Sunday, February 24, 2008

Adjust any Colour of the Rainbow with Blend-If type Sliders

This week's article, as you can probably guess, deals more with Advanced Photoshop Techniques.

How to select a narrow range of any color and adjust Hue, Saturation or Luminance

How to use the Replace Color function to create a tight Mask for use with other Layers

The original article was not planned to start this way, but was to examine the benefits of using the color enhancement features on a jpeg image with Adobe Camera RAW.

Camera RAW has some interesting sliders that I tend to use frequently to initially set the color attributes of the image. I thought that with the extra colours available, I would be able to produce a better image.

These are the 3 Color Camera RAW adjustments

This got me thinking about the Hue/Sat layer adjustments and remembering that you could fine tune the colours even tighter than the default adjustments provided to you when you open the Hue/Sat adjustment layer.

This image below was selected, as I wanted to do something outrageous with a Red Hibiscus. The whole process from opening the file to creating the image below only took about 3-4 minutes.

The above strip shows:
Original Image
Change Red to Blue and De-saturate remaining colours (Hue/Sat)
Another Hue Sat layer to remove any residual reddish tinge in Blue (Hue/Sat)
Create Mask to allow yellow pollen cluster to show and add to Hue/Sat Layers (Replace Color then Color Range Mask)
Create Mask from flower and add a curves layer to darken grey background (Replace Color then Color Range Mask)

The red/yellow grid below shows the actual effects achieved by using the Hue/Sat Adjustment Layer. The corresponding settings used to create the changes are beside each row. Sat (-75) remained the same for all.

The 4 colours in the top (1st) row has only a slight change in hue from each other and are representative of normal colours.

2nd Row – This is the default red channel setting with a (–75) de-saturation applied. As you can see it also affects the 2 orange colours, but the effect decreases as we move towards the yellow colour.

3rd and 4th Row – By selectively adjusting the 2 vertical bars on the colour range menu and the 2 drop-off sliders, I can control the effect of only one of the colours.

5th row - I decided to only effect the 2 orange colours.

As the graph shows, by careful adjustment of the colour range markers (start/stop drop-off) you can fine-tune the colour selection to almost any singular or joining colours of the rainbow.

Any of the other settings can be used to create the same set as that found on Adobe Camera RAW (Hue/Saturation/Luminance).

In the image below, I show 2 examples where in one I change the hue within the narrow range of cooler blues and the other I de-saturate the lemon/lime colour range. I used masks only to adjust half of the image for each change.

You will notice that on the 2 vertical colour bar sets, the top colour shows the range you wish to change and the bottom strip shows the resultant change.

Create a rainbow layer in your image editing software as test layer. By using this layer and a mask to only affect one half, you can compare the overall colour changes of the adjusting layers above in your image. If you then add another B&W gradient on the other axis set to Hard Light (70%) mode, you will get luminance affect also. Some other modes show monitor colour space clipping (bands/gradient edges) because of the larger color gamut created by mode.

In the test example above where the default is on the top and the change applied to bottom half you may notice that when I increased the green saturation it also affected the red saturation (see black circles). By clicking the effects off an on you will notice the changes better.

I have chosen an image that has complex patterns, subtle hues and a full range of colours to best show the selective effect, but it may not be the best artistic expression of this photo. I plan to turn this into a grey scale image but only leave darker reds and blues as they originally are.

Converted to B&W with only 2 narrow colour hues remaining.

There is some work to bring out these 2 different colours, as you need to create 2 separate Hue/Sat adjustment layers to handle each colour separately.

Above: The first layer, above the “Background” layer, de-saturates all the colours on the top-right portions of the image as these areas are out of focus and I did not want any colours there. The next 2 blue layers captures the blue in the image and increases lightness. The same applies for the next 2 red layers.

The image below shows these adjustments

Since each layer de-saturates, then the color set on top will de-saturate the layer below.

To overcome this effect I did 2 ‘merge visible’ to new layers, one for the red set and one for blue set (Ctrl-Alt-Shift-E).

Creating Mask with Replace Color

A mask was created for the red color in order to not affect the blue below.

By performing “Image - Adjustments – Replace Color” I selected all the red parts by using the middle eye dropper (cumulative) to several areas.

I then saved the mask to a convenient location.

To get mask for red layer you press Select – Color Layer and load the layer you just saved. I find it easier to create the mask in the first step than in the second.
To further fine-tune this mask (becomes a permanent change) you perform a curves function (Ctrl-M) and increase steepness in the curve, to create a better B&W mask.

