Holographyforum.org / holowiki.org

Hello
This night, i’ve made my very first silver halide hologram!
This is an endemic Cuban snail “Polymita”.
It was shot using DVD-writer laser, on BB640
plate.

Saludos,

Raúl.

Congrats.

These tree snails are very beautiful. I found a web page about them:
http://www.geocities.com/Eureka/Gold/94 ... hompg.html

How is your diode laser configured?

This is a 100 mw laser but only 50 mw useful for holography.
I focus it through a pinhole (home made spatial filter), then
expanded using divergent lens. I use pinhole because diode
window is difficult to clean so I can´t use naturally divergent
laser beam. Removing diode window isn´t a viable solution for me too.
Saludos,

Raúl.

Congratulations! Very nice!

Very cool, I did not find anything about Polymita on Wikipedia or goggle.. have you a photo to compare with hologram?

-Unfortunately (or fortunately? ) only visiting Cuba we could see one...

Great Raul

Try painting black the backside of your holo to increase contrast.
Will you send a video to Youtube ?
How long did you expose ?
Did you use any presensitizing ?
What kind of bleach did you use ?
What is the viewing angle ?
What are your spatial filter parameters ?

greetings
Adam

This snail Polymita (I’ll send photo soon) can be found only in he north-eastern region of Cuba, where I was born. There is a natural sciences museum with a great collection of them. But recently I discovered that in Havana, they are indiscriminately sold by some people to tourists.
I tried to make an exposure of 0.15-0.30 mj/cm2, as required for these plates. So, I expanded beam to 25 cm diameter, and make a 3-5 sec exposure.
I presensitized in water with some dish washer, to solve possible plate desiccation.
TJ1 developer was used, and sulphuric-dichromate bleach.
Spatial filter was made with a cheap collimator lens from a laser pointer and a homemade pinhole made on aluminium foil using a needle. It was mounted in a homebrew mounting, so hole position can be adjusted. I have to recognize that no calculations where made on this. I just tried several times until got a reasonable beam quality.
I’ve shot a pair of other holos, but they are very dim, under the same conditions. I suspect on movement, due to poor quality of object and plate holder, or may be problem in reusing developer from plate to plate?

Hi Raul,

I found when making pinholes in foil that it worked best if I layered the foil to about 10 layers then made a pinhole. Usually I was able to find the right diameter in the 4th or 5th layer. I can't remember where I heard that tip but it worked pretty well.