annoying fringes in hologram

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annoying fringes in hologram

Post by blue_electric_71 » Tue Jun 29, 2010 12:55 am

Well, I did a total of 5 shoots yesterday and one came out pretty nice
It only happened with that one object (round shiny metal lighter). So I believe it is the object that somehow is not stable. I would surgest you try other objects.
I took your advise and used a hard plastic smurf this time in one of my exposures. (they don't make them like they used to...:)and there is no fringing this time :) So I guess there was some back reflection going on in previous exposures using more shiny objects.
I also used Brewster's angle as accurate as I could. Of course the plate was slightly tilted against the smurf but i tried to compensate with the laser angle.. And I used the rechargeable batteries to power the laser
Watch here:

The plate was resting against the figure which I taped to the table with double tape..maybe super glue would have been better.
exposure was 1 minute, rinsing 20 sec., developing 2 minutes, rinsing 3 minutes, bleach about 1 minute plus 20 seconds, and rinsing for another 3 minutes. And finally spray painted the back the next day.

Thanks Joe for pointing out the backreflection phenomena..But I'll try to shoot some shiny objects using the same set up..

If you look at the board there is a pot. Turn the power down slightly. I have not had to do this but it would be my first idea
Haven't tried this yet.. I did see some videos where they use this to boost the power of the laser to be able to burn holes in things..what does the pot actually do? Does it make brighter holograms, or would it increase coherence length? ..or would it only make the laser unstable

the best two holo's so far in one shot:

Maybe I'll do some more tests tomorrow. At least I got to make a hologram without the fringing this time :D



Colin Kaminski

annoying fringes in hologram

Post by Colin Kaminski » Tue Jun 29, 2010 7:19 am

It sets the current to the diode. If you have a power meter you can adjust it to a new setting repeatedly. Sometimes if you give a diode too much current it will mode hop. I have not seen that with the integraf diode.