Help me restore faded slides.

February 16, 2014 1:41 PM

During the holidays, I came back from visiting my family with about 2,300 of my Dad’s old slides that I’m in the process of scanning. I’ve read through several online tutorials about how to restore the color on faded slides, but I haven’t had much success replicating them.

My Dad always had a preference for cheap, off-brand products, so most of the slides are taken with AgfaColor film. The slides weren’t very good quality to begin with, and they were poorly stored over the ensuing decades, and the colors have faded significantly. (The handful of Kodachrome, Ektachrome and Fuji slides he took have fared much better). One reason I believe the tutorials I’ve read haven’t been helping me is that it looks like this of film is fading in a different manner than a more mainstream brand typically does.

For example, look this photo of Yosemite’s Tunnel View that my Dad took in 1973. Would someone be able to walk me through exactly the steps I need to do to restore the color on this? As a reference, here’s a digital picture I coincidentally took from the same vantage point, in similar lighting conditions. Obviously, the old slide can’t be restored to anything near the digital picture, but is anything salvageable at all?

For an extra degree of difficulty, I don’t have Photoshop on my Mac. The tools at my disposal are Pixelmator, Aperture and VueScan. (Hmm... I guess I share my Dad’s tendency for cheap, off-brand products). A solution in Aperture that I can use to batch-process groups of slides would be ideal.

posted by 1970s Antihero to Technology (12 answers total)

You need to get into the R G and B color curves on whatever program you're using. Most of the problem is all that extra blue so turn that down then boost your green a little and fiddle with the red a bit until you lose any red tint and you should be good to go.

Here's what I achieved in a couple of seconds doing just that.
posted by merocet at 2:44 PM on February 16, 2014

I don't know those tools, but in Photoshop I'd be adding several adjustment layers. One for brightness/contrast. Another for color balance. And I'd probably tweak the levels on the R,G and B (you normally do this by dragging sliders so that they bracket what information you have in that channel).

I had a quick monkey around with the photo and managed to get it to look vaguely lifelike (on preview, mine's bluer than merocet's, but that may be due to the way my monitors are (un)calibrated). It's never going to be a vivid photo because of the amount of atmospheric haze. I don't think I'd be happy applying the tweaks across a number of images unless they were all of similar scenes taken at the same time, though.

Maybe your best bet is to keep a selection of your favourites and then concentrate on bringing those back to life. It's a very subjective process, really.
posted by pipeski at 2:48 PM on February 16, 2014

It would be far more useful to me to show me what your curves adjustments look like than the end result. I'm still having trouble replicating what you've done.
posted by 1970s Antihero at 5:04 PM on February 16, 2014

I can't help you on the technical front, but if your concern is that you don't have Photoshop, there is a free trial and it's only $19.99/mo.
posted by radioamy at 6:24 PM on February 16, 2014

Use photoshop to color correct. then save the improved images, and bring to a photo place that will develop them as slides again, or just use them as digital images. You need a scanner that has a light that will shine through the slides, etc. Photoshop will be your friend with regard to this project.
posted by Jewel98 at 7:15 PM on February 16, 2014

It also took me only a couple of seconds to get something looking like merocet's photo, just fiddling around with the color balance dialog and the curves dialog in GIMP.

(GIMP is free, and the newer versions even work natively on OS X. You can find the download for OS X on their <sarcasm>very intuitive, well-designed</sarcasm> Downloads page*.)

For the color balance doohickey (screenshot from GIMP 2.6), I selected "Midtones" as the range to adjust. Under the "Adjust Color Levels" portion, I chose -11 for the Cyan/Red slider, 26 for the Magenta/Green slider, and -60 for the Yellow/Blue slider. They're just totally arbitrary numbers that boosted green, took down the blue, and removed a little bit of red. I simply moved the sliders around until it looked all right. Here's the result.

Then, I just applied an "S" curve in Curves (screenshot from GIMP 2.6), and got that picture I linked earlier. Again, I just clicked two mostly arbitrary points and dragged them out to make an S-shaped thing that seemed to make the photo look better.

*About a quarter of the way down the page, there's a link that says "Show other downloads." Click that, and you should be able to see the links to downloads for Mac OS X. Photoshop probably has a more intuitive interface, but GIMP is probably good enough for your purposes here.
posted by retypepassword at 8:41 PM on February 16, 2014

I'm on my phone so this will be short. If these are important get a proper slide scanner as flat bed scanners generally don't get good results. Scan as raw and use something like Lightroom for colour and exposure correction. You will also need software for scratch and dust removal.
posted by GeeEmm at 8:50 PM on February 16, 2014

Since you've got so many scans to correct, I would do exactly what mercocet suggests, using GIMP.

BUT, do it in a Batch. Apply it to all of the scans (make a copy of the folder first).

This may or may not work for each-&-every photo, but because the fading is a chemical process, it probably happened almost identically across all of them if they were all under the same storage conditions.
posted by gorgor_balabala at 1:47 AM on February 17, 2014

How are you scanning these slides? A better quality scan might give you more information to work with. I haven't worked with VueScan much, but I do know that it's pretty useful software, so I would start trying to get a better quality scan, if you can.

You might be able to batch process groupings of similar photos and achieve decent results, but I do not think it's going to be possible to find an adjustment that's going to work universally on 2,300 photos. A tone curve is a representation of the tonal range of your image from black to white--so the correct tone curve for this image is going to be completely different than the correct tone curve of another.

And hey, Agfa made great products! In fact, their paper was missed so much, that another company is trying to make paper as close as possible to the original.
posted by inertia at 8:45 AM on February 17, 2014

This is a handy guide to some of the principles of color slide restoration. The version of PS they're using there is pretty equivalent to GIMP, and with GIMP you can batch process based on saved presets. I'd find a handful of emblematic scanned slides, set presets based on them, batch process the rest based on what looks closest, then go through and do slide to slide corrections.


But 2,300 slides is a huge number, so many in fact that it might just be worth paying a pro to do this.
posted by klangklangston at 6:17 PM on February 17, 2014

Thanks, everyone.

The exact control I was looking for in Aperture is the Levels setting. Specifically, Aperture has a button to adjust the R, G, and B channels automagically, and it produces satisfactory results most of the time, which makes it easy to apply to hundreds of photos at once.

The one example I posted needed a little more tweaking to the levels to look right, this is the final result.
posted by 1970s Antihero at 3:48 PM on February 20, 2014

You can pull a lot more green out of the trees, and orange out of the closer tree trunk, if you play around a little more. (But not to the point where you're putting adjustment masks down, because that'd be nuts!)
posted by klangklangston at 4:18 PM on February 20, 2014