Hello
My name is Filipe Alves, from Portugal.
I've been interested in holography for many years, but dealing with holografic silver plates that are quite difficult
to find here in Portugal turned me off so I never tried it for real.
I've been playing around with alternative photography, making Gum Prints that use Potassium Dichromate and Gum arabic,
and when searching for some methods of coating gelatine onto glass I found out that there is a wonderfull
kind of hologram that uses just Gelatine and Dichromate!
So I would like to try to venture onto the world of DCG holograms, but I beleive I need some specific kind
of laser, what kind of laser should I buy, and how much will I have to spend to get one?
Thank you
Best regards
Filipe Alves
http://www.manalokos.com/astro
New holographer, need a laser.
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dave battin
New holographer, need a laser.
hello and welcome to the forum. your best bet is a coherent 315 or 215 laser they will range from 100mw to 10mw, also a JDS Microgreen laser will do. as far as price they will range from $1500(100mw) to $225(10mw) .I would suggest you spend as much as you can afford on the laser, as this will be the heart of your future system. I have 215 lasers to sell ranging in power from 10-30mw in a $250-$425 range. send me a PM if interested, look in our "for sale" section to see these unit as well as other members selling there lasers there..... good luck in your search.
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Tom B.
New holographer, need a laser.
Going directly to DCG with no previous holography experience is the hardest way to get started. Even with prefabricated silver halide
plates & chemistry and a good red laser, there is much to go wrong.
Working with homemade DGC plates, especially if you don't have an blue (Argon) laser, adds MUCH difficulty and might end up discouraging
you entirely. Due to recent work by Jeff Blyth et al, green lasers are now considered somewhat usable for DCG, but the process is not easy.
You should at least try making a holo from a kit with instructions, say http://www.holokits.com/catalog.htm
I highly recommend glass plates versus film - one less thing to go wrong. Then, if interest persists, try DCG, realizing
that it will be a real challenge.
plates & chemistry and a good red laser, there is much to go wrong.
Working with homemade DGC plates, especially if you don't have an blue (Argon) laser, adds MUCH difficulty and might end up discouraging
you entirely. Due to recent work by Jeff Blyth et al, green lasers are now considered somewhat usable for DCG, but the process is not easy.
You should at least try making a holo from a kit with instructions, say http://www.holokits.com/catalog.htm
I highly recommend glass plates versus film - one less thing to go wrong. Then, if interest persists, try DCG, realizing
that it will be a real challenge.
-
manalokos
New holographer, need a laser.
Hello, Thanks for the advice!
Tom B., I know it will be quite difficult, but it is great to do the whole process, and
gelatine comes quite cheap so it will be nice for trial and error... (I can imagine glass plates all around the house)
Do I need different chemistry to do DCG with green laser? Or is it just longer exposure times?
For gum printing I use UV lamps, as the dichromate cures with UV so I guess the best would be a UV laser? =)
Are blue argon lasers much more expensive?
Thank you,
Best regards
Filipe
Tom B., I know it will be quite difficult, but it is great to do the whole process, and
gelatine comes quite cheap so it will be nice for trial and error... (I can imagine glass plates all around the house)
Do I need different chemistry to do DCG with green laser? Or is it just longer exposure times?
For gum printing I use UV lamps, as the dichromate cures with UV so I guess the best would be a UV laser? =)
Are blue argon lasers much more expensive?
Thank you,
Best regards
Filipe
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Joe Farina
New holographer, need a laser.
Hello Filipe, and welcome to the forum. Considering your prior experience, I would suggest going straight into DCG.
The laser is important. From the standpoint of wavelength alone, blue is best. The following lasers are best: helium-cadmium (442), Melles Griot DPSS blue (458), and argon (458 to 488). Something in the UV or short blue would be good also, such as nitrogen (337) or a blue ray diode (405) but there are a couple of problems there. Most important is the lack of coherence length, which might allow a hologram of a postage stamp or maybe a coin, but not much else. Also, since the hologram is recorded at such a short wavelenth, a lot of swelling would be needed for the final hologram to get the fringes to diffract (reconstruct) at a good, visible wavelength (going up further towards the red). So I would exclude UV or short blue (405) for those reasons. As for price, it might be possible to get lucky with a HeCad on eBay, but these lasers don't have much power, and usually short coherence lengths. Much better are argon (with an etalon) or Melles blue, both of which would give you all the coherence length needed, and plenty of power. Now for the bad news, surplus they usually cost around 5 or 6K.
Few of us can afford that, but fortunately there are a couple of good options. First, you could use green as Dave suggests. Expect to load your emulsion with a lot more dichromate, and use longer exposure times. I would get as much power as you can afford, preferably 100mW with a 315M or Coherent 532. The commonly-available green lasers that I would recommend are (as Dave said) the 315, Coherent 532, and Uniphase Microgreen. Although there have been some good results with the 215, it's a bit underpowered.
The second option is to use a dye-sensitized DCG emulsion, which is more complicated, but you can use either red (HeNe), green (DPSS 532), or blue (or all three at the same time). That's the way full-color DCG holograms are made. Hope this helps.
The laser is important. From the standpoint of wavelength alone, blue is best. The following lasers are best: helium-cadmium (442), Melles Griot DPSS blue (458), and argon (458 to 488). Something in the UV or short blue would be good also, such as nitrogen (337) or a blue ray diode (405) but there are a couple of problems there. Most important is the lack of coherence length, which might allow a hologram of a postage stamp or maybe a coin, but not much else. Also, since the hologram is recorded at such a short wavelenth, a lot of swelling would be needed for the final hologram to get the fringes to diffract (reconstruct) at a good, visible wavelength (going up further towards the red). So I would exclude UV or short blue (405) for those reasons. As for price, it might be possible to get lucky with a HeCad on eBay, but these lasers don't have much power, and usually short coherence lengths. Much better are argon (with an etalon) or Melles blue, both of which would give you all the coherence length needed, and plenty of power. Now for the bad news, surplus they usually cost around 5 or 6K.
