RH DESIGNS STOPCLOCK 500

Two Channel f-Stop Enlarger Timer
– dedicated to the Ilford Multigrade 500 Enlarger System.

The StopClock 500 is a version of our acclaimed StopClock Professional f-stop enlarger timer designed especially to replace the standard control pad of the Ilford Multigrade 500 enlarger head. Connected to the Ilford light source it directly controls exposure time and contrast grade to produce high quality prints. Please read the StopClock Professional page for a general description of the features and benefits of the StopClock 500, which incorporates almost all the features of the standard StopClock Professional as well as adding contrast control.

Split-grade printing

The StopClock 500 controls the Ilford light source in a different way to the standard Ilford controller. Instead of varying the relative intensity of the green and blue bulbs to establish contrast grade two exposures are made, one using the green bulb only and one using the blue bulb only. The relative lengths of each exposure together determine both the total exposure and the contrast grade. The split-grade exposure technique allows creative dodging and burning in – for example dodge during the green exposure to increase local contrast.

Because the StopClock 500 controls the contrast grade as well as the exposure time, the programmable sequence stores both time and grade, making burning in at different grades easy.

StopClock 500 Features

• Replaces the standard Ilford control keypad and derives its power from the Multigrade 500 Power Supply.
• Base exposure time 1.0 seconds to 240 seconds, in steps of 1/12th to 1/2 f-stop. Time is controlled to 0.01 seconds.
• Exposure times are set in steps of 1/2, 1/3, 1/4, 1/6 or 1/12 of a f-stop. (The fine 1/24 stop step size and linear mode are not available in this model).
• Nine subsequent exposure times can be programmed, each calculated either relative to the base exposure or the total exposure time thus far. Burn-in exposures are set in steps of 1/12th to 1/2 f-stop. If the base exposure changes, the burn-in exposures are recalculated to maintain the density relationships. Each step can have an individual contrast setting.
• Contrast setting via a split-grade exposure system which varies the ratio of green and blue exposures to achieve contrast control. Contrast is set and displayed in steps of 2 ISO(R) units – equivalent to 0.1 grade over the range 00.0 to 5.0.
• Automatic exposure test strip mode, for quickly producing test strips with 1/12th to 1/2 stop increments either as an incremental exposure or separate complete exposures.
• Automatic contrast test strip mode.
• Exposure Compensation of +/-20% to allow for dry-down or and/or toning with respect to a test print.
• The clear yellow LED display brightness can be set to one of three levels. The display colour has been chosen to be safe for both colour and black and white printing.
• Audible beep at the end of each exposure, and optional seconds tick whilst the enlarger is switched on.
• Rugged steel enclosure and high quality components for reliability. Illuminated control buttons.
• Automatic safelight switching via the Ilford power supply; manual (focus) mode
• A footswitch is available as an optional extra for hands-free operation.
• Exceptionally easy to use!

StopClock 500 Specification

• Timing accuracy: Better than 1%
• Timing repeatability: Better than 0.1%
• Exposure setting accuracy: Better than 1%; resolution 1/12th stop.
• Timing range: 1.0 to 240 seconds per step, up to ten steps.
• Timing resolution: 0.01 sec.
• Contrast resolution: 0.1 grade – approx 2 ISO(R) units.
• Display type: Yellow LED, three levels of dimming, 590nm LEDs are safe for colour papers (Safe except for direct exposure – dimmer than the filtration control lighting on most enlargers)
• Size: WHD 200mm x 65mm x 160mm (7.8 x 2.5 x 6.3 inches)
• Weight: 1900g approx as shipped.
• Input voltage: uses the Ilford 500 Power Supply
• Accessories supplied: instructions.
• Full two year guarantee, plus 14 day refund if you are not completely satisfied.