Photo Cascadia Blog
Archive for the ‘Image Processing’ Category
Lightening and darkening (often referred to as dodging and burning) in selective areas of an image to enhance existing light and shadow, to guide the eye or to increase depth and contour is a technique I commonly use. Both in Lightroom and Photoshop there are many ways to make localized lightening and darkening adjustments.
One of the most popular and effective dodging and burning techniques photographers use is the 50% blended gray layer method. This is a technique I have demonstrated in several of my tutorials, including THIS ONE and THIS ONE as part of previous video blogs I have published here on PhotoCascadia. The 50% gray layer technique works great, but it does have a limitation. Often, after using the 50% gray layer method to lighten or darken, I wish that I could easily make further adjustments to the lightened or darkened areas…for example, I might want to adjust the contrast, saturation or color balance of just the the areas I had lightened or darkened. There isn’t an easy way to do this with a 50% gray layer, but using an empty or transparent layer instead of a 50% gray layer solves the problem. In this video I deomstrate how it works:
I hope you find this technique a useful addition to your Photoshop skill set. Give it a try and leave me a comment to let me know what you think.
In the video tutorial below I demonstrate two exciting advances in the April 21 release of Lightroom CC (2015), Photo Merge to HDR and Photo Merge to Panorama. Lightroom has gone through substantial improvements over the years to give photographers more control in developing their images. However, until now, techniques involving the merging of more than one exposure or frame had to be done in Photoshop or third party software. Now you can merge multiple exposures to create HDR images all within LR and you can also merge frames to create both vertical and horizontal panoramas. Wow! Nice job Adobe.
Both merge features combine raw files to produce a merged DNG raw file, which is brilliant! This means we can merge first and make our adjustments directly to the merged raw file, which I assume retains all the adjustment capabilities of the originating raw files. In addition, the merged HDR or pano DNG can be opened as a tiff file in Photoshop for additional developing there.
Lightroom Photo Merge to HDR is similar to the 32-bit HDR tiff file processing capability that was first introduced back in LR 4 and which I demonstrated in a previous video blog and also include in my Developing for Extended Dynamic Range video series. This process is now greatly simplified in Lightroom CC and no longer requires Photoshop!
Photo Merge to Panorama allows you to stitch, crop and develop multi-frame panoramas without needing to go to Photoshop or some other image stitching application, and the panoramic DNG file can be fully developed in Lightroom like any raw file.
Finally, you can create high dynamic range panoramas by first creating merged HDR files for each frame in the pano series and then merging these HDR raw files into an HDR panorama. The resulting output is a high dynamic range panorama raw file that can be fully developed in Lightroom.
While working with merged HDR images in Lightroom still doesn’t provide the same degree of fine control that you can get when manually blending exposures in Photoshop, and I don’t think it handles the most extreme dynamic range as well, it provides an excellent and efficient option for many situations. Photographers who only use Lightroom can now create blended high dynamic range images and panoramas like the rest of us, which is huge for them. I also think that photographers who have previously used Photoshop or other applications to accomplish these types of multi-image blending tasks will find the new functionality of Lightroom to be a great benefit in many cases.
NOTE: Many people have had trouble getting Lightroom CC (2015) to open after it has been installed from the Creative Cloud desktop app. If you have this issue try logging out of your Creative Cloud desktop app (logging out, not closing it) and then logging back in. This fixed the issue for me and many other folks on the Adobe forums. Also, LR CC installs along side LR 5, so you can open either one unless you uninstall LR 5, and this can be a little confusing. LR 5 shows up as “Adobe Photoshop Lightroom” and LR CC shows up as “Adobe Lightroom” on my computer. It would have been nice if Adobe had labeled them Lightroom 5 and Lightroom CC instead.
While starting out in photography I owned nothing but Canon cameras. I owned the Canon 5d Mk1 and moved way through the series. It all started with the Canon 5D Mark 2, where I would religiously bracket at least three images for every scene. The results I got with my Canon when I just shot a single exposure for the scene was often not enough coverage in terms of tonal range. What was happening was that I would end up either blowing highlights or blocking the shadows.
