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Panchromatic Emulsion

Joe;

They are not banned. The good ones are very difficult to make with a limited market and therefore very expensive. They run about $100+ / gram. Thats about the whole story in a nutshell.

PE
 
The larger companies,specificly Aldrich will sell some dyes
to anyone. But other specific dyes may be sold only to businesses and institution. Sometimes it is difficult to see the reasoning behind Aldriches classification of these dyes. I have not tried Fisher Scientific, but when I purchased some filter paper from them last week, the invoice had, in big bold letters "DO NOT SHIP CHEMICALS". I do not know if this is common, or if I am on the industral equivalent of a "NO FLY LIST". I am not an Arab, have never been in a Mosque, nor have I ever sent a nasty letter to a public official. In fact, I have had security clearances for some of my jobs. I think that it is "one Rule Fit All".
Bill
 

Nor am I, but it seems to get harder to get supplies every year. Just a venting.

Joe
 
Just don't ask about buying iodine or phosphorus - they'll mark you as a meth cook and you'll never be able to buy anything.
 
Kirk,
Anyone who has bought crystaline Iodine from The Formulary has filled out a "DEA card". I don't know who gets these cards, but I have never been"Raided"(yet).
Bill
 
dwross said:
'The Photographic Emulsion' by Carroll, Hubbard and Kretschman', Focal Press.
Click to expand...

That book has been on my want list for a few years now. First time I think I've ever heard of an actual copy of it.

Ed
 
Bill - how's it going? Did you get your analytical balance? My 3-place balance arrived today, I need to take the top off as it looks like the wieghts have gotten out of position during shipping.

Kirk
 
Interesting Kirk.

I just got a "surplus" Kodak/Sartorius 10Kg 3 place scale for $100 at a scrap yard. It is in perfect condition and still has the Kodak ID tag. It is a monster with a top plate about 1 foot square and must weigh in at nearly 10 kg itself. It has a centering level on the top and I/O ports on the back so it can be computer driven. New, it must have cost a mint.

PE
 
Hi Kirk,
Things came up, and I was not able to pick up the balance personaly. It was shiped to me yesterday. My sensitization dyes are still in the freezer. As soon as I get the balance and have made sure that it is properly calibrated, I will let the unoperned dyes come to ambient temperature befor I open them. Then I will weigh and ship to you and the other person who requested portions.
I have been working on a "special" project about which I am not ready to go public. But soon you will read about it in some form.
Cheers,
Bill
 
Photo Engineer said:
I just got a "surplus" Kodak/Sartorius 10Kg 3 place scale for $100 at a scrap yard.
Click to expand...

Wow - that sounds nice. I bet that did cost a lot when new.

I pulled the top on my balance, and there was what looks like a box knife blade stuck to the magnetic dampener. But the mechanism is still out of alignment. Fortunately there is a shop in town that specializes on repairing analytical balances. I'll drop it off and see what they say. At least it was only $25.

Ahh, the joys of ebay...
 
Hi all,
Ijust received my Answorth mechanical anylitical ballance. It looks clean and complete. Exept that some of the weights and other internal parts are "diconected". Fortunatly, the service who last calibrated it in 1983 is still in busines and only about 50 miles from here, in Burbank. I will take it in on Wednesday ,and hopefuly get it up and running.
Bill
 
Sounds good - I've decided to try again at another used balance - this time a 4-place. If it's going in for service, I might as well get something that is really worth fixing. SO there's another $40 into an analytical balance...
 
 
Bill;

Chrome alum is the preferred hardener for gelatin on glass regardless of preparation according to two experts, one of whom coated glass plates commercially.

Usually, you use either chrome alum or glyoxal at 10% in water, but remember that they both decompose over time. Also remember that glyoxal is nominally 40% in water so a 10% solution of that is actually 4%. I use the same liquid measure of either one, but they are both sensitive to other ingredients and I have had melts harden up instantly with both based on the pH and other ingredients present. And, due to the mix of ingredients and the expense, I was unable to identify the precise nature of the problem.

Maybe someday I'll revisit the issue, but for now, I know that Chrome Alum or Glyoxal at equal liquid measure at nominal 10% dilution works. There is more precise information on this in your class notes.

PE
 
 
Bill;

I have seen the sensitized emulsion, but have never worked with it. At our last lunch at GEH, Mark Osterman had about 100 ml of Chlorophyll sensitizer there to show us. Our next lunch is Tuesday. If I can go, I will ask him about it.

PE
 
Bill - did you buy some chlorophyll? Or did you extract it?

It should be easy to grind up some spinach and then leach it with acetone and filter. A little magnesium carbonate can stabilize solutions, but chlorophyll degrades with exposure to light and I think it should be stored in the freezer.
 
Yes, I should have added that chlorophyll is not very stable once extracted and suffers if one overheats it during the sensitization process. It is reported to be very difficult to work with due to this stability problem.

There are some plants that yield "better" chlorophyll than others. This should be available in the literature, but I'll check if I can.

PE
 
Kirk and PE,
Thanks for your support. Kirk,at first I mistook your advice about spinach as pure sarcasm. But now I realize it is a valid suggestion. Why acetone and not methanol? I have found reffrences to extraction via methanol.
As to where I got my chlorophyll, I have used both an aquious suspension and a dry powder. Both were supplied as chlorophyll/copper compounds. In either case a methanol extraction, worked the best, as evidensed by shooting a color chart in daylight.
PE- I am going to give the SDA3057 a second try once I receive my new shipment of silver,later this week. I want to keep both methods going.
 
Bill - my info on chlorophyll is from doing the Standard Methods test for chlorophyll. They filter the algae, grind the filter with the algae in a tissue grinder using 90% acetone with 10% water saturated with MgCO3 as the extraction fluid. Then we centrifuge to get rid of the tissue and filter residue, and then analyse it for the chlorophyll content. So that's where my thoughts come from.
 
I would not use the form containing copper. It has potentials for side effects. Acetone may not be good either. The samples I saw, I was told, were extracted with Everclear.

PE
 
What effects would acetone have? I seem to remember that Bill can't get Everclear in California, but I can in Oregon. At least according to wikipedia, he can't get 190 proof Everclear, but he can get 151 proof. Interesting, you can't buy 190 proof Everclear in New York state as well!
 
Well, at our lunch today, all agreed that acetone was not good as it can interact with gelatin and other emulsion ingredients.

Use either ethanol or methanol for extraction, and some suggest common Ivy as a good source for fresh chlorophyll. I am told that coating the plate first and then bathing in alcohol+chlorophyll is best.

I am supposed to get some references.

PE
 
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