Photo Cascadia Blog
Archive for the ‘High Dynamic Range’ Category
Exposure blending has become a regular tool in the digital darkroom for a lot of photographers. Exposure blending allows you to create an image of a scene in which the dynamic range of light was too great to record in a single exposure. Instead of blown out highlights or ink-black shadows, exposure blending makes it possible to retain good color and detail in the brightest highlights and deepest shadows and also do it in a way that looks natural. As the dynamic range capability of cameras continues to improve there are fewer situations which have a dynamic range beyond a single exposure, but there are still many cases that do. And even if highlight and shadow recovery is possible from a single exposure, exposure blending can sometimes offer gains in final image color, clarity and noise.
But exposure blending can be a challenging and time-consuming technique, depending on the characteristics of the image. In this video tutorial, I demonstrate a fast and easy way to accomplish natural looking exposure blends using the TKActions V6 panel which works for a lot of common high dynamic range situations landscape photographers encounter.
If you are viewing this blog via email you can view the video at this link: https://youtu.be/FxDIIP-5-40
The steps I demo in the tutorial are as follows:
- Start by making basic raw adjustments to the exposures.
- Open the exposures in Photoshop as smart objects.
- Stack the smart objects as layers in a single image document with the dark layer on top.
- Select the top layer and turn off its visibility.
- Turn on Layer Mask mode in the V6 RapidMask2 module.
- Click the Composite or Lights-1 mask button in the module to apply a Lights-1 mask to the top layer.
- Turn the visibility of the dark layer back on.
- Paint on the Lights-1 luminosity mask with a soft black brush to further mask out the landscape area of the image.
- Fine tune the raw adjustments to each of the smart object layers to help them “match” or blend in the transition zone.
That’s it. Make sure to watch the video to pick up some additional tips and variations on the technique. Most exposure blends done using this technique can be accomplished in a minute or two once you get the steps down.
I hope this helps you out when you need to blend exposures. Leave me a comment or question if you have one and I’ll get back to you.
Landscape photographers are increasingly turning toward more interpretive modes of presentation in order to express their own ideas about the scenes that they encounter. New techniques in field work and related digital processing have fueled this development, often enabling photographers to produce images that were nearly impossible to achieve in the film era. These techniques address a plethora of age-old problems in landscape photography, from displaying a vast depth-of-field to escaping the constraints of shutter speeds and fixed angles of view. Whether the goal is to overcome limitations of current photographic equipment or to infuse a photograph with creative subjectivity, digital solutions have opened up a new world of options and have generated a world of terminology to go with them. In response to frequent requests for explanations of certain terms, I offer the following lexicon.
These terms are those that pertain to recent developments, advancements in field work and related post-processing made possible by the digital era. I have intentionally omitted common terms that have direct counterparts in darkroom development, such as dodging, burning, and cropping. This list is hardly exhaustive and is intended to highlight those techniques that have been most significant in landscape photography of the last decade. In addition, I have included terms that describe some newer techniques that I am increasingly asked to explain.
Blends combine separate image files or else different treatments of a single file into a final image. Blending requires the use of layers and masking in editing software such as Adobe Photoshop. A ‘blend’ is generally distinct from a ‘composite’ in its use of source files created during a single photography outing at a particular location.
Possibly the most essential of all blending techniques for landscape photographers is the Exposure Blend, which allows for selective control over tones in an image. A typical use of an exposure blend would be to present sky and land areas of a scene such that they appear to be in balance tonally, as the human eye might see them. Unlike the use of graduated filters, exposure blends allow for targeted tonal changes in any location of the image and at any level of opacity. These blends might combine different exposures produced as separate files or else differently processed iterations of a single raw file. Exposure Blends are typically achieved with freehand masking or with luminosity masking.
Focal Length Blend:
This type of blend combines frames of a single scene that were shot at different focal lengths. The typical use of this kind of blend is to overcome the effects of “pancaking” or diminution of background features caused by the use of a wide-angle lens. By combining a longer focal length for a background with a wider one of a foreground, photographers can restore the prominence and presence of background features that might otherwise appear less impressive than they would in person. Focal Length Blends require manual blending using hard-edged masks.
