Palmetto, El Paso Playhouse, June 2012 - Kodak Easyshare Z1485

Room And The View, Kodak Easyshare Z1485 IS - HDR photo

Kat Kounting, Winter 2014 - Canon GIII Q17 35mm on Agfa Vista 100. 16 years of pennies.

Fall Mobile Dream 2013 - Canon GIII Q17 35mm film.

Java Cup Fall 2013 - Canon Powershot A4000 IS

Sunset El Paso, Feb 2014 - Kodak Easyshare Z1485 IS

Pho Noir, El Paso, TX 2014 - Kodak Z1485 IS

Dove In The Tree, Feb 2014 - Kodak Easyshare Z1485 IS

El Paso Diner 2012, Canon Powershot A4000 IS

The Prokudin-Gorskii Archive: Fixing Color Casting Using GIMP 2.8

The Prokudin-Gorskii Archive: Fixing Color Casting Using GIMP 2.8
If you haven’t read my first article you should read it first:
Restoring the Prokudin-Gorskii Archive using GIMP 2.8. Specific steps at the beginning and end of this article will assume you have read it.

A Brief Word About GIMP 2.8
If you tried GIMP in the past and found it frustrating then try it again with this version. Many of the User Interface annoyances have been fixed and it’s now much better and easier to navigate.

Color casting…
One of the more common problems with the Prokudin archive are weird color casts. This is generally caused by the emulsion on one or more of the separations having badly faded over the years and in this case it’s a red color cast. A good example is the following glass plate composite from the Library of Congress.

In the courtyard of a Sart home. On the outskirts of Samarkand
image

You can see right away that the color has ‘shifted’ away from what it was intended to be.

You might spend quite a bit of time using Curves or Color Balance in GIMP to fix it but it would take quite a bit of fudging around. However, the separations for this photo reveals the true problem with the above photo and it’s easy to fix too…
image
The emulsion on the red separation on the bottom has faded/deteriorated quite a bit. The red separation appears to be 2 EVs overexposed than the blue separation. To a much lesser extent so has the green separation in the middle and possibly 1 EV overexposed/faded. It’s apparent in the bottom right hand corner of the separation where the steps are. 

  • Start GIMP 2.8

  • Crop out each individual separation (see my first article).

  • Open As Layers all 3 of the separations

  • With all 3 separations visible set the Mode to RGB. (Important).

  • Make sure all separations are visible.

To confirm the fact that most of the color cast is coming from the red separation you can turn on the histogram tool. Colors=>Info=>Histogram.

Now one at a time, look at the histogram of each separation by clicking on the filenames of each of the separations. You’ll see in the histogram that the blue and green separations are fairly flat and spread out. However the red separation is skewed all the way to the right third of the histogram and starts coming close to being clipped. We’ll come back to the histogram in a minute, it will be our friend.

Time to fix it…
What may first seem like an extremely tedious or hopeless operation is really quite simple and quick to do. Hopefully, you have not forgotten to change the Mode earlier to RGB. Now you can…

  • Right click=>Colors=>Levels

This will bring up the Levels panel with a histogram. Underneath the histogram are 3 upward pointing arrows, the black point, mid point and white point. What you want to do is reset each of these points. When you do, it will flatten out on the histogram and thereby get rid of the color cast. Here’s how to fix it and it’s quite simple once you get the hang of it. It will take a little practice but not much.

  • Go to the far left of the histogram. The up arrow there is your black point. You want to set it right on the end of the tail of the histogram on the left. Just before all the light falls off completely.

  • Next go to the far right of the histogram. The up arrow there is the white point on the histogram. Again move it to just before the light ends, the far right tail.

  • Finally, go to the middle up arrow under the histogram. Find the tallest ‘hump’ and move the arrow to the top of that hump.

  • Click OK

  • Follow the same procedure above for the green separation.

The color cast has been mostly eliminated. You can now go through the procedures described in my previous article. After you have created a composite you can further saturate, adjust curves and otherwise post process to your liking.

