Present
2003: Feb | Mar | Apr | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2004: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2005: Blog
2006: Blog
2007: Blog

Tuesday, February 18, 2003

This morning I modified the table for a simple split-beam reflection using the same subject I've been using (a bright white snoopy, see below).  I also got out my new Edmunds beamsplitter (pictured above, just in front of the laser.  I haven't mounted it to anything as yet and it's just resting on a simple stage that allows me to rotate and translate it so that I get the beam ratios I want.

A bit blurry, but here is the mirror and lens used for the object beam.  There's an extra mirror stuck to the rightmost stand.  I often leave "extra" optics stuck to the stands, face down, when they're not in use.  That way they're always handy.

And finally, the subject.  In the center is visible a small part of the plate holder and just "behind" that is snoopy with his head more or less toward the object beam.  The object beam is coming from down-center and the reference beam is coming from the right. On the other side of Snoopy is a mirror that redirects some of the excess light back onto the other side of him.

You've probably noticed that the dates on the pictures are from the next entry.  I decided to put them here since this is the first day I'd used that setup.  I just happened to take the pictures on the following day.

I made two holograms today, one with a 7s exposure and the second with a 2.5s exposure (I was eyeballing the exposure times since I'm experimenting with a new light-meter setup).  Both were pre-soaked in a 10% sugar-water solution for 20 minutes, dried and then used in the plateholder as normal.

The full plateholder I'm using is the one described in the Rebuilding section combined with two plates of glass taped together on one edge.  The glass plates used to be holographic plates that I had removed the emulsion from.  Before exposure I sandwich the film between the plates, tape the top together and then add a binder clamp for good measure.  At some point I'll probably get around to using an index-matching fluid but for now these are working fine.

Wednesday, February 19, 2003

Last night (or, I should say, this morning.  I got home at 12am and rather than going to bed I prepped the lab for a shot in the "morning") I spent some time trying to get the beam ratios to a more optimum level.  The readings I got from yesterday were in the range of 10:1 and I twiddled the beamsplitter to get them to 2:1 for another test shot.

Everything else was the same, 10% sugar pre-soak and normal JD3 processing.  The only problem I encountered is that I didn't give the film enough time to dry after the soak.  It stuck to the plate while settling and I had to pull somewhat hard to get it off.  I also need to pick up a smaller squeegee as the large one I have (it was last used for 4x5" film) is just too large for these small tests.

Yeah, boring shot.  this is today's hologram sitting in the bleach wash.  Ordinarily I'd be swishing it around but I was obviously busy with the camera.

The same film in the post treatment bath.  This is as it's just as it's showing signs of browning under the light.

And again a bit further along.  I let it get 50% darker before rinsing.

Present
2003: Feb | Mar | Apr | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2004: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
2005: Blog
2006: Blog
2007: Blog