One of the most versatile types of blending, the Perspective Blend allows the combination of frames shot using different nodal points. The most common type of Perspective Blend is the so-called “Vertorama”, which is essentially a vertically oriented panorama. Perspective Blends can also combine slightly different camera heights or angles that allow more descriptive or expressive views of certain foreground features without compromising the desired view of the background. Perspective Blends can be achieved with automated stitching software or with manual blending.
A Time Blend collapses together different moments of a natural event, allowing for a more extensive narrative or a more descriptive presentation, similar to what a video might accomplish. While an Exposure Blend might combine different moments that are only seconds apart (or less), a Time Blend could include instances that span across minutes or even an hour or more. A typical example would be a scene with fast-moving atmosphere and quickly changing light that showcases the most significant moments of the event. Another common variation on the technique is combining different shutter speeds in a single image, such as having a longer shutter speed to blur moving water and a shorter one to freeze foliage movement. Time Blends typically require freehand masking.
This technique was developed to overcome problems of extreme dynamic range during twilight or night. The basic approach is to photograph land portions of a scene with ample ambient light separately from the night sky, keeping the camera in position on a tripod as long as it takes to create good exposures of both the land and the sky (typically about an hour). Twilight Blends can be achieved with freehand masking or with luminosity masking and usually require a substantial shift in white balance for the land portions of the image.
These effects accentuate or augment a scene in ways that emphasize a mood and contribute to the style of a photo’s final presentation.
When light shines through atmosphere that diffuses it substantially, any shadow areas behind the light lose contrast. The effect is often a pleasing, “glowy” one that emphasizes the light source. This natural phenomenon can be accentuated dramatically or even imitated outright by overlaying pixels that add brightness and diffusion. These pixels might be layers of bright color or selected areas of a blurred and brightened copy of the image file. The opacity of the effect is generally highest closer to the light source, typically requiring freehand application for naturalistic results. Photographer Ryan Dyar is widely regarded as the greatest pioneer of this technique, and his portfolio contains many images that exemplify it.
Light Painting in processing is akin to dodging and burning in that it selectively brightens or darkens areas of an image, often with a change in hue involved as well. A typical application might add brightness and warmth to selected highlight areas and add cooler hues to darker ones in order to emphasize visual hierarchy, to direct eye movement, or to emphasize depth. Light Painting is usually best controlled with a combination of luminosity masks and freehand application, and it may involve the use of numerous layers that build up to a result like glazing techniques in oil painting. (Note that this is a processing technique that should not be confused with in-field “Light Painting”, which involves using artificial light sources and long exposures in low light situations.)
This effect does have a direct counterpart in darkroom development, but I decided to include it in this lexicon because it has been widely adopted and adapted in the digital era. Photographer Michael Orton originated the technique using slide film in the mid-1980’s as a means of emulating the “Pen and Ink and Watercolor” technique of painting that produced a dreamy effect through its combination of media with different qualities. To create a similar effect with photography, Orton sandwiched together two slides that he took of a single scene, one slide with high detail and little color, along with a second slide that was out of focus and very colorful. Digital applications of this idea are numerous, ranging from subtle treatments that simply offset the effects of web sharpening, to more emphatic treatments that lend a painterly, glowing quality to an image. Numerous software filters, plug-ins, and scripts exist for automated applications of the effect, and of course manual applications are possible using layers in Photoshop.
The following techniques are among those that have been foundational in the more progressive strands of landscape photography in the digital era. They have opened up new options for composition, subject matter, conditions, locations, and timing to the extent that they lie at the heart of a distinct zeitgeist that has become evident in the last decade.
Focus stacking combines files shot with different focus points in order achieve a greater depth of field than would be possible in a single file. With this technique it is possible to have sharp focus on features at the very closest focusing distance of a lens while also having the same level of sharpness for everything else in a scene, all the way out to infinity focus. There are numerous standalone software programs that can automate the process of focus stacking, and Photoshop has stock features for focus stacking as well. Focus stacking can also be achieved manually via blending with layers and masks, although a manual blend is easiest to achieve with images that do not require the combination of many focus points.
The acronym for “High Dynamic Range”, this term describes any process that combines different exposures for the purpose of increasing the range of tones in an image beyond what is achievable in a single exposure. Many photographers reserve this term to distinguish automated processes that effect image tonality globally in a photograph, as distinct from manual blending techniques that allow highly selective control over tones in an image (see Exposure Blending above).
