Magenta Slides & Colour Correction

Most people don’t realize that eking memories out of slides and getting those moments into a useably modern format is only one part  – and often the easiest part – of the digitization equation. Because what if your slides are really old? Or really dusty? Or stuck in a slightly damp basement? Or some/all of the above…

Dusty slides are the easiest thing to deal with. Damp slides are quite a bit more concerning – but for now we’re going to focus on my personal favourite… really old slides. Really old faded slides with a magenta cast.

Why is this my favourite? Because it happens to practically everyones slides – so it’s a pretty prevalent problem. No matter how well you store your images, slides get old and discolouration happens. Why does it happen? Well, film uses unique combinations of three dyes (cyan, yellow, and magenta) to create the whole cast of colours in an image. These dyes each have different “shelf life” and as the slide ages they will fade at different rates, magenta being the most hardy and last to go. Different film manufacturers battled this in different ways, Kodachrome Kodak Kodachrome being the most successful with the average life of their colour being rated as upwards of 60 years (counting on proper storage techniques). They were most successful to the point that the differences between slides shot on Kodachrome and other types of film is very apparent today.


Now the challenge in shooting overly magenta slides isn’t that the red tones have become too saturated. The problem is that there are minimal, or worst case scenario, no cyan or yellow dyes left in the image. This results not only in a pink picture but a loss of information. (Just like when you majorly over or under expose an image on a digital camera – if the information isn’t there it can never be reconstructed). 

So how do we go about restoring this? To start, the white balance and the colour balance sliders in Lightroom and Photoshop (or which ever software you’re using) will be our best friends. A surprising amount of colour correction can be done using just these two tools. After this the next thing you’re going to want to check is – is your picture still properly exposed? I often find that I need to brighten up the image a touch and then add back a few points of black to create some saturation or bring out out a few shadow/“outline” details. Once you’ve done that you’ll have a pretty good idea of exactly how much yellow and cyan evaporated from your image. While not everything can be restored my favourite trick is making a very soft/feathered section of the sky and manually changing the hue to reflect a blue tone, I’ll then do the same thing with the grass so it reflects a little more green. If it’s an indoor picture I’ll loosely select the shadows, desaturate them slightly, and add a bit of blue. I find people don’t see the red tone to the image if your sky and shadows are mostly blue, your grass is mostly green, and your skin is it’s proper peachy-to-chocolatey colour.

You can find a before and after photo directly below. And directly below that you can see images that illustrate the steps I’ve detailed above. Enjoy!

Our starting image and finished image! Follow along below for the step-by-step
Adjusting the white/colour balance, then adjusting the exposure 


Using the stamp tool in “lighten” to deal with the pesky dirt and dust 
(I like to use lighten so you don’t change any pixels except for the darker dust spots. I find it’s easier to not interupt patterns/areas that are decidedly non-patterned this way. I also like to keep my sample area right on the edge of the brush so my colour stays truest).



↑ Smart sharpen just on the face to bring out a couple details
A soft selection on the body to bring out some dynamic range and outlines in the clothing curvesAgain, a soft selection of the sky, and then the mountains, to first add some blue and then add some green & black 




2 thoughts on “Magenta Slides & Colour Correction

  1. When diving red light loss causes the cameras white balance to freak out. When diving in green water, when the colour red is taken out of the spectrum, the only colour left is green! The leaves for some horrible looking lime green footage. Simply throw our magenta filter on there and it reduces excess green colours leaving behind naturally balanced colours. Take a peek at our comparison video below and see what we are talking about. Comparison Video

    1. Yup! I’ve experienced that underwater shift of colours myself – it’s quite weird to work with a loss of red/magenta, instead of an over abundance. While the filters work great sometimes I find the cheaper quality ones tend to just creat a purple cast instead doing what they’re supposed to.

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