It was the general consensus that several years ago to capture dynamic range in any photography scene you needed to take several photos. This would range from-3 under exposure to +3 overexposure. I would bracket at 1-stop exposures so that I included the wide spectrum of tonal values in the scene. At the time, several third-party applications were coming out as well as Photoshop that would be capable of merging several images into a single Image. When arrival of these applications, HDR (high dynamic range) became the big thing. It was really fascinating to capture so many images and merge all of them into a single file. The results for the time we’re Incredible and people started to compare it to medium format photography. But like a lot of things in photography, HDR went too far and quickly received a bad name.
So I chose to explore a few applications and found one called exposure fusion within a program called Photomatix Pro which merged all images together to include all the dynamic range and yet receive realistic result. I was very happy with the results once I learned to fine tune the application but nevertheless took a lot of time to post process images in HDR.
I realized that I was spending a good portion of time now post processing and lot less time in the field shooting so I was always looking for a better solution.
A few years had passed and lots of people still were involved heavily with HDR even though cameras were getting better and better. Digital cameras were now getting behind the movement of more megapixels. The change came for me when Nikon decided to put out a D800 at 36 megapixels. I waited and waited for Canon to follow suit but it never happened. At this time I chose to make the move over to Nikon from Canon because the Nikon D800 had been receiving rave reviews. For my business this was perfect. I could now make larger prints and have the option to crop within the image. This cropping would allow me to eliminate things from the image and still have enough resolution in the image to print large.
In the beginning, the transition was hard and slow moving from Canon to Nikon but eventually it was a saving grace. One of the most unexpected benefits was the dynamic range of the Nikon D800. I immediately noticed that I was capturing the whole scene in terms of tonal range in a single file. For a while I thought this might be a mistake. But exposure after exposure I was able to post process the images from the single file.
As time went on, I began to grow more confident in being able to take a single exposure. Eventually I was not even bracketing as a backup except for situations of extreme contrast. I even noticed I was able to under expose the image and then bring out the shadows in post-processing. With the Canon if I had tried to bring out the shadows I would always have noise that would show throughout the image. This was not the case with the Nikon, which was pretty amazing to see and still is nice to demonstrate to people who shoot Canon.
Shooting one single exposure allows you really to focus on the composition and light. It has also had the added benefit of really allowing me to get into the scene and not worry whether I have everything I need in terms of exposure.
I now own the Nikon D810, which is even better and such an amazing camera when it comes to controlling highlights and avoiding blocked shadows in a single exposure. I shoot freely in low light situations and don’t worry about covering the tonal range of a scene.
When it comes to the histogram on the Nikon D810 I am often asked one should look for when shooting one exposure. Through trial and error I have found excellent results with the histogram if I aim to most of the data and information just to the left of the middle, which would mean I slightly underexpose the image. I know this goes against everything we have been taught from before with exposing to the right, but the Nikon D810 is a revolution and is changing the game. Aiming to have my information on my histogram slightly to the left I do need to make sure I don’t have any clipped highlights as the Nikon is much better at shadows then it is with clipped highlights. So when focusing on a landscape scene I generally will set the exposure on my foreground and go about a half stop to one stop under while making sure I don’t blow the highlights in the sky. I always like to review my histogram after each image just to make sure all the information is present.
The Original Camera Raw Image One Stop Underexposed
Histogram With Information Underexposed 1 Stop to the left
The Long Exposure On The Water
I will be very curious to see in the upcoming months if the new series of Canon 50 Megapixel cameras will focus on dynamic range or will it just be a megapixel monster?
Needless to say I am a very happy with the results of the dynamic range of the Nikon and look forward to get out and shooting lots more now that I don’t have to bracket!
This week on the blog I am sharing a complete chapter from the new edition of my Developing for Extended Dynamic Range tutorial series. In this chapter I demonstrate how luminosity masks and a technique called masking-the-mask are useful in creating better tonal balance in high dynamic range exposures. Dynamic range is one of the many challenges we face as outdoor, natural light photographers. Dynamic range is the visual contrast (difference between the darkest and lightest values) in a scene or an image. A common way to handle extreme dynamic range light, in the 12 to 25 stop range, is by bracketing exposure values and blending the exposures in Photoshop to create a properly exposed final image. While I find multiple exposure blending to be an essential technique, with advancing camera technology it isn’t needed as often as it once was. Some current digital cameras have the ability to record a dynamic range of 11 to 14 stops, unimaginable just a few years ago. A dynamic range of 13 stops equates to a contrast ratio of over 8,000:1 and 14 stops, a contrast ratio of over 16,000:1. Such contrast range means it is possible to capture many high dynamic range scenes, which were previously out of reach, in a single exposure. Unfortunately, the dynamic range of the best monitors is only in the 1000:1 range. Prints can only achieve a dynamic range between about 50:1 up to perhaps 300:1, depending on paper, printing process and lighting. So even if our cameras can record a wide dynamic range in a single exposure, we still need to work with shifting the the bright and dark tones in the image to create tonal balance and retain tonal detail, while still giving the perception of the actual dynamic range that we saw.
