Tag Archives: split grade printing

The best mid range enlarger for split grade printing.

Philips PCS 130 color/black-white enlarger and Philips PCS 150 control unit.

The Philips PCS 130 is a very underrated enlarger. If you are a fan of split grade printing, but have not quite got your head round it, this enlarger will make it really simple for you. Launched in 1979, this enlarger was aimed at the home colour printing enthusiast. Their Tri-One colour system, being additive (red, green, blue), rather than subtractive filtration (cyan, magenta, yellow), was said to be more precise and to offer better colour saturation.

The enlarger can take negatives from 35mm, up to 6×7 cm, though the correct condensers and negative masks might not be easy to locate.

Now that colour is almost totally in the digital domain, these enlargers are no longer used for colour printing. Many enlargers with colour heads are employed by black and white printers to make split grade prints, however, subtractive filtration is often confusing and differs from one manufacturer to another. This particular control unit, having red, green and blue lights, each controlled separately, is perfect for split grade printing.

For those of you who are new to Multigrade papers and filtration, I need to give you a bit of information about the paper; In the old days, papers came in fixed grades, that is to say they had a fixed contrast and this was given as a number on the box. Grade 2 was normal contrast and was designed for printing a properly exposed and processed

negative. Lower grades were for contrasty negatives, and higher grades were for flat negs, or underexposed negs.

Multigrade paper was designed with two layers (actually three, but these two are the most important). One layer is sensitive to blue light, and gives a high contrast image, the other layer is sensitive to green light and gives a low contrast image. The Multigrade filters are subtractive, they take out some, or all of their opposite colour. The same thing happens with enlargers with colour heads using dial-in filtration. The dedicated Multigrade enlarger heads work with blue and green lights and this is what the Philips has. The beauty of this control unit is that each lamp can be switched on or off individually. The red light does not affect the paper, but it is useful when focusing, because all three lights combine to give white light.

This is the control unit for the three lamps, with the timer on the left. The black buttons above the dials turn each lamp on or off individually.

Okay, are you all with me so far? This bit is quite simple, but when I discovered it, it was a game changer. Split grade printing had never been easier.

A negative is in the enlarger, the focus is done, the lens is a couple of stops down and you are ready to do a test strip. Find an area of the image where you have thin or empty parts of the neg, -the shadows. Now look for an area of density which represents the highlights. Can you place your test strip so that it spans both areas? This is where the test needs to go. Do the test exposure with all lights on.

Now the direction that you move your card as you do the individual exposures, should provide a bit of both extremes of tone on each strip that you expose. Each exposure on the test strip should tell you what is happening in shadow and highlight areas.

When the test is processed and in the fix, lift it out to check the result. Count along and see where the black first appears (the shadows). What exposure was that? Write it down and put a B next to it. Look at the test again and count along to see where the tone in the highlights looks correct. Write that number down and put a G next to it.

Put a full sheet of paper in the masking frame/easel. Turn all of the lamps to off. Set your timer to the time you wrote for B, and expose your paper with just the blue lamp turned on. Now set the timer for the G time, and expose your paper with just the green lamp. Process the paper and check the print, it should be pretty damn close to correct. This is split grade printing with one test strip!

I often do extra work on an image after this stage, but that is an individual choice, you may prefer a straight print. Nevertheless, this method, with this enlarger, saves a lot of time and testing. I don’t check the auction sites for enlargers because I have four different types in my darkroom and I don’t need any more. I have no idea how often these enlargers come up for sale, but I’m willing to bet that they don’t fetch high prices, because most people don’t realise how good they are.

If anyone reading this has a spare one, please leave a comment below, because I am sure that somebody reading this will want one.

I wish you well with your printing.

If you have enjoyed this post and the information here and elsewhere on my blog, would you consider a small donation via Ko-fi please? You can send as little as £3.00, or more if you are feeling generous. This money goes towards materials used for the tests and printing for these articles. The link is; Ko-fi.com/andrewsandersonphotography

Split grade printing

First posted 12 March 2010

Split Grade printing in it’s most basic form is a process whereby two exposures are given, one through a Grade 5 filter and one through a Grade 00 filter. These two exposures can be varied in order to arrive at the correct contrast for almost any negative. I have another, simpler version which I will write about at a later date, but for now I’ll explain this method.

As I said, there are two exposures given, one through a Grade 5 and one through a Grade 00. That is the theory anyway, -but in reality some negatives only need one filter to print. This is especially true with extremely thin negatives which can only be printed on a Grade 5.

Let’s go back to basics: To simplify, the photographic emulsion in a Variable Contrast or Multigrade paper is made up of two light sensitive layers. One is sensitive to green light and gives a long range of greys from pale white through to dark grey, it won’t give a deep black unless it’s grossly overexposed. The other layer is sensitive to blue light and gives a very high contrast result, consisting of mainly black and white, with very few intermediate tones.

White light gives roughly equal amounts or both green and blue light, so exposing without a filter activates both layers giving a contrast between the two extremes, -roughly grade 2, depending on enlarger type. Using a Grade 2 filter also activates both layers equally, but reduces exposure time because of the density of the filter.

When two different exposures are given, one of the layers is activated more than the other and this moves the contrast away from grade 2.

Because this subject needs a full explanation beyond the space I have here, I have made a demonstration video which should make the point more clearly.

The video is currently unavailable, but I will restore it soon and give the link here. Please accept my apologies.