Agitation for pushed film

Lauffray

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Hello all

I've been developing myself for a little over a year now, for film at box speed things have been generally well, for pushed film, not so great 😛
I get murky midtones and shadows and exploding highlights, a result of over agitation I'm assuming.

how often do you guys invert when pushing film using non stand dev times ?
I push TriX and Neopan to 1600 using either Rodinal(1+50) or Xtol(1+1), following the times on the massive dev chart, I know these are all very different combos but I suppose the inversion intervals shouldn't be too dissimilar ?

any other thoughts on the matter, things I should know when pushing ?

thanks ! 🙂
 
Less aggitation is better I find. I do the minimum and also gently. I perform two gentle inversions followed by a rap to release air bubbles. I use stainless steel tanks: four reel and eight reel for 135 and 120. I mostly use Diafine.

Interesting to note that I'm going to try RanceEric's Microphen to develope Tri-X at 3200 ISO. Rance also uses only two inversions per minute, but his developement time becomes extended to 25 minutes. He gets real nice negatives that dont have blown highlights and excessive contrast. Kinda a bit like stand developement.

Good Luck.

Cal
 
More agitation = more speed, so for given contrast at a maximum speed, you want more agitation and less time. This is not just personal opinion: it comes from an ex-member of the ISO standards committee. The difference in speed is slight, but detectable.

Rodinal is a truly disastrous developer choice for pushing fast film, as it gives a very low true ISO speed and big grain. Whereas with Xtol you're probably getting ISO 500, you'd be lucky to see ISO 320 with Rodinal. In other words, EI 1600 is about a stop and a half with Xtol (500>1000>1500), whereas with Rodinal it's over 2 stops (320>640>1250>1600).

This does not mean that it is impossible to get results you like with Rodinal, but it is sensitometrically verifiable.

Cheers,

R.
 
Thanks for the detailed response Roger ! I wasn't too far from Calzone's times, strange.
So what time/inversion combos would you guys recommend with xtol ?
 
I haven't experimented with Rodinal yet.

Rodinal is not a high intensity developer like Microphen or Acufine, but many here on the forum still use Rodinal to push film.

Roger is correct: increased agitation=increased film speed, but the work around is lengthy developement times to a certain extent. This is what LanceEric perfected with Microphen. Lance cuts Ilford's recomended agitation but makes up the loss in speed via longer developement times. If you look for a recent thread you will see some of his remarkable night shots, ISO 3200 with Tri-X.

If I were to use Rodinal I'd try to adopt Rance's idea of minimal aggitation (two inversions per minute) to prevent blowing the highlights and experiment to find out how long a developement is required for optomum midrange and shadow detail. I'd do this because stand developement is not practical for me. I develope either 4 reels or eight at a time because I shoot a large volume of film.

BTW I'm not so sure Rance's concept will work with Rodinal.

Cal
 
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More agitation = more speed,

YMMV, though - more agitation means more development in the same time period only for developers whose concentration is low enough to deplete at the film surface if left alone, i.e. one-shot developers. Many developers suitable for large tank use list development times for a one-minute and a three-second agitation regime which are within 25% of each other...
 
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within 25% of each other...

That's probably the kind of speed boost Roger's ISO committee friend was talking about; maybe 1/3-1/2 a stop.

I find Xtol isn't the best for pushing - it exhausts too quickly, even at full strength. TMax developer, Microphen and DDX are better.

Marty
 
That's probably the kind of speed boost Roger's ISO committee friend was talking about; maybe 1/3-1/2 a stop.

I find Xtol isn't the best for pushing - it exhausts too quickly, even at full strength. TMax developer, Microphen and DDX are better.

Marty

Dear Marty,

That's about it. And a lot more like 1/3 (or less) than 1/2.

Cheers,

R.
 
A somewhat tangential question - is there a "rule" for substituting inversion with spinning agitation? Does 15 sec of inversions = 15 seconds of spinning?

I have one tank that supports agitation, but I lost the stupid plastic cap (which didn't seal well anyway).

Randy
 
I develop Tri-X and Neopan 400 pushed 2 stops in XTOL 1:1 quite regularly. I follow the times suggested in the massive dev chart (13 minutes or so), agitating constantly for one minute, then twice every minute thereafter. The results look good to me, although some would consider it a touch too contrasty.
 
Try Xtol at a higher dilution - 1:3 works well for this. Extend the time by 50 percent (over Massive Development Chart recc.). Agitate gently for the first minute and then 10 seconds every three minutes. Try it on something you can repeat - not the first ever flying saucer in your back yard - and then modify. It seems to keep the highlights from burning out and gives decent shadow detail. BTW, you can always use Diafine - simple, cheap, and works well. But DO FOLLOW the agitation directions that come with the developer.
 
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