What! Dave says HDR sucks? Are we in for some kind of major turnaround here? If you’ve read this blog for any length of time you’ll know that I’m a huge advocate for HDR so the post title can’t be coming from me, surely? You have to admit, though, that had I called it “Why a Sizeable Percentage of the Photography Community Thinks HDR Sucks”, you probably wouldn’t have clicked through that link, would you? 🙂 This post, however, puts forward my suggestions on why HDR sucks to so many seasoned photographers.
Just to keep the record straight, I most certainly don’t think that HDR (High Dynamic Range) photography sucks but I do have a pretty good idea why so many people seem to think that it does. Hopefully I can illustrate some of these reasons in this article which I’ve illustrated using embarrassing images from my past (all of these are still on Flickr – think of it as a kind of penance for me). I felt this was somewhat kinder than picking bad examples from other photographers but, if you want to see some, just wander through Flickr’s HDR group.
First of all, there will be people who hate HDR for reasons that are not covered by this article. I include in this group, the people who discount photography in general as a form of art. These people are of the opinion that all art must involve laying carbon, ink or paint onto paper or canvas by hand and, since photography doesn’t do this, it can’t be true art. To these folks, I say just move along and go back to your crayons since there’s nothing here for you.
There are another group who reject HDR and all forms of post-processing or digital manipulation of images on the grounds that the results are not “real”. This group appears to consider only single exposures valid but fail to take into account the fact that the capabilities of digital cameras are changing and improving all the time, and that the amount of processing performed on the images in-camera is increasing with every generation. As things move forward, assuming “real” is defined as the result of a single shutter click, these people will have to expand their definition of “real” to include wider and wider dynamic ranges and even in-camera HDR so they will likely change their opinions in the end. (As an aside, these people are often quite happy to include monochrome imagery in their definition of “realistic” photography. I find that rather strange.)
The majority of people who claim to hate HDR, I suspect, hate not HDR but badly applied tonemapping (the part of the HDR workflow which generates the output image that you end up seeing). HDR describes a set of techniques and not a look, but too many people fail to realise this and associate the term with funky looking images where the techniques have been applied very poorly. It’s disappointing but true that badly done HDR is extremely easy to recognise due to several commonly-made processing errors that stand out. Let’s consider a few images that exhibit these problems and which people should be encouraged to dislike. Click each to see the original on Flickr if you would like to see a larger version.
Why HDR Sucks (using my images as examples)
- The basic picture is pretty uninteresting. It’s a snap of an excavator. I did use a wide angle lens and I did shoot from a low angle to try to create an interesting perspective but the effect isn’t pronounced enough to really make this anything special. There are pictures to be had in this scene but, nowadays, I wouldn’t have shot this one.
- The ghosting in the clouds is horrid. You’ll need to look at the high resolution version to see this but there are multiple images of each cloud in the sky. This occurred due to the time between each of the 3 exposures that comprised the original bracket used to build the image. At this point in my development, I didn’t notice this and didn’t retouch the sky to get rid of the problem. Ghosting is a problem in all HDRs where any movement occurs between the individual exposures. A good photographer will notice this and fix it before publishing the picture.
- You can see a great example of tonal inversion in the clouds. When you push the HDR tonemapping too far, you end up finding that areas which should contain highlights turn grey. There’s a fine line between dramatic skies (which can be created really well when tonemapping) and overcooked skies like this one.
- What was I thinking with that vignette? I suspect I was worried about the fact that I had a bunch of blown-out highlights in the sky (another indication that my tonemapping wasn’t right) and tried to fix them by merely reducing the brightness of the sky and edges by painting partly-transparent black over those areas. The result is a horribly unsubtle blob of a vignette. Yuk.
If you produce work like this, please discard it immediately or, at least, learn to recognise the processing errors and practice techniques needed to fix them. In this particular case, more subtle tonemapping parameters followed by some time in Photoshop to replace the horrid sky would likely have yielded a far more acceptable image.
Katz’s Never Kloses
Take a look at the sky in this picture, for example. Have you ever seen a clear sky that shade of grey? The tonemapping choices I made to get the car looking about right caused the sky to become horribly unnatural. The fix here would have been to try different tonemapping settings or, more likely, generate a couple of versions of the image, one where the foreground looked right and one where the sky looked right then blend them in Photoshop.
