StopClock Professional: the standard version suitable for almost all enlargers which use tungsten or halogen illumination. This includes those which use low-voltage (12v or 24v) bulbs and a transformer.

200-250v 50-60Hz (UK and most other countries)

Easy to use if you’re beginning yet versatile and powerful enough for professional printers, the legendary StopClock Professional really will save you time and paper. Using our F-Stop exposure system in conjunction with a built-in automatic test strip generator and ten exposure memories per channel, you can set up a complete printing sequence quickly and easily, often with reference to just a single test strip! Once the paper’s on the easel and the lights are switched off, making the print becomes a simple matter of pressing the foot switch and shading the relevant areas of the print. No times to remember, no fiddling with timer settings in the dark. The two channels make split-grade printing a breeze, and there’s even a special mode which effectively allows the exposure and contrast of variable contrast paper to be controlled separately. And if the base exposure is changed, the StopClock recalculates all the burn-in exposures to maintain the correct density relationships! A special compensation mode alters exposure times to allow for the effects of “dry-down”, the change in apparent print brightness as the paper dries. It can also be used to compensate for the effects of toning.

StopClock Professional Features

• Base exposure time 1.0 seconds to 240 seconds, in steps of 1/24th to 1/2 f-stop (or of 0.1 or 1.0 seconds in linear time mode). Time is controlled to 0.01 seconds.
• All exposure times are set in coarse and fine steps of actual exposure rather than simple seconds, producing consistent changes on the paper. The fine step size is 1/24th f-stop (approx 2%). The coarse step size can be set to 1/2, 1/3, 1/4, 1/6 or 1/12 of a f-stop. Coarse/fine button toggles between 1/24th and the set coarse time step.
• 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 is changed, the burn-in exposures are recalculated to maintain the density relationships.
• Two completely independent channels, each having separate base and burn-in exposure times.
• Split-grade mode, in which exposure can be controlled using one channel while the second can be used to adjust contrast. Equivalent contrast is displayed in steps of 0.1 grade.
• Automatic test strip mode, for quickly producing test strips with 1/12th to 1/2 stop increments either as an incremental exposures or separate complete exposures.
• 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.
• Can be connected to our ZoneMaster for exposure metering.
• Automatic safelight switching; manual (focus) mode; 750 watts (500 watts in 115v versions) switching capacity;A footswitch is available as an optional extra for hands-free operation - see the accessories page
• Exceptionally easy to use! All timing, including switching between channels, can be controlled from the footswitch.

Video Presentations

Watch these QuickTime videos to learn more about the StopClock Professional. Alternatively, visit Beyond Monochrome to see videos about all our products with explanatory notes.

StopClock Basics

Advanced Features

Programming the StopClock

Making Test Strips

Please note that the flickering visible on the display in these videos is a result of the recording process and is NOT representative of the product - the display looks steady to the eye.

StopClock Professional Specification

• Timing accuracy: Better than 1%
• Timing repeatability: Better than 0.1%
• Exposure setting accuracy: Better than 1%; resolution 1/24th stop.
• Timing range: 1.0 to 240 seconds per step, up to ten steps per channel, two channels.
• Timing resolution: 0.01 sec.
• Switching capacity: 750W per outlet, 750W total (230V only; 500W total for 115V version.). Suitable for cold light enlargers.
• Display type: Yellow LED, three levels of dimming, 590nm LEDs are safe for colour as well as b+w 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: 2200g approx as shipped.
• Input voltage: 200-250V AC 50Hz (100-125V 50/60Hz optional)
• Accessories supplied: Mains lead, enlarger/safelight connectors, instructions.
• A footswitch is available as an optional extra for hands-free operation - see the accessories page.
• Full two year guarantee, plus 14 day refund if you are not completely satisfied.

Please Note: The StopClock Professional is designed to control enlargers in which the lamp can be switched on and off simply by applying mains power - this covers the great majority of enlargers but excludes some which have closed-loop control systems such as the Durst Autocolor, Fujimoto, etc.

A special version is available for the Ilford Multigrade 500 system. We do not support the Ilford Multigrade 400 or 600 systems.

If you use a cold light (or cold cathode) enlarger, consider our StopClock Vario Compensating Timer.

Our policy is one of continuous development, therefore these specifications are subject to change without prior notice. E&OE. June 2010.

StopClock 500: a dedicated version for use with the Ilford Multigrade 500 enlarger system, it directly replaces the Ilford control unit and offers greater flexibility and reliability.

