Digital Lab Lessons

The purpose of this page is to promote digital photography and help others realize and maximize the full potential of their digital images. 

This page was last updated on Friday, July 18, 2008 01:42:49 PM


Lab Lesson # 6 -  7/18/08

Correcting Difficult Lighting Situations and Thick Haze 

As we all know as photographer's, morning and evening light is optimal providing the best opportunity for color while afternoon light is "cool" and often leaves a bad taste in the eye of the viewer! However, here on the east coast on one of those "hot and humid" mid-summer days all that haze creates the same "diffuse" effect leaving the photograph's color shall we say "terrible"! Shooting with a 500mm lens only magnifies the issue. The overall fix to obtain the image below from the original below it involved first fixing the over/under exposure hotspots. Since slight overexposure is more readily fixed than underexposure digitally, I opted to properly expose the front of the engine then tone down the side where we get the direct sunlight. I used software called "color washer" to bring back the true color of the image. This software works optimally when you have a black reference and white reference. Just so happens our subject provides that! I sharpened the image then got rid of the graininess (image shot at ISO 400) by using Kodak's digital gem software. I then contrasted the image to further reduce the haze ending up with the final image. Digital darkroom time approx. 30 minutes.

Lab Lesson # 5 -  11/12/04

Correcting Light Contrast in Night Photography 

Night photography can be tricky and variations in lighting can make a good photo almost impossible to achieve. In the lesson we will explore a technique to correct severe lighting contrast in night photography.

In the photo above, in order to correctly expose the background, the foreground, or subject is underexposed. This is a 10 second exposure at f 4.5 with ISO at 250.

Attempting to correct the foreground exposure ruins the shot as the background is way overexposed. This is a 30 second exposure at f 4.5 with ISO at 250. What needs to be done is to take both shots then merge the foreground of this shot with the background of the first shot. CAREFULLY cut out the underexposed portion and overlay it onto the first shot. 

As can be seen, this dramatically improves the photo, however you will need to use the smudge tool to correct the contrast lines created via the overlay.

A closer view of the affected area. Use smudge tool to take pixels from new area and push them up to dark area. This took me about 45 minutes.

After color correction, exposure correction, and sharpening this is the final product! Compare with the original photo below.

Lab Lesson # 4 -  6/23/04

Removal of Obstructions from a Photograph 

The purpose of this exercise is to show that obstructions can be removed from a photograph which ruin a shot! I used basically the same painstaking technique as in lesson #3. Total time was 5 hours.

I was tempted to go with chain saw in hand after I reviewed this photo and permanently get rid of that pole!


Lab Lesson # 3 -  1/9/04

Removal of Obstructions from a Photograph

The purpose of this exercise is to show that obstructions can be removed from a photograph even when the obstruction is right in front of the engine!

In the above photo we see an otherwise good picture absolutely ruined by two very nasty obstructions right in front of the lead unit. 

In the first step, the plow was cloned over the yellow stick below the air hose opening in the plow. The opening from the left hand side was cloned and added to the right hand side.

Next, the hand rail and MU socket had to be built by carefully cloning pixels over the offending yellow stick.

Next, the stick was completely removed by cloning the track and ballast then the control box. The tough part was re-building the silver portion of pipe in front of the box.

Next, the heater vent has removed by cloning the ballast and track. Relatively easy!

The tricky part was carefully rebuilding the plow and knuckle.

After some image rotation, cropping, and contrasting we are left with the final image below. There is absolutely no evidence of any image tampering even up close. An 8x10 print is completely undetectable! The project took about four solid hours but the results are self evident!

Lab Lesson # 2 -  12/8/03

Slide and negative restoration

The purpose of this exercise is to show what can be done to fix your slides and negatives that may have suffered from bad processing. Over time, if the film processing was not correct, your slides or negatives will see a degradation of color. Don't throw those slides or negatives away! In this lesson I will show you how to correct the degradation.

