Details of all RH products courtesy of Dr Richard Ross, and for full specifications see his website; rhdesigns.co.uk
Full versions of equipment manuals

RH Stopclock Professional

Easy to use if you’re beginning yet versatile and powerful enough for professional printers, the 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!

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; comes complete with a footswitch for hands-free operation
Exceptionally easy to use! All timing, including switching between channels, can be controlled from the footswitch.

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, footswitch, enlarger/safelight connectors, instructions.
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. January 2006.

RH ANALYSER PRO
Black & White Enlarging Exposure Meter & Timer with Grey Scale Print Tone Indicator

The analyser enables a black and white print to be made quickly and easily from almost any negative. This is achieved simply by using a light measuring probe to spot meter the important areas of the image projected on the enlarger baseboard. The Analyser then displays the measurements on a grey scale, indicating the tones that will appear on the print. You can adjust the contrast (paper grade) and brightness of the print using the grey scale indicator. When you are satisfied with the indicated readings, simply place a sheet of paper under the enlarger and press the Print button. The Analyser will turn on your enlarger's lamp for the correct time to produce a print with the indicated tones. The Analyser is supplied ready calibrated for Ilford Multigrade paper; however a simple calibration procedure allows the Analyser to be optimised for your own enlarger's characteristics and your preference of materials and processes.

Features

Up to eight spot readings of a negative can be taken and the corresponding tonal value of each on the final print will be displayed on the 15 step grey scale.
Densitometric readings can also be displayed.
Simple controls (harder , softer, brighter, darker) allow print contrast and brightness to be previewed without the use of test strips or prints - saves time and paper.
Over and under exposure warnings. 9 stop measurement range.
Exposure times of 1.5 to 97 seconds are calculated automatically by the Analyser using the metering probe in conjunction with paper grade and built-in calibration settings. Exposure times can be adjusted manually. Basic and burn-in exposures are accurate to 0.1 stop maximum resolution and microprocessor controlled to within a tenth of a second.
Adjustable calibration caters for preference of paper, processing, and enlarger characteristics for every grade of paper from 00 to 5 including half grades.
Automatic test strip generation for fine tuning of print exposure.
Switching capacity of 750W handles most enlargers, including cold-cathode types.
Automatic safelight switching, optional switch-on delay allows enlarger vibrations to decay after adjustments.
Industrial grade components throughout, including gold-contact switches and heavy duty relays, for maximum reliability.

Analyser Specification

Microprocessor controlled electronic densitometer and timeswitch based on a quartz timing element.
Analyser as standard switches the mains supply to the enlarger, low voltage switching is available to special order and may be required if you use a voltage stabiliser with your enlarger.
Timing accuracy: better than 1%, Timing repeatability: better than 0.1% Calculation accuracy: better than 2%
Resolution; one fifth of a stop for grades 00 to 3.5, one tenth of a stop for grades 4 to 5.Timing range: 1.5 to 99 seconds per exposure, Timing resolution: 0.1 sec Measurement range: nine stops, with over and under exposure indication
Up to eight spot measurements per exposure
Calibration: built-in, user adjustable exposure and contrast settings for all grades from 00 to 5 in half gd. steps
Switching capacity: 750W per outlet, 1000W total.
Display type: Red LED, 4 digits for time and paper grade: 15 segment bar graph for grey scale.
Size: WHD 180mm x 65mm x 140mm,
Weight: 700g approx. excluding accessories.
Input voltage: 200-250V AC 50Hz
Optional extra: Footswitch.

Features

Up to eight spot readings of a negative can be taken and the corresponding tonal value of each on the final print will be displayed on the 15 step grey scale.
Densitometric readings can also be displayed.
Simple controls (harder , softer, brighter, darker) allow print contrast and brightness to be previewed without the use of test strips or prints - saves time and paper.
Over and under exposure warnings. 9 stop measurement range.
Exposure times of 1.5 to 97 seconds are calculated automatically by the Analyser using the metering probe in conjunction with paper grade and built-in calibration settings. Exposure times can be adjusted manually. Basic and burn-in exposures are accurate to 0.1 stop maximum resolution and microprocessor controlled to within a tenth of a second.
Adjustable calibration caters for preference of paper, processing, and enlarger characteristics for every grade of paper from 00 to 5 including half grades.
Automatic test strip generation for fine tuning of print exposure.
Switching capacity of 750W handles most enlargers, including cold-cathode types.
Automatic safelight switching, optional switch-on delay allows enlarger vibrations to decay after adjustments.
Industrial grade components throughout, including gold-contact switches and heavy duty relays, for maximum reliability.

Analyser Specification

Microprocessor controlled electronic densitometer and timeswitch based on a quartz timing element.
Analyser as standard switches the mains supply to the enlarger, low voltage switching is available to special order and may be required if you use a voltage stabiliser with your enlarger.
Timing accuracy: better than 1%, Timing repeatability: better than 0.1% Calculation accuracy: better than 2%
Resolution; one fifth of a stop for grades 00 to 3.5, one tenth of a stop for grades 4 to 5.Timing range: 1.5 to 99 seconds per exposure, Timing resolution: 0.1 sec Measurement range: nine stops, with over and under exposure indication
Up to eight spot measurements per exposure
Calibration: built-in, user adjustable exposure and contrast settings for all grades from 00 to 5 in half gd. steps
Switching capacity: 750W per outlet, 1000W total.
Display type: Red LED, 4 digits for time and paper grade: 15 segment bar graph for grey scale.
Size: WHD 180mm x 65mm x 140mm,
Weight: 700g approx. excluding accessories.
Input voltage: 200-250V AC 50Hz
Optional extra: Footswitch.

