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Ray Rogers
09-09-2008, 09:22 PM
OK Ray,
Now we both know what Ron knows about these dyes.
Bill

Sorry Bill,
I don't think so!

But, just so people do not get the wrong idea,
please let me point out that I never asked you to find out what Ron knows about these dyes...

(Afterall, when I want Ron not to share his knowledge with me, all I have to do is ask him a question! :D!)

Ray

Photo Engineer
09-09-2008, 10:19 PM
Ray;

Of all of the dyes made only a few passed muster and made it into products. Kodak produced over 2000 new emulsions each year but only about 20 made it into a new product. The same is true of dyes. That is about 1% so I did not deal with many dyes. Paul is the one that dealt with all of them AFAIK except for the chemists who made them!

As for Bill's comment, I think he has covered it well. You both know as much as I do, but Paul knows much much more. You met Paul at the ICIS meeting, and in fact he introduced you to me! Ask him if you need more information.

PE

Ray Rogers
09-09-2008, 10:23 PM
Ray, are you happy?

PE
I am happy when my speed and contrast are high, and my fog is low.

The same goes for my emulsions!
:D

Ray Rogers
09-09-2008, 11:24 PM
Ray;

Of all of the dyes made only a few passed muster and made it into products. Kodak produced over 2000 new emulsions each year but only about 20 made it into a new product. The same is true of dyes. That is about 1% so I did not deal with many dyes. Paul is the one that dealt with all of them AFAIK except for the chemists who made them!

As for Bill's comment, I think he has covered it well. You both know as much as I do, but Paul knows much much more. You met Paul at the ICIS meeting, and in fact he introduced you to me! Ask him if you need more information.

PE

Very good response Ron.

It is true that very few actually made into common use.
I don't doubt for one second that the best could have been very well kept secrets. We do appreciate your guiding us around the pitfalls,
especially in such cases as this, where code names are in still in frequent use and we really are forced to... yea, work in the dark.

Several days ago I noticed that the product number you quoted did not appear on their website, so I knew something was wrong... since Bill had said he had bought that dye I thought it wise to confirm before he opened it, that they had not sent him the wrong dye... just today you mentioned that the name and curve you obtained from them were labeled differently and in addition to all this... I have detected changes in their homepage over the last 18 hours as well.

So, would you like to hear the News from Lake Wobegon... ?

Ray

Kirk Keyes
09-10-2008, 01:23 AM
I have detected changes in their homepage over the last 18 hours as well.

Mr. Peabody - "Sherman, this sounds like something for the Internet Wayback Machine."

Sherman - "Mr. Peabody, what's the Internet Wayback Machine?"

Mr. Peabody - "Well, my boy, it's something that I invented in my spare time. I was tired of printing out entire websites so I could keep track of their changes over the years. So I let the Internet Wayback Machine do it for me."

Sherman - "You mean like taking a snapshot of a website, and then storing it online so we can see what a web site was like?"

Mr. Peabody - "Yes, Sherman. Afterall, there's better things to do than stand around on the Internet taking snapshots..."

http://web.archive.org/web/*/http://hwsands.com

Kirk Keyes
09-10-2008, 01:24 AM
Sorry, I couldn't think of any better puns...

Kirk Keyes
09-10-2008, 02:04 AM
Hi Kirk,
I wonder,do you have any sugestions as to other dyes, with published structures , that could be used as green and red sensitizers.

Well, I have no first hand experience, but I have a nice book from the 1940s on infrared photography. It has a really nice section on the history of sensitizing dyes.

It says that Erythrosine was discovered in 1884 by Eder. And that there was a renaissance in dye sensitization in 1904, and that Ethyl Red was one of the first dyes identified at that time. Cole Parmer lists Ethyl Red at about $55/25 grams.

It then says that shortly after ethyl red, came Orthochrome T, Pinaverdol, and Pinachrome - all isocyanine analogues, as was ethyl red.

Then Pinacyanol was discovered, and it was the most important sensitizer for red, and it was used in all panchromatic emulsions up into the 1930s. It was a family of compounds, with one variety marketed as Sensitol Red by Ilford for this purpose in the 1920s. Sigma-Aldrich lists Pinacyanol iodide at $90/gram.

The book says Pinacyanol gave good sensitivity in the red and on down into the green, but that it was also used with Orthochrome T, Pinaverdol, or Pinachrome for increased green sensitivity. Pinaverdol was known as Sensitol Green, to go with Pinacyanol's Sensitol Red name.

Also mentioned, Pinaflavol as a green sensitizer form after the First Great War.

And Kryptocyanine and Neocyanine are discussed as popular infrared dyes from the 1930s.

Ray Rogers
09-10-2008, 02:18 AM
Sorry, I couldn't think of any better puns...

This should be useful.
How often is it updated?
I have no idea how it to explain it if we can't confirm my observations...

I am not even going to try...

except that I did save the version in question...

Thanks Kirk,

Ray

Photo Engineer
09-10-2008, 09:35 AM
Just FYI, Kodak used to list about 20 spectral sensitizing dyes in their chemicals catalog. They are still available somewhere AFAIK, and I have previously posted that list here on APUG. I suggest you look it up and use it to your best advantage. Also, Mees and James has a page or more of data on sensitizing dyes using the same data format that I have used here on APUG. After all, a spectrosensitometer is a spectrosensitometer.

However, doing R&D on sensitizing dyes is a very expensive and time consuming undertaking. Do as much as you wish, but the ones that I suggested here to Bill work very well for Br/I emulsions. In addition, Erythrosine works well if you use the methods I spell out. Data for that is in Mees and James as well.

