The Greenish Tint of Azo : LUSENET : Large format photography : One Thread

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 selenium does the job (I seem to need more like 1:45, but no matter). Still, the resulting 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 stumbled onto a funny little book called "Photography Made Easy", which was published in England in many printings/editions between 1900-1930 or thereabouts (author "A. Child Bayley" I believe). It has a chapter called "Printing with Gaslight 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 injections of potassium bromide (and one or two other adjustments of lesser importance). It's interesting to me that the two perhaps best-known amidol-for-Azo formulas -- Michael Smith's and the one in Lootens (the two are virtually identical) -- follow this old recipe in that the P.B. content is very slight (2cc per liter!); yet, untoned Azo in the Smith amidol developer has the distinct greenish tint. Does anyone understand this? Does anyone use a developer -- esp. an amidol formula -- that produces a neutral black on Azo? -jeff buckels (albuquerque nm)

-- Jeff Buckels (, April 04, 2001


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.

-- (, April 04, 2001.

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.

-- Sean yates (, April 04, 2001.

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.

-- David Goldfarb (, April 04, 2001.

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.

-- Brian Ellis (, April 04, 2001.

You might try developing in Amidol for 50-90% of the required time & then move it to Dektol for the remainder. This will change the color a bit. Experiment and you might find a color you like. Water quality does make a difference. I get a different tone from the paper when using our tap water rather than distilled water for developing.

-- Dan Smith (, April 05, 2001.

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:

-- Ed Buffaloe (, April 05, 2001.

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

-- Jeff Buckels (, April 05, 2001.

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".

-- DK Thompson (, April 05, 2001.

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.

-- Ben Calwell (, April 05, 2001.

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.

-- David Goldfarb (, April 05, 2001.

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.

-- Wayne (, April 05, 2001.

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.

-- Bill Bartels (tlr220@msn,.com), April 06, 2001.

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.

-- David Stein (, April 06, 2001.

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