There are many tools and techniques available for shifting tonal values in an image for better tonal balance, including raw highlight and shadow recovery, dodging and burning and the Shadows/Highlights adjustment in Photoshop. A common tool I use is Curves or Levels adjustments guided by the use of luminosity masks. In the video chapter below I demonstrate the great control, precision and flexibility that luminosity masks provide when working with targeted tonal balance in a single exposure image. It also provides some great extended instruction in the use of the TKActions Panel. I hope you find the information helpful in your image developing. Make sure to view the video in 720p HD!
This chapter is one of 36 in the updated edition of the Developing for Extended Dynamic Range tutorial series. The series takes a complete look at working with high dynamic range light from capture to single and multiple exposure developing methods. You can go here if you would like more information or to see more chapters. I’d be glad to field any comments or question you have in the comments section below.
by Zack Schnepf
I get one request more than any other, to see what my photos look like before and after I process them. I found this incredibly helpful myself when I was starting out in photography. I’ve done this before and I think I will make it a regular series here. The following are a selection of images that I think turned out well and capture my experience in the field. The top photo of each set is the final master image.
This first set of images is from one of the most amazing mornings I’ve ever spent in the field. Sean and I set out several hours before first light in the pitch black, frigid, icy morning. This was a morning we had hoped to see while on our trip. It’s very rare to get the first snow during peak fall color. Sean and I had hoped for such conditions somewhere on our trip, but knew the chances were very low to witness such an event. We were extremely fortunate to be able realize our dream of capturing just such an event. This was one of my favorite moments during that morning. The dynamic range was too much even for the Sony A7r. To overcome the limitations of the camera I captured 3 different exposures capturing all of the tonal information. Using my tonality control techniques with the aid of Tony Kuyper’s actions and action panel I was able to blend the exposures together in photoshop to produce the final image. Thanks again to Raynor Czerwinski for sharing his local knowledge of this spot with us. If you find yourself in Crested Butte, be sure to visit him and his wife Susan at the John Ingram Fine Art Gallery.
This set of images is from another location from my trip to Colorado this fall with good friend Sean Bagshaw. This is Chimney rock and Courthouse Mountain. On the evening we photographed here we were fortunate to witness some spectacular light and atmosphere. I processed this again using my tonality control techniques with the aid of Tony Kuyper’s actions and panel. Each image always presents it’s own challenges. In this case I used 3 separate exposures and double processed one of them for a total of 4 exposures. This allowed me to really target each tonality zone to achieve the look and feel that captured the experience for me.
This set of images is from another spectacular evening from the Colorado trip. This storm rolled in quickly spoiling the sunset I had in mind and replacing it with something so much better. Sean and I had to make a split second decision to abandon our current location and rush to another location we had scouted earlier. It was spectacular, but the camera was not capturing what I was seeing. Again, I used my tonality control techniques with the aid of Tony Kuyper’s actions and panel to bring the drama back into this image. The final image captures my experience extremely well.
For all these images I was using my tonality control techniques and Tony’s action panel. For more information about my video, or to purchase a copy visit the video page on my site: http://www.zschnepf.com/Other/Videos2
I’m currently producing a video on how I use Tony’s panel with my techniques. It will be available in the next few months.
You can follow me on Facebook
It would be ideal if every image we took could be displayed as a fine art print on somebody’s wall. These days, however, most photographs will be viewed on a screen via a website, so it is important to prepare our images for optimal viewing on the web. Unfortunately many websites, such as Facebook, further process the images we upload, compressing them and causing loss of detail and sharpness and introducing glitchy artifacts. Dedicated photography sharing websites, like 500px.com and WhyTake.net, handle our images with much more care, but the bottom line is that once we upload an image to any website other than our own, how it is processed and displayed is beyond our control. For this reason it is even more important that we do as much as we can to optimize our images before posting.
One of the most frequent questions I receive is how I get my images on the internet to look as good as they do. Various talented people, none of them me, have developed a variety of excellent techniques for preparing images for the web. Thanks to them, people like us are able to feel confident that the images we share look as good as they can. Sizing, sharpening and using the correct color space are the three most important elements of prepping images for optimal web viewing. I cover this topic in some of my tutorial sets, but it comes up enough that I wanted to address it on the blog and my YouTube Channel. In the following video tutorial I cover several techniques for sizing and sharpening images for the Internet. Some of the techniques can be easily accomplished on your own in Lightroom or Photoshop. Other techniques involve very advanced, multi-stage sizing and sharpening algorithms programmed into actions, scripts or plug-ins. In the notes below the video I include links to all of the web sizing/sharpening apps I demonstrate in the video. If you have a web prep technique or app that you would like to share, please comment in the blog comments or on the YouTube page. Sharing is one way we all progress.
Apps I reference in the Video:
- TKActions Panel
- My luminosity mask videos packaged with Tony’s actions available on my site: www.outdoorexposurephoto.com/video-tutorials/the-complete-guide-to-luminosity-masks-tony-kuypers
- Just the actions are available on Tony’s site: www.goodlight.us
- Andreas Resch WebSharpener (MAKE SURE TO DONATE!): www.andreasresch.at/2013/04/07/web-sharpener-better-sharpening-for-the-web
- PhotoKit Sharpener 2.0: www.pixelgenius.com/sharpener2
- Nik Sharpener Pro: www.google.com/nikcollection/products/sharpener-pro
Web Sizing/Sharpening Examples
(Click on images to accurately display size and sharpening)
This month we welcome Tony Kuyper as our guest photographer. Tony’s body of work centers around the desert sandstone of the Colorado Plateau and is as beautiful as it is definitive. In addition to his photography, Tony is well known to outdoor photographers for his skills in the realm of digital image developing, specifically in the use of luminosity mask techniques. His popular tutorials and Photoshop actions are well regarded by many of the best contemporary nature and landscape photographers. Tony is also one of the most kind, generous and humble people I know. I first became acquainted with Tony almost ten years ago and have since had the pleasure of getting to know him personally, spending time with him in the field and collaborating with him on Luminosity Mask instruction. Tony generally avoids the spotlight so I thank him for agreeing to this interview and giving us a view into his world.
Sean: Give us some biographic back story on Tony Kuyper.
Tony: My background is in the sciences. I got an “A” in Physical Chemistry in college! After getting my degree I moved to Arizona in the 1980s and have mostly been here since. I worked as a pharmacist for the Indian Health Service for 30 years.
Sean: When and how did you get your start in photography?
Tony: There really wasn’t a definitive start to it. It’s always been evolving. Arizona was a whole new world for me compared to the Midwest. I did a lot of hiking and camping trying to see it all. It’s natural, I think, to want to take pictures to hold onto some memories. But in the early days I was just using an instamatic camera. I eventually moved on to a 35 mm and even did a decade of large-format. So it’s really just a long continuum.
Sean: Your photography is centered in the American Southwest, primarily southern Utah and Northern Arizona. What about this landscape attracted you photographically and what keeps you coming back?
Tony: The initial attraction wasn’t photographic. The Colorado Plateau was just an incredible place. It was easy to fall in love with this landscape after living my first 24 years in Iowa. Photography was a way to interact with this place on a more personal level, and that eventually became more central to my travels around the area. Being in the desert feels right for me now, and that helps create a good mindset for taking pictures.
Sean: Your photography includes some wonderful large landscapes, but you are most known for your sandstone abstracts. Other than light, what are the most essential elements you look for when capturing this type of scene and what are you hoping viewers will take note of when viewing this body of work?
Tony: I tend to compose less complex scenes, so these images are in line with my general approach to nature photography. Many of these sandstone details are taken in the shadows, not direct light. In the shadows, the color of sandstone shifts considerably, depending on the source of reflected light. Only by getting in close and excluding direct sunlight can you really see what’s happening. The camera, especially in the film days, was critical to this. Our eyes naturally shift the colors to what we expect, but the camera is objective and helped me see sandstone’s alternate hues. The unexpected colors coupled with the amazing shapes and textures make for an interesting subject. So these abstracts are really just my way of exploring sandstone. Hopefully viewers will be able to see the beauty in this rock from a less traditional point of view.
Sean: To quote from your website you say, “Over the years, capturing light has become less and less my goal. Instead, I increasingly prefer to give in to the unpredictability of the situation and simply allow the light to capture me.” Tell us a little more about that statement.
Tony: I’ll say up front that Guy Tal had a big influence in developing this perspective. I photographed with him several times and was always impressed that any light was good light for him. He always came back with some amazing images. I came to understand it was not about approaching the landscape with preconceived notions of what would make a good picture, but rather to find a way to understand the area and eventually allow it to show me what it might have to offer in terms of light. Images created in this manner end up having deeper meaning. There’s something almost magical when I turn it all over to fate and find that it makes better choices than I do. It’s a new connection to something to I didn’t even know existed.
Sean: What does your standard camera rig consist of for most of your photographs?
Tony: Pretty minimal. Canon 5D2 camera, carbon fiber tripod, Tamron 28-300 lens, polarizer, and spare battery and compact flash cards.
Sean: Attention to image developing has long been an important component of your photography. What is your basic philosophy and approach to image developing?
Tony: Two things come to mind. First, connect with your image and let it tell you what to do. Each image is different and requires a unique approach. I find making actual prints to be extremely helpful in listening to the light. It’s much easier to interpret what the image needs when looking at a print than at the monitor for me. The second is to learn to use your tools and develop a skill set that is comfortable. Today’s cameras and Photoshop let us do some amazing things, but it takes some experimentation and practice with both to understand how to best use them. Other than that, I think photographers should be free to do what they want with their images. As David Kachel observed, a sense of realism is important to photography, but strict adherence to reality is not. So the whole process becomes one of interpreting light rather than simply reproducing it, and that opens up a lot of possibilities.
Sean: You are arguably the original and best known luminosity mask user and educator in the world of outdoor photography. Briefly, what are luminosity masks, how did you begin working with them and how is it that you discovered them for the rest of us?
Tony: Luminosity masks are selections based on tonal values in the image. They are created from the image’s pixel values, not from a selection tool. They can be manipulated to target specific tones and blend most adjustments perfectly into the rest the image. I Googled the term “luminosity mask” in April 2006, found out how to make the initial “Lights” selection, and was instantly fascinated with the possibilities. I knew about adding, subtracting, and intersecting selections and played with combining various masks somewhat randomly for several months to get at specific tones in my images. Based on these experiments, the Lights-, Darks-, and Midtones-series were developed for the “Luminosity Masks” tutorial published in November the same year.
Sean: Speaking to anyone not familiar with luminosity masks, what advantages do they have over other Photoshop adjustment methods?
Tony: The perfect blending that luminosity masks provide is probably the biggest benefit. While regular selections and brushes can be feathered spatially into the surrounding pixels to facilitate blending, luminosity selections are feathered tonally. This means that pixel content, specifically the brightness values, determines what gets blended, not just proximity to the selection edge. So as brightness varies across the image, the luminosity mask or selection will automatically adjust. The image is essentially its own mask. Photoshop makes it easy to manipulate the initial “Lights” mask to target different tones, so it’s possible to get this seamless blending in any tones you adjust. Sorry if that sounds a bit geeky, but that’s how it works. This perfect blending can be used to create very balanced lighting in the image. For nature photographers, it’s like to having studio lighting in the great outdoors.
Sean: Many of the talented outdoor photographers I’m familiar with today include luminosity mask techniques in their image developing skill set. When you first began experimenting with luminosity masks did you have any idea how important they would become to modern outdoor photography?
Tony: Not really. The scientist in me thought it was pretty neat what the different luminosity masks could do, so that’s why I wrote the tutorial, sort of like writing a research paper. However, it was my quirky way of using Photoshop and a bit complex at the time, so I didn’t think it would be widely adopted. The actions to make the masks were available right from the start and that probably helped others get on to using these techniques more quickly. But overall the interest in these techniques was definitely more than I expected.
Sean: In 2006 you published your first luminosity mask tutorials and Photoshop actions on NaturePhotographers.net. How have the actions, and the way that they are used, evolved since you first put them out there?
Tony: While the initial series of masks (Lights, Darks, Midtones) are useful, I quickly found that the narrower tonal range selections made from the primary Lights- and Darks-series to be more useful. These secondary masks became more important to me and I’ve developed tools to make them accessible. Something else quite unexpected is that I also use the Darks series of masks frequently in sharpening my images. They’re an effective way to reduce or remove light halos and over-sharpening while maintaining proper image sharpness.
Sean: The techniques and actions you introduced almost a decade ago have become a standard tool for outdoor photographers all over the world. Do you see them continuing to evolve and improve, and if so, how?
Tony: I think the basic knowledge about luminosity masks is becoming more widespread, but there is still some confusion about how to use them effectively. Deciding when use them, which mask to choose, and how to efficiently incorporate them into the workflow are some of the issues. Developing tools and educational materials to streamline luminosity mask integration will help more people adapt to them. It’s something I’m continuing to work on.
Sean: What piece of advice do you have for photographers interested in improving their image developing skills and realizing their creative potential?
Tony: I think the best way to improve at anything is to make it personal. For photography, that means having a genuine interest in the subjects you photograph. It’s easy to tune into the light and find images when you care about your subject. This also makes image development a creative exercise instead of a chore. If you’re personally committed to what you photograph, you’ll naturally work to improve your technique both in the field and at the computer. You’ll practice and study and find ways to get better.
Sean: Where do you see your interests in photography going in the future?
Tony: I recently moved to Tucson. It’s a whole new world to explore. Very different than the Colorado Plateau, but lots of variety. I’m going to have to branch out from sandstone, but am definitely looking forward experiencing light in a new place.
I’ve been a little bit out of the loop for a while now tending to my baby who’s now almost 5 months old. Those who say it gets easier after the first 3 months must have had better luck. He is a real sweet guy, doesn’t cry much, and we are having a great time with him, but boy is he a challenge to get to sleep! Unfortunately his sleep has regressed for now. He was sleeping 7-9 hrs straight at night, and for the past month he has been at about 3 hr stretches at first, then less until morning. I know this is better than some, but it is sure hard to get used to when he was doing so much better. He has been diagnosed with acid reflux so we are pretty sure this has been part of the challenge.
I apologize to the people who have been waiting so long to get in on a workshop, but plan to start getting busy soon-things just take a bit longer with the new one around!
I have contacted most of you who wanted a workshop last season and gave you first grabs at my schedule for this year. I have filled up one workshop, and some private spots, and am tentatively scheduling another for May 29-31st. Cost would be $495/person and I am keeping it at 5 people max. This workshop would start a bit before sunset on the 29th, and end after a sunrise shoot/early morning shooting on Sun. This would be in addition to any private or small groups I can fit in as well around the same timeframe.
I am also accepting clients for other times of the year as well if my schedule permits.
More information on my workshops can be found here.
Feel free to fill out a contact form on my website if you are interested in setting something up and I will try my best to accommodate you best I can.
If you are just interested in finding out a bit about my editing tips and tricks, my set of image editing videos can be purchased here.
In the last part of this series I talked about starting the process of pre-visualization in the field, you can read the first part of the series here: http://www.photocascadia.com/blog/pre-visualization-part-1-starting-the-process/#.VB9OpksyPiM Just as important, is continuing the pre-visualization through my digital processing workflow. In this segment I’ll talk about how I use my pre-visualized idea to control my image throughout the workflow.
Just like in the field, I want to have a roadmap to help guide me through the processing. I remind myself what I’m trying to achieve with this image and what I’m trying to communicate. This helps to guide me while processing. Typically, this leads to a lot of problem solving, trying to figure out what tools and techniques in Lightroom and Photoshop will help me realize my final vision. I usually experiment quite a bit. Along the way I discover what is working toward my final vision for the image and what is not. A lot of times I like to walk away from processing and come back later, this gives me a fresh perspective and a chance to re-evaluate how the image is turning out according to my vision.
This is just a guide however. During this process I’ll often evolve my overall vision for an image. If a particular technique is working really well and starts to take the image in a new direction that I find compelling I’ll consider adjusting my pre-visualized ideas. It’s common for images to turn out even better than I had imagined, of course it goes the other way as well. I’ve had many stubborn images that just don’t turn out the way I had anticipated, but most of the time they come pretty close to my pre-visualized idea.