Below is the Library of Congress version and my version which is post processed in GIMP 2.8 and minimally restored.

Library of Congress version straight from the glass plateimage

My restored version using GIMP 2.8
image

From here you can further make sharpening, cropping, corrections and restorations now that you know how to get rid of the color cast. Prokudin’s ingenious, 100 year old process is timeless, artistic and scientific.

Prokudin’s method has stood the test of time for creating some of the most beautiful Technicolor photographs made then and now. I personally love the extremely high dynamic range he was able to achieve bringing out incredible depth and color that can’t be easily duplicated with digital cameras. I always ask myself, How will digital photos fare 100 years from now?

If there is an interest here in restoring the Prokudin-Gorskii photographs using GIMP 2.8 then let me know and I’ll write up more howto’s. In particular, how to restore severely damaged and broken glass plates of Prokudin-Gorskii using GIMP 2.8. It’s not nearly as difficult as it might first seem.

 

Restoring the Prokudin-Gorskii Archive using GIMP 2.8


Restoring the Prokudin-Gorskii Archive using GIMP 2.8

The Prokudin-Gorskii archive is unique in the history of photography. Owned by the Library of Congress, we are given an archive that anyone can use to reproduce every photographic plate available in the archive. I’m sure Prokudin would be quite amazed to know that his collection is now available to anyone through modern 21st century technology. In fact, it could be argued that the following link could be the very first
color ‘selfie’ ever made.
Sergey Prokudin-Gorsky. Self-portrait on the Korolistskali River, 1912
image

As each new advance is made in digital imaging and editing software the opportunity to refine the restoration and reproduction of the plates and photographs are endless as well as exciting.

The Photoshop bomb...
The problem I came across is that even though there is documentation on how to do this in Photoshop I only found one old article on how to do this in GIMP (GNU Image Manipulation Program). Not only that but I knew close to nothing about using GIMP. That article got me started and is located here:   It’s worth reading.

What follows are the basics in restoring the images into the beautiful and dramatic Technicolor photographs not seen in almost 100 years. I’ll be doing this using the open source GIMP editing software. Although there is quite a learning curve involved with GIMP (and Photoshop as well) the following simplifies learning to restore these photos and will show you the basics of using GIMP at the same time.

Not everyone has Photoshop nor do they want to go to the expense to purchase PS for the purpose of restoring the photos. GIMP 2.8 is more than adequate, easier to use than PS and it’s professional quality software. There have been great improvements in GIMP so if you’ve tried it in the past, give it another try.

A brief word about GIMP
If you’re coming from a Photoshop world GIMP’s UI can be frustrating but then again if you use PS/Elements you’re probably not reading this. There are tutorials on the Internet that explain how to do this in PS.

GIMP is free to download and is widely supported with great tutorials on Youtube, documentation on the Internet and in book form. It’s exceptionally good software and I encourage it’s use particularly in the restoration of the photos.

If you have an old version of PS and can’t afford or don’t want to upgrade, you should seriously give it a try. It’ll do anything PS does and more. We’ll go through the complete process from start to finish.

Downloading and installing GIMP (GNU Image Manipulation Program)
Go to the GIMP website and install it from there. I use Windows but there should be no problem with the Linux or Apple versions. Here’s the link: http://www.gimp.org/downloads/.
As of this writing, the current version is 2.8.10. download, save and install it. It’s really that simple.

Browsing the Prokudin Collection
You can browse individual photographs and download each photo as a .TIF file. Prokudin made a blue, green, red filtered shot of each photograph. You’ll want to download the largest TIF file for each one you want to combine. This link is the example I’ll be using…
http://www.loc.gov/pictures/resource/prok.00938/?co=prok

image

The blue separation is always the top image,  the green separation is always the middle image and the red separation is always on the bottom. Give it a unique name when you save it. From the photo above here’s the download link…

http://lcweb2.loc.gov/master/pnp/prok/00900/00938a.tif

The photos have a numbering system that I haven’t figured out but the glass plates are always named ddddda.tif where d=digit. Each photo is 1 negative (3 frames) : glass, black & white, three-color separation ; 24 x 9 cm which is slightly larger than today’s medium format 6x9 120 roll film. Once cropped each photo is roughly a 8x9 cm negative.

