How Do You get Drying Marks Off a Film ?

[robert_parker]

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I wonder what everyone’s view is about the use of rainwater, as an alternative to distilled water, in the final rinse?

[farnz]

6 hours ago, robert_parker said:

I wonder what everyone’s view is about the use of rainwater, as an alternative to distilled water, in the final rinse?

Probably depends where you live or where it's collected.  If you live in London, for example, I would expect it to have an acidic content owing to the diesel and petrol fumes in the air that it falls through, but if you live in the Torridons in far north-west Scotland it would be much cleaner.  Also, much of the UK sits on a chalk (limestone) base so the water will already be 'hard' and is likely to contain particulate chalk.  Scotland is mostly granite so is less likely to contain particulate matter I would have thought.

@LocalHero1953 as our resident expert on geological matters might wish to debunk what I've written.

Pete.

[david strachan]

It's rare to get perfectly pure water from a rainwater tank; particularly an aging tank.  Besides the suspended dust, rainwater, all water, is a very strong solvent and will dissolve even the most insoluble materials over time. Including tank metals and plastics.

Ground water, or spring waters, dissolve a lot of minerals as they move through strata.  In the case of the Great Artesian Basin in Australia the waters are thought to be about one thousand years old from recharge point in the eastern Australian mountains to discharge at the numerous Mound Springs in South Australia.  The waters are just potable. They support our inland pastoralists and animals.

I only use distilled water, from the supermarket, for final film rinse...with a dash of photoflo...and squeegee, as mentioned.

...

Edited February 15, 2021 by david strachan

[convexferret]

I've just scanned 4 rolls of HP5+, final rinse in water from my dehumidifier's tank plus a touch of Ilfotol. Not a mark in sight.

[LocalHero1953]

3 hours ago, farnz said:

Probably depends where you live or where it's collected.  If you live in London, for example, I would expect it to have an acidic content owing to the diesel and petrol fumes in the air that it falls through, but if you live in the Torridons in far north-west Scotland it would be much cleaner.  Also, much of the UK sits on a chalk (limestone) base so the water will already be 'hard' and is likely to contain particulate chalk.  Scotland is mostly granite so is less likely to contain particulate matter I would have thought.

@LocalHero1953 as our resident expert on geological matters might wish to debunk what I've written.

Pete.

It's probably related to water hardness (the amount of calcium and magnesium in the water). In the south and east much of the water comes from the Chalk and is fairly hard. 

I have heard it said that Peak Imaging, in Sheffield, produces the cleanest negatives - much of the regions water comes from rainwater or the Millstone Grit, and is very soft.

These things aren't black and white: a city's water supply is quite likely to come from a river in the first instance, and whatever the groundwater contribution to the river flow, it may have quite a bit of rainwater that hasn't passed through the rock, and so is very soft.

Scotland uses very little groundwater, doesn't have as much chalk or limestone, and has more than enough soft rainwater! (Scotland has granite, but it is localised; much of Scotland outside the lowlands is metamorphic, but originated as sandstone and shale - not much that is of limestone origin, so its waters are soft).

[robert_parker]

That’s fascinating-as somebody who used to live on the hills just near Sheffield I remember Sheffield tapwater as being particularly soft and that it commonly was used for purposes where distilled water would’ve been mandatory -for instance, in the days before fluoridisation, being used to top up car batteries.

I wonder if collecting rainwater in a barrel here on the Somerset coast would give a source of water of appropriate quality, given the roof and guttering is it was collected from hadn’t been heavily contaminated.

[farnz]

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4 minutes ago, robert_parker said:

I wonder if collecting rainwater in a barrel here on the Somerset coast would give a source of water of appropriate quality, given the roof and guttering is it was collected from hadn’t been heavily contaminated.

I'd recommend washing the water first.

Pete.

[bags27]

Have to say that I went from no watermarks to lots of watermarks. No change in my developing process. The change was I used to scan with a cropped sensor camera (CL) and now scan with a MF camera (Fuji GFX-R). In other words, I get far better resolution, but that includes the watermarks that I couldn't see previously. Lots of work in PS now....

[LocalHero1953]

On 2/15/2021 at 4:17 PM, robert_parker said:

That’s fascinating-as somebody who used to live on the hills just near Sheffield I remember Sheffield tapwater as being particularly soft and that it commonly was used for purposes where distilled water would’ve been mandatory -for instance, in the days before fluoridisation, being used to top up car batteries.

I wonder if collecting rainwater in a barrel here on the Somerset coast would give a source of water of appropriate quality, given the roof and guttering is it was collected from hadn’t been heavily contaminated.

Sorry, missed your post, but the answer is yes, where you live. I was brought up in Bath where the tapwater is both hard and heavily chlorinated (from Chew Valley Reservoir, which had quite a lot of Mendip limestone groundwater). Later, when visiting my parents there from this part of the country I noticed that our car, left out in the rain overnight, was washed clean. Here in the east, our car looks dusty after rain - the weather, coming mainly from the west, picks up all the particulate air pollution on its way to us. But in general rainwater is soft and should be good for film washing (though I haven't tried it).

[bags27]

Suddenly I thought I had watermarks when scanning with my new-to-me Fuji GFX R. Figured a MF sensor, compared to my CL's cropped sensor, was showing things I hadn't seen before. So, I worked and worked on preventing drying marks, until last night I realized that the used camera I bought had a dusty sensor! Cleaned the sensor, and no more "watermarks" !!

But: in the process, I did some research, and I've adopted a new formula for the final bath, and I do notice that my negatives now dry super fast and clean:

add to the distilled water 1:400 of PhotoFlow AND 1:32 of Isopropyl alcohol. I plan to mix this by the gallon.

The other thing I learned (but should have known) is: hang 135 film by its short end, rather than by the leader. Obviously, you don't want the extra water running down on the developed negatives.

Other things I've read but haven't tried yet:

Wipe negatives with Pec-Pad Photowipes. We should all have these (I just got mine), whether or not we use them for drying negatives.

Some people hang their negatives diagonally. I could do this, and it makes sense. Even better would be horizontally, I imagine. Whatever keeps water from running down the length of the negatives.

That's it!