Few of us can afford that, but fortunately there are a couple of good options. First, you could use green as Dave suggests. Expect to load your emulsion with a lot more dichromate, and use longer exposure times. I would get as much power as you can afford, preferably 100mW with a 315M or Coherent 532. The commonly-available green lasers that I would recommend are (as Dave said) the 315, Coherent 532, and Uniphase Microgreen. Although there have been some good results with the 215, it's a bit underpowered.
The second option is to use a dye-sensitized DCG emulsion, which is more complicated, but you can use either red (HeNe), green (DPSS 532), or blue (or all three at the same time). That's the way full-color DCG holograms are made. Hope this helps.
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Tom B.
New holographer, need a laser.
Here's Jeff's green DCG recipe: http://www.holowiki.com/index.php/G307_DCG_Formulamanalokos wrote:Hello, Thanks for the advice!
Tom B., I know it will be quite difficult, but it is great to do the whole process, and
gelatine comes quite cheap so it will be nice for trial and error... (I can imagine glass plates all around the house)
Do I need different chemistry to do DCG with green laser? Or is it just longer exposure times?
For gum printing I use UV lamps, as the dichromate cures with UV so I guess the best would be a UV laser? =)
Are blue argon lasers much more expensive?
Thank you,
Best regards
Filipe
Since it is a new development, there is not much data on how well it works with different types
of gelatin etc.
Formerly, only Argon lasers were thought suitable for DCG. Here's one surplus dealer listing
http://www.lasersurplus.com/products.php?subcat=Gas
Looks like you can get something for less than a couple thousand. Without an etalon though, (an addtional expensive piece of
optical gear which will likely be hard to find) the depth of hologram you can make will be only a few inches at best But then,
bright DCGs will not have much depth anyway. Solid state blue at 488 nm would be ideal, but these are still expensive - the ones you
want (Single Longitudinal Mode) are still very expensive in the 10K $ range.
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manalokos
New holographer, need a laser.
Hello,
Thank you all of the advice,
Dave got me a nice 215 30mw to get started,
now I have to start training the gelatine coating process.
That G307 formula looks nice, and does add new possibilities
to other photographic methods like "gum bichromate", I didn't know that glicerine would
sensitize Dichromate to lower wavelenghts!
There are a lot of crazy setups I want to try
once I get to make the first successfull holos, I can't wait to start! =)))
Best regards
Filipe
Thank you all of the advice,
Dave got me a nice 215 30mw to get started,
now I have to start training the gelatine coating process.
That G307 formula looks nice, and does add new possibilities
to other photographic methods like "gum bichromate", I didn't know that glicerine would
sensitize Dichromate to lower wavelenghts!
There are a lot of crazy setups I want to try
once I get to make the first successfull holos, I can't wait to start! =)))
Best regards
Filipe
-
Colin Kaminski
New holographer, need a laser.
Make sure to handle dichromates safely! They are a poison.
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manalokos
New holographer, need a laser.
Thanks Colin,
I know, it can be quite dangerous, specially in gelatine,
dichromated gelatine sticks everywhere, including the skin.
This way I think I managed to get some micrograms in my mouth
the other day even after washing the hands carefully! It is really not a good experience! Burning sensation
of the nasal cavity and mettalic taste in the mouth. Scary!
I still have done no holograms, but I am converted to the uncle Dave's Dip-n-shoot
method! It is much safer.
Best regards
Filipe
I know, it can be quite dangerous, specially in gelatine,
dichromated gelatine sticks everywhere, including the skin.
This way I think I managed to get some micrograms in my mouth
the other day even after washing the hands carefully! It is really not a good experience! Burning sensation
of the nasal cavity and mettalic taste in the mouth. Scary!
I still have done no holograms, but I am converted to the uncle Dave's Dip-n-shoot
method! It is much safer.
Best regards
Filipe
-
holo_cyware
New holographer, need a laser.
An interesting fact I noticed is that every time I work with AmDi in any form I feel a burning sensation in the nose, eventually having a runny nose no matter how careful I am (latex gloves, face mask, no dust form handelig (just crystals), sodium metabisulfite shower afterwards (just joking here)). The point is that i'm fairy sure I'm allerging to it, and it's in no way some sort of autosugestion - it took a while till I noticed it.
This clearly shows that no matter what you do, you get exposed to minute amounts anyway. There are risks everywhere, and dicromates are not something to take easily. Still, if you don't plan on salting your food with it and you are careful I think it's an acceptable risk to take. There are many accounts in the industry and it seems one can be exposed for like 20 years with aiborne dicromates, even developing septum perforation, but not necessarily a cancer. It doesn't mean that a simple exposure won't lead to cancer though; it's a matter of luck eventualy.
This clearly shows that no matter what you do, you get exposed to minute amounts anyway. There are risks everywhere, and dicromates are not something to take easily. Still, if you don't plan on salting your food with it and you are careful I think it's an acceptable risk to take. There are many accounts in the industry and it seems one can be exposed for like 20 years with aiborne dicromates, even developing septum perforation, but not necessarily a cancer. It doesn't mean that a simple exposure won't lead to cancer though; it's a matter of luck eventualy.