ZONEMASTER II

Black and White Enlarging Exposure Meter with Grey Scale Display and built-in Densitometer function
- now with improved sensor and easier calibration!

Banish the Test Strip!

A baseboard enlarging exposure meter featuring our patented grey scale print tone indicator which shows you the tonal range of the print, so you can place important tones and preview the look of the print without the need for endless test strips. Includes a spot-metering probe with densitometer function, a wide exposure time range (1 - 240 secs) with steps in intervals of 1/3, 1/4, 1/6 or 1/12 f-stops, and storage for the characteristics of eight different papers. All the features of our Analyser Pro for users with an existing timer - or it can be connected to our StopClock Professional for instant transfer of the computed exposure to the timer.

The latest version features a new sensor and measurement subsystem which provides much faster response, especially at low light levels, and greater stability with changes in temperature and over time. In addition, a new Calibration Kit makes calibration faster and easier, and we’ve re-written the User Manual to make it clearer and easier to read. There’s never been a better time to choose an ZoneMaster II!

Why the ZoneMaster II is different

Enlarging exposure meters often suffer from a number of shortcomings. In many cases, a single reading is taken from a mid-tone area of the negative (or from a diffused image) and exposure based on that reading. This can work quite well but it won’t advise you which paper grade to use.

Enlarging exposure meters which indicate a suggested paper grade do so assuming you want your shadows to be at maximum black and your highlights at paper base white. This isn't always the case, particularly in portraiture work. And if it isn’t the case, then you’re on your own - back to the test strip!

The ZoneMaster II is different because it tells you exactly the shade of grey that you will get on a print for any spot measured area of the negative. You can see the effects of changing the paper grade without making a print - the ZoneMaster's display indicates the changes in print tone for each measured spot as you alter the grade setting. You can manually override the ZoneMaster's suggested exposure time in order to produce a lower or higher key print, and see the expected results before committing a piece of paper. You can even make your own grey scale for use with the ZoneMaster using your favourite materials and processing, so that its indications will be as close as possible to the final print. You no longer need to worry about compensating for dry down (the increase in density of a dry print as compared to a wet one) because the display indicates the tone on the final, dry, print.

All this adds up to a significant saving of both time and materials, and with paper prices rising this can only be an advantage. Darkroom work is much more enjoyable when your success rate is high! The ZoneMaster comes with a fourteen day money back guarantee of satisfaction, so why not try one for yourself?

ZoneMaster II Features

All the metering, control and display functions of the Analyser Pro are included in the ZoneMaster II with the exception of the enlarger / safelight switching.
Built-in densitometer shows the log.D value of each spot reading relative to the brightest sample, and can be used to assist in refining your film development technique.
Adjustable calibration caters for your preferences of paper, processing, and enlarger characteristics.
Quickly determines pre-flashing and fogging exposures for contrast control, plus contact-sheet exposures.
Can be connected to our StopClock Professional Enlarger Timer for instant setting of required exposure time
Powered by a single PP3 / MN1604 type battery (included) or from an optional plug-in mains power supply - see the accessories page for details.
Splash-proof case and illuminated, tactile touch sensitive controls for reliability.
Full two year guarantee, plus 14 day refund if you are not completely satisfied.

ZoneMaster II Specification

Metering spot size: 2mm diameter approx
Internal measurement resolution: 1/60 stop
Timing range: 1.0 to 240 seconds per exposure.
Time setting intervals: 1/3, 1/4, 1/6 or 1/12 stop; user selectable at any time.
Times for Test Strips can be displayed using the currently set time interval.
Calibration: built-in, user adjustable exposure and contrast settings for all grades from 00 to 5 in half grade steps. Eight individual calibration sets.
Display type: Red LED, 4 digits for time and paper grade: 15 segment bar graph for grey scale
Illuminated keypad
Can be connected to the StopClock Professional for full enlarger control.
Size: Main console: WHD 145x85x28mmm (5.7 x 3.3 x 1 inches) approx. Sensor: WHD 80x56x24mm (3.1 x 2.1 x 1 inches) approx.
Weight: 500g approx as shipped, including battery.
Our policy is one of continuous development, therefore specific

RH DESIGNS PAPER FLASHER

The PaperFlasher makes it easy to flash and fog photographic materials to control contrast and add tone to otherwise blank areas. It comprises a tiny, lightweight, electronically stabilised light source, and a battery operated control box and timer. The light source can be mounted on the darkroom ceiling, on the enlarger lensboard, or in any other convenient position using Blu-Tak, double sided tape, Velcro or similar.

PaperFlasher Features

Makes flashing and fogging easy - no need to remove the negative or use a separate enlarger
Electronically stabilised light source for repeatable and consistent results
Light source is small (40x40x20mm, 1.5x1.5x0.8 inches) and lightweight, making it easy to mount almost anywhere
Battery-operated - inherently safe and portable. Control box size: 105x60x22mm (4.1x2.3x0.9 inches). Socket for optional foot switch.
Built in timer with a range of 1.0 to 84 seconds
Accurate and repeatable timing with 0.1 second accuracy
Test strip generation in 0.1 and 0.5 stop steps for quick and easy determination of exposure
Filters for intensity and colour control can easily be fitted to the light source
Single PP3 type battery (included) provides long life and is easily replaceable. Rechargeable types can be used.
Illuminated tactile switches, splashpoof case.
Dimensions: Timer: WHD 110x65x28mm (4.3 x 2.5 x 1.1 inches) approx. Weight as shipped 250g approx.
Full two year guarantee, plus 14 day refund if not completely satisfied.