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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, March 4, 2003

If you've seen the latest rebuilding entries, you'll have seen the canopy and new table I've put together.  Since then, I've replaced the canopy with thicker black plastic (the idea I had that clear plastic would be less unattractive to my mate was rubbish.  The black isn't any worse and has the benefit that I can open my office door without ruining film).

With the new canopy in place, I've been running as many tests as time would allow.  I'm off to build an exposure robot (more details later) but here are a couple of shots of recent successes.

This is an etched-glass sculpture that Susan gave me on our anniversary.  It reminded her of us in that they're locked together kissing and up on their toes like Irish Dancers.

My version of the porcelain cat (Holography Forum denizens will know what I'm talking about).  Snoopy is my ideal test subject.  He's bright shiny white and sits still for long periods without complaint.

Thursday, March 6, 2003

Here are a few pictures of the in-progress hologram control R2D2 robot.  I've been doing some research with the goal of automating the settling and exposures (so that I can reduce the chances that me moving about will ruin a hologram) and I realized I already had what I needed.  A Lego Mindstorms kit.

With that in mind, I started coding up an exposure control program.  I finished it this morning and so far, it works well with the test shutter and light meter.

I've got two touch sensors that I use for incrementing and decrementing the settling and exposure times and one more that is used as an "accept" button to tell the software that a given entry is complete.  The software automatically goes into "settling" mode after the times are set.  Once settling is complete, it automatically opens the shutter for the required amount of time, closes the shutter and plays an alert sound (all appropriately R2D2 sounding).

There's also a light sensor that will eventually be used to verify that the shutter is open and closed at the right times.

I've been doing a fair number of tests with the laser diode recently and was getting good results when I managed to crack the housing lens.  Apparently they should never be cleaned with alcohol.  As I was cleaning it, it just cracked right across the middle.  I've since ordered another three ($8 each) and expect to start some more experiments with the laser diode next week.

In the meantime I've been working with my old trusty 5mW HeNe and cranking out some good Snoopygrams.  I'm going to make several as giveaways and then make some single-beams of other subjects.

Sunday, March 16, 2003

Holo-bot hard at work.  I keep him in the bathroom next to my office.  He's off the floor and much happier.  The NQC source for the controller program is available here if you would like to play around with it.
In the background you can see the remains of a shoot and my washing up area.

In order from the left to the right are: the laser, my shutter (the small square just to the right of the laser exit hole), a card to block back reflections from upcoming optical components, a lens that increases the spread of my spatial filter, a card to block light reflected from the spatial filter mount, the spatial filter.

All of that cleans up and spreads the beam which is then bounced off this transfer mirror and

Shines the cleaned-up beam onto Snoopy.
Yes, that really is a paint can with the laser taped to it and yes, it really does work just fine.  At the time I put this layout together, Snoopy was on the only stage suitable for putting the laser on so I had to make do with what I could scrounge.  Having recently painted my office (and still needing to finish up some of the edges) I had a small full can that was just the right height.  So I taped the laser to the can.  The foam at the top allows the laser to move so that I can rotate it when I need to change the polarization.  Btw, I normally have a large black card between the laser and the film to block any stray light.  I've removed it so you can see the components.

The trilobite-shaped thing in the fourth image is a Millennium Falcon that will end up on film sometime soon.

Monday, March 17, 2003

And here's the final Snoopygram.  It's extremely clean and bright.  I made one on Sunday and two more this morning.  They're all nice bright clean single-beam holograms.

One note about the spatial filter.  Until I'd put that sucker back into my setup I'd forgotten just how much it cleans up and brightens the holograms made with it.  It actually does make a huge difference in the quality of my holograms, not just because it removes the odd swirl from the beam but because it evens out the entire beam.  Get one, you won't regret it.

Wednesday, March 19, 2003

I've been on an absolute tear making copies of the Snoopygram as giveaways.  This morning I made my first hologram of the day such that it wasn't pre-soaked in the sugar solution and plays back red.  I had intended to try using that for making contact copies but I have to rotate the master about five degrees in order for it to play back brightly.  I think things will go better if I set things up to create a transmission master and make copies from that.

I followed up by making two more green versions of Snoopy.  Tomorrow I'm going to make a double-sided version and see what happens.

Thursday, March 20, 2003

This morning I did several shots.

I did a double-exposure of Snoopy.  For the first exposure I had him in the orientation you see above and for the second shot I rotated him 180 degrees and flipped the film.  I ended up with a somewhat dim hologram that when you turn it you can see either side of Snoopy.

I also tried to do some test shots of the Millennium Falcon and a Celtic stone.  Unfortunately they didn't come out well at all.  The details follow from the post I made on the Holography Forum.

Saturday, March 22, 2003

"Holograms certainly can be a forgiving (or masochistic) species" (posted the Holography Forum).