PE

Photo Engineer
09-10-2008, 10:21 AM
Just FYI, I have found the name to the benzothiazole dye noted above. It is: 5-chloro-2-[5-choro-3-(4-sulfobutyl)-2(3H)-benzothiazolidene)-2-metyl-1 propenyl]-3-(4-sulfobutyl)-benzothizolium hydrixide, inner salt, sodium salt CAS # 30457-67-1

Have fun with that one!

PE

dwross
09-10-2008, 10:26 AM
Hi All,

As some of you know, I am a voracious book collector. I basically look for anything with 'photographic emulsion' in the title, and if the price is right, I takes my chances. I just lucked onto a doozy (I hope). 'The Photographic Emulsion' by Carroll, Hubbard and Kretschman', Focal Press. No copyright except the description that the articles are reproductions of papers written between 1928 and 1934. The book is almost entirely about sensitization - chemical and spectral. Two chapters that look like they especially pertain to this thread are titled, 'Spectral Sensitization of Photographic Emulsions' and 'The Photographic Emulsion: Variables in Sensitization by Dyes'. There are enough tables and charts to make our little emulsion making hearts go pitter-pat.

The weather has just plain been too nice for me to keep a few promises I made about starting to get my library onto The Light Farm, but this book is a real kick in the pants. I'll get at least the above-mentioned two chapters posted tonight, and try to add a bit of the book (followed by other books) every day. A journey of a thousand pages...

Denise

Kirk Keyes
09-10-2008, 03:00 PM
Of all of the dyes made only a few passed muster and made it into products.

I think part of what Denise and I are interested in is finding more generally available materials and tools with which to make emulsions. And while some people are interested in reproducing Azo or Brovira or Type 55, I think we want to find ways to apply what's been learned in the past for the future. I know you do to, Ron.

But it seems like if we are going to enlist more people into the practice of film-speed emulsion making, then perhaps we can cut a few corners here and there. 2 grams of dye for nearly $400 is a really big investment. And I commend both you Ron and Bill for taking the leap. But what about the guy that can't spend that much, or for a hobby, doesn't want to spend that much. (I know, photography in general is the wrong hobby for the person that doesn't want to spend much money...)

I think it would be really great for us to spend some time and effort to find some less expensive, maybe not cutting edge or commercially preferred, but still functional dyes that we can use.

Photo Engineer
09-10-2008, 03:05 PM
Well, take a look at the Kodak dye list I posted here previously. They still sell those, and the prices, like all exotic organics are going to be high. However, remember that Chlorophyll was the first red sensitizer. I have seen it done! It isn't good, but it works!

PE

Kirk Keyes
09-10-2008, 03:10 PM
'The Photographic Emulsion' by Carroll, Hubbard and Kretschman', Focal Press.

Denise - it looks like I'll be coming to Newport on Saturday for the big shindig. Could you bring this book along so I can take a look?

Kirk

dwross
09-10-2008, 04:27 PM
Denise - it looks like I'll be coming to Newport on Saturday for the big shindig. Could you bring this book along so I can take a look?

Kirk

Ya shoor, yeh betcha. (Sorry, I'm practicing up for my annual trip to Minnesota next week- right smack in the middle of Fargo, i.e. Brainerd :)).

Glad you're going to be able to make it to Newport!

Kirk Keyes
09-10-2008, 07:07 PM
Well, take a look at the Kodak dye list I posted here previously.

Do you remember which thread title that was in? I can't find anything on this site with searches, even though I can find stuff on the rest of the internet, with Mr. Peabody and Sherman's help, all the way back to the beginning of the internet...

Photo Engineer
09-10-2008, 07:18 PM
What the heck. I can just take up more of Sean's disk storage with another upload. Note, there are two IR dyes at the head of the list.

I have tried to get information on these, but cannot. If you can, let me know. All Easman Organic Chemical numbers in Rochester are shut down, or refer you to Tennesee Eastman, but TE knows nothing about these dyes. The EOC building is there but the parking lot is empty. The plant behind it appears to be functioning.

PE

Ray Rogers
09-10-2008, 11:02 PM
Note, there are two IR dyes at the head of the list.

[SPACE]

I have tried to get information on these, but cannot. If you can, let me know.PE

Ron,
Space Confuses Me!:munch:... what kind of information do you want,
and on which dyes; the 1st two? or the whole lot?

If it's price, forget it, I haven't a clue.
But just from glancing at the list I belive these are mostly the more inexpensive ones.

Ray

wildbillbugman
09-10-2008, 11:10 PM
But what about the guy that can't spend that much, or for a hobby, doesn't want to spend that much. (I know, photography in general is the wrong hobby for the person that doesn't want to spend much.

Kirk,
I will not step on lines or cracks.
I assure you that I niether can, nor want to spend that much money. But I am obssesive-compulsive. Must have me precious. Me precious be so gooood and fiiine. Me wants me precious. Must have the precious...........
Bill, me precious.:p:p:p:D:D

Kirk Keyes
09-11-2008, 12:06 AM
Bill - yes, I should have added obsessive-compulsive to the list. And I'm that way sometimes too. Ask my credit card companies...

But if we can find a set of dyes, that cost say $25/gram or less, and they work at 70% of the effectiveness of the high-end dyes, then I think I would be happy. I mean, afterall, I don't need to reproduce the look of Acros or T-Max, as I'd just prefer to buy them if I want them. (And I do and will, at least for Acros.)