Now available assembled: F-Stop Timer

F-Stop timer kits:
http://www.nolindan.com/da/fstop/

Completely assembled and tested electronics: $128
You make the box or use the enclosure from your old
timer.

Also available as an electronic component kit for $68.


Read about f-stop timing:
http://www.photovisionmagazine.com/a...pprinting.html
http://www.photo.net/bboard/q-and-a-...?msg_id=0050ln
http://www.ephotozine.com/techniques...e.cfm?recid=71

The advantages of f-stop timing:

1) Intuitive: it works like a camera's shutter
speed dial, each 'click' is 1/10th of a stop;

2) Finer control: time is always set in 1/10th stop
intervals with 1/10th of a second accuracy from
1.0 seconds to 955.4 seconds. Like having a 4-digit
timer at a two digit price.

3) Easy test strips: The timer automatically generates
the correct sequence of times to produce equal zone
interval test strips in 1/10th, 1/5th, 1/2, 1, 2...
zone steps.

4) Better prints: Better and easier control of time
translates into better control of print values and
allows complex burns and dodges with far less tedium.

5) Burning and dodging are automatically compensated:
If the base exposure changes because of a change
in print size, paper sensitivity or mere whim then
all the burn & dodge exposures automatically track
the new base exposure.

6) Easy complex burns: Burns within burns, such as
burning the sky for 2 stops, the clouds for .7 stops
more than the sky and the dark side of the clouds
for 1 stop more than that, are all computed and
automatically adjusted by the timer when paper or
print size changes the base exposure.

6) Concentrate on the print, not the math: All
multiplications by 1.41 (for a 1/2 stop increase) or
by 1.072 (for a 1/10th stop adjustment) are
done by the timer. Complex f-stop to time charts
are no longer needed.

TIMER FEATURES:

o Exposures timed in 1/10th stop increments

o 9.9 stop range: 1.0 to 955 seconds

o Test strips in 0.1, 0.2, ... 0.9, 1.0, 2.0
and 3.0 stop increments

o Multiple burns at tenth and whole stop values

o Progressive burns within burns

o Simple and intuitive operation, no
doubled-up key functions

o 10A relay rated at 300W incandescent,
safe for cold-light heads

o Foot-switch input (foot switch is user supplied)

o High quality components: UL/CSA rated; switches specified
for 50,000,000 cycles; relay for 20,000,000 cycles; long-life
capacitors rated for 105C. All name brand parts: Microchip,
Fairchild, Bournes, Cherry, Omron, Microtran, Panasonic,
Vishay ...

AVAILABILITY

$68 - Kit of all electronic parts:

o Pre-programmed microprocessor
o All electronic parts: LEDs, resistors,
capacitors, transistors, keyswitches,
relay, transformer, power cord, AC outlets...
o PC board artwork
o Schematic, assembly instructions, operators'
manual

Printed circuit boards and chassis kits available.

For more information, questions: email


--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.