A luminosity mask is a blending tool that allows precise targeting of tones in an image. The most common uses of a luminosity mask are exposure blending, dodging, and burning, but these masks are useful for a huge variety of editing tasks, including color work, light painting, adding light bleed, and creating custom Orton effects, among others. A luminosity mask is a type of “found mask”, which is any mask created from one of the eleven standard channels available in different image modes within Photoshop. The channel that all luminosity masks derive from is the Gray channel, which contains only the luminance values for a given image. Channels that contain color values, such as the Red or Blue channels, can also be very useful and work in the same way that luminosity masks do. Because found masks use gradations of tones or colors that exist as pixels in a photograph, they are much more precise for blending tasks than freehand masking is, and they are less likely to produce unwanted ‘halos’ and artifacts, as can happen easily with simple applications of hard-edged masks (that is, those created with selection tools such as the Lasso Tool). There are numerous Photoshop action sets available to create luminosity masks quickly and easily, the most popular being those available from Tony Kuyper.
Stitching refers to the process of seamlessly combining frames shot by panning a camera horizontally, vertically, or both. There are numerous standalone software programs for creating stitched images, and some are very sophisticated, allowing photographers to stitch together frames from very wide focal lengths and from different nodal points. Photoshop also has features that enable automated stitching, and of course manual solutions exist as well.
Warping is a selective distortion of an image that has countless uses. Common examples include altering the relative proportions of certain parts of a scene, pulling unwanted edge details out of the frame, shifting regions of an image within the frame, correcting leaning features, and adding curvature to straight elements. Warping can be accomplished with the very edge of an ultra-wide-angle lens or with software tools, but blending with another layer of image data that contains normal proportions for the rest of the scene is usually necessary in either case. Although numerous software programs have warping features, Photoshop includes the most variety of them and offers the greatest amount of control, especially given the option to use masking for more targeted effects.
WHEN, WHY, AND HOW MUCH?
My own preference is to use processing solutions creatively but conservatively, always striving for a high level of naturalism and subtlety and without creating images that have no basis in my own experiences. Nonetheless, those limitations are merely my preferences for my own output, and I enjoy seeing compelling photographs that push beyond the limits that I might set for myself. Perhaps the most important consideration for any type of processing is the rationale for choosing a particular technique. Like any decisions in art, those that work in the service of a creative goal are more likely to produce satisfying results. Anything done with intention tends to register with more viewers, allowing them to discover points where craft and ideas come together in powerful, meaningful displays of creative choice.
**Special thanks to the artists whose images are linked in this article and who collaborated with me on the selection of them!
Can you guess which of these techniques went into the photographs displayed in this article? Do you have any questions about any of these terms? Would you like to suggest terms for inclusion in future versions of this lexicon? If so, please feel free to chime in below.
Erin divides her time between Cascadia’s Californian southern boundary and Slovenia, traveling and photographing extensively from home bases in both locations. Make sure to bookmark Erin’s site at www.erinbabnik.com. You can also follow her on Facebook, Twitter and Instagram.
by Zack Schnepf
I think the histogram is one of the most important and useful tools in all of photography. It’s a tool I rely on throughout my entire workflow, but I notice it’s a concept that many students have a hard time fully understanding. It can be confusing at first, but once you understand your histogram, you can master your exposures. In this article I’ll share how I use the histogram and why I find it so usefulI. I’ll discuss how I use it the field and in post production.
What is a histogram, how do you read it, and what information does it gives you? Basically, a histogram is a graphical representation of the tonality of an image. It shows what tones and colors exist in an image and the concentration of these tones. Here is the basic anatomy of a histogram. This histogram is from the image below of First Snow on Gothic Peak. The left edge of the graph represents pure black, any tones beyond the left edge have no detail in them. Conversely, the right edge represents pure white, any tones beyond the right edge have no highlight detail, they are just pure white. The middle of the graph represents the mid tones of the image. So, left to right is the luminosity scale, or how bright or dark the tones are. In this histogram you can see overlapping graphs of the three color channels RGB(red, green, blue) The height of the graphs indicates the concentration of tones of color and luminosity tones. For instance, in the histogram you can see I have a spike in the blue channel toward the left side, that tells me I have a lot of dark blue tones in this image. There is also a spike in the red channel right in the middle which tells me I have a large concentration of red midtones which you can see in the red foliage of the image. The Height of the peaks is not important for judging exposure, so don’t worry how high the peaks are. One of the most important things I look for in the field and in post processing is information that might be getting lost in either the shadows, or highlights. In this histogram you can see that all of the information is being contained. I can tell, because none of the color channel graphs are bumping into either edge. I’ll elaborate on this further in the sections below.
