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Well, good news and some problems!
First, I tried a Single Beam Reflection with the same exposure as the transmission gratings, ie 120 mJ. Nothing! This corresponded to a 4 minute exposure on my setup, so I went with 6 minutes. Nothing! Then I doubled the exposure to 13 minutes and got something. It was dim, but under direct sunlight you could make out an image. So, I kept increasing the exposure. Finally at 25 minutes I got this: So, in conclusion, the material can be used to make holograms. The sensitivity is very low, almost 4 times dcg for transmission and about 10 times dcg for reflection. This may be solved by altering the proportions of the components maybe? The brightness is similar to dcg brightness.

Dinesh wrote:Finally at 25 minutes I got this:

Congratulations, Dinesh! The good news really is that you got an image at all.

This may be solved by altering the proportions of the components maybe?

Yes, that's what I'd hope too:
- You might put in more FAO;
- switch from FAO to FAC (= ferric ammonium citrate). I assume it will have better light absorption at 457nm (at 405nm it was far less efficient than FAO. Moreover, once in solution, it has to be cooled to prevent mold formation);
- try thicker or thinner layers;
- choose another gelatin (I might send you some of my culinary stuff - let me know).

Did you add a surfactant?

Yes another thing came to my mind. Listening to the radio in the early 1970s (?) we were brainwashed to take for granted: IT NEVER RAINS IN SOUTHERN CALIFORNIA.
Based on that, may I assume the relative humidity in your lab is pretty low - say <50%?

Dinesh wrote:Well, good news and some problemsThe brightness is similar to dcg brightness.

what's the formula & process Dinesh? so I can try this on my end.
ther are some forulas on http://www.silverprint.co.uk/recipes.asp dont know if this will work

Martin wrote: choose another gelatin (I might send you some of my culinary stuff - let me know).

OK. I have Knox gelatin at 200 bloom and 300 bloom. If you send your gelatin, I can give that a try.

Martin wrote:Did you add a surfactant?

Yes. Three drops of Kodak Photoflo to my mix of gelatin and FAO.

Martin wrote:IT NEVER RAINS IN SOUTHERN CALIFORNIA.

Well, it does rain in Southern California, but usually not much. Sometimes, like last year, it rains A LOT!! I had dcg holograms disappear right in front of my eyes! I also lost a nice Rabbit Holes hologram. Normally, we have unsealed dcg's from years ago. However, yes, usually, RH<50%

ooo Iron-silver this might be interesting using the hardning of the Ammonium Ferric Citrate, and the senitvity of Silver

The Process
Sensitiser

note: rinse all utensils in distilled water before use.
Make 3 separate solutions;

6g Ammonium Ferric Citrate in 22ml distilled water
1g Tartaric Acid in 22ml distilled water
2.50g Silver Nitrate in 22ml distilled water

dannybee wrote:what's the formula & process Dinesh? so I can try this on my end.

Here's what I did

Dinesh wrote:30 gms 250 bloom pork gelatin
6 gms FAO
300 mls water

Processing was as follows:
10 seconds in 1% Hydrogen Peroxide
2min water @ ~ 18 deg C
dehydration with IPA as per dcg

Dinesh wrote:

Martin wrote: choose another gelatin (I might send you some of my culinary stuff - let me know).

OK. I have Knox gelatin at 200 bloom and 300 bloom. If you send your gelatin, I can give that a try.

I'll send you a PM.

Sometimes, like last year, it rains A LOT!! I had dcg holograms disappear right in front of my eyes! I also lost a nice Rabbit Holes hologram. Normally, we have unsealed dcg's from years ago. However, yes, usually, RH<50%.

I see, sounds quite dramatic - hope everything is back to normal again.
I seem to remember that most of the ferric processes need some degree of humidity in the layer. So low RH might be an issue. In my lab I usually have >70% RH.
Adding some humectant, e.g. sorbitol (say up to 5% of the weight of gelatin), may help. I'm not sure if glycerol would be a good idea...

dannybee wrote:ooo Iron-silver this might be interesting using the hardning of the Ammonium Ferric Citrate, and the senitvity of Silver

The Process
Sensitiser

note: rinse all utensils in distilled water before use.
Make 3 separate solutions;

6g Ammonium Ferric Citrate in 22ml distilled water
1g Tartaric Acid in 22ml distilled water
2.50g Silver Nitrate in 22ml distilled water

I tried that one. At 405nm that mixture didn't produce anything holographic. Speed was low. I believe the material doesn't provide the necessary resolution. Note by the way, that these ferric/silver nitrate mixtures are supposed to produce metal (= "black") silver. So similar to AgX, you'd have to bleach the layer subsequently.

I agree with Martin, Danny's formula looks like a Van Dyke process variation, where the FAC reduces the silver nitrate to silver, but of a colloidal, not black, variety, yielding a luscious brown tone. FAC is the light sensitive compound, the silver is there for the density, not unlike the role FAC plays in changing potassium ferricyanide to the Prussian Blue potassium ferrocyanide in the cyanotype process.

See for instance, Christopher James, The Book of Alternative Photo Processes, p. 219 et seq.