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.
First silver halide Polymita
First silver halide Polymita
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?
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?
First silver halide Polymita
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.
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.
First silver halide Polymita
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...
-Unfortunately (or fortunately? ) only visiting Cuba we could see one...
First silver halide Polymita
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
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
First silver halide Polymita
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?
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?
First silver halide Polymita
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.
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.