For simplicity and ease I prefer the Camera RAW color controls, but when I need to I can fine-tune almost any colour.

If you have a chance, please let met know how this articles works for you as I find it more difficult to write detailed technical articles. I’m never quite sure if I have too much detail or I assume too much Photoshop knowledge.

Niels Henriksen

A Photographer’s Adage

Photography is like fishing. You go out in the morning with no idea of what the trip will bring. Sometimes luck is on your side and all your crab pots are full of prime Lobsters. Other times you get nothing. - Bob Croxford, From Cornwall With Love by Bob Croxford

Sunday, February 17, 2008

Help – I am stuck in a Toronto Hotel Room

For some reason I seem to have a penchant for corny titles. I suppose for those who might remember when, I was also a big fan of a TV show called ‘Hee-Haw’ (a country version of Rowan and Martin's ‘Laugh In’ from ‘69-71). Now that was corny humour. So I hope you might find a bit of humour too.

Whenever I can, I always try and travel with a camera, and I am not opposed to even buying the disposable waterproof cameras when heading out for white water rafting. This article will show what could be accomplished when you are stuck in a hotel room and you have a zoom lens with you.
After returning from daylong sessions at a weeklong Project Management conference in Toronto, Canada, I would spend a few minutes photographing the surrounding cityscape from my hotel room before heading out for the evening.

I was fortunate to be on the 20th floor and therefore I had a decent vista, at least in one direction (south) that did not have many towering skyscrapers blocking my view. The late afternoon summer sun was at its lower angle on the horizon, which created more textures, and shadows on the textures of city buildings. With the strength of the light being slightly reduced it also reduced the contrast range or harshness.

The lens I used is ‘BIGMA” (4+ lbs) which it is sometime referred to (Sigma 50-500mm f4-6.3 EX DG/HSM lens) is a good performer as a zoom lens but definitely not a carry around the neck type. The effective focal length with a 1.5 crop gives you a lens in the range of 75 to 750mm, quite a respectable magnification power of 15x human eye (50mm). This is a lens that I do not use too often but when you need it can be quite fun.
This reach allows you to isolate architectural elements of buildings and find unique or abstract compositions.

Dpreview Sigma 50-500mm

Now looking at the images years later after taking them, it almost seems strange that I could capture such diverse group by looking out of a hotel window.
The image below with the wild and abstract orange colours becomes interesting by the inclusion of the green frames and the one open widow reflecting the blue of the sky, creating an RGB triad.

f6.3 1/160s 500mm

The simplicity of green and vertical stripes is contrasted by a large, strong zig –zag line in the building design. The closed blinds on one floor re-enforces the horizontal lines established by the green tiles.

f6.3 1/160s 370mm ISO200

I enjoy the strong horizontal and diagonal lines but the abstract patterns on the center green panels is where my gaze remains. The glass panels have the appearance of curtains but are the result of reflections from another building and then the glass distorting the shape.

f6.3 1/320s 500mm ISO200

I like how the building shape and the angle I was shooting created repeating curved blue lines.The reflection of the white building provides complementary curves.

f6.3 1/40s 420mm IS0200

This B&W image is a view a little lower from the image above. There were these trees on the roof top of a shorter building. This was s little oasis of life amongst the skyscrapers.

f6.3 1/120s 500mm ISO200

A summer storm has just passed and the dark rain sky can just be seen behind the building now lit by the setting sun.

f6.3 1/400s 500mm ISO200

A few other images.

I was even able to get a daylight moon. Cropped with strong sharpen applied.

f6.3 1/60s 500mm ISO200

Niels Henriksen

A Photographer’s Adage

People who earn less than half of their income from photography are amateurs. This has nothing to do with the quality of their photography. - Ken Rockwell

Sunday, February 10, 2008

The Mask – To Hide or Reveal our Personality

First I would like to announce that some of my fellow photo bloggers such as Brian Auer , Neil Creek , Andrew Gibson ,
Andreas Manessinger, Cody Redmon , David Ziser , and Joseph Szymanski have decided to start a Fine Art Blog Photo Blog .

Many of you may already subscribe to their blogs, but I would like you to go over and subscribe to their new site. As the site progresses, there will be a great collection of fine art photo images that should enthral us all.

These photographers, through their personal dedication and love of photography, provide a great resource for all of us and I think that it is important to show our support for their effort.

In this article, I will discuss the use of masks to enhance or change an image to best bring out the vision I had. As a secondary point you might also be amazed that this image was taken by a 2Mb point-and-shoot camera made in the year 2000.

