Kodak 400TX development time

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billingsjohnt
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Joined: Thu Dec 15, 2011 4:17 pm

Kodak 400TX development time

Postby billingsjohnt » Thu Dec 15, 2011 4:58 pm

I am in the process of establishing the proper development time for 400TX film with my camera and darkroom equipment. However, the time resulting from tests so far seems unworkably short.

Details - I first established my personal ISO speed for this film, 500 in my my case. Then I exposed a roll (120 size, 12 exposures) one frame each at Zones I through VIII, two more at zone V, and two unexposed frames, and developed it for five minutes and 37 seconds in HC110 B. Next, with an unexposed negative in the enlarger I did the two second interval strip test to find the minimum exposure needed to produce maximum black; this was 18 seconds at f22.

Then, with the Zone VIII negative in the enlarger I gave a piece of paper the same exposure , 18 seconds at f22, with half of the paper covered to prevent any exposure. The expectation is that, if the negative was developed for the proper time, the exposed half of the paper should exhibit a very slight tonality, or departure from totally white, compared with the covered half. This procedure is described in the book entitled The Zone VI Workshop by Fred Picker.

The paper printed completely white with no discernible difference from the covered half, indicating that the negative was developed too long. The next logical step would be to process another roll with a shorter development time, say 25 percent less, and try again, but but here it gets puzzling. The Kodak data sheet for 400 TX recommends 3/3/4 minutes but a footnote at the bottom cautions that development times shorter than five minutes may yield unsatisfactory results. At 5 1/2 minutes I am already nearly at that.

Might a more dilute solution than B (1/2 ounce in 16 ounces of solution) do the trick?

I note that the Massive Development Chart recommends 7 1/2 minutes for 400TX at 68F. That's what I started with before going to 5 1/2 minutes.

I am using Ilford RC paper.

Thanks for any help,

John Billings


Ornello
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Re: Kodak 400TX development time

Postby Ornello » Thu Dec 15, 2011 8:46 pm

1) The zone system is a fraud. Forget about it.

2) You cannot determine the speed first until you establish the contrast. You're doing it backwards.The 'true' speed of most B&W films is about 2/3 ISO, based upon my research.

3) Use a condenser enlarger and set up your system on grade 3 graded paper (not grade 2) and match your VC paper to that standard.

4) Develop your film so that a normal sunny day scene (cloudless sky) prints properly on grade 3. If you find that some scenes need more or less contrast, simply alter the paper contrast slightly.

5) I bet that the development times you end up with will be about 30% less than published times.

6) If times are too short (under 5 minutes), use a solution of boric acid (1%, 5-10ml) to reduce the strength (alkalinity) of the developer., rather than diluting it Diluting it too much will produce poor consistency. Strive for 8-10 minute developing time.

7) Everything else you may have heard is rubbish. Throw the Picker book away.

So, expose at about EI 250 to start with.

8) Everything listed here is the result of experimentation and is proven sound. I am not surprised the times you end up with are shorter than called for. I have complained for years that recommended times were way too long and developers too strong.

billingsjohnt
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Joined: Thu Dec 15, 2011 4:17 pm

Re: Kodak 400TX development time

Postby billingsjohnt » Fri Dec 16, 2011 12:49 am

Ornello:

Thanks for the detailed information; I'll try it.

Ornello
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Re: Kodak 400TX development time

Postby Ornello » Fri Dec 16, 2011 9:44 am

billingsjohnt wrote:Ornello:

Thanks for the detailed information; I'll try it.
You may have to experiment to get the right amount of boric acid 1% solution. I suggest you start with D-76 1:1 (without boric acid) for 7 minutes (@ 20 degrees C/68 degrees F) as your first trial. Again, print on grade 3. (Bear in mind Kodak suggests 10 minutes for this combination; what I am suggesting is of course shorter.) If the prints are too contrasty, try adding 5ml of 1% boric acid solution to the D-76 1:1. Keep experimenting until you get at least 8 minutes and the prints look good on grade 3. Don't dilute too much because too-dilute developer is not consistent. In other words, lowering the Ph is better than diluting. You may have to do lots of trials to get everything right. The one thing not to change during this process is the paper grade. Once you have the negative developing time worked out, you keep it, and make slight adjustments in contrast with VC paper. The highest contrast setting you normally will use is perhaps grade 3.5.

Be sure to bracket your test rolls in half-stop increments. Again, I would not be surprised if your results mirror mine, and you find that 2/3 of ISO works best. Are you using Hasselblad? Be sure to allow for the small-aperture effect with leaf shutters.

Agitation should be gentle, with two inversions of your tank once per minute. Do not use a rotary-type (constant agitation) automated processor. Those are not suitable for B&W negative development.

Be sure to use an acetic acid stop bath.

Bear in mind that the longer your developing time, the more consistent your results will be. It is impossible to be perfectly consistent in filling and emptying tanks, so longer times diminish the percentage of error. A 10-second difference on a 6 minute time is much greater than a 10-second difference on a 12-minute time.

