First Light with Integraf Kit

Present your work.
tommyNaN
Posts: 14
Joined: Thu Apr 30, 2020 9:46 pm
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Re: First Light with Integraf Kit

Post by tommyNaN »

Yes, the horzontal bands are from light hitting the top edge of the plate, and bouncing back and forth inside the plate.

I use a black dry erase marker to cover the top edge of the plate, and block the light from getting into the plate. Then before putting it in the developer, rub the dry erase marker off with a paper towel.
maskedkoala
Posts: 17
Joined: Mon Jun 29, 2020 10:24 pm
Location: Florida

Re: First Light with Integraf Kit

Post by maskedkoala »

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Exposure test. 1s and 2s didn't appear to hit the threshold. They also didn't get very dark in the developer. I did some very rough estimates (no power meter) and determined my power density was something like 10-20 uW/cm^2 which would put optimum exposure around 4-8s for PFG-01 (80uJ/cm^2 sensitivity), and indeed, the brightest quadrant appears to be 8s. My next run I'll try 4, 8, 16, and 32s. I'd like to have some first hand experience of what overexposure looks like, so hopefully I'll hit that at 32s and still have a hologram. I'm wondering if I should also run tests with different developer times. I've been developing for 2 minutes, but I think that can be shortened up.

Less green this time. The first time around I bleached for 2 minutes, so I'm guessing that's what led to extra shrinkage and the bright green color shift. This time I bleached for a minute, and next time I'll do regular checks and just take it out when it's clear. Then again, the bright green is kind of nice...

I have some dry erase markers on order to black out the edge, but I thought I'd try a sharpie and use rubbing alcohol to get it off. The sharpie didn't coat very well, so that failed, and I also totally forgot to remove it before I put it in the developer, so I ended up with a lot of debris in my chemical baths :oops: .

Also ran a hologram of an eyeball trinket thing right after the coin test. Exposure was 5s which was a bit short. The wife says the dimness actually adds to the creepiness, but I'll shoot it again with a 10s exposure this weekend.

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Since the chemicals were mucked up, I tried pouring the bleach into the developer. It bubbled a bit and turned a deep emerald blue/green, so I think as suggested above, that might be a good way to neutralize it.
lobaz
Posts: 280
Joined: Mon Jan 12, 2015 6:08 am
Location: Pilsen, Czech Republic

Re: First Light with Integraf Kit

Post by lobaz »

Well done.
You can make a box (say 12x12x12 cm) with black inside surface. Make a 6x6 cm hole in the center of one side. This hole to a black interior will be much darker than your black paper you use for the hologram background.
maskedkoala
Posts: 17
Joined: Mon Jun 29, 2020 10:24 pm
Location: Florida

Re: First Light with Integraf Kit

Post by maskedkoala »

Excellent idea. It turns out that 6 pack boxes for cans are very close to that--roughly 12 x 13 x 20 cm. I just happened to have one of those around... weird!

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I used clear acrylic paint to cover the inside with left-over wrappers from the plates.

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I cut out strips from another box and glued them together to create clamps for the plate. 5 pieces of cardboard = width of plate. Then one additional piece on top over sized by 1/8 inch to hold the plate.

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:|

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I knew this would come in handy someday.

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Success!

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BobH
Posts: 440
Joined: Tue Jan 06, 2015 10:26 pm
Location: Mesa, AZ

Re: First Light with Integraf Kit

Post by BobH »

Excellent!
lobaz
Posts: 280
Joined: Mon Jan 12, 2015 6:08 am
Location: Pilsen, Czech Republic

Re: First Light with Integraf Kit

Post by lobaz »

Good! If possible, try to cover the upper edge of the glass. If light gets through that edge inside the glass, you get those ugly horizontal strips crossing the upper coins. Covering that edge is even more important in hologram recording, otherwise those strips are permanently stored in the hologram.
maskedkoala
Posts: 17
Joined: Mon Jun 29, 2020 10:24 pm
Location: Florida

Re: First Light with Integraf Kit

Post by maskedkoala »

Thanks. I've been trying tommyNaN's suggestion of using dry erase on the edge. That makes it a little better, but doesn't seem to be enough. I think I'll try electrical tape next time.
jrburns47
Posts: 165
Joined: Mon Sep 14, 2015 2:48 pm
Location: Oyster Bay, NY

Re: First Light with Integraf Kit

Post by jrburns47 »

Try 3M type 235 black photographer’s tape in 1/4” width of you can find it. Wider versions available on eBay & Amazon.
BobH
Posts: 440
Joined: Tue Jan 06, 2015 10:26 pm
Location: Mesa, AZ

Re: First Light with Integraf Kit

Post by BobH »

I second what Jody just said. A roll of black photographer's tape, paper based, will be waaaaay better than electrical tape, which has no place in a holography lab because it's constantly in motion, and the glue on it stays gooey. One can always cut the width they need from a 1" wide roll, which should last a long, long time. A small roll of black aluminum foil will also last a lifetime, but you'll find many uses for it (and it's just cool stuff).
BobH
Posts: 440
Joined: Tue Jan 06, 2015 10:26 pm
Location: Mesa, AZ

Re: First Light with Integraf Kit

Post by BobH »

I like to use a card to cast a shadow to cover the edge of the plate during recording. Nothing to remove or clean off after the exposure.

For Denisyuk shooting, I like to use a piece of film that's much taller than necessary, to move the line cast by the top edge of the plate further up in the scene. Then, cut the excess material off the top and the scene won't have an unnecessary line across it. Waste a little film for a much better image, after you know everything is working well.
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