| Calculating
Transmission Densitometer |
The calculating
densitometer uses a PIC 16F84 microprocessor and the Texas
Advanced Optical (TOAS Inc., the TSL230, available at The
Company Store) to read transmission density values, send them
your PC and calculate a film's characteristic curve in real
time! |
| Calculating
Transmission Color Densitometer |
The color densitometer
does the above, but makes RGB measurements using the Texas
Advanced Optical TCS230 chip. It's a bit more complicated. |
| Calculating Reflection
Densitometer |
This project is
"in process" -- it is an adaptation of the Calculating
Densitometer which uses a TCS230 and array of blue LEDs to
measure the light reflected from photographic paper. |
| "Correct"
Darkroom Timer |
The timer counts
logarithmically or linearly so that you can change magnification
and let the timer make the appropriate time adjustment. The
timer has a function which allows you to make test strips
automatically (in full or half-stops!). You can also enter
reciprocity factors for large prints. |
| JOBO
Processor "Fixer Upper: |
I love my JOBO
processor for doing my 2 1/4 and 4X5 film, but the motor became
"balky" after a few years service. This seems to
happen for many users of the older JOBO units. The factory
fix is quite inexpensive.
This project uses a motor-control
chip from National Semiconductor and an inexpensive pulse width
modulator chip to supply duty-cycle modulated voltage to the
motor coil. Instead of reducing the coil voltage for lower
speeds, the voltage is "chopped" by the PWM
chip. It certainly worked to extend the life of service
for my processor. |
| Calibrate Your Monitor
and Printer (coming soon!) |
This project is
"in process" -- using the TAOS RGB to frequency
converter chip, a PIC 16F84 microcontroller and MacBeth
"color checker" as a standard, you can compare the
color values of your screen to those derived from your printer
or scanner and make the appropriate color-curve corrections. |
| LED
Enlarger Head and Controller |
These printed circuit
boards are used with the BX-24 controller chip (it has on-board
fixed point math and 4 ADC converters) to drive an array of Red,
Green and Blue LED's. Also incorporated on the board is a
switching power supply and precision current limiting driving
the LED arrays. |
| Photomultiplier
Disasters |
Why, even with decades
of experience with high voltage electronics, you should not
attempt to fix a MacBeth reflection densitometer. |
| How
to Align the Beseler 45MXT |
Ok, you bought the
enlarger used on EBay, here's a copy of the manual |
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