Film dryers - how do they work?

[Steven Lee]

Specifically, I am interested in this one from Heiland.

The problem I am trying to solve is dust. Currently I dry my film in a closet where the air is completely still. I noticed that when I scan immediately after drying I get no dust. Zero. But if I let it hang overnight or if I put it into a ziplock bag after drying, then I get 2-5 specks of dust per shot which is annoying. And for some strange reason 4x5 sheets get 5x more dust than roll film, and it's starting to affect my LF enthusiasm because I'm dreading the painful post-scanning dust cleanup.

How does this film dryer work? It looks like there's a heat source and the filter are at the top which seems counterintuitive. How's the air circulation work then? Does anyone have first-hand experience using this dryer or a similar one? Do they block all the dust?

Thanks!

 

[Bill Burk]

I have a Spiratone similar concept, filtered heated air blows down and there’s holes in the bottom of the bag for air and water to go out.

 

[Steven Lee]

How's your dust situation, @Bill Burk ?

 

[mshchem]

I would check humidity levels in your house, maybe static is a factor??. I have a beautiful 1970's era film dryer, I rarely use it, not because I have had problems with it, it's just that there's nothing better, IMHO,than letting film dry naturally. I just let my film hang in my darkroom until dry, then I sleeve.
I've had static issues, when the house is too dry in the winter. This is when I turn on the whole house humidifier.
In the summer I run dehumidifier in the darkroom.

I'm sure that the Heiland unit is topnotch.

 

[koraks]

How does this film dryer work? It looks like there's a heat source and the filter are at the top which seems counterintuitive. How's the air circulation work then? Does anyone have first-hand experience using this dryer or a similar one? Do they block all the dust?

I think it's conceptually similar to the old Jobo dryers. These were also essentially an old-fashioned spiral space heater with a plastic shroud attached, blowing warm air across the film. There are several DIY spins on the same concept, usually with filters (like the Heiland one). There's always a lot of debate about how useful, beneficial or detrimental these things are. Proponents argue that the filter keeps the dust out well enough and quick drying reduces the timeframe in which dust can adhere to the sticky emulsion. Critics point out that filters aren't perfect and certainly don't remain so, and that forcing a large volume of air across the film is a great way to powder-coat it with whatever happens to floating around in the room. YMMV.

I'm sorry, I have no silver bullet. Dust is, alas, to an extent a fact of life in my darkroom. My mitigation process is rudimentary and only mostly effective - not perfectly so. A roll of film will generally have a few specs of dust on it here and there. On sheet film, the whole generally doesn't bother me since I mostly use sheet film for contact printing. When enlarging 4x5, I generally still print fairly small (up to roughly 11x14" mostly) and tiny dust tends to be not all that much of an issue at that point. When enlarging 35mm, I wipe off the film surface and inspect the film just before I slide the carrier into the enlarger, blowing off any tiny specks that may linger at that point.

I find that the dust that settles onto the film once it is dry, is removed easily by wiping it off, so it doesn't bother me too much. I hang my film to dry in places in my darkroom that don't see too much dust being kicked up; a corner just behind the door, a line above the sink. It's good enough. On the rare occasion I scan and need to process/print/share without dust, I just clone it out. It helps that this doesn't happen too much. I admit that if I had to scan most of what I shoot, I'd find the dust removal tedious enough to consider getting a PhotoShop license and harness its AI healing functionality to get rid of it.

 

[brbo]

I admit that if I had to scan most of what I shoot, I'd find the dust removal tedious enough to consider getting a PhotoShop license and harness its AI healing functionality to get rid of it.

It's still manual labour using content aware cloning tool in PS. But if you mean the experimental neural "Photo restauration" filter... As it is now it's way more harmful than leaving dust and scratches alone. I've posted the results before:

 

[koraks]

It's still manual labour using content aware cloning tool in PS.

Yes, that's for the moment the best we can get, I think.
I do have good hopes for much better versions of automatic, full-image restoration. I saw the comparison you've posted here before and indeed, it's...unsettling. At the same time, it also demonstrates the potential strengths. I think it's a matter of time before they publish something that will work well enough.

Mind you, as said, it's mostly a theoretical exercise for me, at the moment. I'm well aware of the problem of dust on scans, have dealt with it for about two decades now, but my way of dealing with it has mostly been to move away from digital towards analog/darkroom prints. It's not a panacea, but at least the dust generally looks smaller that way, most of the time...

 

[Paul Howell]

I have an old Unicolor film dryer, not sure who made it for Unicolor. It will take 2 35mm or 1 120 reels. Has a heater and uses a filter for incoming air. I used it in the 70s when still freelancing when I need to provide prints rather than negatives. I replaced the oringial washable filter with a hepa filter, last time I used worked find. In general I dry in the shower that I use to wash prints. My converted bath to darkoom is pretty well sealed, I can close the AC vent when drying film, no issues with dust.

 

[Bill Burk]

How's your dust situation, @Bill Burk ?

It’s awful. I don’t use the bag or the air, just clip and hang overnight. Photo-Flo does most of the work, and I use a diffusion enlarger.

But in theory the bag should help.

 

[MattKing]

Film dryers are designed more to speed throughput than to enhance results.
They are very relevant for labs, and much less useful for individual users.

 

[pentaxuser]

I have the UT 100. In terms of use and construction it pretty well mirrors the Heiland dryer I only use it for film and have never need to use the heating element - only the fan blowing ambient filtered air. No dust problem that I can see


pentaxuser

 

[cliveh]

Never use a film dryer, as they blow dust particles into wet emulsion. Always dry film in ambient temperature over night. Patience is a virtue.

