Back in the lab

You ever look back at something you did months ago and wonder, "why did I do that?"

I did that this evening with the controller that I’ve got in my lab.

I’m starting work on another hologram for a professor at A&M and needed to do a bit of maintenance on the table. Strange, but every time a new hologram request from her comes in, there’s something that needs doing in the lab before I can get started.

This time the HEPA fan wasn’t shutting off during an exposure and the table light sensor wasn’t working.

It turned out with the HEPA fan that somehow I’d wired up the relay connection with an additional 5v going to it. I have no idea why I did that. Fortunately it just caused the controller chip on that port to heat up (and not work) but didn’t blow anything. Odd that it was working for a while and then just stopped.

The light sensor just turned out to be a loose connection at the junction between the table wiring and the controller wiring. Gremlins.

I also found a problem with the holocontroller software not always shutting off the fan and fixed that.

Now I just need to straighten up the lab, prep some film, paint the subject and shoot. All tomorrow morning.

December lab update

It’s been a busy year in a number of way which is why I haven’t been posting too many lab updates and tutorials.

I’ve got a number of tutorials in the pipeline and pictures that need taking but the next two weeks promise to be just as full so I’m not sure how much I’ll be able to get to while I’ve got the time off my "day job." We’ll see though.

Click through for some pictures and descriptions of what I’ve been up to.

Continue reading December lab update

Aligning an external mirror laser

For several weeks I had a functionally dead Spectra Physics 907 laser. This was especially bad because this laser is the one I use for mastering my holograms which meant I couldn’t make anything new until it was fixed.

During those weeks I picked brains and websites far and wide and managed to get the laser lasing again (several times in fact) but couldn’t get the beam quality back the way it was before I screwed it up. I ended up enlisting the help of a local laser expert and was able to get beam power and quality back where it needed to be.

What follows is a tutorial on how to re-align an external mirror laser. Most specifically the Spectra Physics 907. I also include some tips on cleaning the mirrors and removing stuck boots.

Before I go any further I want to thank the following people:

The guys at the Holography Forum who provided suggestions for getting the beast aligned. Tony, BobH, Wler, Colin, Ron Michael, Martin, JohnFP, dcgman.

Sam Goldwasser for making public such a treasure-trove of information about lasers.

Tom Ehrichs for spending time cleaning and aligning the laser. I gained as much by watching him work as I did by him working.

Continue reading Aligning an external mirror laser