View Full Version : The Greenish Tint of Azo

Jeff Buckels
4-Apr-2001, 16:36
The greenish tint of untoned Azo has long been remarked. It is easy to "get rid of". In his well-known essay, Michael Smith notes that a 1:125 dilution of sel enium does the job (I seem to need more like 1:45, but no matter). Still, the r esulting tone is not something I'd necessarily be going after otherwise. I don' t think Azo "takes selenium beautifully" as some papers do. The other day, I st umbled onto a funny little book called "Photography Made Easy", which was publis hed in England in many printings/editions between 1900-1930 or thereabouts (auth or "A. Child Bayley" I believe). It has a chapter called "Printing with Gasligh t Paper". The author notes the greenish tint of "certain gaslight papers" and, in order to keep the green down, prescribes developer formulas with very small i njections of potassium bromide (and one or two other adjustments of lesser impor tance). It's interesting to me that the two perhaps best-known amidol-for-Azo f ormulas -- Michael Smith's and the one in Lootens (the two are virtually identic al) -- follow this old recipe in that the P.B. content is very slight (2cc per l iter!); yet, untoned Azo in the Smith amidol developer has the distinct greenish tint. Does anyone understand this? Does anyone use a developer -- esp. an ami dol formula -- that produces a neutral black on Azo? -jeff buckels (albuquerque nm)

David F. Stein
4-Apr-2001, 20:25
I'm all for traditional techniques, formulas, mixing stuff from scratch, but why make it hard in yourself. Try Agfa Neutol WA print developer and you will get a beautiful, magical silver image (no blues, no greens) and selenium or other toning will only be an option.

Sean Billy Bob Boy yates
4-Apr-2001, 20:52
My problem with Azo has never been green, but rather BLUE from Dektol. I've compared prints from the same negative on Azo in Dektol and in Amidol (although I can't say which of the many published formulas) - and to my eye the Amidol prints looked 'ere so slightly warm - ish. Not green atal.

David A. Goldfarb
4-Apr-2001, 20:59
I also use Agfa Neutol WA 1:11, 2 minutes, and I finish with Rapid Selenium Toner, 1:15, 3 minutes, and get neutral to warm blacks. At 4 minutes in the Selenium it goes all purple-brown.

Brian Ellis
4-Apr-2001, 21:43
Like someone else, my problem has always been a blue cast to Azo when used with Dektol or Ilford Universal developer (I've never tried Agfa Neutol but if I can find some maybe I will). The blue cast could be removed with the selenium toning but I had to be very careful to pull the print from the selenium just before it started turning purple (I don't like the purple look any better than the blue look). All in all, a pain. Amidol (Michael Smith formula) works fine for me - no green, the blacks are a little on the warm side.

Ed Buffaloe
5-Apr-2001, 08:27
Try Samuel Fein's amidol formula. He uses benzotriazole instead of bromide as a restrainer. It gives much more neutral tones with almost any paper (though I must state that I haven't tried it with Azo). I have it on my site at:

http://unblinkingeye.com/Articles/Developers/Formulas/formulas.htm (http://unblinkingeye.com/Articles/Developers/Formulas/formulas.h tm)

Jeff Buckels
5-Apr-2001, 12:44
Alright now, here's a follow-up to the Agfa Neutol WA guys: One of the two really good things about the Azo/Amidol combination is that it works great w/ two-bath (amidol/water) development. Like many, I picked this up from Michael Smith's well-known article. So, have you guys tried this w/ Neutol? -jb

5-Apr-2001, 14:03
Jeff, I'm not an expert on this or anything, but I thought I might say a little something about "gaslight papers". A real good book on this sort of thing (although not a how-to book) is James Reilly's "Care and Identification of 19th Century Photographic Prints". He says early developing-out contact papers (gaslight papers) ranged in tone from a "warm greenish-black to a cold blue-black". My experiences with Azo, have been like others, that it's a cooler blue tone. But I have an old Kodak ad on my wall here from the 20's for a paper called "Velvet Green" that was a version of Velox (contact paper) that had a green tint built into the paper base, to "lend the true atmosphere of out-of-doors"....another good, old book is "The Silver Sunbeam".

Ben Calwell
5-Apr-2001, 14:34
My Azo contacts were bluish when developed in Dektol 1:2. However, when I went to a 1:1 dilution (which helped increase my contrast), the blues, to my eye, went away. Maybe it's my water, or a case of seeing what I want to see, but I no longer see the blue cast. Selenium toning also helps.

David A. Goldfarb
5-Apr-2001, 14:37
I haven't tried two-bath development with Neutol WA, but it's an interesting idea. I'll need to get a couple of tray ladders one of these days to fit all those extra trays in my work space at one time.

5-Apr-2001, 22:27
I havent used Azo a lot, but I recall it coming out a tad green when I mixed up some ID-62 and accidentally doubled the bromide. When I left out the bromide and used only benzotriazole, it was slightly blue.

Bill Bartels
6-Apr-2001, 18:33
I also like the print color I get with the Azo and Neutol WA. I do not however think it has the compensating properties of Amidol the prints come up way too fast with the Neutol. Since learning to develop by inspection I have not had any negatives that need water bath development. I tone with very dilute selenium which has little or effect on print color.

David F. Stein
6-Apr-2001, 20:05
Good discussion. I would also now add that per Paul Smith's notes, a shorter development time tends towards a warmer image tone-45 sec comes to mind. In conventional developing, older developer will also tend to be warmer and I often seed new developer with old-not sure how Azo responds to this. Agfa Neutol (WA or regular) also has a long usage life-store in glass bottles between print sessions. No need for a new mix just to do a few contact prints.