Make 3 Cropped Photos
Once you’ve downloaded the image you’ll need to crop each of the blue, green, red separations. Below is how to do this in GIMP it’s quite easy.

  • Start the GIMP software

  • Click on the Crop tool in the Toolbox panel on the left of your screen

  • Make sure the Tool options panel is visible.

  • Windows => Dockable Dialogs => Tool Options

  • In the Tool options, make sure ‘Fixed’ is checked and set the ‘Fixed’ field to ‘aspect ratio’.

  • Set the ‘aspect ratio’ to 9:8. This will insure that all 3 separations are close to the same size. This will save you time later in the restoration process.

Don’t be tempted to change your ‘ruler’ to inches or centimeters. See my footnote below for an explanation why.

Now you’re ready to make 3 crops.

  • Go to the top photo in the upper lefthand corner and mark your crop from left to bottom right corner of the top negative. The aspect ratio will be maintained.

  • Click in the middle of the crop to set the crop.

  • From the menu, File => Export As.. and export the file as a TIF file. Give the file a distinguishing name…for example I called the first crop Blue00938a.tif, the middle crop I called Green00938a.tif and the bottom crop Red00938.tif.

  • Repeat the above steps for each cropped separation.

When you are finished you should have 3 high resolution blue, green, red separations.

This is the best stage to go to each negative and repair damage and remove ‘dust’ using your favorite ‘clone/retouch’ tool.

 Restoring In GIMP
Since his photos were created 100 years ago there has been fading of the chemicals and emulsion that is coated on the glass plates. In addition to that, the filters he used to make the photos may have been inconsistent or made with values specifically for his projector when showing the photos at his lectures. It’s explained here: http://www.loc.gov/exhibits/empire/making.html. We’ll adjust and restore  the separations to create an image in brilliant and beautiful Technicolor (honest, color separations such as these are the basis for making Technicolor movies decades later).

  • Open the three files at once in GIMP as a set of 3 layers…

File => Open As Layers => <filenames.tif>

A Windows dialog box opens up. Go to the folder where you saved the separations. In my example it’s Blue00938a.tif, Green00938a.tif and Red00938.tif. Hold down the Control key and with your mouse click on each of the files while keeping the Control key held down. Then hit enter and they’ll open as 3 layers in the Layer panel. Next, make sure all the ‘eyes’ are visible, they should be by default.

  • Right click inside one of the images and set the Mode to RGB…

Right-click image => Image => Mode => RGB

Setting the Image  Mode to RGB is CRITICAL otherwise you won’t be able to ‘colorize’ each layer. You’ll be confused in the following steps if you fail to do this.

Next you need to line up the images. To do this you need to go to the Layers panel on the right of your screen and change each layer to ‘Difference’.

  • Click on the Mode drop down arrow

  • Scroll down until you find Difference then click on that

  • Go to the next layer and repeat until they are all changed from Normal to Difference.

Mode => Difference

Using the difference blending mode is what will allow you to properly align the images using your mouse and arrow keys. It’s not too difficult but it does require some practice.

At this point you might want to zoom your separations to make alignment of your separations easier to see.

View => Zoom => Zoom In

  • Next we have to be able to move the layers around so we must first choose the ‘move’ tool in the Toolbox Panel on the left hand side of your screen…

Tools => Transform Tools => Move.

  • Next line up the images by using the Move tool.

Note that the ‘eye’ in the layers tools will show each layer when you see the ‘eye’. This can be confusing and takes some getting used to.