As far as enlarging is concerned, optimum apertures of enlarging lenses are usually around f/5.6-8. I see no reason to use f/22.

You work backward from the 'known' to the 'unknown'. You start with grade 3 paper and work back from there. Everything is contingent on that. You are given a fixed contrast of paper and adjust everything to that to set up your developing time and speed rating.

There are three sets of variables:

1) Taking lens contrast, Paper contrast, Enlarger and enlarging lens contrast
2) Exposure
3) Developing time

For optimum results, you generally want to get the most contrast possible in your taking lens and enlarging system (though not a point source, which is actually too much). Grade 3 paper generally provides an optimum starting point. By building in a more vigorous contrast system in the enlarger (using conventional condensers) and paper, you can use less development, which substantially improves gradation and sharpness, and reduces graininess. Generally speaking, a slightly thinner and flatter negative printed on a slightly higher grade of paper will produce overall better quality than a slightly heavier and contrastier negative printed on a slightly softer paper. Be sure to give adequate exposure though. ISO generally gives slightly too little exposure. About 2/3 ISO (on some films, 1/2 ISO) works better.

To make a 1% boric acid solution, dissolve 10 grammes of boric acid in a liter of water.

pentaxpete
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Location: BRENTWOOD,Essex,(UK)

Re: Kodak 400TX development time

Postby pentaxpete » Sat Jan 07, 2012 2:26 pm

Very interesting read -- but what is the 'Small Aperture effect'please -- I have Hasselblad too --- regards--- Peter
Got COMPUTERISED and 'slightly Digitised Pentax K10D' but FILM STILL RULES !

Ornello
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Joined: Thu Jan 19, 2006 9:49 am

Re: Kodak 400TX development time

Postby Ornello » Sat Jan 07, 2012 10:29 pm

pentaxpete wrote:Very interesting read -- but what is the 'Small Aperture effect'please -- I have Hasselblad too --- regards--- Peter
Leaf shutters open in a circle, just like an iris. At small apertures, then, the shutter shows the entire aperture right from the get-go.

http://www.karinlauphoto.com/film-expos ... iency.html

Ornello
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Joined: Thu Jan 19, 2006 9:49 am

Re: Kodak 400TX development time

Postby Ornello » Sat Jan 07, 2012 10:29 pm

Ornello wrote:
pentaxpete wrote:Very interesting read -- but what is the 'Small Aperture effect'please -- I have Hasselblad too --- regards--- Peter
Leaf shutters open in a circle, just like an iris. At small apertures, then, the shutter shows the entire aperture right from the get-go, giving more exposure than it would at a large aperture.

http://books.google.com/books?id=e5mC5T ... cy&f=false

http://www.karinlauphoto.com/film-expos ... iency.html

foolscape
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Location: Portland, Oregon
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Re: Kodak 400TX development time

Postby foolscape » Sun Jan 08, 2012 3:40 pm

Ornello wrote:1) The zone system is a fraud. Forget about it.

7) Throw the Picker book away.
Response to # 1) Ornello's advice is good when it comes to roll film. If you are shooting 35mm and 120, the Zone System is less relevant than if you are shooting sheet film, but don't discount it entirely. I've been using the Zone System for many years with good results. It really shines when you can develop each shot individually, and especially if you contact print larger negatives.

Response to # 7) I agree. Fred Picker's shortcuts don't make much sense (to me) in practical terms. If you want a workable Zone System primer for modern films, try Bruce Barlow's book: http://www.circleofthesunproductions.co ... ocused.htm

Overall, if your development times are too short for dilution B, try the "unofficial" dilution H, which is dilution B with double the amount of water. Also double your development times. This allows for extending those pesky, short development times.

--Gary

Ornello
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Joined: Thu Jan 19, 2006 9:49 am

Re: Kodak 400TX development time

Postby Ornello » Sun Jan 08, 2012 8:23 pm

foolscape wrote:
Ornello wrote:1) The zone system is a fraud. Forget about it.

7) Throw the Picker book away.
Response to # 1) Ornello's advice is good when it comes to roll film. If you are shooting 35mm and 120, the Zone System is less relevant than if you are shooting sheet film, but don't discount it entirely. I've been using the Zone System for many years with good results. It really shines when you can develop each shot individually, and especially if you contact print larger negatives.

Response to # 7) I agree. Fred Picker's shortcuts don't make much sense (to me) in practical terms. If you want a workable Zone System primer for modern films, try Bruce Barlow's book: http://www.circleofthesunproductions.co ... ocused.htm

Overall, if your development times are too short for dilution B, try the "unofficial" dilution H, which is dilution B with double the amount of water. Also double your development times. This allows for extending those pesky, short development times.

--Gary
As far as developer strength is concerned, it's better to weaken the alkalinity of the developer than to dilute it excessively, by adding boric acid. Extremely dilute developer produces results that are inferior to developer weakened by the addition of boric acid. I have learned this by trial and error.


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