Roll your eyes: it's another glass/film/glass question

[Justin W]

Nice one!

Is that a do-it-myself anti-halation measure?

I will most certainly be making transmission masters with my stereogram machine, and had wondered idly whether that was a viable idea or not.. Thank you for bringing that up, Ed!

The flatter the better when it comes the black, eh?

[BobH]

Ed's suggestion will only help if you use index matching fluid.

[Justin W]

Oh.

I see...

Wait, no I don't.

Bob, I'm new here. Would you mind explaining that to me, please? I have a feeling that within that explanation you may render will lie a fundamental something about burning film that I need to learn...

[Colin Kaminski]

Holding film still is a challange in the best of circumstances. Moving things on the bench and getting every thing still makes it harder. Index matching will make your live much easier. With the PFG films I would use a glass sandwitch and index matching fluid. (I like lamp oil.)

[Justin W]

I guess it appears that this is one of those truths I'll just have to face (and I could, before coming to terms with this index matching situation, feel myself on the verge of heading down that same old road where I heard sound advice over and over and decided to ignore it), the fact that index matching is necessary for quality holograms on triacetate film...

Oh, how I wish a dry sandwich was ok, but alas... I'll index-match.
I feel inclined to try paint thinner, as suggested once and also found in the wiki, mainly because I don't relish the thought of washing my film before processing it. Letting it air dry (evaporate) sounds cool to me. I'm squinting my eyes and peering ahead into the future and seeing myself doing this with an eye dropper...

So paint thinner, then, doesn't damage emulsion?
Does anyone know whether paint thinner dissolves masking tape adhesive?

[dave battin]

justin please see this old thread;

I know this is an old subject, but I would like to add my bit of info. What are you using to laminate film on glass? Thanks to Ron and Bernadette Olson of Laser Reflection who graciously added an extra pack of (outdated) PFG-01 film with my order, I finally had a chance to experiment with much greater speed and a little less care than before. I now get consistantly good results with my laminating process. With this process and Jeff's ascorbate developer I get much brighter holograms than before:

• - First I clean a piece of picture frame glass with ordinary dishwasher fluid.
  - I tape a piece of film (emulsion away from the glass) on two if it's edges to the glass. The edges connect at the same corner of the film.
  - The whole construction now resebles a little pocket. One side of the pocket is the film. The other side is the glass.
  - With a syringe I pour some ordinary lamp oil between the film and the glass (into the pocket).
  - Any air bubbles can now be gently stroked upwards to the top of the pocket with the back of a dry finger.
  - With a soft cloth I remove the excess fluid from the edges that are not taped down yet.
  - I tape down the long edge of the film that is not taped down. And again remove any excess fluid from the final untaped edge.
  - I tape the remaining edge.
  - I wait five minutes to see if the tape holds and does not separate from the glass. If it does not in this time (clean glass, and excess fluid removed), it will not during the rest of the processing of the film.
  - Some times I still discover a small bubble between the glass and the film after all edges have been taped down. I can still move this bubble to the side of the film with the back of a dry finger because the corners of the film/tape are not completely water tight.

If I want to use TEA, I do it after the film has been laminated to the glass. It's much easer to use this way and not so difficult to squeegie. Also the back of the glass can be cleaned with a towel after TEA treatment.
Using this system I never wait long for the film to settle. Just use it after the 5 minute check and results show no film movement. For Denisyuks, this process is perhaps not so suitable because the taped edges filter some light from the laser and thus show up in the hologram.
I keep the film on the glass also during development and bleaching. There is much less chance of scratching the film when it is still stuck to the glass. And again easier to squeegie when necessary.

* A note for the other beginners with PFG-01: I have tried dry and wet laminating between two pieces of glass before I started using the above process. The problem I had with that was that to get reasonable results, I had to use Brewster's angle to avoid internal reflections (glass/film/glass). Most of my holograms did not show up very bright doing it that way because with Brewster's angle reference beam, so little light reflects directly back to the plate from less reflective objects. Laminating with lamp oil and taped film lessens the need for Brewster's angle considerably and seems to allow the use of illumination closer to the normal of the film (more perpendicular). Oh, yeah. Did I mention that I paint the edges of the glass plate black with a water proof black marker?

ive always used scotch tape to hold down the edges with no problem (using the above method).

[BobH]

A piece of black glass as the backer for your film sandwich will only work as an anti-halation layer if it is index-matched to the film. Otherwise, you'll get reflections off both glass pieces and the film.

Another thing you can do instead of index matching is to paint the film base black before exposure. Then, mount it dry and expose. When done, put the film into a tray of water and gently peel the paint layer off the base. It will come off, but you need to be gentle. Then process the film.

Problem with that technique is that you need to spray paint in safelight conditions. And it's messy. And you need to do a bunch of cleaning. I find dealing with index matching fluid much easier.

[Justin W]

Howdy all

What I'm considering doing now (after liking the thought of anti-halation as mentioned along this thread) is to give VRP a whirl. I've been using VRP-M to this point, as it will create both reflection and transmission holos.
My new project, however, will be stereograms, and my masters will of course be transmission - and because I do so imagine that this format lends itself well to rainbow transmission H2s, I'm going to look into that.

And if (per Bob's post) a black-backed film will give acceptable results dry mounted, then that sounds just swell.

So... I've never dealt with an anti-halation layer before... What am I in for with VRP? What is the standard and accepted method of anti-halation removal?