In the field, I rely on my histogram as a guide to give me an accurate assessment of each exposure I capture. One of the biggest mistakes I see when teaching photo workshops is a student judging an exposure using the LCD on their camera. I’ve been burned by this too many times to count. I’ll be shooting in a low ambient light situation, take a quick look at the image on the LCD and think it looks great, but when I get home and view it on my computer I realize it’s way underexposed. The low ambient light makes the image on the LCD seem really bright. The only way to truly judge an exposure in the field is to check the histogram. Below are 2 bracketed exposures of the same scene. One exposed to capture the tones in the bright sky and the other exposed to capture the tones in the foreground area. In the field, the darker exposure looked good on the LCD, you could even see detail in the foreground grasses, but one look at the histogram told me those foreground tones were way too dark. You can see on the histogram for the darker exposure, the highlight detail is being captured well, there is no information being lost in the highlight, but there is a large spike next to the left edge of the histogram. This indicates a high concentration of dark tones that contain very little detail. I wanted to take another exposure to capture detail in the shadows.
This lighter exposure has plenty of detail in the shadows. You can see in the histogram, the detail that was being lost in the shadows is being captured well. There is now plenty of detail in the foreground grasses and stream. On the other hand, the highlight tones are blowing out. You can see there is a huge spike on the right edge of the histogram and it goes right up to the edge and beyond. Anything beyond the edge has no detail in it. This is what is known as a high dynamic range scene. You could try to compromise and get an exposure in between and use Lightroom and Photoshop to recover the tones that are being lost, or you can bracket exposures and try to combine multiple exposures that contain a lot more information. Either way, the histogram is the tool that will tell you if you have captured the information you need, or not.
In post production the histogram helps me determine which tonality adjustments to make. Below is an image captured while teaching a workshop in the Palouse this spring. You can see on the histogram, most of the color and luminance tones are concentrated in the middle and left side of the image. This indicates that it is a low contrast, dark exposure. This is important information to determine what post processing this image needs. I would like to add contrast, but also brighten the image.
This is after one contrast adjustment. I was able to increase contrast, brighten the image, and control some highlights that were getting too bright. You can see the tones in the histogram are more spread out, but the highlights and shadows have plenty of detail information in them. From here I can decide if want to add more contrast. I can also lighten, or darken the overall exposure. Either way, the histogram will help guide me to the finished image.
You can learn more about Zack and his instructional videos on his website
I recently got the chance to co-host a Photo Walk in Vancouver, BC, Canada with 500px. We also had the luck to have Fuji as a sponsor for the event and to have a representative from Fuji join us. About 80 people participated in the Photo Walk. There were lots of Fuji giveaways and everybody walked away with some goodies including a lucky participant that won an underwater camera.
For those that were wondering what exactly a Photo Walk is. Here is the short answer; it’s an organized photo event that brings photographers together from all walks of life with a common interest in taking pictures.
There are many benefits to joining a Photo Walk in your local area. It gets photographers together with like-minded goals. It introduces you to the events and organizations that are in your area that have to do with photography. Also, it gives you the chance to meet all kinds of people with diverse backgrounds that, when together, share ideas and thoughts. The Photo Walks often take place in an area of the city that really highlight the area’s beauty. It’s a great way to see your city as well learn new things.
For this Photo Walk I chose the Vancouver Seawall in Stanley Park as the place to meet the group of photographers and really showcase Vancouver’s stunning city skyline views. Vancouver is well known around the world for its tall buildings and gorgeous harbor views of the city. The Vancouver Seawall is just a short walk from the main downtown area, yet allows one to feel like you are far enough away from the city to really enjoy it without the crowds.
The group started at the historic Vancouver Rowing Club and worked its way around the seawall shooting all different perspectives of the city skyline. Right away we encountered a great spot for photographing fall colors. Some people got adventurous and laid on the grass and took turns photographing the fall leaves. The photo below is an example.