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;
• 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.
• A footswitch is available as an optional extra for hands-free operation - see the accessories page.
• Full two year guarantee, plus 14 day refund if you are not completely satisfied.

Our policy is one of continuous development, therefore these specifications are subject to change without prior notice. E&OE. November 2008.

Please note: This version of the StopClock works only with the Ilford Multigrade 500 enlarger system, it cannot be used with other enlarger types including other Ilford Multigrade systems. Our timers cannot be used with Ilford Multigrade 400 or 600 systems.

Based on the StopClock Professional this Vario version incorporates a light monitoring system which can compensate for variations in the enlarger’s light output during an exposure. Cold light (or cold cathode) enlargers use one or more fluorescent tubes rather than incandescent bulbs as a light source. As these tubes warm up their light output increases, sometimes very significantly, and this can lead to difficulties in matching the final print to the test strip and inconsistencies between prints made at the same nominal exposure. The StopClock Vario’s light sensor measures the light level continuously and if it increases, the timer speeds up to shorten the exposure time. If the light level decreases, the timer slows down. This maintains the total volume of light, and hence the exposure of the paper, constant. Result - predictable prints!

Two versions are available. For Zone VI cold lights which have a light sensor factory fitted, a connecting cable is included. For other cold lights which don’t have a sensor, we provide a light sensor and cable assembly which you can fit to your lamphouse yourself - full instructions and a fitting kit are included.

The Vario incorporates all the features of the standard Professional model with the exception that it cannot be connected to a ZoneMaster II exposure meter. You can of course use the meter separately and transfer the time manually but please read the note below.

If the light sensor is disconnected, the Vario behaves just like a standard StopClock Professional, meaning that if you have a second enlarger using a standard light source, you can use the Vario with that as well.

StopClock Vario Features

• Base exposure time 1.0 seconds to 240 seconds, in steps of 1/24th to 1/2 f-stop (or of 0.1 or 1.0 seconds in linear time mode). Time is controlled to 0.01 seconds.
• Enlarger light monitoring system adjusts the exposure time automatically to compensate for variations in enlarger light output.
• All exposure times are set in coarse and fine steps. The fine step size is 1/24th f-stop (approx 2%). The coarse step size can be set to 1/2, 1/3, 1/4, 1/6 or 1/12 of a f-stop. Coarse/fine button toggles between 1/24th and the set coarse time step.
• 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.
• Two completely independent channels, each having separate base and burn-in exposure times.
• Split-grade mode, in which exposure can be controlled using one channel while the second can be used to adjust contrast. Equivalent contrast is displayed in steps of 0.1 grade.
• Automatic 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.
• 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; manual (focus) mode; 750 watts (500 watts in 115v versions) switching capacity.
• A footswitch is available as an optional extra for hands-free operation - see the accessories page.
• Exceptionally easy to use! All timing, including switching between channels, can be controlled from the footswitch.

Video Presentations

Watch these QuickTime videos to learn more about the StopClock Professional.  Alternatively, visit Beyond Monochrome to see videos about all our products with explanatory notes.

• StopClock Basics

• Advanced Features

• Programming the StopClock

• Making Test Strips

Please note that the flickering visible on the display in these videos is a result of the recording process and is NOT representative of the product - the display looks steady to the eye.

StopClock Vario Specification

• Timing accuracy: Better than 1%
• Timing repeatability: Better than 0.1%
• Exposure setting accuracy: Better than 1%; resolution 1/24th stop.
• Timing range: 1.0 to 240 seconds per step, up to ten steps per channel, two channels.
• Timing resolution: 0.01 sec.
• Switching capacity: 750W per outlet, 750W total (230V only; 500W total for 115V version.). Designed especially for cold light enlargers.
• 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: 2200g approx as shipped.
• Input voltage: 200-250V AC 50Hz (100-125V 50/60Hz optional)
• Accessories supplied: Mains lead, footswitch, enlarger/safelight connectors, instructions.
• Full two year guarantee, plus 14 day refund if you are not completely satisfied.

Note on the use of exposure meters

Because any changes in light level are compensated for during exposure only, small errors may occur when using an exposure meter with an enlarger controlled by a compensating timer. For best results ensure the enlarger is well warmed up and ensure that the exposure is made as quickly as possible after the measurements are taken.

Our policy is one of continuous development, therefore these specifications are subject to change without prior notice. E&OE. June 2010.