1st time on DCG Project

Dichromated Gelatin.
Zeta
Posts: 42
Joined: Wed Jan 10, 2018 9:30 am

Re: 1st time on DCG Project

Post by Zeta » Wed Mar 07, 2018 2:40 am

This one using silkscreen, 10 micron super transparent yellow
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Last edited by Zeta on Wed Mar 07, 2018 2:52 am, edited 1 time in total.

Zeta
Posts: 42
Joined: Wed Jan 10, 2018 9:30 am

Re: 1st time on DCG Project

Post by Zeta » Wed Mar 07, 2018 2:46 am

I also have voltage regulator between power supply and controller.

I already ordered new complete laser set it will be arrive 18-20 this month.

pluto
Posts: 95
Joined: Fri Feb 05, 2016 2:06 am

Re: 1st time on DCG Project

Post by pluto » Wed Mar 07, 2018 3:38 am

Zeta can you take a close up picture of the silkscreen one? Is there any texture to the coating or is it smooth like veil coating?

Steven
Posts: 34
Joined: Sat Jan 31, 2015 8:14 pm
Location: Cornwall, UK

Re: 1st time on DCG Project

Post by Steven » Wed Mar 07, 2018 10:51 am

Zeta wrote:This one using silkscreen, 10 micron
Zeta, you coatings look to be too thin or need more AmDi, but I suspect the former.

You are using a 10 micron (10µm) silkscreen, I assume that is thickness when the gelatin is still in it's wet state?
You must allow for the emulsion thickness to shrink due to water loss after the coating has dried.
The wet coating thickness needs to be significantly thicker than your desired dry thickness.
Much depends upon the gelatin to water ratio and the thickness of the mesh.

Your silkscreen coating seems to leave a ripple effect in your coating.
Keep the glass on a level surface and keep it warn for longer to allow the ripples to smooth out before letting the gelatin set.
Your silkscreen method does appear to result in a coating that has an even thickness across the plate, if you ignore the ripples.

Steven.
Success through failure - the amateur DCG holographer's path to enlightenment.

Zeta
Posts: 42
Joined: Wed Jan 10, 2018 9:30 am

Re: 1st time on DCG Project

Post by Zeta » Wed Mar 14, 2018 2:07 am

Update

This one is veil coating
2 ways transmission but no subject
laser 442 10 min exp with different post process time.

1
https://youtu.be/l0FjWMzcfUo

2
https://youtu.be/5oC6PdWd_YI

3
https://youtu.be/swQTz6-l6-s

pluto
Posts: 95
Joined: Fri Feb 05, 2016 2:06 am

Re: 1st time on DCG Project

Post by pluto » Wed Mar 14, 2018 1:19 pm

Hard to say anything about the results without a subject.

When you get your new laser system setup, I recommend doing a super simple denisyuk/reflection hologram. Also for the videos, it might be easier to keep the light and camera stationary, and tilt the hologram instead.

You're exposing with a 442nm laser here? Keep in mind the formulation is much different for 442nm than 532nm... the amount of dichromate required is much less. For instance, I believe for 488nm I use 200-21-1.5, and DCG is four times more sensitive to 442nm than 488nm so you would need even less dichromate.

10 minutes of exposure at 442nm is quite a long time, especially for such a small hologram. How powerful is your HeCd?

By the way, the silkscreen technique seems promising! I'm just wondering why I've never heard it suggested until now...
Last edited by pluto on Thu Mar 22, 2018 11:40 am, edited 1 time in total.

holomaker
Posts: 677
Joined: Wed Jan 07, 2015 8:01 am

Re: 1st time on DCG Project

Post by holomaker » Thu Mar 22, 2018 9:41 am

Sorry I missed these posts! Way back in the beginning your laser was plugged in correctly and was ready to laze ! When the amber LED comes on , all is good, wait at least ten mins for the laser to stableize , the back of the controller needs the two pins jumped together as well. How long did u allow it to sit w amber light on ?

holomaker
Posts: 677
Joined: Wed Jan 07, 2015 8:01 am

Re: 1st time on DCG Project

Post by holomaker » Thu Mar 22, 2018 9:48 am

The photo of your fist vail coated plate looks correct, color wise. When I would vail coat I would cut the plate up and realized the top portion of the plate was ready to shoot in 1 hour or less, and thirds the bottom was much thicker and needed hours to dry. I found using a diluted rapid fix as the developer quickly took out the milky ness...

Zeta
Posts: 42
Joined: Wed Jan 10, 2018 9:30 am

Re: 1st time on DCG Project

Post by Zeta » Mon Apr 02, 2018 6:36 am

Hello my new laser just arrive this morning. 532nm 50mw

About the old one the amber light is on about 40-50min and then off and back on again but no laser.

About the new one, is this expanded beam good for the reflection hologram?
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or just shine the plate everything will do.

pluto
Posts: 95
Joined: Fri Feb 05, 2016 2:06 am

Re: 1st time on DCG Project

Post by pluto » Mon Apr 02, 2018 12:36 pm

Zeta wrote:Hello my new laser just arrive this morning. 532nm 50mw

About the old one the amber light is on about 40-50min and then off and back on again but no laser.

About the new one, is this expanded beam good for the reflection hologram?

S__25460912.jpg

or just shine the plate everything will do.
Looks good enough to get started. I think I see some striations that are typical of lower quality optics, but it shouldn't be a big deal.

What are you using as your beam expander? Eventually it would be good to invest in a double concave lens with a -9mm focal length (for example). These are sold by Edmund Optics for about $40, but you will have to create your own mount for it.

These also have anti-reflection coatings which should get you the most green light passing through.

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