Our own tests show that Tektol has a superior tray life and shelf life to Dektol.
Conditions and testing methodologies differ. PE seems to have left a tray of developer in the sink for 10 days and run one print a day through it. Although he may have found a way to produce a result which shows off Dektol's resistance to oxidization, that is not a real world test, and it is clearly not part of a suite of tests designed to independently evaluate Tektol.
The majority of printers I know (myself included) fill a tray and use it for one session or one day. Most people who reuse print developers either cover the tray at night or decant the working solution into a bottle. Under any of these conditions, I would expect Tektol to outperform Dektol.
Tektol is virtually inexhaustible. This means that if you take a tray of developer and run as many prints through it as you can, it will keep working perfectly. In fact, the tray will actually become empty through developer carry-over before you are likely to reach capacity.
There are many different ways to test tray life and capacity. The best way though it to try it for yourself.
John, you are probably correct in all of your statements about the environmentally friendly nature of these products compared to others on the market. I can't say without knowing the contents which I do not. The only disturbing implication in your post is the one that I have lied or misrepresented the facts about the tray life or capacity of the developer.
I... DON'T... LIE!
As a scientist, I cannot afford to lie. I can err, being human, but I don't lie. So, that said, I would not have made my post without evidence. Here are 4 pictures, the two top ones are Dektol 1:3 and the two bottom ones are Tektol 1:9, just partway into the test. The origninal image quality of the Dektol example can be regained by extending development time, the Tektol cannot. These all had exactly the same development time. Both developers dropped in activity during the test, but the Dektol dropped less.
The test used 1 liter of each developer in an 8x10 tray. The test was conducted several times for different combinations of commercially available developers all of which performed more poorly than Dektol.
As you can see, the fresh Tektol performed as specified when fresh but fell off rapidly. It dropped in pH rather quickly during the time of the test. The Dektol did not drop significantly in pH.
I take that as an endorsement. Great results with
Originally Posted by Ian Grant
some little character of their own and an environmentally
friendly nature. Phenidone is the least toxic developing
agent and vitamine C is not at all. That activator,
Vitamine C, accounts for the shorter in tray life
span. Were I to use the developer a least
practical volume would be put in tray
then used for one session. Dan
Developer lifetime is a function of exhaustion and pH drop caused by development and air (CO2 and Oxygen).
As such, I have run many many developer tests that have been verified by tests in the field. This test that I use is one we used at Kodak to 'certify' a developer, and developers using this method of initial testing have been sold for years. Why not use this test, it works and is quick and reliable. It is a good indicator of how the developer withstands actual use and keeping.
After posting this, I saw Dan's post and feel this is good point. If you are going to use Tektol for one session and a limited number of prints, there is absolutely no problem, but if you have a lot of prints, and/or are called away from a session, then you can begin to see differences that can be compensated for with Dektol but may not be with Tektol.
If you run sessions requring identical prints from start to finish, this is where tray life and capacity come to the fore. You will see this in large jobs or long jobs. There appears to be little safety factor when compared to Dektol.
I stress again that fresh, it performs as advertized. This may or may not be important to you. I am putting this data on the table for those who may find it important.
Last edited by Photo Engineer; 04-25-2007 at 07:54 PM. Click to view previous post history.
Reason: Added 3 paragraphs to follow up on other commetns.
now you kids behave back there or i will turn this forum around right now.seriously though thanks for all the input.it is awesome that people feel so strongly about film and that there are places we can go for support.thanks guys.
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I've been working on a bottle of both Tektol developers and wrote a paragraph about it in this thread recently. I think they produce results similar to Ansco/PF 130 and Agfa Neutol WA. Tray life is about the same as the Agfa developer and Dektol which is about a week after mixing if decanted to a bottle. Print life is maybe about 30 8x10s, which IIRC is about the same as Dektol. Tektol not as active as Neutol was so the waterbath technique for contrast control doesn't work with it. Tektol Neutral is not quite as active as the Standard version so prints require a little longer development as compared to the Standard version. Both are nice developers. I especially like using the Standard version on Polywarmtone (now discontinued :<)
I have yet to see a developer that has the longevity of 130. That stuff just doesn't quit.
