Enlarger Silicon cell densitometer details .....
Short Form Specification
| Sensitivity | Range x1 | 0.3 V/lx |
| Range x10 | 3 V/lx | |
| Output Voltage | maximum | 9.5 V |
| Offset voltage | typically .05 mV | |
| Dynamic Range | greater than 4 decades | |
| Dimensions | 62 x 90 x 15 | mm |
For film testing, it comes complete with a calibrated test target,
white card and black card ,
spreadsheets, connecting cable, sample data sheets and battery.
The photometer is normally connected to a low cost 1999 display
digital multimeter which is not supplied.
Download the 2 frame 6.66 stop step spreadsheet below.
This requires open software LibreOffice to be installed.
2 Frame 6.66 stop test Chart Spreadsheet, ods version 1.0 30/11/25
Ultra Low Cost Enlarger CdS sensor densitometer details
Developed by b-wtechnik this device and its free spreadsheets are made available as a kit,or individual parts,
or finished items, to suit the darkroom DIY enthusiast, all at "parts cost" and available from ebay. Typical overall cost (Nov. 2025) is £15
including a 4 digit multimeter.
Download further information and spreadsheets below:
CdS cell Densitometer Spreadsheet (LibreOffice)
Note the CdS sensor can be used with the "2 Frame 6.66 stop" method
ENLARGER PRINT TEST TIMES
Enlarger print times test method .ods
Enlarger print times test method .xlxs
Enlarger print times, calculator only .pdf
The "Enlarger print times, calculator only" pdf is text only, not a spreadsheet
These tests determine:
1. the paper exposure time through a filter of 1.2 log density to give a just noticeable image
and
2. the paper exposure time to give a maximum black.
They should be close to being the same.
