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Tips & Comments

  • Since lith film is easily damaged by handling, I recommend leaving at least a half-inch border around the enlarged negative for manipulation with tongs or fingers. 
  • Liam Lawless states:  “A sheet of thin black card under the film during exposure minimizes halation and avoids recording any marks or scratches on the easel.”  I use a piece of photographic paper exposed and developed to total black.  The reverse side is used for focusing.
  • You can dodge and burn the film during the initial exposure, just as you would a print, and it will have the same effect, on the final print made from the copy negative, as if you had done the dodging and burning during the printing process.
  • If you change anything, recalibrate.  For instance, when I ran out of Dektol one day I mixed up some D-72, thinking it would be nearly the same.  I found that I needed to add an additional gram of potassium bromide per liter of 1+2 working solution to reduce fog.  In addition I had to switch to an exposure factor of 4 (instead of 3) and use a 10 to 14 second flash (instead of 6 to 8 seconds).
  • It is worth spending a couple of hours getting one negative just right in order to fully understand the properties of the materials you are working with, and with a particularly difficult negative, it may take that long to get a usable copy.  You would do well to recalibrate with negatives of unusual contrast.  It is nearly impossible to make a good copy neg from a bad original, but it is usually possible to make significant improvements.  Obviously, however, you cannot put detail in where it does not exist in the original.
  • Do not succumb to the temptation to reduce development time, stop time, or clearing time.  It is very important to develop fully, stop fully, and completely clear the film before redeveloping.
  • A black tray is ideal for the clearing bath, because you can get some idea of the relative values in your image.  What you will see is a semblance of a positive image, the high values being represented by the white unexposed silver halide, and the low values by the clear areas of the film which appear black in a black tray.  In the tray, however, the image will appear to be of lower contrast than your developed-out negative will be.
  • The Arista APHS film is dark on its base side.  Its emulsion side appears considerably lighter under the safe light.
  • Place the negative in the carrier emulsion side up, so when the image is projected onto the lith film it will be reversed from left to right.  Later, the copy negative will be turned emulsion side down for contact printing, and so will be correctly oriented.
  • Orthochromatic film must be handled under a red safelight.  A Kodak 1A (light red) filter should work, or a red-painted darkroom light bulb.  Electron Microscopy Sciences carries a full line of safelights and filters, as does Porter’s Camera Store.
  • Keep the developer fresh.  Bromides build up quickly in the developer, acting as a restrainer.  This tends to increase contrast as well as overall density in the resulting copy neg.  Ideally, you would use the minimum amount of developer possible and prepare a fresh solution for each negative, but failing that, at least prepare fresh developer after every four negatives you make.  Using separate developers for the first and second developments is probably a good idea.
  • Remember that Less is More.  If you lose shadow detail, you must reduce the initial exposure, not increase it.  

Kodak R-21A Reversal Bleach

Distilled Water

700 ml

Potassium Dichromate

50 g

Concentrated Sulphuric Acid

50 ml

Distilled Water to Make

1 liter

Dilute 1:9 for use, and discard after 1 session.

       Potassium dichromate is an oxidizer and therefore presents a fire hazard.  Never dispose of excess solid in a wastebasket--always wash the solid down the drain with plenty of water.  This chemical is toxic and a known carcinogen--wear gloves when handling.  Do not allow to come in contact with mucous membranes.
       Concentrated
sulphuric acid must always be added to water slowly, never water to acid.  This chemical is highly corrosive and may cause severe burns if it comes in contact with skin or mucous membranes.  Wear eye protection at all times and handle with extreme caution.  Do not breathe fumes. 

Kodak R-21B Clearing Bath

Sodium Sulphite

50 g

Sodium Hydroxide

1 g

Water to Make

1 liter

       Sodium hydroxide is highly corrosive.  Contact with skin or mucous membranes may cause severe burns.  Handle with extreme caution.  Do not breathe dust.  Note:  The sodium hydroxide in this formula may be omitted with little or no adverse effect.

Permanganate Reversal Bleach

Distilled Water

700 ml

Potassium Permanganate

50 g

Concentrated Sulphuric Acid

50 ml

Distilled Water to Make

1 liter

Dilute 1:9 for use, and discard after 1 session.

       Potassium permanganate is an oxidizer and therefore a fire hazard.  Dispose of carefully.  Dry crystals and concentrated solutions are caustic.  Do not breathe dust or fumes.  Handle with gloves.
       Concentrated
sulphuric acid must always be added to water slowly, never water to acid.  This chemical is highly corrosive and may cause severe burns if it comes in contact with skin or mucous membranes.  Wear eye protection at all times and handle with extreme caution.  Do not breathe fumes.    

Clearing Bath for Permanganate Bleach

Sodium Bisulphite

50 g

Water to Make

1 liter

Kodak SH-1 Film Hardener

Water

500 ml

Formalin (37% Formaldehyde)

10 ml

Sodium Carbonate (mono)

6 g

Water to Make

1 liter

       Formaldehyde is highly toxic and a suspected carcinogen.  Do not breathe fumes.  Use under a vent hood or outdoors.

Maximum Density for Various Processes

Kallitype, Van Dyke, P.O.P.

1.8 - 2.0+

Salted paper, Argyrotype

1.6 - 2.0+

Palladium

1.6

Platinum, Carbon

1.4

Cyanotype

1.2 - 1.4

Silver

1.2 - 1.3

Single-coat Gum

0.9 - 1.2

Michael Mutmansky sent me some comments on the reversal process:

1.  He had very bad luck with the permanganate bleach and recommends the dichromate bleach instead.
2.  He noticed deposits of what he believes to be silver chloride on the surface of some of his negs, and speculates that there may be enough silver in the used bleach to redeposit some onto the surface of the negative.  A bath of fixer will remove this deposit.
3.  Redevelopment can be done in any developer.  He uses Pyrocat-HD.
4.  The sodium sulfite clearing bath should be saved after use.  When processing is complete, the sulfite solution can be poured in to the used bleach which will convert the chromium to a safer form.  Dick Sullivan has a good writeup on this procedure at http://www.bostick-sullivan.com/Technical_papers/gum_dichromate_green.htm.
5.  Fresh stop bath is essential so that development is stopped fully before the lights are turned on.  Michael leaves the lights off until the print is partially bleached.

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