# Air Evac bottles



## Actor (Oct 29, 2009)

I've ordered a couple of one gallon Kalt Air Evac bottles from Freestyle.  According to the tracking number they should be here tomorrow.  Does anyone know how much these hold when fully compressed?  The first thing I'll do when these get here is measure this minimum capacity but I'm hoping someone can tell me now.

Kalt Air Evac Bottle - 1 gallon | Freestyle Photographic Supplies


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## Torus34 (Oct 29, 2009)

Reducing chemical degradation through oxygen exclusion is good darkroom practice. I extend this to film developer and hypo. My basic tank is an old Nikkor(r) which takes about 15 oz. I make up film developer [D-76 or Microdol(r)] and fixer in gallon lots. These are then apportioned into Snapple(r) bottles. The bottles are topped off with a little water [the slight dilution is not significant] and then capped with almost no air headspace. Both developer and fixer are used for one 'run' and discarded. One gallon thus processes 8 rolls of 120 or 16 rolls of 35mm film.

This provides almost airtight [sorry] assurance of consistent solution strength from roll to roll, a necessary component of the 'visualize the final negative/print before you hit the whoopie button' philosophy.


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## Actor (Oct 29, 2009)

Torus34 said:


> One gallon thus processes 8 rolls of 120 or 16 rolls of 35mm film.


A roll of 120 has less area (~65 sq in) than a 36 exposure roll of 35mm (~90 sq in).  Why do you get fewer rolls per gallon with 120 than with 35mm?


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## Torus34 (Oct 29, 2009)

'Cause my tank holds either 1 roll of 120 or 2 rolls of 35mm.  It's 1 16oz bottle of soup/tank-full of film.

Regards,

Jim


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## Actor (Oct 30, 2009)

Torus34 said:


> 'Cause my tank holds either 1 roll of 120 or 2 rolls of 35mm.  It's 1 16oz bottle of soup/tank-full of film.
> 
> Regards,
> 
> Jim


Got it.

But it only takes 8oz to develop a roll of 120, the problem being that 8oz won't cover the film.  However, I'll bet 12oz would cover it meaning that you'd save enough to develop a fourth roll after developing three.


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## Torus34 (Oct 31, 2009)

Uh huh. I could also save by using the fixer for two tanks of film. Calculations based on film area and the manufacturer's directions show that I would be 'safe' in doing so.

However, as I noted in my little series of articles, it's important to pin down as many points in the film exposure/film development/paper exposure/paper development as possible. Otherwise, it becomes very difficult [and it's already hard] to visualize the finished print before snapping the shutter. Uncontrolled variables pile up and get in the way. Over the years I've made my personal protocol as simple and unvarying as possible. One Snapple(r) bottle of solution/tank of film does this nicely. The small savings that would accrue from tweaking this are not significant to me in my pursuit of the finished framed, matted, wall-hung print. I've also 'standardized' on D-76 and Microdol(r) developers and plain pipe rack Kodak(r) fixer. For prints, it's Dektol(r).

I also bracket where possible. The 'best' negative is often that which contains the greatest range of 'zones'. Bracketing helps me to avoid blocked shadows or blown highlights. Again, film cost is of little concern if being frugal results in a 'lost' print. And yes, I have [and use] an excellent light meter.


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