My latest H2

Jem · Post by **Jem** » Sat Aug 27, 2011 2:15 pm

Hi all

Today is a good holography day

This is what I've been working towards for the past few years...

5" x 4" H2. 35mW HeNe, 15 second exposure, developed in Pyrochrome, bleached in Acid Dichromate.

It's been a long time and it's caused a lot of hard work and heartache, but I am now confident my table is finally stable

Jem

Jeffrey Weil · Post by **Jeffrey Weil** » Sat Aug 27, 2011 6:35 pm

Hello Jem,

Excellent job. It looks great.

I especially like that you made it into a final, finished piece. You didn't stop at tests.

We need more posts like yours.

Jeff Weil
NorthBeach Holography Inc.

Kiffdino · Post by **Kiffdino** » Sun Aug 28, 2011 2:26 am

Very nice. Looks very clean and sharp.

Jem · Post by **Jem** » Sun Aug 28, 2011 2:41 am

Thanks guys, the support i've had on this (and the other) forum over the years has kept me going when things were looking pretty dire. I've taken on board the many suggestions that have been given to me and followed a lot of the great advice regarding getting my table sufficiently stable. I'm a pretty determined sort of person and never lost the belief that one day i'd be producing holograms worthy of showing to you all.

I also have John Sonley to thank, as without his help I would probably still be making single beam denisyuks.

One thing I didn't mention in my OP (and you can't see in the photo) is the fact that the base of Buddha sticks out in front of the plate by around 25mm, his hands are just in front of the plate and the rest of his body is behind the plate. This H2 was made from a 7" x 5" transmission master so the parellax is quite good on the finished H2.

Cheers

Jem

Jem · Post by **Jem** » Sun Aug 28, 2011 3:27 am

I've just taken a bit of video with my iPhone and uploaded it to Photobucket...

http://i660.photobucket.com/albums/uu32 ... e1de3f.mp4

Be patient, it'll take a couple of minutes to load

kaveh1000 · Post by **kaveh1000** » Sun Aug 28, 2011 4:35 pm

Great job. Nice bright image.

If you try this again, I would reduce the beam ratio, so have more reference beam than you have now. Right now, I bet you can clearly see the image projected from H1 on a card, even when the reference beam is shining on it. This means you have significantly differing total exposure on different parts of the H2, and you get variation in playback color and brightness. The tell-tale is the "burn-in" best seen at the edges of the image.

My rule of thumb was to have a brightness of the image beam such that when you blocked it, you would just see the brightness change.

Jem · Post by **Jem** » Mon Aug 29, 2011 3:50 am

kaveh1000 wrote:Great job. Nice bright image.

If you try this again, I would reduce the beam ratio, so have more reference beam than you have now. Right now, I bet you can clearly see the image projected from H1 on a card, even when the reference beam is shining on it. This means you have significantly differing total exposure on different parts of the H2, and you get variation in playback color and brightness. The tell-tale is the "burn-in" best seen at the edges of the image.

My rule of thumb was to have a brightness of the image beam such that when you blocked it, you would just see the brightness change.

Thanks for your kind comments

I'll adjust the ratio and give it another go. I had the ratio on this one set so that at the brightest part of the H1 (projected) image I was getting 1.5 ref Vs 1 object.

I'll report back

Jem

Tony · Post by **Tony** » Mon Aug 29, 2011 8:31 am

Wow excellent job Jem. The video really compliments the work.
Continued best of luck to you.
Tony

Jem · Post by **Jem** » Mon Aug 29, 2011 9:24 am

O.K., so i've just made a couple more holograms using the same subject. I increased the reference beam slightly and now there's virtually no latent image burned into the plate as before. As to whether it's that much brighter... The Jury's still out on that one

One thing that I did do on the second hologram was up the exposure time slightly. This seems to have shifted the end result towards the green instead of gold.

Cheers

Jem

kaveh1000 · Post by **kaveh1000** » Mon Aug 29, 2011 3:24 pm

I don't seem to be getting notifications of the thread, so not replying quickly.

Glad you got a more uniform image. Actually probably it will not be as bright, but I think better compromise. Keep us posted on new images.