB3. We brought up the LD-2000 abstract editor, selected an all-white circle, and collapsed the x and y size down to zero. This is Bill's method for producing a high-power static beam. It's not perfect, but it's darned close. I would not expect a 20% drop in measured power.

    Adam

  3. #13
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    Something doesn't seem right, that all 3 modules have lost power though. If it was just the green i'd say perhaps, but for all 3, including 2 diode modules to be down just doesn't add up.
    Coincidence maybe, but an unlikely one, all things considered. Anything else in the signal chain like an adjustable buffer, colour correction board or anything?
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  4. #14
    Bradfo69's Avatar
    Bradfo69 is offline Pending BST Forum Purchases: $47,127,283.53
    Join Date
    Jul 2010
    Location
    Wilmington, DE
    Posts
    6,202

    Default

    No color correction board. No adjustments for color gain or even invert. It's a pretty simple (but pricey!) projector and I agree it doesn't make sense that all three are down in power and that it happened over a fairly short time span.

  5. #15
    Join Date
    Feb 2011
    Location
    New Hampshire
    Posts
    3,513

    Default

    You have a few loose ends that make this hard. You said in the OP that it seemed as if the DHOM had dropped sometime much earlier. Even if the red and the blue are the only two that actually are lower then it is still almost impossible that the two modules reduced at the same time to the same extent without there being a common cause. Just to eliminate the optics and especially the common optics, is there anyway you can interrupt the beam from each laser with a separate mirror and using whatever modulation you like (it won't matter), see if there are any optical losses compared to the normal beam path?

    How did you establish that it was generating 3W out the window before SELEM 2012? If you are using the same techniques as in an FB3 and the same power meter then these shouldn't need to be changed.

  6. #16
    Bradfo69's Avatar
    Bradfo69 is offline Pending BST Forum Purchases: $47,127,283.53
    Join Date
    Jul 2010
    Location
    Wilmington, DE
    Posts
    6,202

    Default

    In re-reading the OP, I don't see where you are interpreting that one module dropped much earlier. I'll try to be more clear... and I'm also correcting some dates since I was a year off.

    In late 2010, I had Marc Arotsky from CT Lasers begin building me a 3 watt RGB projector. It took nearly a year and he delivered it to me at SELEM 2011. It's a long story but, in the end, it was outfitted with a new Kvant 640nm rated at 1.2 watts, and (I believe) a DHOM green module that was 1 watt and an either 800 or 900 mW DHOM 445 blue. Upon delivery at that SELEM, Mark measured the white output at the aperture with a Coherent meter at being better than 3 watts. I don't recall what software/hardware he used or pattern to measure it. Most likely LD2000. Regardless it was a super bright projector and aside from Franks 6 watt monster was the brightest box there. I proceeded to use it for about two years and over time put perhaps 75-100 hours on the projector. It went to TexLEM, SELEM 2012 and then SELEM 2013.

    I bought two 2.5 watt Plutos in June 2013 and I know at SELEM 2013, I brought everything with me. The Pluto's got put in the auditorium so I didn't notice how they looked against the CT Lasers box in ClubSELEM. I finally put it up on the scaffolding on Saturday and from what I recall, and have seen in peoples video's it was still appearing to be it's usual brightness. Not long after getting home from SELEM 2013, perhaps in September, I had a wedding where the CT Lasers box was the center projector and was flanked by the Pluto's. When I saw a video clip from that wedding, it was apparent that there was a power issue from the CT Lasers box as the Pluto's were SO much brighter. I tried cleaning the dichros, aperture glass and carefully cleaned the scanner mirrors. The output in general wasn't looking "right". (Maybe I was getting spoiled by how much nicer a Chinese built projector really can be!)

    Not long after that, Mark Edgar came over with his meter and we determined the projector was only doing about 2.2 watts before the scanners but after the dichros. He couldn't get the head of the meter in between the module and dichro so, that's the best we could come up with. My meter head is useless for anything remotely other than out the aperture since it's a Scientec head about the size of a quart mayonnaise jar. We suspected the power loss to be in the Kvant red module because on the wall, the lines from it appeared to be wider than they were originally. We thought perhaps there was an internal alignment issue. I basically shelved the projector after that. I've had a couple of e-mails back and forth with Mark Arotsky over the past year but, lets just say his business skills are severely lacking.

    I've got plenty of projectors so as I indicated, it just sat in a closet from September 2013 on, until I brought it to SELEM this year in hopes of getting others opinion and metering the individual modules. As mentioned, buffo tuned the scanners, and metered each module and I posted the results above. 880mw for the red, 800 for the green and 660 for the blue. I have also double checked and the output is sharp as it should be for all colors, the red appears fine. It's just down on power across the board.

    That brings me to yesterday where I finally posted the issue after being home from SELEM for a couple weeks and wanted to throw it out there for ideas/suggestions. It now sounds like it's going to be taking a trip to Maryland to be evaluated so, hopefully we'll get an answer soon. It may also just be scrapped and rebuilt into something else. I'm just irked that I have a $9k projector with low hours that does nothing but sit in a closet that is also NOT as professionally built as I was lead to believe when I first stated getting into this game.

  7. #17
    Join Date
    Feb 2011
    Location
    New Hampshire
    Posts
    3,513

    Default

    Thanks for the clarification. That wasn't that long ago and $9,000 for 3W seems really high and for 2.2W well...No wonder the Plutos are so attractive despite a few issues. Is Mark going to evaluate this or are you sending it to someone else?

  8. #18
    swamidog's Avatar
    swamidog is online now Jr. Woodchuckington Janitor III, Esq.
    Join Date
    Nov 2006
    Location
    santa fe, nm
    Posts
    1,545,752

    Default

    the case CT Lasers uses costs almost as much as the entire pluto:

    http://www.onestoplasershop.com/enclosures.htm
    BT1000 Galvo Enclosure

    Quote Originally Posted by planters View Post
    Thanks for the clarification. That wasn't that long ago and $9,000 for 3W seems really high and for 2.2W well...No wonder the Plutos are so attractive despite a few issues. Is Mark going to evaluate this or are you sending it to someone else?
    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.

  9. #19
    Bradfo69's Avatar
    Bradfo69 is offline Pending BST Forum Purchases: $47,127,283.53
    Join Date
    Jul 2010
    Location
    Wilmington, DE
    Posts
    6,202

    Default

    Very good memory, Swami. Although mine was actually in the BT500.

    A third of the cost of this projector was the Kvant 640nm. Keep in mind this was pre- Mitsu "Holy Grail" thread days and at the time the "best out there" was $3,2000. I got smacked in the face with the cost of this hobby pretty early in the game!

    No, it's not going to Marc...yet. Ultimately I'll have to deal with him about it... and a number of other things.

  10. #20
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    Yup, I can sympathise with you on the red. I bought one of the first '6 banger' Kvant 637nm 1W modules, at the best part of £2k when they first came out. Great module, still going well, everything still perfectly aligned, but DAMN, the laser modules I've bought since for far less than that one combined... Lets see how I feel about the money spent in 3 more years time, and whether its holding its own.
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •