If you type the term ‘HDR’ into google images you’ll very quickly see why HDR photography has a bad reputation. While we all differ in our tastes, in recent years, those strongly saturated, blurry and noisy HDRs have fallen out of fashion, even amongst HDR photographers.
The goal, among many, is now a clean HDR look. HDR programs are attempting to tidy up their processes to meet the needs of the demanding HDR photographer. However, a large number of photographers are beginning to take the blending process into their own hands, and produced beautifully balanced HDRs using luminosity masks, probably the cleanest alternative to HDR software.
In fact, luminosity masking has become an exciting buzz-term in the world of digital photography, and there’s good reason for that.
If you’re new to luminosity mask exposure blending, you can see a beginner’s tutorial on dPS in my previous article: Exposure Blending Using Luminosity Masks Tutorial
In this article we’ll take a look at the benefits and challenges of luminosity masks versus HDR software.
Benefits of Luminosity Masks
1. Image quality
We’ve all seen over-saturated, noisy, messy, HDR images. One guaranteed way to avoid the poor image quality we normally associate with HDR is to manually blend your exposures in Photoshop using luminosity masks.
When exposure blending with luminosity masks, you’re working only with the RAW files to restore highlights and shadows. You do not affect any other part of the image. In other words, your final blended image will be, more or less, exactly the same image quality as your RAW files.
You do not affect any colour changes, you retain absolute sharpness, you don’t flare up noise (which means you can shoot at a much higher ISO), and you will not exaggerate chromatic aberration.
This is the major reason why so many are turning to luminosity masking to create natural, balanced HDRs.
2. Complete control over what we blend
Artists of any genre fight for complete control over their ability to express themselves. And so it is in photography. One of the problems with using HDR software is that we have very little control over the blending process.
We rely on an algorithm to choose which areas to blend with which exposures. Then we’re given some sliders to adjust. Although this gives us greater control over the process, it isn’t giving us 100% control.
Through luminosity masking, we begin with a base exposure, and we then decide for ourselves which exposures we wish to use in the blending process, and which areas we wish to adjust, and at what opacity.
The image below is a good example of how you can make very precise changes with luminosity masks.
This image is made up of 11 exposures; six of which were used for the light trails, four were used for exposure blending, and one was used as the base exposure. You can learn how to create light trails like this here: How To Add Dramatic Car Trails To Your Photos In Photoshop
Below you’ll see the RAW file used for the base exposure.
The only highlights I wanted to control in the image were the street lights, and even then I still wanted them to be bright. Through bright lights like this night cityscapes are able to give off a lot of energy and dynamism.
I very gently blended in three darker exposures to gain a little bit of control in those areas, without darkening them too much. If I ran my exposures through an HDR program, all of the highlights in the image would have been affected to some degree, which is exactly what I didn’t want.
For the darker areas, I only wanted to bring back information in one area, the side building to the right, which is noticeably dark. I used an exposure two stops brighter and, with luminosity masks, I easily painted details back into this area.
#3. No more halos and fewer ghosts
Halos simply don’t exist in luminosity mask exposure blending if you’ve done it correctly.
As for ghosts, you will rarely encounter a moving object that is difficult to blend. Since you use a base exposure, which will be done for most of your images, and simply reduce specific highlights and shadows, there shouldn’t be any ghosting.
The only challenge you may have, which is also a challenge when using HDR software, is if you have moving leaves on trees, for example, between exposures. Then the blending process is a little bit trickier.
#4. Become a better photographer
In my early days I was a die hard tone mapper. I’d approach a scene and think, “this would be a cool HDR subject”. I’d fire off some brackets and take them into Photomatix when I got home. I had a predefined routine of what to do, what result I wanted, and how to get there. I had tunnel vision.
When I began exploring luminosity masks, everything changed. I began to read a scene, not as an HDR subject, but in terms of its unique beauty and mood. I started to grasp more fully the use of light in controlling mood, whereas previously I was simply relying on getting the ‘HDR effect’ each time.
Rather than shooting off a set of automatic brackets, for a complex scene I will often bracket manually, changing the aperture, ISO and shutter speed to capture different elements of the scene. Then I’ll blend in each of the elements to hopefully get the best out of that scene.
In the Hong Kong Light Trails image above, the base exposures and brighter exposures, the light trails, and the darker exposures were all shot manually with different settings to achieve different effects.
It is through using luminosity masks, and taking my imagery into my own hands, that I have pushed myself in the field to achieve more.
#5. Combine with other HDR processes
One of the beautiful things about luminosity masks is that you can combine them with other exposure blending methods to complete the blending process. 32-bit processing is becoming an interesting way of blending exposures cleanly, but we are a long way off before the process is good enough and our monitors can handle true 32-bit files.
However, we can overcome the limitations of 32-bit processing by combining it with luminosity mask exposure blending. The tutorial below will show you exactly what I mean. The video is taken directly from the Art of Digital Blending course:
Challenges with Luminosity Masks
HDR software is simpler
Luminosity masks require more patience and a steeper learning curve than HDR software. The concept takes a little bit of time to get used to, and it will certainly challenge you to re-learn a few things.
While HDR software will take all of the leg-work out of it for you, luminosity masks require you to really think about your exposures and deepen your workflow.
Luminosity Masks don’t work on every occasion
Every now and then you’ll come across an image where luminosity masks won’t create a smooth blend between exposures. This happens because there isn’t enough contrast between the areas you wish to blend and the areas you don’t wish to affect.
In which case, using 32-bit processing or HDR software would be a good alternative.
Luminosity masks work in 8-bit mode
Like all live selections in Photoshop, luminosity masks work in 8-bit mode. They don’t affect the bit depth of your image, so if you’re working at 16 bits that won’t change. But there may be a chance of posterization in some cases.
A quote from Photoshop staff on the Adobe forum claims:
“The selection mask is 8 bits, regardless of the document precision. That fact has no affect on the precision of the image.
No, it won’t change the image or cause future posterization — the image data is still the same precision as it always was.”
So while this shouldn’t be an issue, it is something to be aware of.
HDR images don’t have to be messy, garish and overdone. There are many ways to cleanly blend exposures to create a beautifully natural and balanced HDR. Having luminosity masks in your arsenal, will give your workflow a superb cutting edge, that can quite literally change your imagery over night.
It will require a little bit of extra work on your part, but often the best things in life do.