Create black&white image with effect color

Lightzone's color selection makes it easy to create black and white images that have an effect color. This method is usable if you want a single color to pop out. If you want to emphasize a multicolored object you have to use the mask tool in LZ or GIMP-like image processing software. Here is my step-by-step guide.

Below is the original image after basic enhancements, which I want turn it B&W, but leave the old lady's walking aid red. In this image you could safely pick the color directly. Risk in that method is that if there is same tone in other parts of the image, those would be also left colored. The method I describe is slightly more complicated, but it will guarantee, that there are no unwanted colored spots left.

Select the B&W tool and draw a mask around the object you want leave colored. You don't need to follow the object's outline, it's enough that there is not same tone within the area. In the B&W tool settings tick the "Invert mask".

The next step is turn also the area around the walking aid B&W. Select a second B&W tool and in the color settings select the eye-dropper. Click on the walking aid and tick "Invert" – and there you are!

I like this image more, when it's pure B&W, but I selected this to show the power of LZ on an object that has a very complex shape. It would a huge task to draw a mask that follows the outline of the walking aid.

If you use the same method with other tools than B&W they may not sum as nicely as B&W. My suggestion would be to remove the transition zone in the mask and link the mask to the tool's second appearance. Then you would be applying the same transition only once to each pixel.

Artistic with LightZone

I played during the last weekend with LZ and tried to find ways how to create little different look to my photo.

My daughter was going to a masquerade ball, dressed in black dress, red shoes and red masque with yellow feathers. Here is the original image with the in-camera settings.

I had an external flash placed quite near on the right and a white door facing my daughter. The setting gave the strong shadow on the white wall and still the reflecting light illuminated her face.

In LZ I set

• the WB to 6000K and decreased exposure by 1/3
• applied standard Canon 600D raw tone curve
• added vibrance (+30) to mids & highlights
• softened the skin with standard style "Skin Glow" and changed the skin color to match the skin in the image
• added color to masks and shoes with additional Saturation +20 and Vibrance +10 (2 × Hue/Saturation tool: applying to red and yellow)

This was now quite good standard portrait. But I wanted to do some more. I wanted to create an image that looked like made bt "Andy Warhol". I used Gaussian Blur on mids & highlights and highly over-did it. I set the radius to 150 to achieve the result below.

I'm happy with the final result and also that I could achieve all in LZ. The tool stack helped to experiment and revert to previous version easily and I didn't have to work with multiple tools and copies.

If you want the get really psychedelic results, use large radius and set the blend mode to difference.

LightZone default Tone Curve for Canon 600D

Finally I have had some time to do some more experimenting. Some posts in the LZ forum hinted that there might be some issues with the Raw Tone Curve for Canon 600D. I unlocked the Tone Curve and just experimented changing the default mode "RGB" to "Luminosity". The difference is huge and the luminosity setting produces much more natural tones. The RGB image is over saturated.

RGB Tone Curve (default)

Luminosity Tone Curve

As a reference, here is again the same image in DPP. The image in DPP is warmer (more yellow), but otherwise the overall saturation of reds and yellows are quite much alike with the luminosity setting and in DPP.

Canon's DPP

Histograms

Based on the discussions in the LightZone forum and my own experiments I found that histogram ≠ histogram.

I created in DPP a slightly processed JPG of the same image I used in my previous post. I opened then the JPG image both in DPP and LZ and the RGB histograms were different even the images looked the same. I had earlier assumed that the differences in the histograms were caused by different processing of the raw image, but that is not true. The histograms don't visualize the same thing!

Canon Digital Photo Professional

LightZone

I found a piece of software ImageJ that has an option to copy-paste the channel histogram data into Excel. I then generated a simple channel intensity vs. pixel count chart and that corresponds quite well with the DPP histogram. It looks like the scaling of the y-axis in DPP is not linear, e.g. the first peak in blues is about a third of the highest peak in DPP but in Excel it's about two thirds (200k vs 320k). I tried to change the x-axis to logarithmic so that I could have produced the histogram in LZ, but the result wasn't the same. I guess LZ shows some kind of luminosity vs. channel intensity histogram as the x-axis would indicate.

Linear and logarithmic histograms generated in Excel

Experimenting with different digital darkroom software

I have used a long time Canon's Digital Photo Professional (DPP) for processing my raw images. Sometime ago I found RawTherapee (RT) and used it a little, but wasn't really fond of it. I found the learning curve too steep. Couple of weeks ago I learned about LightZone (LZ) and it has been more to my taste than RawTherapee. In LightZone I have more control of the process than I do in DPP, but LZ is easier to grasp and achieve what you want to than RT.

Today I was trying to create similar styles as DPP has (mainly landscape and portrait) and I found significant differences how the programs process the raw image and found that my task is not going to be that easy.

Here are the images, no additional processing, just "developing" the raw image. Images are taken with Canon 600D, EF-S 18-55mm f/3.5-5.6 IS II (@ 55mm, f/9.0, 1/800s, ISO 200).

Digital Photo Professional

RawTherapee

LightZone

Findings

DPP's and RT's RGB curves look quite similar, but the LZ produces totally different curves. The peaks at the shadows have in LZ moved to midtones and the small peaks at high tones are in LZ significantly higher. In fact the in LZ the highest peaks are at high tones as in the two other programs they are in the shadows. The differences are also visible in the image. The Canon's version of the paint of the tram is faded and worn and in LZ the reds and yellows shine bright. RT is somewhere in between, little emphasing reds, nearer to Canon.

I will continue experimenting.