ilford 500 H and 500C

[Ricardo Maydana]

Dear darkroom friends,

I’ve been working with an Ilford 500H head and the 500C pad, diving deep into the magical world of split grade printing. Along the way, I discovered two more Ilford gems: the Power Dial and the CP500. Both seem to allow control over the green filter’s intensity—which would be absolutely amazing, especially since I’m printing negatives with densities up to 1.00 in key highlight areas. Every nuance matters.

The 500C pad lets you adjust the green filter intensity from 1 to 6, but it doesn’t really specify what percentage or grade each step corresponds to. I’ve been running contrast tests, spending hours and going through sheets of paper, but haven’t quite landed on consistent results yet. Hence, the research.

I’m wondering—has anyone here developed a method to properly test these filters? Or maybe swapped out the pad for one that allows finer control over filter increments? I’ve also started exploring F-stop printing, which feels like another beautiful rabbit hole worth getting lost in.

Any wisdom, experiences or even curious guesses are more than welcome. This craft is just so much richer when we explore it together!

#darkroomprinting #ilford500 #splitgrade #fstopprinting #filmphotography #analoguecommunity #ilfordlove

[esearing]

My control pad burned out. Since 2018 I have been using the RH Designs Analyzer 500 controller that has 1/10th filter grade values as well as time adjustments up to 1/12 stop. I usually work around G2.5-3 and 1/4th time stops. The probe/meter on mine is about 3/4 stops low for Ilford MGFB Glossy and 1.5 stops for MGFB Warmtone. You can store the variance and paper used as a calibration but I find I really don't need to. You can even make your own step wedge print and put it on the analyzer.
You work with green and blue lights and can choose to pause between them or not. It does have a burn mode that allows you to add time but I rarely use it and just hit the print button again and control light and time with a sheet of cardboard to burn corners or a hole if in center section.
for less light intensity you can move the green light further from the mixing box but its difficult to keep it there without some duct tape engineering, or cover the mixing box hole slightly. Or you could use an ND glass before the green filter but again requires some creative engineering. Easier to stop down the lens.

Like all electronics that fail, I had to purchase a second unit after the first one's buttons started not resetting or changing the display. After this system dies I will likely switch to a Heiland LED head and controller. You can read about it on the RH Designs site.

https://rhdesigns.co.uk/product/analyser-500

[Thom Bennett]

I recently started using the Ilford 500H system with the 500CPM controller and have been using it for split-grade printing using the f-stop printing method. I was using an old Aristo VCL 4500 but the Ilford system is much easier because you have up to 9 exposure memories you can store which makes it easy to run f-stop test strips and then do the split-grade exposures.

I'm curious now about the Power Dial (Switch?) on the back of the controller that allows changing the percentage of Green light. I've just left it on 4 (the recommended setting for the CPM unit but, as referred to below, the C unit recommends 1 as the normal setting) but, from what I can glean from Ilford's explanation is that if you have negs with low contrast, you can increase the intensity of the Green light to help increase the contrast in the high values? Or is it just an increase in exposure for the Green light to better balance with the Blue? Or a bit of both?

Looking forward to learning more about your tests and getting the most out of the system.

Table 3.1. Program switch
Switch Lamp type Program position:

1 ESD 120V 150W Balanced lamps
2 ESD 120V 150W Increases green light by 10%
3 ESD 120V 150W Increases green light by 20%
4 ESD 120V 150W Increases green light by 30%
5 ESD 120V 150W Increases green light by 40%

Under normal operating conditions, the
control unit is used with the program
switch set to position 1. However, the
output from individual lamps can vary,
giving a biased output on one of the
colours and producing a notable change in
print density as prints are made through
the contrast range. The variation can be
minimised as follows:

1 If the density is high at the low contrast
end, interchange the lamps and proceed to
2 as necessary.

2 If the density is low at the low contrast
end, optimum balance and density over the
contrast range can be obtained by
selecting a higher number in the range 2-5
on the program switch.

[esearing]

I just figured out another feature of the RHDesigns controller. It has a test strip mode that allows your chosen time stop increments (1/4 or 1/6 etc) to make a 7 exposure test strip. I usually burn my lighter corners or edges. So I just figured out by setting test strip mode to the final time, I can have 3 dodge times and 3 burn times. This is a little more accurate and repeatable than 100% time for burn , move, and cover