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Thread: Another Hologram

  1. #11
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    I love H1 to H2 image plane holograms. It's basically the only type of hologram that I've been making for the past couple of years. They are definitely tough to make and it's a real thrill when you get a good one! A drawback of this technique, at least for me since my table set-up is pretty small, is that the viewable angle of the H2 is pretty restricted. This is because I use 4X5 plates to make both the H1 master as well as the H2. If I were to go to an 8x10 master the view angle would be greatly improved. Too bad no one seems to make 5X7 holographic plates (and I don't use film; at least not yet).

  2. #12
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    Quote Originally Posted by RonZ View Post
    I love H1 to H2 image plane holograms. It's basically the only type of hologram that I've been making for the past couple of years. They are definitely tough to make and it's a real thrill when you get a good one!
    I've been working on making H2's for quite some time, but I was having real stability problems. As you're probably aware, you need much more stability to make a split beam H2 white light reflection than you do for an H1 transmission hologram. I now finally feel that stability problem is behind me and I can move forward with reasonable confidence.

    A drawback of this technique, at least for me since my table set-up is pretty small, is that the viewable angle of the H2 is pretty restricted. This is because I use 4X5 plates to make both the H1 master as well as the H2. If I were to go to an 8x10 master the view angle would be greatly improved.
    Yep, I know what you mean about a small table , mine is 1000mm x 600mm. The key is good planning and a short focal length collimating mirror. I have an 8" f3 (24" focal length) mirror. I battled against the odds because I wanted to use an overhead setup rather than have the reference beam coming in from the side, that's what held me back, I dare say i could have moved things along a little quicker had I given in and gone for side reference. But, my motto is 'never say die' and my persistence has finally paid off. This means that it's really easy for me to move between making H1's and H2's, basically all I have to do is move a beamsplitter and adjust a mirror and i'm good to go . I also wanted consistency so I could easily replicate holograms, I hope that's what i've achieved with the setup i've now got.

    I was also afraid to use anything other than glass plates as I didn't really want to get involved in index matching. However, I had a good tutor (John Sonley) who taught me the dark art... Well, actually it's really easy once you know how. Then on further experimentation I started to use halfwave plates in my setup, this allows the beam polarisation to be rotated at will. So, now I just set my H1 reference beam to hit the plate at Brewster's Angle (~56 degrees) and adjust the polarisation for minimum reflection... Viola... no woodgrain effects and no index matching fluid required

    So, don't be put off by film. It's really quite easy once you get used to handling it... Honest

    Too bad no one seems to make 5X7 holographic plates (and I don't use film; at least not yet).
    John and I recently each bought a 100' roll of old Agfa film that we can cut up into any size, I use 7" x 5" masters as my current plateholder won't take anything larger. When I get time i'll make a bigger plateholder, but then i'll probably need a larger collimating mirror... Does it ever end?

    What I used to do before I got the roll was to use a 5" x 4" on its side for making the H1 master, of course you're limited to smaller objects and the vertical parallax is somewhat restricted, but it does help a bit.

    Are you on Skype Ron?, if you are PM me your Skype address and we'll hook up sometime and i'll show you my setup.

    Cheers

    Jem
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.... Douglas Adams 1952 - 2001

  3. #13
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    Hi Jem,
    Yes, I am on Skype and I will PM you with my Skype name in a bit. Thank you for the offer to compare notes, I look forward to doing so. Right now I am looking out my window as TS Irene is pretty much peaking in my area. Unfortunately, I stupidly injured my back this morning when I brought in two large potted plants to protect them from the wind. My wife was there and tried really really hard to help me but my testosterone poisoning prevented me from accepting her help until it was too late!! I did end up (having to) accept her help for the second pot. Why don't I ever learn this bloody lesson!

  4. #14
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    Great work Jeremy! Persistence is a necessary characteristic for a holographer.

  5. #15
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    Hi Ron

    Got your PM, thanks and i've replied. I guess you're about 5 hours behind me. I hope the back improves soon and Irene hasn't caused too much other damage.

    Bob, Thanks , yes persistence has tried my patience to the limit at times (I love it really)

    Cheers

    Jem
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.... Douglas Adams 1952 - 2001

  6. #16
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    Mar 2010
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    Quote Originally Posted by Jem View Post
    Hi all

    I've been working on my holography setup to try and improve a few things. It looks as though my endeavours are finally paying off ...



    This what I've been working towards for the last few years.

    Today is a good holography day :-)

    Jem
    Great dark room work JEM! The shadow is a nice touch, what method of recording do you use? Optical of corse.
    I whant to say outstanding to you JEM! after talking with Bill from Pangolin and his BYOND presintation and your simple out of the box thinking and suggestion on how to solve his lensing problem for the projectors apature to make audiance scanning more safe. Very smart!! of corse the smart ones do keep it simple! MY HATS OFF TO YOU!!!!!!!!!!!!
    BEAMANN (GODSLIGHT SHOWS)

  7. #17
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    Quote Originally Posted by beamann View Post
    ...after talking with Bill from Pangolin and his BYOND presintation and your simple out of the box thinking and suggestion on how to solve his lensing problem for the projectors apature to make audiance scanning more safe. Very smart!! of corse the smart ones do keep it simple! MY HATS OFF TO YOU!!!!!!!!!!!!
    awww, shucks, you're making me blush now

    I'd say the lenses were a 100% joint effort, not just me (despite what Bill says ). It's been great working with Bill and it's nice to see them come to fruition

    Thanks again for your kind words.

    Jem
    Quote: "There is a theory which states that if ever, for any reason, anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.... Douglas Adams 1952 - 2001

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