Through proper editing and enlarging techniques I am able to print this at 11x14” and it has been one of my popular sellers. The main reason I can make such a large increase in size is because this is an abstract image with relatively little fine detail.

It doesn’t take the best and most expensive technology to have great pictures. The extra features though will help you in more tricky situations and may ease some workflow issues.

A tranquil place to contemplate your thoughts

In photo-editing programs such as Photoshop, masks allows us to fine tune local detail to almost any extent we desire within the image. It is all dependant on the amount of effort we wish to pursue.

The original image from the Canon A40

The first thing I did was to enter in LAB mode so that I could both increase the saturation of the reflected colours and by using LAB I could also increase the separation between the red/green and blue/yellow which would help to give the appearance of more contrast in the fall foliage.

I found that the floating weeds on the pond where reflecting too much of the light from the blue sky and these needed to be darker which at the same time makes the fall colours appear brighter due to the relative difference between the two.

The image below shows the areas I had selected for improvement.

You will note that I planned to fix areas of reeds that had blurred objects in front of them. This was accomplished by finding other sections of suitable reeds in the image and copying them to a new layer and then using the transform function to stretch and tilt to fit correctly.

This is a very complex image, at least from the point that there has to be many layers and masks to handle the numerous changes that are required.

This image shows the steps I used to achieve the changes.

You will see that there is no overall sharpening in this file (except to fix any specific problems that would apply to any version) as I create a separate image for each size and type of output and sharpen it to meet the output needs.

It is difficult to see the mask detail in the layers’ palette and therefore I have reproduced them in the image below.

As you can see there are a lot of layers used to fine-tune specific sections within the image. These range from changes in hue or saturation to some colours, to adding new parts of reeds that were obscured by the very out-of-focus foreground reeds (light blurred parts). Some of you may think this is more work than is necessary or even warranted, but if you have ever spent time making a painting then you may appreciate that time is not really important to an artist but only the final image. For commercial work, time is critical and good enough tends to be the main criteria.


Creating masks from these types of images is a complex process and there is no magic wand (well there is but it tends not to work too well) to create them.

Other than hand painting your own mask, the best method is to find one of the many channel to use as the starting point. Some of you may wonder, how can I use the term ‘many’ with only 3 channels. In actual fact there are 10 channels available for use and these are:

Sources of Masks

RGB mode - Red, Green and Blue

Lab mode - Luminosity, a and b

CMYK mode - Cyan, Magenta, Yellow and Black

Note: As switch between RGB and LAB to get a copy of the channel, there is no destruction to image. This is not the case for CMYK, as there tends to be a loss of saturation. To overcome this problem, make a copy of the image, convert to CMYK and then copy the desired channel back to the original image.

Fine Tuning the Masks – Curves and Paste

When creating a local editing mask it should normally be either pure white or pure black, but when you look at any channel this is not the case as there is a full range of grey tones.

Select the mask that gives the best separation between the elements that you wish to enhance and the rest of the image. Don’t worry if it is the wrong colour (black blocks and white let’s effect through) as the mask can be inverted later on.

As you are making the mask, make a copy each time you fine tune. This permits you to go aback to a pervious version and recreate it or use it for other purposes. The copies can be discarded when finished.

The 2 main tools I use to take a grey scale and convert to pure black and white is to use either the curves tool or the copy and paste method with Fade to a different mode.

There is no set formula or order to create a mask. It tends to be a bit of trial and error. Experience will increase your success rate as you understand how these changes affect grey tones.

The example I have selected is to create a mask to work on the very dark reeds in the foreground.

As you can see the red channel provides the greatest separation between these elements, but definitely is nowhere near perfect.

I applied a curve function to the Red channel and this removed a fair bit of mid-tones.

I then copied the channel and did a select all (Ctrl A) and a paste into the same channel (Ctrl V), which has no effect, but now the magic. I did a fade (under Edit) and changed to Screen mode.

You can try many of the modes to see which has the best effect. Those that create the greatest B&W also tends to reduce some of the edges you need so I select a compromise version and then will further fine-tune it.

Then I take a paintbrush and clean-up in mask

Paint with Dodge and Lighten

Sometimes, especially where there are fine details, the mask edges will be corrupted by applying these methods and I may use the paint brush first set to low opacity and soft edge and paint over the mask edges using dodge and lighten mode.

In the dodge mode only the darker pixels become blacker and there is either no or very little effect on lighter pixels

The same applies to painting in the lighten mode but reverse. The light pixels becomes lighter but there is little effect on darker pixels.

