How do you make Agfa 8E75 T3 HD sensitive to GREEN light

John Sonley · Post by **John Sonley** » Thu Oct 18, 2012 9:44 am

Ed - I'll ask my buddy Jem to come in on this one - he's the one trying to get green sensitive film and I think he's already tried to use red Agfa on green light.Based on thiose curves you've included, which I've studied on the original Holotest publicity - yes, the red filomj does have some sensitivity to green - but it's about an order of magnitude down

Dinesh · Post by **Dinesh** » Thu Oct 18, 2012 11:01 am

Jeffrey Weil wrote:The classic "need corp account" problem!

It's really not a problem. When those companies ask for a corp account they don't check anything out. They just keep going on the order form.

Next time a company like that asks who you are just make up a company name. Seriously, this will work.

So don't say, I Jeff W need some chem, you say, I from J.W. Holography Inc. need that chem. Problem solved just that easy. Sometimes they will ask for an email or fax on company letterhead......Microsoft office is your friend.

Jeff W

Actually, Jeff, it's really not as easy as all that. The controls on chemicals are tightening. After almost 10 years of getting dichromate, recently I had to sign a waiver of sorts declaring why I wanted the dichromate. I was consulting for a very well know holography company last year and they ran out of pyrocatechol. They ordered some more from Sigma Aldrich (with whom they'd had good relations for years) and waited and waited and waited. In the end, it turned out that this company did not have a "company account" and so the order just froze. Apparently Sigma Aldrich required some new paperwork that this company was unaware of. In fact, dichromate is a banned chemical in some European countries and, some feel, soon may be banned here. Pyrogallol is already banned here (the reasons are immaterial, it's actually banned). That's not to say there are not sources on the internet, but sooner or later they'll dry up too. I think it'll soon become a problem for a lot of holographers.

Jeffrey Weil · Post by **Jeffrey Weil** » Thu Oct 18, 2012 11:13 am

Hey Dinesh,

Sure, you had to write them a letter or whatever....but did they check with the state you see if your a real corp or not. No, they did not.

I'm not saying they wont mess about with paperwork, they will. But they don't ask for anything "official" or registered.

Just write what they want and your good to go. Now, if it's a chem that even corporations have a hard time getting that's different. I was just refereeing to the whole corp account thing.

Jeff W

Joe Farina · Post by **Joe Farina** » Thu Oct 18, 2012 11:44 am

Unfortunately things have changed drastically in the last 20 years, especially in the last 10. Back in the late 80's, I was able to get mercuric chloride as a private individual, no problem. I used to have an account with Alfa Aesar for many years, which I cherished, but they cancelled my account, because I hadn't placed an order with them recently. This year, I was stopped dead in my tracks for 4 months, because I couldn't get TMG.

Jeffrey Weil · Post by **Jeffrey Weil** » Thu Oct 18, 2012 11:58 am

mercuric chloride! Holly $%#@

I guess it depends on where you go too. I also tried getting that in the 80's. From the formulary.

Their response was amazing. At first they asked in a questioning voice...."are you really sure you want that"? Then they told me I could buy it from them but there was absolutely no way to get it to me. Not by ground, not by air.

They said I had to go and pick it up from the counter! I'm in Florida, pretty far away from Montana.

I guess Joe it's not just what you want, or what year it is...it's also about who your ordering from. Your place in the 80's would ship mercuric chloride but mine would not.

Jeff W

Joe Farina · Post by **Joe Farina** » Thu Oct 18, 2012 12:24 pm

Jeffrey Weil wrote:it's not just what you want, or what year it is...it's also about who your ordering from.

Yes that's true Jeff. I've recently seen some other sources for TMG, and one of them might allow the order to go through. Hopefully some companies will try to fill in the gap, left by others who are very restrictive.

There is also a danger in buying chems off eBay, they may not be of adequate quality or purity. I had a recent problem which was probably due to some acetic acid (eBay) and a definite problem due to some contaminated IPA (online purchase from an unfamiliar supply company).

dannybee · Post by **dannybee** » Thu Oct 18, 2012 12:38 pm

hey John I can spot you dye .I have more than enuff. I would send it like jeff sent me in a birthday card

dannybee · Post by **dannybee** » Thu Oct 18, 2012 5:44 pm

I have used iso to load the dye, It doesnt have to be Methanol, and it makes it much better sensitivity

Jem · Post by **Jem** » Sat Oct 20, 2012 3:26 am

Great thread, and thank you John for starting it

Hopefully another four weeks and I should be able to get back to some holography. It's been crazy busy over the summer so everything had to be put on the back burner.

Can't wait to get back in the Lab (err.... shed

)

@Ed... Yes, I tried a couple of sheets of red sensitive Agfa with a 532nm laser. It does expose but it puts up the exposure time (and therin lies the problem). I'm trying to get exposure times as short as possible as my table seems not to be as stable as it perhaps ought to be over long periods

Take care guys and thanks for all the help.

Regards

Jem

John Sonley · Post by **John Sonley** » Sat Oct 20, 2012 3:56 am

Danny - thanks for the offer - I've sent you a pm