A. Slide Restoration

This is the original image that came off of my slide scanner of a northbound D&H train at Catasaqua in 1982. The first step, after cropping in the photo, is to correct the color. I have tried to do this manually by playing with the color balance to no avail (actually total frustration!). I found a Photoshop plugin that works wonders on color restoration called Color Washer. You can download a demo version to try and after about five slides I was completely sold! It is $50 to get the full download. 

Here is one iteration using Color Washer. If the color correction is severe as in this case you may need to do it twice.


As seen above, the second round of Color Washer gets the color almost totally correct. It is a little under exposed so it was lightened using the levels tool under adjust under image. Due to degradation in the film itself, little speckles show up in the image. These can be removed by using the despeckle plugin under the noise option under filters. This will then allow you to sharpen the image without enhancing the speckles and thus ruining the image. Dust was removed by selecting the sky portion of the image (where dust is most visible) and using the dust and scratches option under the noise option under filters. The image was then slightly contrasted resulting in the final image below.

Final Image! - Northbound D&H manifest at Catasaqua - 1982

Let's look at one more example


After! - Eastbound manifest at Aqueduct on Middle Division 15 miles west of Harrisburg - 1981

Let's review the Steps in Order


1. Crop

2. Color Washer

3. Despeckle

4. Sharpen

5. Lighten

6. Contrast

7. Remove dust and/or scratches


Allow 15 minutes to complete this project!

B. Negative Restoration

In the original scanned image above we see the typical "aqua" haze seen in degrading color negatives due to poor processing.  

Above is the image after one round of Color Washer. It removed the blue but now has a yellow cast. This is easily removed by going to color balance under image and adding blue, in this case +40.


Now the color look pretty good. We next need to despeckle. Let's look up close at a before and after to show the importance of this step.



After! With the speckles removed the image can them be sharpened, contrasted, and dust/scratches removed. In this case the sky had to be cloned to remove the scratches (white in this case) resulting in the final image below.

Final Image! - RF&P units from a Chessie coal drag in 1974

Let's review the Steps in Order


1. Crop

2. Color Washer

3. Despeckle

4. Sharpen

5. Lighten

6. Contrast

7. Remove dust and/or scratches


Allow 15 minutes to complete this project!

Lab Lesson # 1 -  11/29/03

Getting rid of an ugly shadow

The purpose of this exercise is to show what can be done to fix a very valuable photo hat suffers from some minor but fixable flaws. The photo below has all of the elements of a great picture, namely good lighting, a colorful subject, and interesting background detail. What ruins the picture are the ugly shadow running clear across the tracks and up the engine and the distracting pole on the right hand side.

1. In order to eliminate the shadow from the fuel tank, adjacent pixels were cloned to match the darker pixels in the shadow on the fuel tank. This process was repeated for both the front and the side of the fuel tank (original photo left and retouched intermediate photo right). The key to finishing the fuel tank is creating a realistic fuel tank edge with cloned pixels from the untouched edge at the base. The fuel tank in the finished photo is the last picture in the sequence.


2. In order to eliminate the shadow from the engine, adjacent pixels were cloned from area A and added to area B to match the darker pixels in the shadow then contrasted to match the adjacent surrounding pixels (original photo left and retouched final photo right). This was relatively straight forward since the handrail created a natural boundery.


3. In order to eliminate the shadow from the tracks, adjacent pixels were cloned from areas A (both ties and ballast) and added to areas B to match the darker pixels in the shadow then contrasted to match the adjacent surrounding pixels. The key here is to find the pattern in the tracks and ballast and clone according to the pattern. (original photo left and intermediate retouched photo right)


The final touch was a minor adjustment in the canvas and cropping to get rid of the pole to the right. This painstaking process took 3 - 4 hours to complete but the rewards are self evident in the final photo below. Absolutely no evidence of the photo being tampered with are evident in an 8 x 10 printout on photo quality paper. The results, in my opinion, are simply outstanding. 

Final Product!

If the photo is of sufficient value to fix then the rewards definitely outweigh the labor. The quality and content of the photograph will be key determining factors in whether the labor (or cost of someone else doing it for you) is worth it.