Here is an example of carrying the vision I had for this image in the field through my digital processing workflow. The color, tone, and overall mood was being lost in the Raw capture. It took a lot of work in Lightroom and Photoshop to bring out the potential I had seen in the field. Having that pre-visualized idea in my head helped to realize my vision for this image. Even though this was a single exposure capture, I used many of the tools and techniques that are covered in my Tonality Control Video, you can learn more here: http://www.zschnepf.com/Other/Videos2
On the topic of creating high dynamic range (HDR) photographs I was recently asked a question about the viability of taking a minimal number of bracketed exposures in a high contrast situation and later filling in the gaps in the exposure range with digitally generated exposures. While this isn’t a new concept in high dynamic range photography, it is one that comes up frequently and isn’t entirely intuitive. I felt that others might benefit from reading the Q&A or sharing their own thoughts on the topic.
QUESTION: I photograph with a Nikon D5000. One of the features I am less than satisfied with is that auto bracketing is limited to three exposures. Sometimes that is simply not enough. The conventional wisdom seems to indicate:
1. don’t spread out your brackets more than one or two exposure values (EV).
2. Lightroom/Adobe Camera Raw can safely push/pull an exposure ±2 EV
What if I exposed three captures -3 EV, 0 EV and +3 EV? Then I should be able to make virtual copies of these in Lightroom, spreading each ±1 EV and the ends also ±2 EV. I would then end up with effectively an 11 stop range which is large enough for all but the most extreme lighting conditions I have encountered.
Do you think this technique has a decent chance of producing a quality HDR image? Note that my goal is to produce fine art prints, so to be useful for me it would have to produce very clean digital negatives.
ANSWER: The first consideration is how the high dynamic range image will be created. You can combine bracketed exposures using one of many HDR software applications or you can manually blend exposures using masking techniques. Exposure requirements will vary depending on the contrast of the scene and the blending technique. Having a full set of exposures at one stop increments can be more important for HDR software than manually blending exposures. HDR software usually does best (and often requires) being given a full range of exposures with narrow and consistent EV increments, as you point out. One stop is common, but I know people who go to extremes and bracket in 1/2 or 1/3 stops. I don’t use HDR software in my workflow. All the HDR software I have used tends to create image quality and adjustment control issues of various types, regardless of how the bracketed exposures were created.
Even though I usually take a full range of exposures, often only two of the exposures are required when manually blending using masking techniques. If I have one complete exposure for the sky and one complete exposure for the landscape, then I only blend these two exposures and keep my life simple. This video from my Extending Dynamic Range tutorials demonstrates a simple two exposure blend.
You may get lucky while using your camera’s three shot auto bracket feature and find that you captured the precise two exposures you need for such a blend, but since every scenario is different there isn’t a reliable way to reproduce this every time.
In more extreme contrast situations there may be brighter areas of the sky or very extreme areas of shadow and highlight in the landscape that require the use of additional exposures. When manual blending, one can make decisions about which exposures and how many exposures to use on an case by case basis. Having a full range of exposures to choose from is helpful in this respect. Blending exposures with masks is a challenging skill, but with practice I find that better control and better final image quality can be achieved. Some very fine printed images are being created with HDR software to be sure, but if the best quality is your goal you will eventually run into some downsides.
So, if you don’t capture a full range of exposures is it a good option to fill in the gaps digitally? As you describe, it is possible to create virtual copies in Lightroom with different EVs. Per the “conventional wisdom” Lightroom or Adobe Camera Raw certainly can be used to push or pull exposure. However, to what degree this can be done and what can be considered “safe” is subjective. It depends on whether you push or pull the exposure and what side affects you are willing to accept.
If the best image quality is your goal, having “properly” exposed captures can be just as important as the number and increment of those exposures. What constitutes a “proper” exposure isn’t necessarily intuitive. Digitally reducing exposure (pushing) in Lightroom or Adobe Camera Raw is generally “safe”. In fact it can actually be preferable. One way to hide noise in an image is to digitally decrease exposure making the image darker. Intentionally over exposing (also known as Exposing To The Right or ETTR) and then digitally lowering the exposure produces better image quality. This is why ETTR is commonly advocated in digital photography. When it comes to bracketing, digitally creating +1 EV and +2 EV exposures from a +3 EV capture in Lightroom should give great results in the mid-tones and shadows. The highlights will be clipped but these should be contained in your darker exposures. For a more complete run down on the virtues of ETTR and some examples check out this article by Jeff Schewe.
