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.