Printing RA4 Color Photos in a Darkroom


This is a comprehensive tutorial on the basics of printing color photos in a darkroom setting. It will cover subtractive color systems, the use of filters, and good color darkroom practice as well as include a step by step guide to the process with two examples.

Printing your own color negatives is almost the same as printing from Black & White. There are a few key differences however, which do make it more time consuming and expensive. But once you have had a go and get to know the process, it’s magical.

To follow this tutorial most effectively it would help if you already knew how to Print B&W negatives or at the very least know your way around an enlarger as I am not going to be explaining basic enlarger use here. If you do need to see a tutorial on darkroom basics, there are quite a few on the site already which is why I am choosing not to cover it again.

A B&W tutorial can be found here.

Credits: asharnanae

Tools and materials:

  • Darkroom – either a purposely built one or another light-tight space. Preferably with running water, electricity and good ventilation.
  • RA4 Chemicals – or other C-type paper processing chemicals.
  • Mechanical Print Processor – or a manual heat controlled vertical slot processing tank system, like the Nova slot tri-mate processor.
  • Color Enlarger – These differ from B&W enlargers because they have yellow, magenta and cyan filter dials in the heads, without these you will not be able to affect the color cast of the image.
  • Printing frame – when you need to place your paper accurately in the dark it is very useful for quick easy working.
  • Measuring jugs/cylinders – You will need various buckets, hoses, bottles and such to mix, drain and replenish your chemicals.
  • RA4 Color Darkroom paper – I use Fuji Crystal Archive
  • Gloves and tongs – For mixing or handling chemicals and prints
  • Print Dryer or rack – A mechanical dryer speeds up the processing a lot as you have to judge the test strips whilst dry, not wet.
  • Flat wash tray with water – if your processor does not wash your prints you will need a washing tray.
  • Color negatives – You will need these to print from!
  • Timer – this will be useful if you are manually processing your prints.
This is a DeVere Color Enlarger

Setting up your darkroom space

Once you have all your tools and materials gathered you will have to organize your darkroom space carefully, and make sure it is clean and clutter free. Firstly, you want to produce good prints, and having a clean space will make this easer. Secondly and most importantly, you will be printing (and processing if it’s not by a mechanical processor) in COMPLETE DARKNESS! You can’t use safe lights of any kind, as color paper is sensitive to ALL light.

This means that you will have to know your way around your darkroom space and make sure it is safe as possible for you to move around essentially blind. There are some safe lights available for color printing but I have been recommended by every color printer I have met not to bother with them as they still do fog the paper.

When you are manually processing, a timer is essential. The time you leave your print in each chemical will alter the colors of the final print so the more accurate you are the better your print will be. This is why you also need a thermostatically controlled chemical bath, as the heat of your chemicals will also effect the color of your final print.

This is where a mechanical processor is worth the time, effort and money. As soon as the print is in the processor it is light-safe. It also regulates temperature and time of processing. This means that not only can you turn the light on if you wish but all you have to do essentially is wait for it to come out of the processor. Some processors will also wash and dry the print for you which is even better.

Mixing and handling the Chemicals

Follow good safety practices when mixing your chemicals and keep them stored appropriately. Color printing is a time consuming business and not something that can be done in a rush.

It is best if you can leave a mechanical processor in one location for the duration of its life. They do not like to be jerked, juddered or otherwise slapped all around the place. The baths they have inside them are full, close together and open topped so they can spill into each other easily. This will foul them and you will spend days cleaning out all the contamination. Avoid excessively moving it at all costs.

The same can be said of Slot processors. Do not move them while the are in use. If you have to move them then drain it down and clean it, then move it.

Color chemicals fade out a lot more quickly than B&W and need constant replenishment in both mechanical and manual processing. You will need to drain out and replenish around 100ml of chemical every ten 10×8 prints. Some mechanical processors will have auto draining and replenishing bottles which you just have to keep empty or full.

After that, the color chemicals will last for a long time if they don’t have air getting to them which is why I would not recommend open trays. The vertical systems have lids and have far less surface area open to the air when you are processing. Once mixed, the chemicals can last up to 6 weeks if kept well.

Most chemicals say they need to be kept at around 35 degrees Celsius when in use. But they do now sell kits for room temperature. And with experimentation you can use any color chemical at room temperature, it just means adjusting the timing of the development. Consistency is key as long as you use the same temperature regardless of what that might be, you will get consistent prints. Heating the chemicals just makes it much quicker.