Another problem in this shot is the strange variation in brightness over the front of the car. Why are the sides of the hood so much brighter than the centre? I’m not sure if that’s a tonemapping artifact (Photomatix does some really strange things to areas of the same colour that are crossed by high contrast lines – try tonemapping an image of a suspension bridge taken on a clear day if you want to see what I mean) or whether I tried to rescue the image by using some bad dodging to darken part of the car but, regardless, it’s something that should have been fixed before I thought of posting the image.
Wildflower Center Cistern Roof
As I mentioned before, HDR is a set of tools not an end in itself. To generate a good HDR photograph, you need to start with a great scene and compose the image well then, if necessary, use HDR techniques to overcome any camera-related limitations if the brightness range is wider than you can capture in a single shot.
Although I don’t like this picture, there is a picture to be taken in here. If I was reshooting this, I would likely have zoomed in and generated a pattern picture with the skylight sitting on one of the thirds. Maybe I’ll try that next time I’m at the Wildflower Center.
Texas House HDR
This problem is most commonly seen in skies. When you are about to publish an HDR containing a blue sky, take a look outside then look back at your picture and ask yourself if you’ve ever seen a sky that colour. If it seems a bit on the over-blue side, please fix it.
Live Oaks at Fort Bend County Courthouse
Fixing this type of problem is straightforward in Photoshop (this image is the example I used in my tutorial on the Magic Blue Sky Halo Removal Method but I was just being too lazy that evening to do the job properly.
Another couple of problems are evident here. I need to fix (or, at least, reduce) the converging verticals which make the courthouse lean into the shot and I also need to clean up the front of the courthouse building itself which is suffering from a bit of tonal inversion caused by my aggressive tonemapping. Again, these are pretty easy to fix in Photoshop but I was just being lazy.
The point here is that even if you have the material to produce a great image, if you do a slapdash job of processing it, you can ruin the result. Take the time necessary to get the image right (or as right as you can make it) and only publish it when you have done as good a job as you can.
I’ve spent quite a while airing my own dirty laundry but hopefully you see what I’m getting at. Pictures like these are the ones that the HDR-averse are seeing daily and which are causing them to come to the conclusion that HDR in general sucks. What they don’t realise is that the same techniques which were used so badly above are being used all over to great effect and that, because the job is done so well, you don’t actually notice the technique – you see only a spectacular image and not the tools behind it. Here are a few of mine that I hope fall into this later category. All of these use HDR and exposure blending techniques but would you immediately recognise them as HDR images?
To anyone reading this who professes to hate HDR, therefore, I would ask one thing. Please consider the image itself rather than the methods used to create it. I’ve offered several images that are, indeed, terrible and which do, as it happens, use HDR. Condemning HDR in general based on these (and other) example is, however, throwing the baby out with the bathwater since there are many, many examples of the same techniques being applied and resulting in good images.
Episode 56 of PhotoNetCast has just been published and you can find it on the site or over on iTunes. The uncut video of the original recording is also available to give you a better appreciation of what a good job Antonio does in editing the audio version 🙂
Here’s the last of my HDR tips for this week. I’ve been saving this one for a while but, if you shoot in climates where you can rely upon clear blue skies, it’s a killer tip and could save you hours (even if I do say so myself).
Do you often find yourself with a mess like the following after tone-mapping? Frankly, this is an image I really don’t like – the tone mapping is wildy unsubtle but it serves as a great example for this tip.
The foreground looks the way it was intended to look but the sky is a horrible collection of haloes and weird areas of different shades of blue. Wouldn’t it be great if I could just drop in a new sky without having to spend a week masking around all those blasted leaves? Well here’s a tip that will fix your sky in about 2 minutes flat as long as it’s predominantly blue. This will work if there are some clouds but it definitely works best when the sky is clear.
Take a look at the original brackets you used and decide which one has the best sky tone. I typically like the -2EV image since I like nice, dark, saturated skies but it’s entirely up to you. Open the tone mapped image and the original image with the good sky as layers in Photoshop with the tone-mapped image below the original bracket.
Now we’re going to use a bit of magic that very few people seem to know about. Make sure your magnification is set so that you can see the whole sky area of the image then right click on the top layer (with the original image) and select “Blending options…” (in CS5 at any rate. It used to be called “Advanced Blending…” or something similar in some previous versions as far as I can remember and you accessed it from the layer effects list I think). The dialog that you will see allows you to control how this layer blends with the one below it and one of the great features it offers is the ability to blend based on the colours in either this layer or the one below it.