I was going through a frustrating phase last night.

I had created a few holograms on Thursday morning and they had come out all foggy and looked either overexposed, burned-out or I'm not sure what.

I was certain that I had not overexposed them since I'd used the same exposure times as my successes the previous several days and I hadn't changed the table layout other than to use different subjects (I had enough Snoopygrams for now). The things I changed though are that I did not pre-swell using 20% sugar (which works really well btw) and instead, I used fixer to change the color.

I made that change only because I was in a bit of a hurry and didn't want to take the hour that it takes to prep, swell, squeegee and dry the film.

Well, last night I started a series of tests to determine the best way to use a processing regime with fixer and I made a number of holograms and varied the exposure times, distance from the plate to subject, fixer times, etc. All of them came out foggy (although the real images didn't show the same fog).

Virtual

Real

The next to last test consisted of processing a hologram and leaving the fixer out. That resulted in a red hologram, visible mainly in strong laser light (IE, dim) but with no discernable fog. Interesting.  Interested in that's what I would normally have expected.  It appears that the fixer is causing all sorts of problems.

Ok, by now you're wondering what all this has to do with the subject. Here's how...

For the last test I pre-soaked a piece of film in 10% TEA solution (I was out of sugar water and didn't feel like making more. Yeah, I'm lazy but I'm always learning new things and a day where you learn something new is a good day), squeegeed, let it dry for several hours (I had margaritas waiting for me) and exposed.

The forgiving part comes in when I'm removing the film from the holder and some of my office lights come on. I have X10 controllers strewn liberally around my house and these in my office are on an automatic schedule so that our house looks lived in when we aren't here. Unfortunately the controller can't tell when we are here and the lights came on last night like they always do.

I had a brief moment of combined panic and disappointment, then tried to shield the film with my body (the lights were behind me), spied an open plate carrier (from the days when I could get Agfa plates), threw the film in the box and doused the lights.

At this point I'm wondering if it's even worth trying to develop the film. I decide that it is. After all the developer had already been used on three pieces of film and had been sitting out, but covered, for something close to six hours so why not combine ruined film with exhausted developer.

So I throw the film through the chemicals, watch it go dark really fast in the developer, clear really slow in the bleach and I don't bother to give it the full time in the post treatment. I toss it into a container and run water over it while I rinse all the trays and then leave it in the water while I go to bed.

This morning I get up, towel it off and let it sit to dry.

What do I end up with? A fairly decent bright green hologram. You baby them and end up with chemicals all over you, you abuse them and they come through for you.

Later in the afternoon I quickly made a housewarming present for a friend who really likes R2D2.

Unfortunately the pictures are a little fuzzy because I had to hold the hologram and take the picture and couldn't seem to keep my hands steady enough.

Tuesday, March 25, 2003

This morning I ran a print-out test.  I'd asked about it on the Holography Forum because I was planning on sending a hologram to a friend in Jamaica and his most convenient light source is likely to be the Sun.  Unfortunately I had noticed undesirable darkening of some (but not all ?) of my holograms and wanted to find out how I could prevent that.  Most of the replies went along the lines of "don't look at them in the Sun" and I couldn't prevent that (plus, holograms look so good in sunlight).

For the test I used my color board (a white board covered with little dots of paint of various colors that I used to see how they would look in a hologram) and after development I cut the film strip so that I could vary the post-treatment step on some of them keep some of the film protected from bright light while exposing others to sunlight and bright indoor lights.

I found that a post-development bath in 10% acetic acid combined with longer rinse times is preventing print-out with my current developing regime.

Wednesday, March 26, 2003

I did two TEA test shots this morning. I was wondering how long I could go between TEA treatment and development.  One with a piece of film that was treated with TEA on the morning of 2/25 and one with a piece of film that was treated at 10pm on 2/25.

The older piece definitely showed some fogging where there's no image (the "black" areas) but the image itself is nearly as bright as the same hologram from yesterday.

The newer piece shows no fog at all.

While not a rigorous test, it appears that I can get away with at least a 7 hour delay between pre-swell and exposure.

[note added 11/26/03] - Since this test we've frequently soaked, squeegeed and dried film several days, as long as a week, before using it and never noticed any fogging that could be blamed on the TEA.  The only time we've had any fogging of that sort is when we've left the film in the TEA bath for 15-20 minutes.  Five minutes seems to be the magic number for us.

Thursday, March 27, 2003

Today I tried a few latensification tests as recommended by Slavich.  They say that it's optional for CW (continuous wave) exposures such as the ones that I am doing but I wanted to see what the differences might be.  Following their recommendations, it seems that the time I should use is about 3 seconds.

After the tests I did an exposure of the Celtic cross and while it came out nice and bright, I couldn't swear that the latensification had any affect on the final image.

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