Water Quality

[tony_p4]

After having a couple of Emails about my development times and

looking around the threads at the varying development times I have

started to think (scary).

 

So my question is do development times vary depending on the part of

the world you are in and quality of the water, i.e. additives?

 

I know a guy who use to be a photojournalist and actually developed

his film using sea water (yep really). But he told me that the salt

actually reduced his development times whilst increasing grain.

[ken_miller4]

Your developing times depend on more than just water: they depend on *everything* - your meter, film, developer, water, duration, temperature, agitation technique, visualization, etc. etc.

 

The only way to determine how long *you* should develop your film is to start with the manufacturer's recommended time, and adjust as required.

 

Above all, be consistent. Always develop your film the same way.

 

And don't worry about the thinking thing - we all do it occasionally. It's kind of fun, really, once you get past the pain part.

 

Cheers!

 

-klm.

[dennis_oconnor2]

There is a famous 'high speed' version of a developer where the only change was they added non iodized table salt...

Troop and Anchell talk about his in their book...

 

denny

[tony_p4]

Many thanks for your feedback guys. I promise not to make thinking a habit, for one thing it messes up my pictures ;)

[the_macman]

It doesn't.

All waters which are labeled as drinkable city water, no matter where in the

western world should give very comparable results with very little differences

in between.

 

There should be a noticeable difference between pure water and the saltiest

of city waters, but witing predictible parameters. Salty sea water is a huge

leap from the saltiest of city waters.

 

Bottom line: ANY city water will not considerably influence your times.

[discpad]

I'd be a bit careful about throwing all potable water in the same catagory: In the U.S. chlorine is generally used as a disinfectant; while in Mexico iodine is used (it causes my mother a nasty allergic reaction). Also, ozone is sometimes added in lieu of chlorine in a few places.

 

I don't take any chances: At 99 cents per gallon, I mix my developers & fixer with distilled water from the grocery store. If my volume picks up, however, I'll grab a $150 reverse osmosis kit and plumb it into my kitchen sink... Besides, distilled or RO treated water makes great coffee & tea! :)

[john_elder1]

I changed to using only distilled water for developing film when I had significant differences in development in 3 different cities while using the same camera, film, lens, and thermomiter! This occurred over a short period of time. I now confidently use distilled water for film and print development with extremely consistent results. Testing was done with a tobias densitomiter.

[the_macman]

Clorine or iodine are at such low concentration that it doesn't make any

difference on film. What makes a difference is concentration of various salts,

this is what may react at various levels and constitute chemical complexes

with developers ingredients. I put all city waters in the same category,

because city water in all western world falls under some limits of salt

concentration and the concentration that will really hurt film devt is well

beyond that.

[discpad]

There are also many people here in the U.S., especially in farm & rural areas, that have well water with their own pump & pressure tank in the basement or garage. This well water can be all over the map when it comes mineral content, as well as contaminents to the groundwater.

 

There's nothing like MTBE -- What the enviro-nazi's demanded to be added to gasoline for alledgedly slightly "cleaner" air -- in the groundwater supply.

 

I wonder what MTBE does to photographic chemistry?! :(