dirt problems

[Mark Kononczuk]

Hi,
what are these spots?
(this is a detail from a 4x5 fomapan negative)
Is it:
a) dust on the scanner
b) dust on the negative
c) particles stuck to the negative
d) dust from the air
e) other

????

I'm hoping it is a scanner thing ( I can't see any bits on the neg with my naked eye) and when I print this using my enlarger in the darkroom it will disappear. Wishful thinking?
Either way I have bought some distilled water for rinsing with the next batch of negs.

 

[thronobulax]

Can you put the neg on a light table and examine with a high power loupe to see if it is the neg? This almost looks like pinholing. How was the neg processed?

 

[David M]

I’m assuming that this is a positive and the white areas are the fangs. Black dots are from dust on the neg in camera during exposure. White dots are from dust in either the scanner or enlarger. In this case, there are hairs too. A good clean of all the apparatus should work. You need to wipe the dust away, not redistribute it. A microfibre or Selvyt cloth should work. Have you recently cleaned the darkroom or tidied it up? These unnecessary activities throw dust into the air. Were you wearing your hand-knitted woolly Xmas sweater? Did you scratch your beard? Did you leave the negatives entirely alone in a room while drying? Did you filter the water? A very dry darkroom encourages dust.

Air bells are round and sometimes have a characteristic ring.

 

[Mark Kononczuk]

Hmmm. yes, I never thought of that, white dots and black dots. hopefully it is just dust floating around the scanner.

' Did you leave the negatives entirely alone in a room while drying? ' - what do you mean by this?

filter the water during the rinsing stage or filter the water just to rinse before hanging up?

I do tend to have 'bits' of something stuck to the negative after rinsing, so i have started wiping them of with my fingers before hanging them up to dry. I do have water from my own well, so maybe it's that, or maybe the fixer or developer not dissolved fully? Or temperature too low? It was minus 20 degrees C outside when I was developing the last batch of negatives.
I also use cheap standard vinegar in water as a stop-bath, is that wrong?

 

[David M]

Do you dry the negs in a place where people are moving round? They will be stirring up dust, inevitably. Or in a draught? They should be isolated until dry.
I would suggest filtering all of the water. If it’s well water, try allowing it to settle for a day or two, then pour off and filter.
Vinegar? Clear - “white” - vinegar might work. Many people don’t use a stop at all, but simply use a water rinse, with agitation.
Dou you use a wetting agent before drying?
If you overuse fix, it will precipitate sulphur particles. Perhaps you should filter it after each session.
Your outside temperature sounds amazing, but your solutions should be used at 20C. Storing solutions at very low temperatures may cause precipitation.
Do you wash out your equipment thoroughly? Do you dry it with a cloth?
Hope this helps. It’s all I can think of at the moment.

 

[martin henson]

I assume its a 4x5 neg, clean you film film holders, if you use a changing bag, is it clean, there are so many things that can cause this, I do not think it the scanner, but worth a wipe down

 

[David M]

Yes, the scanner and whatever is holding the film, might nee attention. If you are using a cover glass, dust that each time.

 

[Mark Kononczuk]

thanks for all those suggestions. do you dry clean a film holder or wash it with water? mine are the elite fidelity type. so - filtering developer and fixer doesn't affect their chemical function? coffee filters or cotton wool?

 

[thronobulax]

thanks for all those suggestions. do you dry clean a film holder or wash it with water? mine are the elite fidelity type. so - filtering developer and fixer doesn't affect their chemical function? coffee filters or cotton wool?

Some ideas:

• First, I store film holders in anti-static bags of appropriate size. These are the gray ziplok style bags in which electronics are shipped. Example:
  
  
  

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  This keeps site dust off the dark slides before- and after exposure and reduces the tendency for static attraction of dust. It also keeps the holder exteriors from getting crufty.
  
  
• Both the interior and exterior of really dirty holders can be wiped down with a damp, lint free towel and then cleaned as described below. Don't use paper towels or anything that might impart lint to the holder. Dirty dark slides can be washed with warm, soapy water and then rinsed thoroughly and dried, again, with a lint free towel. I use microfiber towels for this purpose.
  
  
• When cleaning a holder, I remove the dark slides and gently tap both long vertical sides against the sides of a table to dislodge any particles of cruft. I then use clean, compressed air to blow out all the grooves along both sides and bottoms. I also put the air nozzle into the opening where the slides go and blow that clean.
  
  
• I then blow clean air over the surfaces of the dark slides and insert them into the holders.
  
  
  
• I use an older SCUBA tank and repurposed regulator as my air supply - I know that air is clean and dry. Whatever you do, do not use anything other than a clean air supply - cans or whatnot. The air coming from your usual compressor is filthy with dirt and oil. The propellant in canned air can also be nasty so you really want something made for photographic use if you cannot find a friendly SCUBA shop. (The SCUBA tanks do have to be annually recertified as safe - very important with 3000 pounds of pressure inside.)
  
  
• Filtration with ordinary coffee filters will be fine. The purpose is to remove particulates from solution and it generally does not affect the solution.
  
  
• HOWEVER, if you see a lot of solids in your fixer or developer, you're not mixing them right. They should always be mixed with distilled water (to avoid local water and mineral variability - distilled gives you the same mix no matter where you travel). They should also be mixed at the temperature indicated by the manufacturer. Many Kodak powders, for example, need to be initially mixed at 120F/50C. Pour a bit of power in at a time, stirring until everything is dissolved.
  
  
• Store the mixed chemicals in brown glass bottles - especially developer. Most plastics are porous to air which will degrade the chemistry via oxidation. Once in the bottle, agitate a bit more and let stand overnight. Many chemicals need time to fully go into solution - Dektol is noteworthy this way. My source of "free" 2-4l brown glass bottles is the local brewer. I get to have a jar of nice beer or two, thoroughly clean the bottles with hot water, and repurpose the bottles.
  