Ok, one of the annoyances/features that annoy me is that when you click on the ‘eye’ it doesn’t highlight the file. When you start aligning separations the Move only effects the highlighted file and it may be the wrong one. Make sure when you make a layer visible that you ALSO highlight the file you’re aligning by clicking on the file name to the right of the ‘eye’.

Once you clicked the Move tool you should be seeing the Tool Options panel along the left side. Make sure Move: Layer tab is active (hover over the icon). Also important, make sure ‘Move the active layer’ checkbox is checked. This will allow you to roughly align each separation.

  • Click inside on one of the active layers and

  • Then use the up, down, left and right arrows to move the layers around to line them up.

Pick one of the images as your ‘base’ image (I usually pick the top layer) and then one at a time make one of the other layers active and use the arrows on your keyboard to finish lining up the layer with the ‘base’ layer. This takes some practice until you get the hang of it.

HINT: The idea here is to get rid of the ‘white’ parts of the two images you are trying to align. On the Prokudin images this is nearly impossible. Why? Because he had to take 3 separate photographs of the same scene as quickly as possible, on a glass plate, through 3 different filters. I think it’s remarkable that he was able to do it at all.

Nearly always something moved either camera shake, a human, the wind moved a tree branch, swaying grass, flowing water or whatever it was. However, it sometimes has a very nice effect and adds to his artistry.

Note that pressing the arrows on your keyboard will move the image one pixel at a time in the direction of the arrow. This takes some practice and you’ll probably end up redoing it several times to get it just right and remembering all the steps. I wonder were it not for the absolute beauty of these photos would it even be worth doing at all? 

Changing The Layer mode to Screen…
Before you ‘colorize’ your composite image you’ll want to set each layer to Screen mode. It’s very easy so do the following…

  • On the Layers panel,  Click on the Mode drop down arrow

  • Scroll down and click on Screen.

  • Go to the next separation.

Do NOT skip the above step, otherwise you’ll not get the combined separations into a beautiful photograph..

Colorizing each image…
Once the separations have been aligned/registered while still black and whites and Layers have been set to Screen we can move on to colorizing them. This is where setting each separation to RGB and Screen earlier is now important.

  • First make all separations ‘invisible’ by clicking off the ‘eye’ next to each file in the Layers panel.

  • Then click on one of the layers and to the left of the filename make the separation visible by clicking on the ‘eye’. The separation should now be visible and only one ‘eye’ should be visible in the Layers panel on the right of your monitor with the layer name to the right highlighted.

  • Right-click in the separation, for this example choose the blue separation.

  • Click on Colors and then click on Colorize
    Right-click active layer => Color => Colorize

  • Click on the ‘eye’ to hide the layer and then click on the ‘eye’ of the next separation in this case choose the green separation. Again you should only have the one separation visible now.

  • Repeat the previous step using the values below.

  • Repeat the process for the red separation

    Now make all layers visible in the Layers panel and you should now see a color photograph.

Here are the beginning values for Colorizing the separations

  • red: Hue = 0 Saturation = 85 Lightness = -45 or -50

  • green: Hue = 120, Saturation = 85, Lightness = -45 or -50

  • blue: Hue = 240, Saturation = 85, Lightness = -45 or -50

Normally saturation and lightness would be a lot less (75 and -30) but as stated earlier the photos are almost 100 years old and there has been fading and deterioration of the emulsion on the glass plates. I found these values to be a good starting point for bringing out the Technicolor beauty of each photo. Looking at the comparisons below I think setting the Lightness value to -50 would have been better.

The final image…
Once you’re finished editing the final result then you can export it to whatever file format you wish, either PNG, JPG, TIF or even DNG if you install the special plug-in for further editing if you want. For the final image you can File -> Export As and choose the format you want to work with.

One thing I did not look into and maybe should is flattening and feathering the separations. However comparing my final image with that of the Library of Congress image it doesn’t appear to be necessary.

