Re:working with he cd at 446nm

JohnFP · Post by **JohnFP** » Tue Jun 01, 2004 9:34 am

I used to work with a HeCd in Shipley Photo resists. What is your question?

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working with he cd at 446nm
March 29 2004 at 12:05 PM steiner lech

Response to Member links

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if anyone works at 446nm with photoresist, can make response, thanks, lech

dave battin · Post by **dave battin** » Tue Jun 01, 2004 8:50 pm

now you have mastered the coating and shooting,when will we see some projection on your holograms!the hecad laser is such a joy to work with (while its working)! what manufacture hecad do you have?

JohnFP · Post by **JohnFP** » Wed Jun 02, 2004 11:31 am

It was many years ago I used a HeCd for Rainbow resist copies from a two channel master. I do not remember the manufacturer. I now use a Argon Ion.

Ahhhh, projection. The next step. No, I do not believe I will be making masters in the near future. Not my thing. I would like to try some focused images soon using a lens and the inside of the mold technique. I will be trying some tranmission HOEs but not masters for copies. I like the simplicity of single beam set ups. If I can stay away from a beam splitter I will. I would like to find ways of doing everything in a single beam set up that has only been possible with H1 H2 configurations.

dave battin · Post by **dave battin** » Wed Jun 02, 2004 6:07 pm

john you can do a H1,H2 configuratin using one beam , basically you need to shift your H1 color to the blue(thru thickness, dichromate ammount and hardness of fix) ,place your H1 about 1/2 inch away from your undeveloped H2 expose both with one beam and presto chango instant H2.i can show you some pictures later. Lee Lacey a fantastic holographer in th mid west showed me the setup
and i couldnt believe how simple it is....

d a battin · Post by **d a battin** » Wed Jun 02, 2004 6:18 pm

thought you mightlike to see one http://www.geocities.com/greenpagoda/holopage1.html

if you go to the link you will see one i made a while back.

i remember making this, and seeing the unicorns horn projecting out for the first time made the hair on the back of my neck stick up !

JohnFP · Post by **JohnFP** » Thu Jun 03, 2004 4:54 pm

Dave, yes there are many things I want to play with and try. Unfortunately I do not have a lot of time. I may get into the lab once a week or once every two weeks for 4 to 6 hours. The next hologram I want to make is of the broken mirror then dispay its back (pseudo) side to get some image in front of the plate. They have always been my favorite also. Another one I wanted to do was a hologram of a coat hook that was image planed to look like it was coming out of the hologram with a capion above that read, "Hang Your Hat Here".

Bob · Post by **Bob** » Fri Jun 04, 2004 3:33 am

Has anyone really made a "single beam" hologram? It takes two beams to interfere. The Denisyuk technique, for example, uses what I'd call a temporal beam splitter. The reference beam hits the plate at one moment, and some time later the object light hits the plate. If the light is coherent long enough, you'll get a recording.

Steve Provence used a minimalist approach to his work as well for many years. He would expand and collimate the laser beam, then pick off pieces from one side with tall thin mirrors to provide slit illumination for multi-color "Rainbow" masters. The light from the other side of the "single beam" provided a reference beam. This is a great example of spatial beam splitting.

Ed Wesley wrote a great paper for the Proceedings of the International Symposium on Display Holography, Volume 2, 1985, called "Seven Single Beam Projects". All are essentially spatial beamsplitting as well.

I'd engourage you to do as much as you can with either of these beamsplitting choices, and I'm certain that your results will be as impressive as those already presented. If you'd like a polarizing cube beamsplitter, however, I'd be happy to trade a New Focus Model 5811 for one of your excellent holograms! 8^)

JohnFP · Post by **JohnFP** » Fri Jun 04, 2004 6:37 am

Yes, You are technically right. But as I intend to move to larger format and the efficiency of DCG being high, I feel there is no need to introduce the traditional "beam splitter". I am striving exactly for what you state and that is to use the plate as the beam splitter and use additional mirrors very near the film plane for additional lighting.

Bob, is the cube wavelength selective and if so, what wavelength(s)?

Bob · Post by **Bob** » Fri Jun 04, 2004 2:48 pm

The specs for it are linked below. What does the efficiency of the recording material have to do with choice of object illumination geometry? I've always wondered why holographers using DCG only do Denisyuk recording. Dinesh is probably an exception.

Splitting the beam before it's expanded probably requires more equipment, but the use of spatial beam splitting requires all mirrors to be super clean. It also restricts beam ratio manipulation, lighting angles, and baffling. All objects beams will have the same divergence as the reference. If the "hot spot" of the beam is centered on the recording plate, the other beams will have an intensity gradient. This all results in a very low efficiency system, very wasteful of light. It also requires the use of a single frequency laser.

I applaud your choice and direction, but you'll have a "tough row to hoe".

http://www.newfocus.com/product/model.c ... delno=5811

Colin Kaminski · Post by **Colin Kaminski** » Fri Jun 04, 2004 3:35 pm

"Dinesh is probably an exception. "

All of Dinesh and Joy's DCG work I have seen is H2.