  
• When mixed properly, you will see no solids in your chemistry. Fixer will show some evidence of silver over time, but I change my fixer religiously and within manufacturer's recommends long before this is an issue.
  
  
  
• Cleanliness in very part of your darkroom/processing area is paramount. Carpets and rugs are dust collectors. So are window sills, and door ledges. Generally, you need to deep clean the area of interest - every sill every corner, every part of the floor, etc. several days before you use again. If you can dedicate the area to processing, and maintain good habits, cleaning should rarely be needed. Pets and other dirt generators are not allowed in - ever. (My cat, who has run of the home, hates this and complains loudly.)
  
  
  
• Clean up spills immediately. First use a paper towel to absorb the spill and do this until nearly dry. Then use damp paper towels to clean completely. Don't use a mop for this - it just collects chemistry. Why? Because dried chemistry become a powder that can go back into the air and end up polluting your negs.

 

[David M]

The locking end flap on film holders has a hinge made of tape. Washing might damage this irretrievably. Holders are full of nooks and crannies so you might find it difficult to dry them properly.
So no washing. A good brushing to dislodge dust inside the grooves, a good blowing and perhpas a wipe with a microfibre cloth or a slightly damp lint-free one. Very old hankies are sometimes mentioned. Once they are clean, a regular brush and blow each time you load film should suffice. Storing in bags is good. You might like to check whatever you use to carry your camera and vacuum it out.
I find the Paterson filter works well for me, but a coffee filter is even better. Filtering will not affect the chemistry of a solution. If you do find anything much on the filter, it shouldn’t be there and you need to track down where it came from.
From time to time, our municipal water here seems to contain more particles. I presume it’s from repairs nearby, but it’s worth looking out for.
I’ve not heard of using scuba tanks of air and I’ve had no trouble with the ordinary squeezy bulb or occasionally, the propellant cans.
You can reduce the dust in the air in a room by boiling a kettle for a few minutes.
Check the place where you load and unload the holders.
Next check your scanning area, the scanner itself and anything else that might touch the negs. Give them a blow before scanning.
How do you store your negs?
We seem to be giving you a gigantic catalogue of possible mistakes.
I think you can see that this means we have all made those mistakes from time to time, so you are not alone. Most of us will have made more, and much sillier mistakes than you.

 

[Mark Kononczuk]

thanks.
that's a lot of cleanliness pecautions to bear in mind. i will start applying them. on another note, does the temperature of the developer significanly affect the negative? guessing, i suspect that higher temperature will increae contrast? ( i use ilford id 11).

 

[David M]

Yes, it certainly does.
There are four variables in develop]ing: time, temperature, dilution and agitation. It’s customary (and advisable) to vary only one of them for control of development and contrast. Normal practice is to standardise temperature, agitation and dilution, and use time to control the amount of development and hence negative density and contrast. This copes with almost all situations.
As very short development times can produce uneven development, it’s sometimes advisable to use a higher dilution to give a longer time. Five minutes is usually advised as the minimum time to avoid this problem.
Changing temperature is possible, but with the proviso that developers have several components and each one may behave differently at different temperature, giving unexpected results.
On this forum, you will see some very learned discussions of one particular developer and minute refinements in using it. I’m sure that, as Tom Lehrer said, they’ll all grow up to be footnote writers. They are solving problems that you don’t have, so you should read them for interest only.
Let’s recap.
There are four variables in developing film: time, temperature, dilution and agitation. It’s customary and advisable to vary only one at a time and keep the others constant.
Time is the easiest to vary. Increasing time increases negative density and contrast. Greater dilution reduces density and contrast. Increase agitation increases density and contrast. There is some general advice that very short development time will risk uneven development, so you should not use times shorter than five minutes.
The place to begin is with the instructions that Kodak and Ilford put on the box and publish on the web. They are not fools and have more experience of photography than the whole of this forum combined.
With a little experience, you may want to make changes. Large Format photographers seem to like to see more shadow detail in the negative. The way to do this is to give more exposure and it’s convenient to set a lower film speed on your meter to achieve this.
A lower film speed will give denser negs and that may give highlight densities that are difficult to print (or scan). Reducing development will tame this extra density.
Most, but not all, photographers end up setting half the box speed on their meters and giving about twenty percent less development. These are not immutable laws.
The Zone System offers a simplified way to fine tune this business of deciding what film speed to set on your meter and how much development suits your own preferences. It also helps to deal with scenes that have unusually high or unusually low contrast.
It’s very well documented on the web, so you can do a search. Choose the simplest. If you see the word “densitometer”, run a mile unless you really, really enjoy making graphs more than you enjoy photography. Existing densitometer addicts can ignore this.
I would suggest that you might care to read either Ansel Adams or John Blakemore’s books, but other members of the forum may have their suggestions. As they are all better photographers than me, it will be good advice.
Take all advice, especially this, with a pinch of salt.

 

[Mark Kononczuk]

I like your advice about just fiddling with one variable. especially when i recall the headaches i used to have with trying to work out which part of the process had gone wrong with blank images on collodion wet plates.

 

[David M]

I think you can see that I’ve made a lot of mistakes myself. I still do.

 

[thronobulax]

Great photography is discovering the images that exist between your mistakes - Me

 

[Mark Kononczuk]

hello.
how do you dry your negatives?
i got hold of a plastic box thing with holes. i put wires in the holes and use little carpentry clamps to hold the negatives. i leave this in the bathroom after i have created lots of steam with hot water. i think i need to cover the box with somekind of sheet that lets out moisture but doesn't let in dust and other particles?