As far as the environmental stuff is concerned, I have no opinion. Its not my field.
I had no idea these more eco-friendly chemicals existed. I work in a custom black and white lab and would be interested in finding out more about them. I worry about cancer at times and what not and if these other chemicals aren't as harmful, then it could be a nice alternative. However, I don't think PE fibs, as he is an invaluable resource to the analog cause.
A couple of APUGers get political and often go the low road in almost every thread I post something, so I'm not surprised to hear that Ron Mowrey said he tested tray life etc., against Dektol, and made statements that aren't true. (Indeed, I didn't know he paid to buy my products...)
Originally Posted by PHOTOTONE
Shortly after I came up with preliminary versions of DS-14 formula, which gave rise to Tektol Standard, I made a lot of different print developers and compared tray life by keeping them in an array of open beakers and testing the chemical state of the solution and running sensitometric strips periodically. DS-14 developer can be kept in open tray overnight for no or negligible sensitometric change, and takes many days before it dies completely. If you go through pure-silver archive anyone can see exactly how I tested these developers. I did another test run with Tektol Standard 1+9. Translating the test data into real life darkroom operations, the developer volume reduces noticeably due to evaporation of water before the developer dies. Most darkroom workers replace the developer way before this happens. Also in terms of processing capacity, unless you use squeegee to remove developer from the paper surface, you'll lose much of the developer volume before the developer comes anywhere near the exhaustion level. In reality, tray life of DS-14 and Tektol Standard compares to some of the better glycin developers.
Anyone can search on pure-silver, APUG, and other sites for what the users say. Tektol or DS-14. I also hear that several photographic magazines are writing product reviews, and you'll know when they get published.
Thanks for your interesting review and information. Now I ask so that I can understand your findings... How did you measure the tray life? Do you have rough estimate of how many milliliters of solution and how many square centimeters of air surface? Also, what was the average testing temp?
Originally Posted by Alex Hawley
It is true that Tektol developers, especially Tektol neutral tends to take a bit more time to develop if you compare to Dektol stock or 1+1, but the reason why water bath technique doesn't work is primarily due to the difference in the developing agent. Hydroquinone is retained within the emulsion longer than ascorbate when the paper (or film in the case of film developer) is removed from the developer and immersed in plain water or alkaline bath. In my early days of experimenting with ascorbate, I also tried to make two-bath film develoeprs with ascorbate, but for this reason it does not work (well, I didn't know the reason at that time but now I do).
Tektol not as active as Neutol was so the waterbath technique for contrast control doesn't work with it.
True. I could make it to match the developing speed, but I thought it would be more important to make the neutral version (TND) really cold, solid black, and make it mixable with the standard version (TSD) so that people who want half cold developer can make it by simply mixing them.
Tektol Neutral is not quite as active as the Standard version so prints require a little longer development as compared to the Standard version.
I also miss Forte papers. Fortezo was my best favorite warmtone paper that makes nice split toning effects and Polywarmtone was also very good.
Both are nice developers. I especially like using the Standard version on Polywarmtone (now discontinued :<)
Again, I'm curious to know how you compared TSD with 130...
I have yet to see a developer that has the longevity of 130. That stuff just doesn't quit.
To be very precise, Phenidone is not much better than Metol, but chemical allergy is much less common and, since it is used in such a small quantity, its environmental load is much lighter and also is more easily treated in the waste water.
Originally Posted by dancqu
Although no one asked me to remove Dimezone S from Silvergrain chemicals or formulae, I am actually getting ahead of current standard of safety and environmental damage to see a possibility of making practical developers free of any compound of the Phenidone family and is also free of hydroxybenzene or p-aminophenol derivatives (hydroquinone, catechol, pyrogallol, Amidol, Metol, glycin, etc.). I found this candidate compound in the course of improving some other developers and this compound is readily biodegradable. Not much to report yet, but will.
You assumed vitamin C developers are short lived but that's not always the case. If you have the ingredients (which I think you do, from your postings from other threads) mix a batch of DS-14 and see.
Vitamine C, accounts for the shorter in tray life span.