Digitally increasing exposure (pulling) is where you will run into problems. Dark regions of an image are very data poor so they have a low signal to noise ratio. The reason they are dark is because relatively few photons (signals) were collected by the sensor. Digitally increasing the exposure of underexposed images boosts the signal but also boosts the noise. With a low signal to noise ratio the noise will overpower the signal. An image captured at -3 EV and then digitally lightened two stops to -1 EV will show substantial quality issues. For best image quality it is preferable to avoid lightening dark areas as much as possible.
If you are using HDR software the following is important to note. As far as I know, no HDR software is capable of reading the exposure adjustments you make to raw or DNG files in Lightroom or Camera Raw. Raw adjustments are only parameters contained in the metada and HDR software does not access these parameters. This means that in order for HDR software to use your digitally bracketed exposures you would first need to open the virtual copies and save them as tif files with different EVs, and then load the tif files into the HDR software.
So, your proposed technique can work to an extent if you take the right steps. In many cases it may even produce very good results. However, to minimize noise, it would be best to create your digital exposures by always lowering the exposure of the brighter frames and not the other way around. For example, generate +1 and +2 EV virtual copies from a +3 EV capture, -1 and -2 EV copies from a 0 EV capture and -4 and -5 EV copies from a -3 EV capture.
There are occasions in which I will create exposures digitally for the purpose of blending. Sometimes I fail to take a complete range of bracketed exposures or I’m not able to use one or more of my exposures due to things moving in the frame between shots. At a minimum I make sure I have one exposure for highlights, one exposure for mid-tones and one exposure for shadows. Usually I try to capture a full range of exposures if I can. This ensures the most flexibility. A properly exposed series of images with one stop increments will give you a more complete gradient of tonal information to work with compared to capturing just three exposures taken at three stop increments.
Taking all of the above into account, let’s address the central motivation behind your question, the limited auto bracketing capability of your camera. If your camera would auto-bracket more than three exposures it is unlikely that you would be considering using digitally created exposures in the first place. I recommend making it a non-issue by not using the auto bracket feature at all, regardless of how many shots your camera will bracket. My camera will auto bracket up to seven EVs but I never use auto bracketing unless I have a specific reason to (such as hand-held bracketing for example). Nearly every scene requires a different number of exposures and the range of exposures is rarely centered perfectly around the meter’s 0 EV. Using an arbitrary number of auto bracketed exposures means regularly capturing too many or too few exposures (in your case with a max of three, usually too few). And if the actual exposure is shifted from what the camera meter picks as 0 EV, then you might have the right number of exposures but going in the wrong direction. Manually bracketing exposures solves these issues. I take my first frame at 0 EV and then I check the histogram. Sometimes one exposure is all I need. If the histogram shows clipping of highlights or shadows or both, then I compensate my exposure up and/or down one stop at a time until I have one frame with a histogram that properly exposes for the shadows, one frame with a histogram that properly exposes for the highlights and some number of one stop increments in between. Sometimes the scene dictates two exposures, or three or five or eight or eleven. Whatever the contrast range requires, this technique ensures that I have what I need, but not more. This video from the Extending Dynamic Range series illustrates this concept further.
Another manual bracketing technique I use is tonal region bracketing using my camera’s live view feature. In aperture priority mode I move the exposure target box around on the screen to various tonal zones, such as an area of brightest sky, mid-tone land and dark shadows, and take a shot in each zone. The camera automatically adjusts the exposure for each zone as I shoot. The result is a series of exposures that should contain the proper exposure for each tonal zone. They may not be one stop increments, but as long as I have optimal exposures for highlights, mid-tones and shadows I don’t care. Of course, this technique doesn’t work well when using HDR software which expects consistent EV increments.
Finally, not every scene we encounter has high contrast light so bracketing is frequently not necessary. When photographing in balanced, low and medium contrast light situations all the tonal information readily fits within a single exposure. I regularly come across people auto bracketing nine exposures in low and moderate contrast light, just as a matter of habit. In such situations it isn’t necessary to take two exposures, let alone nine. I start with one exposure and look at the histogram. If I see that all the tonal values have been captured, I’m done. Taking valuable time and filling up memory cards with additional exposures is something I do only if I absolutely have to. Many of my images are captured in a single exposure. With a single exposure I attempt to get a proper exposure (ETTR) without clipping the highlights. In post this enables me to decrease the EV and do as little shadow recovery as possible. This gives better results than starting with an underexposed image and trying to lighten it to bring out shadow detail. Again, see the Jeff Schewe article for more insight into why this is the case.