Dr Beer’s Variable Contrast Developer
By mixing varying parts of a low contrast metol formulation with an energetic hydroquinone solution, a working developer of flexible contrast and surprising utility can be crafted. When used in combination with multi-contrast paper a fine degree of contrast control is possible. Refer to the table below for mixing ratios. Typical development time is about 3 minutes.
Dr Beer’s is also agreeable in a two bath work flow by mixing one tray of low contrast working strength developer and a second tray of high contrast; the effect of whichever bath is used first will predominate and the amount of time the print remains in either bath will by course impact the final print. Experimentation is the watchword.
Mix chemicals in order given; begin Part A with a pinch of the sodium sulfite to minimize oxidation of the metol.
Developer Stock Solution : Part A
750 ml water (125 degrees F)
8 gr metol
23 gr sodium sulfite (anhydrous)
20 gr potassium carbonate (anhydrous)
1.1 potassium bromide
+ water to make 1000 ml
Developer Stock Solution : Part B
750 ml water (125 degrees F)
23 gr sodium sulfite (anhydrous)
27 gr potassium carbonate (anhydrous)
8 gr hyrdroquinine
2.2 gr potassium bromide
+ water to make 1000 ml
| ← low contrast – high contrast → | |||||||
|---|---|---|---|---|---|---|---|
| Beer’s No.* | #1 | #2 | #3 | #4 | #5 | #6 | #7 |
| Solution A | 8 | 7 | 6 | 5 | 4 | 3 | 2 |
| Solution B | 0 | 1 | 2 | 3 | 4 | 5 | 14 |
| water | 8 | 8 | 8 | 8 | 8 | 8 | 0 |
* There’s no correlation between Beer’s number and paper contrast number; the difference between the lowest contrast formulation and the highest is about ¾ to 1 grade. First select the grade of paper or contrast filter that best matches your desired result and then utilize Dr Beer’s to zero in the quality.
Fomapan 100 Schwarzchild Effect
Some time ago I found reciprocity failure compensation numbers for Fomapan 100 film [aka Arista EDU Ultra]. This emulsion is notoriously bad at handling long exposures. “Murray@uptowngallery” on APUG simply took the three points noted in the official guidelines from Foma and plotted out all the seconds in between. So far they’ve worked for me. Perhaps they’ll work for you. I’ve set it all up on a one page PDF.
because i always lose this piece of paper
Easy bellows extension exposure compensation. All you need is [a] a list and [b] two numbers.
a) The list: F-stops in 1/3 increments. Keep this close.
3.5
4
4.5
5
5.6
6.3
7.1
8
9
10
11
13
14
16
18
20
22
25
28
32
b) First number: know the focal length of your lens in inches; divide mm by 25.4 to arrive at the customary unit. Some common conversions: 90mm=3.5″ 150mm=6″ 210mm=8.26″ 240mm=9.4″ 300mm=11.8″ Locate this number (as close as possible) on the F-stop list.
3) Second number: measure the bellows extension in inches from the center of the lens plane to the center of the film plane. Locate this number (again, as close as possible) on the F-stop list.
Method: total the number of 1/3 stop differences on the list between the focal length and the bellows extension and that will be the approximate increase in exposure required.
Example: 150mm/6″ lens is about 6.3 on the F-stop list and with a bellows extension of 9″ would be 1 full stop of added exposure. Another: 210mm/8.26″ lens is 8 on the F-stop list with a bellows extension of 10″ would equal a 2/3 stop increase in exposure.
Adams’ Ansco 130
a softer working print developer
Developer Stock Solution
750 ml water (125 degrees F)
2.2 gr metol
35 gr sodium sulfite (anhydrous)
78 gr sodium carbonate (monohydrated)
11 gr glycin
+ water to make 1000 ml
Mix chemicals in order given; begin with a pinch of sodium sulfite to minimize oxidation of the metol.
Use diluted 1:2. Activity will be slow, with a developing time between two and eight minutes. Provides brilliant slightly warm tonality with excellent separation of middle and highlight values. Over time working solution will darken quite brown, but maintains an exceedingly long tray life.
Working strength developer may be further adjusted with the following two solutions:
10% KBr Solution
1000 ml water
100 gr potassium bromide
Use to prevent fog; add 10-25ml/liter as needed to working solution of developer.
Hydroquinone Solution
750 ml water (125 degrees F)
25 gr sodium sulfite
10 gr hydroquinone
+ water to make 1000 ml
Use to boost print contrast; add as required to working solution of developer. Will cool slightly image tone.