When you buy your chemistry, just make sure to read the mixing and timing instructions carefully and experiment until you have a successful process.

Explaining Color Casts and their Removal

Color printing is different to B&W in two main ways. First off, you are using the filters to affect the color of the print and not the contrast. Secondly, you use the filters in conjunction and not one at a time.

Color enlargers all have three colored filter dials which you use to alter the light that you shine onto the paper. Changing this combination of filters alters the color of your final print. The dials are CYAN blue MAGENTA or pink/red and YELLOW. The dials generally run from zero to 200, sometimes it’s less. I have seen some which can only go up to 140.

The color system used here is Subtractive which can seem a little illogical at first glance. Cyan, magenta and yellow can be used to produce any shade of color but to alter a color cast we generally use only yellow and magenta. This is because if used all at once the three colors make grey or neutral density so to avoid this you only use two of the colors. The industry standard is to always skip the cyan and to set the dial at zero. You can make all other combinations of color by adding or subtracting (alone or in combination) from the magenta and yellow dials.

To make sure you get an exposure that has no neutral density and has a general all round starting place which you can add or subtract from when printing any photo I always start with Dial Settings of: 0-Cyan 40-Yellow, 40-Magenta at the darkroom I work in. Though some like to use 0-C 50-Y 60-M or 0-C 60-Y 70-M, it will depend on the enlarger you are using as to what the basic settings are best set at. From this basic setting you can do your first test strip and then alter the dial settings from their.

So when/why then do we need a cyan dial? Well, cyan comes into play in two ways. Adding density to negatives and in extreme color cast correction.

By adding cyan you can increase the neutral density of a negative if the exposure time is very short. A color print should have an exposure time of no lower than 8 seconds. If it is less than this, your enlarger may not have time to balance the light properly, so you will get the wrong colors from your final print. So if you have a negative which is very thin and even with the lens stopped down to its full amount, you still have an exposure of less than 8 seconds. You can add cyan to your filter mix to reduce the light further. If you do add cyan to your mix then add the same amount to the yellow and magenta dials as well. This will bring your color balance back to where it was. So your starting filter setting may look like this: 30-Cyan 70-Magenta 70-Yellow.

If you have a print where the color cast is so far off to one side then you can add cyan to help correct the contrast. Add 30 to 50 points on all three dials, this will have effectively reset your zero point. But it will significantly effect exposure time.

So how do you use the color filters to change the color cast? The easiest way to think about it is that you have to add more of the filter color you want to remove from the print. So if you have a print that has a magenta color cast, you would add more points to your magenta dial to remove the color cast from the print. “But what about Cyan” I hear you cry. For cyan casts then you need to reverse because we want to push the print towards the magenta/yellow colors you would now subtract both yellow and magenta points from the dials, this would then remove the cyan cast.

Kodak used to produce color cast viewing filters that you could use to help judge a test strip or prints, they look like this:

A handy and logical chart is the one shown below, it shows you the main color casts, their contrasting, harmonizing and removal values. I always have this handy when looking at my test strips and prints as it is very easy to get things backwards if you’re not careful.

This is a chart I produced myself, you are welcome to reproduce it.

Step By Step – The process of printing

  1. Load your chosen negative into the Negative holder on your enlarger.
  2. Move your printing frame into place so it is easy to align your print.
  3. Turn on the enlarger light to its brightest and set the size and focus of the print. Re-align your print frame.
  4. Dial in 50 yellow, 60 magenta and 0 cyan on the filters. This is a base filter value to start from for each print.
    (Although at the darkroom I am using, I dial in 0 Cyan, 40 Magenta, 40 Yellow on the enlarger as recommended by the technician in charge. The optimum base values will change depending on the enlarger and paper and process you use.)
  5. Cut down the light of the enlarger by stopping down the lens. Its best if you use F8 or F10, though on some very dark or light neg’s this may be different.
  6. Turn off the focus light and set the run time to 4 seconds.
    (A good time to use for test strips is 4 or 5 seconds. 8 seconds is the minimum amount of time a full print should be exposed for, so 4 second bursts works well from this, though 5 seconds is easier to calculate.)
  7. Turn off all lights, remove a test strip of paper from the box and then recover the unused papers. Place the strip within the print frame area and make sure it’s up the right way.
  8. Working in the dark, cover up all but one fifth of the test strip with thick card, hover the card over the test strip, do not touch it or you will get movement blur and double imaging. Push the run button to start the enlarger exposure. Once the first exposure has finished, move the card about an inch to uncover more of the test strip. Press the run button again.
  9. Repeat this process until you have a fully exposed test strip. Use large test strips, you will need to look at a lot of the print to properly judge the colors, also machine processors will not take small test strips. About one third of a 10×8 sheet is normal.
  10. Process the test strip. (If you are using a mechanical processor the lights can now be switched back on, but if you are manually processing leave them off until your print is properly fixed.)
  11. Wash and dry the test strip. (Unless you processor does it for you.)
  12. Take the test strip into natural light for evaluation. (Never be tempted to look at the test strip under any conditions other than daylight, or calibrated daylight conditions, as it will skew the color cast significantly.)
  13. Look at the color and density of the image. You will need to evaluate which color cast needs removal. Refer to the color cast sheet. Judge the correct density you need and record how many seconds takes. It is best to keep detailed notes on the filter settings and number of seconds you are using each time.