 

[Paul Howell]

While in the Air Force we used pro lab film drying cabinet, just a heated box no fan to push dust. My unicolor dryer was risker, but with good filters did not have aqn issue. The only possible issue with the film drying cabinet was ramping up the temperature and causing the emulsion to peel off.

 

[Pieter12]

I suspect the ziplock bag is part of the problem, creating static and attracting dust. How well do you clean your negatives before scanning?

 

[Steven Lee]

I suspect the ziplock bag is part of the problem, creating static and attracting dust. How well do you clean your negatives before scanning?

You may be right. Again, my usual routine is to scan immediately after drying, i.e. I give it about 2 hours after developing, then I chop off about two inches at the bottom (there's a tiny bit of residual water there), give it a quick pass with a rocket blower, and scan. When I follow this routine I get no dust, sometimes literally zero specks on a roll.

But when I don't have the time to scan right away, I have to leave film hanging overnight. This somehow attracts stubborn dust which is later resilient to a rocket blower somehow. Same thing happens when I put it into a ziplock. Your suspicion is probably valid, i.e. the bag is not dust-proof. I tried anti-static cloth but had a couple of accidents when it left faint scratches, so I abandoned that practice because it didn't help much anyway.

 

[Pieter12]

You may be right. Again, my usual routine is to scan immediately after drying, i.e. I give it about 2 hours after developing, then I chop off about two inches at the bottom (there's a tiny bit of residual water there), give it a quick pass with a rocket blower, and scan. When I follow this routine I get no dust, sometimes literally zero specks on a roll.

But when I don't have the time to scan right away, I have to leave film hanging overnight. This somehow attracts stubborn dust which is later resilient to a rocket blower somehow. Same thing happens when I put it into a ziplock. Your suspicion is probably valid, i.e. the bag is not dust-proof. I tried anti-static cloth but had a couple of accidents when it left faint scratches, so I abandoned that practice because it didn't help much anyway.

In my case, I have found dust seems to be mostly on the base (not emulsion) side of negatives, less prone to scratches. I use a combination of compressed air, an anti-static brush and ilford antistatic cloth to clean negatives prior to enlarging (I don't scan). Sometimes have to resort to a pec pad. I usually don't have to do an inordinate amount of spotting on my prints. Do you use a ziplock bag to store your negatives long-term? You might want to try archival sleeves.

 

[mshchem]

I have a couple Kodak Static Eliminator units, amazing devices. 5kV ionizer with a compressed air connection and a 2 inch camel hair brush. I use these when needed to put negatives in and out of the poly printfile pages, polypropylene and polyethylene plastic can really build up a charge.

Back in the 60's a company sold the brushes with radioactive Polonium cartridges. Good for dusting negatives and eliminating political rivals

 

[Pieter12]

I have a couple Kodak Static Eliminator units, amazing devices. 5kV ionizer with a compressed air connection and a 2 inch camel hair brush. I use these when needed to put negatives in and out of the poly printfile pages, polypropylene and polyethylene plastic can really build up a charge.

Back in the 60's a company sold the brushes with radioactive Polonium cartridges. Good for dusting negatives and eliminating political rivals

Still available. https://amstat.com/products/anti-st...__nLVo9ELHYGwU99Q3e-THWhSN0sGx2hoCHRMQAvD_BwE

 

[mshchem]

Still available. https://amstat.com/products/anti-st...__nLVo9ELHYGwU99Q3e-THWhSN0sGx2hoCHRMQAvD_BwE

https://www.orau.gov/health-physics-museum/collection/consumer/miscellaneous/static-eliminators.html

Not in my darkroom

 

[Steven Lee]

My wife's suggestion to solve to this problem is, as usual, effective and simple: just don't develop film unless you have 4 hours to dry and scan afterwards. When I ask myself why not take her advice, my inner self admits to wanting another toy

 

[BobUK]

Before I had a permanent darkroom that could have the door closed and left overnight undisturbed I followed the advice given on another forum.
Run the shower for a couple of minutes to put a bit of steam into the bathroom. Let the steam clear, then hang the film up to dry in the shower cubicle.
As the steam clears it is supposed to catch the dust in the atmosphere, thereby cleaning the air.
Worked fine for me, but we rarely have very humid atmospheres in the UK so it may differ region to region.

 

[Bill Burk]

I’ve got a small staticmaster in my darkroom.

Really my problem is if I leave negatives hanging too long they get fly dots on them.

 

[pentaxuser]

Never use a film dryer, as they blow dust particles into wet emulsion. Always dry film in ambient temperature over night. Patience is a virtue.

"Never" is certainly a very absolute term. Do you know this to be the case from experience and if it is from experience what was your set-up i.e. did your dryer have proper filtration where the fan drew the air in.

Maybe I have just been lucky and after about 18 years of using a dryer my luck based on "never" use a dryer must now be getting into the astronomical realms

If Steven had not reported a problem and offered what he believes may be cause, I wonder how we'd have responded. I have a feeling that if he or say a newcomer to film processing had simply asked what we thought of the potential pluses and minuses of a film dryer our responses might have been different and possibly more balanced

pentaxuser

 

[albada]

Never use a film dryer, as they blow dust particles into wet emulsion.

A dryer that's kept clean and has a good filter will not blow dust. My DIY dryer is a blower drawing air through a HEPA filter, with no heater. I seldom see a dust speck, unlike before.

Mark

 

[loccdor]

When enlarging 35mm, I wipe off the film surface and inspect the film just before I slide the carrier into the enlarger, blowing off any tiny specks that may linger at that point.

What is your wiping method?