Notes On Printing…
Resolution and photo sizes for printing
Aspect ratios using pixels/inches/cm(Prokudin cropping)
8x9cm = 9:8 aspect ratio (Prokudin cropping)
3.14in x 3.54in = 9:8
4 x 6  = 3:2
5 x 7 = 7:5
8 x 8 = 1:1
8 x 10 = 5:4
8 x 12 = 3:2
20 x 30 = 15:10

Next to see if you can print at the size you want you’ll need to divide the height and width by 300 (dpi for most consumer grade printers). Quality printing and most printers can only print that much anyway. Beyond 300 dpi does no good unless your printer is a high resolution inkjet. The result of this division by 300 should be greater than or equal to the height and width of the cropped size in inches. So after you have cropped you’re photos for printing

8x9cm =942 x 1062
24x27cm =
4x6 = 1200 x 1800 = 4 x 6
5x7  = 1500 x 2100 = 5 x 7
8x8 = 2400 x 2400 = 8 x 8
8x10 = 2400 x 3000 = 8x10
16x20 = 16x20
8x12 = 2400 x 3600

Final thoughts…
I have done this enough times that the complete process takes less than 15 min/photograph and maybe less than that. After you’ve done about a half dozen of his photos you’ll be able to do them in short time as well.

You’ll also notice that no matter what, you’ll not be able to blend in and align the separations regardless of what you try. Keep in mind that in the early part of the last century, lenses were not color coated…something we don’t think about and take for granted today. It wasn’t until the 1950s that lenses were commonly color coated. Color coating corrects the way light reflects off of glass entering a lens. The color blue before color coating of lenses was commonly the biggest ‘offender’. Remember, color photographs did not commonly exist 100 years ago so color coating of lenses to correct chromatic aberrations were not necessary. This is why you’ll see this problem in what was surely very still Prokudin photos but not the black and white versions.

Another interesting aside is many of the photos have a very pleasing ‘swirling’ effect in the depth of field portions of many photos that occur around outer edges of the photo. He had to take ‘long’ exposures so he had to open up the aperture all the way. This suggests to me that at least one of the lenses Prokudin used was a Petzval lens which was in common use at the time.

The Petzval lens at the time was a huge improvement over the previous meniscus lens. Rapid rectilinear and anastigmat lenses could have produced a similar but much less significant effect and were new lens designs at the time. The Petzval lens is very sharp in the center but less so as you get towards the edges. Currently, we don’t know what lenses Prokudin used and we may never know.

The Russian Empire at the time of his photographs was going through devastating famines and economic collapse ultimately leading to the Communist Revolution in just a few short years that followed. Because the Tsar commissioned Prokudin to photograph the Russian Empire none of the famine and collapsing economic conditions were photographed by Prokudin.Oddly, no part of World War I was photographed either which also occurred during this time.  It’s evident that foremost he was a scientist, technologist, photographer and artist yet he was savvy enough to realize where his bread was buttered. Had he been otherwise, his art likely would not have survived.

It’s interesting to consider the possibilities of making your own photographs using this method. Lots of people do and it’s called Trichrome or Trichromie, color separation photography. There are lots of resources for this I’ve found on the Internet. Also it would be fun to make a trichrome view camera using 120 roll film and shooting 6x18 cm mask possibly using a dark slide for the separations? Hmmmm…..

Below is the composite generated by the Library of Congress and the one I created. Note that I did not do any retouching/cloning to fix damage on the glass plate. My only modification to the photo was sharpening and cropping. The church no longer exists. This is the only visual record of it that exists.

Library of Congress version
image

My composite version done in GIMP
image

With a little more post-processing I could achieve a very rich photograph and the total time involved would not be that much. With more damaged photos it will take considerably more time fixing the damaged areas.

Mini Mums, October 2010 - Kodak Easyshare Z1485 IS digital camera. No post processing except for the vignetting. From a bracketed shot.

Southwestern Sunset December 2012 - Kodak HD Single Use Camera ISO 800 film.

Creamy White Roses, October 2013 - Canon Powershot A4000IS

Mid-Summer Afternoon, 2012 - Kodak HD disposable camera