Notes: At this point you may need to look carefully at the color cast sheet as your cast could come from multiple directions. The image could be too warm but does this stem from a yellow, orange, red, scarlet or magenta cast? The best place to look for very slight color casts are the neutral and grey areas of a print.

Remember that to remove a color cast, you have to dial in MORE of the color you want to remove. Thus, to remove a magenta color cast you would dial in more magenta filter points. Also remember that you do not generally use the cyan dial to remove a color cast so check what combination of addition and subtraction in the magenta and yellow dials will remove the cast you have showing.

Thirdly, remember that altering the dials significantly will alter the time you expose your print. So if you dial in a lot more on both dials, make sure you up the time on the next test strip to compensate. The reverse is also appropriate.
14. Go back to the enlarger and make the necessary changes. Dial in the new filter settings and time. Turn all lights off again.
15. Make another test strip. You can fine tune the time by the second with this test strip if you want to.
16. Process the test strip like last time. Once fixed, you can turn the lights on again.
17. Once dry, evaluate the test strip. Has the color cast been removed? Do you need to alter the settings again? Refer to the color cast sheet if necessary. (Remember to make notes of each step with time and filter settings.)
18. Make changes to filters and the amount of time it takes. This time, make a whole print. This is where your print frame is invaluable. Turn off all lights and get out a whole sheet of paper and expose it for the required time.
19. Process your print. Once fixed, turn on lights.
20. Once dry, evaluate the print. Look at the neutral areas like grey roads and paths, do they still have a color cast? If they do, check the cast sheet again and alter your next print accordingly. The reason for doing a full print rather than a test strip is that unless you can see all the areas of the print, the fine color casts may escape you. You may also feel that the image benefits from one slightly different color cast or another. Make sure the density is also fully resolved. You should usually have full black and white, plus the other color hues. So unless you have a very odd negative, make sure you have exposed for long enough.

In an example of this process I will talk you though the decisions I made for the following negatives.

The Church

Credits: asharnanae

This negative is normally colored, and as such is a good one to use to show the evaluation and removal of a color cast.

The first test strip – dials at 0 cyan, 40 magenta, 40 yellow with 4 second bursts on the timer.

Looking at this test strip, it is apparent that the image have a red/orange color cast. That the density is still not fully correct at 16 seconds at the end of the test strip, but it’s not far away. So I decided to add a further 30 yellow and 20 magenta to the settings and use a bit more time on the next test strip.

The second test strip- dials at: 0 cyan, 60 magenta, 70 yellow with 4 second bursts on the timer.

Looking at the next test strip, the image is now slightly still red in cast but the density is better at the top end of the test strip. So I decided to add a further 20 yellow and magenta and print my first full print at 20 seconds.

The first print – dials at: 0 cyan, 80 magenta, 80 yellow with timer set to 20 seconds.

This first print is well resolved in density. It still has a slightly warm cast overall, although I quite like it as the shot was taken in the afternoon in summer and the color evokes that time of year. But to see how the shot would look slightly cooler, I added 5 more points of magenta and yellow to push the next print just slightly further towards cyan.

Final print – Dials at: 0 cyan, 85 magenta, 85 yellow with timer set to 20 seconds.

The last print is cooler in feel. It leans towards the cyan cast now. The grey areas of the church tower have just started to go slightly cyan/blue. So I could do a further print with 2 points less magenta and yellow to get the in-between and most neutrally colored print.