Do switch back and forth with the dodge and lighten regularly as you work the mask because if you stay too long in one mode it will impact the opposite (lighter or darker) pixels. By changing, you restore the pixel before it goes too far into either whiter or blacker.

In the image below, I used this method to increase contrast between the reeds and background before I applied the curves.

You will notice the reeds have become slightly darker and the background lighter. This permits the curve function to better separate the edges.

This may all sound quite complex and in some ways it is but when you have practiced these methods you will be able to very quickly create these masks and spend less time removing the few pixels that still remain to be changed.

Please feel free to ask any questions, as in writing this article I wanted to provide enough information to help you explore these approaches without boring you with pages and pages of extraneous detail.

Niels Henriksen

A Photographer’s Adage

One advantage of the discovery of the Photographic Art will be, that it will enable us to introduce into our pictures a multitude of minute details which add to the truth and reality of the representation, but which no artist would take the trouble to faithfully copy from nature. - William Henry Fox Talbot, Fox Talbot, photographer by Robert Lassam , ISBN: 090019374

Sunday, February 3, 2008

Replacing Skies or What Mood Today

For many images, at least when they are taken outdoors, it’s the skies that set the mood or re-enforces it for the scene.

When you are doing an outdoor shoot, especially if it is some distance away, the skies may be quite different from your starting point. Weather’s only constant is its variability. This results in skies completely changing from a bright and sunny day to dark and cloudy within the period of an hour. Sometimes it can also stagnate for days.

What is a person to do if when we get to our location and then the skies no longer suit the vision we have?

You could wait a bit and see if it changes or revisit the location in the hopes that the sky will be to your liking. For some photographers who believe in a more purist or photojournalistic approach, this is the only technique when wanting better skies.

If you are a bit like me and look upon photography with more artistic freedom, you will have a folder of many different skies that range from dark and gloomy to bright cirrus and even vivid sunsets. Then just grab the sky you want and insert into the image with minor effort.

The sun was beginning to peak through after a summer rainstorm had passed through. I liked the light on the tree leaves, but I wanted more drama and intensity as I had just witnessed the storm go though.

Well, it is almost this simple. There are a few techniques that will help you better match the sky to your photo image.

First and foremost, waiting for the skies to change is a great solution. The real light that comes from many parts in the sky, which illuminates your surroundings, can never really be duplicated by photo-editing new skies. There is benefit to be gained by waiting around as you slowly start to observe new interactions of light within your environment. Sometimes we don’t always have the luxury of waiting around as it could even take days.

For colour images it is important that the WB for the image and sky are the same. If working with jpegs this is not as easy. If image is going to be B&W then this doesn’t matter, only the contrast range should match.

The image below is one of the temples near Yokosuka, which is just south of Tokyo. The temple being on the edge of the ocean had skies that day that had a fog like quality and it would not be possible to come back another day.

The colours were a bit drab and
were enhanced

When selecting a sky it is important that the lighting of the sky matches the scene. This means that the WB is the same, and that the sun angles are about the same location in the sky.

Both building and sky where shot about the same time of day and facing the same direction.

The light sky did not add much to the gargoyles image of being heavy and dark.

Clouds do have shadows and while not as distinct as those on the ground, these must match the direction of those on the ground.

In shooting skies, try and find some higher ground that permits for the most part an unobstructed view of the horizon. Shoot many positions, as you never know when you might need to combine several for a large sky scene.

Shoot at different times of the day. Sunrise, mid morning, noon, afternoon, evening and sunset.

Shoot in different seasons as the quality of light changes from harsh and crisp in winter to more soft and hazy in summer.

Shoot many different cloud shapes and types, in fact this it is an opportunity to learn about cloud structure to help you catalogue your skies. (wispy cirrus, puffy cumulus, and great towering stormy cumulonimbus)

Forget the polarizer as this filter will change sky appearance in relation to the angle of the lens to sun. Sometimes when you are only capturing a narrow angle of view a polarizer will work. I find that a wider-angle lens in the range of 15mm to 30mm allows me to capture more of the drama in the sky.

Pure blue skies do work for many scenes especially when it is broken up into negative spaces that enhance the scene or the colour perfectly complements or is harmonious with the scene.

The image shot under the plant and looking up at the sky works well. Blue is the complementary colour to yellow and helps to create a strong graphic type image.

Niels Henriksen

A Photographers Adage

Life appears always fully present . . . a brief weary smile, a twitch of the hand, the fugitive pour of sun through clouds. And not a tool, save the camera, is capable of registering such complex ephemeral responses, and expressing the full majesty of the moment.. - Paul Leopold Rosenfeld


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