The shooting of the fall colors gave the group a great chance talk about the potential of an important concept in nature photography called High Dynamic Range or HDR. High Dynamic Photography is the process of taking multiple exposures of the same scene with different exposures and combining them into one exposure. The final exposure is made up of all the exposures and thus has a wider dynamic range of exposure in a single image. Some had done it before and others were learning about it for the first time. People also shared some of their tricks when shooting, as for example, when shooting into the sun at an aperture of f/22 to make a sun star. After finishing shooting the fall colors and trees along the seawall the group moved on to shoot the inner harbor and city skyline. Everyone was eager to learn all about the different ways to shoot the city as well as learn about their camera settings to take advantage of the light. We choose a time to photograph near sunset to show of the late light of twilight on the cityscape as shown in the examples below.
We were also fortunate enough to get a near full moon that gave the group more opportunities to shoot late into the night. The group made its way along the seawall noting some of the local wildlife such as the harbor seals. People also took time to talk about photo equipment and what cameras and lenses to use and in what situations to use them. With a wide diversity of cameras and tripods the group tried out several different pieces of equipment including some newer lenses by Fuji. The Vancouver Seawall is also in my opinion one of the best places to shoot panoramas of the city with reflections. So the group got together and did some panoramas that worked out great with the light and the location. The scenes below show examples of panoramas.
The sun began to set in the west and the last of the day’s light hit the Vancouver landscape city skyline. This gave the group an opportunity to shoot a group photo of some of the participants, which people can share. We managed to all squeeze close enough with the backdrop of Vancouver.
Eventually we made our way back to the start of the Photo Walk continuing to photograph the city at night with all its glorious reflections in the water. The group even found a way to shoot at night without a tripod by placing the camera on the seawall ledge, which made for a great impromptu tripod.
During the few hours together we got to know each other and made new friends. We also learnt lots of new things about Vancouver and photography.
The night ended with people exchanging contact information and well as the promise to post their images on their Facebook page.
Co-hosting the event with 500px gave me a great opportunity to learn some new things as well as meet a great bunch of new people. It was amazing to see how many people showed up from different experiences yet shared a common goal of taking great photos. So thank you everyone who showed up and hope to see everyone again in the near future. And thanks to our sponsor, Fuji and 500px for co-hosting the event.
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.
High dynamic range light continues to be a challenge for outdoor photographers. Another term for dynamic range is contrast. As long as the contrast of a scene, from darkest shadow to brightest highlight, does not exceed the camera’s ability to record dynamic range it is possible to record detail throughout a scene in a single exposure. In nature, especially around sunset and sunrise when the sky is bright and the landscape is much darker, the contrast often exceeds the camera’s dynamic range ability. Going all the way back to it’s beginning, more than 150 years ago, photographers have looked for ways to deal with high dynamic range light. There are many in-camera techniques for this, such as using a graduated neutral density filter to hold back light in bright areas or using some sort of artificial lighting to illuminate dark areas. In the current era, digital images and imaging software have made it possible to combine multiple exposures that contain image detail for all light values in a high dynamic range situation. This can be done with automated HDR software or by using masking techniques in Photoshop to “hand blend” multiple exposure values into a single extended dynamic range scene.
Whatever technique is being used to blend the exposures, it is necessary to first capture or “bracket” a series of exposures that encompasses the entire dynamic range. Knowing when and how to bracket exposures so that you have collected enough detail across the entire light range can be confusing. My goal is to take only the exposures I need, no more and no less. Most non point and shoot cameras feature an Auto Exposure Bracketing (AEB) feature but I find that it often doesn’t succeed in capturing what I need. Sometimes the number of exposures I have set is too many and some times it is too few. Even if I guess right and choose the correct number of exposures, the camera often misreads the scene and doesn’t center the exposure series properly, missing important details either at the shadow or highlight end of the range.
I have the most success when I manually bracket exposures but this requires establishing a well practiced approach to be able to do it quickly and consistently. Help with manually bracketing exposures is a common request during workshops. In the video above I explain how I evaluate a histogram to determine when bracketing is necessary and I also outline two different manual bracketing methods I use to make sure that I have successfully recorded the entire dynamic range.
I’m currently working on a complete update to my video tutorial series called Developing for Extended Dynamic Range and this is one of the chapters. Production on the updated series will be completed and the new videos should be available by the end of January, 2015. I will be sending out an email notice to people who own the original series when it is available. I will also be teaching a weekend class on exposure blending and developing for extended dynamic range in Bend, Oregon in May.
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.
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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.