Of the two casts I generally prefer warmer to cooler and this is what you will have to choose for yourself once you start printing. Many of my own photos are not normally colored. And with these negatives, it is up to you on how you wish the final print to look color-wise. The second negative I will talk you through is very much in this vein.

The Vines

Credits: asharnanae

This is a negative from cross processed Fuji 400 slide film taken with my Diana F+. When I got them processed, they came back with a distinctly warm green cast and this particular shot had quite a green/cyan tone to it. So in this development, I am not trying to remove the cast to make it normal but I’m trying to enhance it to show this vivid color even more.

So for the first test strip I used the basic 0 cyan, 40 magenta and 40 yellow at 4 seconds and got this:

This is much more orange in color and much less blue/cyan than I want the final print to be. So for my next test strip I used 0 cyan, 50 magenta, 70 yellow still at 4 seconds.

The second test strip has not gone that far. It still needs to be far more blue and less orange. So for my third test strip I used 0 cyan, 50 magenta, 90 yellow still at 4 second bursts.

This test strip has started to come over to the blue color cast that I am looking for but it still has some oranges evident in the whites of the print. So I decided to do a test strip at 0 cyan, 55 magenta, 120 yellow still at 4 second bursts.

This test strip has started to go towards the right color but it’s still too warm. Although, I decided to do a full print on this setting and see how it looked from there. At this point I decided that 10 seconds would be good for the density, as 8 was a bit light but 12 was too dark.

After the first full print I still wanted less orange and more blue. This time I wanted a significant change so I dialed in 0 cyan, 60 magenta, 160 yellow now at 12 seconds.

The second full print is now much more blue overall. It has lost the orange completely. But it is a warm-ish blue, nearer to true blue than cyan. So I decided to print a final print with: 0 cyan, 70 magenta, 200 yellow still at 12 seconds.

This print now has a very cool cyan green/blue overall cast and is closest to the one I got back from the processors. Of the three It is hard to choose a favorite color cast as they all have their own good points. But if pushed, I think it would have to be the second full print as I like the blue tones of this print the most.

On a final and side note

It just shows you how much a print can change when you are in the darkroom and it is up to your own judgement as to how to best print you negatives. It is an interesting thing to contemplate that here at Lomography, we tend to eschew any manipulating of negatives in a digital sense. Yet it is clear that when in a darkroom, the scope for changing the final outcome of any given negative is huge, although admittedly it’s a lot more time consuming.

For my own part, I use my scanner as I would my darkroom enlarger. I work within the scope of the negative and the controls that mimic the enlarger i.e. color cast and density and to achieve the ‘print’ that I want. I do not consider this wrong in terms of manipulation as it is just what I would do in the darkroom.

How far you decide to take this though is the rub. I certainly don’t go beyond what I know to be capable in a darkroom setting or what I wouldn’t bother to do in a darkroom to achieve a print like selectively dodging and burning multiple small areas of a print to alter the local exposures. It’s possible, yes. Will I bother to spend HOURS doing it? No. So I choose not to do it digitally either even though I know I could and it would be relatively quick.

Hope you got everything I was aiming for with this tutorial. It’s a long review but I wanted to be detailed so you’d get everything that you need to know.

written by asharnanae on 2013-12-03 #gear #tutorials #printing #tutorial #photos #tipster #development #darkroom #enlarger #ra4 #c-type #colour-darkroom #home-printing


  1. istionojr
    istionojr ·

    one day I will need this tutor, I really do. thanks for sharing. :)

  2. stouf
    stouf ·

    Wonderful! Thanks for putting this together.

  3. mloscik
    mloscik ·

    Great article, the best description I found in entire web!

  4. 35millimetre
    35millimetre ·

    Great guide - thanks!

  5. dynosaur10000
    dynosaur10000 ·

    Very helpful article! I was recently given a color enlarger and really want to try making some prints. I’m testing it out, as it hasn’t been used in some time.

    When dialing in color amounts, are you able to see the color change in the light/projected image? I’m not sure if the mixing chamber is actually doing anything, the tension of the knobs seems a bit off.

  6. asharnanae
    asharnanae ·

    @dynosaur10000 yes, you should be able to see a shift in the light, especially if you make a significant change. if your not seeing the light change at all then it sound like something is going wrong somewhere.

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