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Showing posts with label tank. Show all posts
Showing posts with label tank. Show all posts

Thursday 18 June 2015

Spiraling trouble?

Putting this lot back together was fun.
Y eh! right, there is no way I'm going to start separating a plastic spiral once the film had been processed. I was of that mind set until I started to use medium format film. In the old days I would gently unpick the 35mm film from the spool unwinding it slowly so as not to damage it. Then I was confronted with having to reset the spiral so it would take 120 film and because this film has a larger surface it is very easy to damage as I have found out.

Looking back I have to say what was all the fuss about. I think it is a lot to do with the unknown. If I take it apart will I ever get it back together? I will, just takes a bit of time. In my case the first time was easy I just gripped both sides of the spiral and twisted till it went click. Then gently pulled it apart until it reached the top slot and twisted it back the other way. Done! There that was not so bad. Huh! Not quite as clever as you thought, when it came to doing it again! I couldn't get it to go back together again no matter what I tried. It took ages to get those slots to meet up the right way and then they were backwards. Just before exasperation set in I put them down. Made a cup of tea and chilled. What makes it more maddening is when I went back to the spiral it went straight together with out a hitch.

Now a days it is second nature, don't be fooled it does not always go right first time.

Thursday 15 December 2011

Drying agent?


This is the final thing you do before hanging up your negatives to dry. This helps with the drying process by reducing the water tension allowing it to run more freely and minimising drying marks caused by the lime in the water.

Add three or four drops of wetting agent to the developing tank. Agitate the spiral in an up and down motion for a few seconds and leave for a minute. A further refinement is to add wetting agent to de-ionised water and transfer the spiral to it. Take the spiral out and peal the film from its grip or separate the two halves whichever you find easiest to do.

Sunday 11 December 2011

Agitating the developing tank.


The main reason for inverting the developing tank is to make sure that the film gets equal treatment in the developer. One of the best ways of achieving this is to tumble the tank by turning it from end to end.

Why do we agitate the tank? The developer interacts with the emulsion of the film. It vigorously attacks the silver it come into contact with and becomes exhausted. By inverting the tank you refresh this action, producing evenly developed negatives. It is
important to get this right. To little agitation will allow by-products of the process to build up, leaving pale-toned streamers as they slide to the bottom of the tank. Likewise excessive inversions will produce currents in the developer, creating uneven development. Most process times allow for agitation.
Once the developer is added you should agitate the tank for the first thirty seconds but before you put the tank down give it a slight twist and tap it on a hard surface ( it is a good idea to lay a soft towel down so you do not damage the tank) so you dislodge any air bells/bubbles that may have attached themselves to the film. Then you need to agitate for ten seconds in every minute of the process time about four inversion per ten seconds or as the developer manufacturers instruction advise. For example PMK Pyro recommend one inversion every fifteen seconds. 
I have used this inversion method from the start of my developing career ( no pun intended) and has produced consistent results every time. Once you have found a method that works for you; you should stick to it.