As you will notice, the bits of the tone-mapped image we want to replace correspond with the blue sky in the original image so let’s tell Photoshop to show the original only where it is predominantly blue. Do this by setting the “Blend If” option to “Blue” then drag the slider under “This Layer” to the right. As you do this, you will see that the underlying layer starts to bleed through and become visible. Move the slider to the right until you start to see chunks of the tone-mapped sky appearing then stop. At this point, you will notice something along the lines of the following:
The original sky is definitely visible but you will also see a lot of really horrid fringes around all the tone-mapped leaves. There’s another secret to get rid of these. Hold the “Alt” key and click on the slider you just dragged. You will notice that it splits in two so now grab the left hand half-slider and pull it back towards the left. As you do this, you should see the fringes get smaller and, eventually disappear leaving you with something like this:
You will likely have to juggle the left and right half slider positions to get the best overall effect. It’s a good idea to zoom to 100% to check out the fringes since it’s tricky to see how the individual leaves (or other edges) look when you are zoomed out.
Once you have marveled at how the sky looks, you may be disappointed to notice that this blending has had a muting effect on other sections of the image too. This can, however, be corrected very easily by adding a layer mask to the top (original image) layer and, using a soft-edged brush, painting in black over the areas that you don’t want to be affected. Doing this, you are effectively allowing the underlying tone-mapped layer to shine through completely unaffected. If you accidentally paint any of the sky, just switch to white and paint the mask with that to erase the effect. Typically, the effect on non-sky sections of the image is reasonably subtle so you don’t have to be enormously careful when you are doing this final masking step. Painting this mask is, of course, enormously easier than trying to figure out how to mask around all the leaves!
Hopefully you’ll find this tip useful. It’s saved me hours here in Texas where blue skies are the norm. If you live up north or across the pond, you may find this less helpful but the basic approach can still be used for many other cases where you want to blend based on the colour of particular regions of an image.
I hope you’ve found this week of HDR tips helpful. Thanks for reading!
Quite often, I find that the tone mapping settings I like for part of my image cause other parts to look bad. In these cases, if I’m going for an artistic look, I will save the .HDR or .EXR file from Photomatix then open it twice and tone map it with settings that look good for each area independently. I then take these images into Photoshop and blend them together to give me the look I want in both areas.
If you are generating a realistic looking image, you can usually get away with not re-tonemapping but just blending in one of the original exposures. This is something I frequently do to get rid of blown highlights, noisy sections or weird contrast inversions in skies while keeping the tone mapped look of the foreground.
Open both of your tone-mapped images (or the original and tonemapped image) as layers in Photoshop with the main image on the bottom. Add a layer mask to the top image then fill the mask with black. Using a soft-edged, white brush, paint into the layer mask in the areas that you want the top image to be visible (the sky, for example). Once you’ve done this, you can change the opacity of the top layer to vary the amount of the original effect you let through.
Before anyone complains, I should admit that the picture at the top of this post is not the final version of this particular image since I’ve not uploaded that one to Flickr (you can see it on ImageKind and SmugMug though if you are interested). The final version fixes all the highlights in the clouds using this method.
I have another tip for fixing sky problems coming up but I think I’ll hang on to that one for a couple more days!
Another of my golden rules for processing HDRs is to do as little as possible to the brackets in Lightroom before I export them to Photomatix for merging. The main reason for this is that I want to ensure that I don’t disturb the pixels in each of the bracketed exposures differently and run the risk of messing up Photomatix ability to merge the picture but it’s also because I think of Photomatix as the first step in the process. There are, however, two operations that I typically do before merging the brackets, one of which is cosmetic and the other of which is, in my opinion, absolutely vital.
The cosmetic operation is to correct the image white balance if I didn’t nail it in the camera. The important thing here is to make sure you apply exactly the same change to every one of the pictures in the bracket. Typically, I will correct the center exposure then use the Develop Setting copy/paste operation in Lightroom to apply the same setting to the other images. I do most of my colour correction or tweaking after Photomatix is done with the image but it’s always easier to start with images that are close to where you want to end up.
The more critical operation for me, however, is correcting chromatic aberration. This is a “feature” of lenses (typically cheaper ones, to be honest) caused by the fact that they focus different colour of light at slightly different distances and, hence, give slightly different magnifications to the red and blue channels in the image. This results in colour fringing along high contrast edges near the sides of the image. If you don’t correct this prior to merging, you will find that (a) you end up with an HDR that is less sharp than it could be and (b) the fringing effect will be magnified an enormous amount by Photomatix.
If you are lucky enough to be using very high quality professional lenses, you may never see this (I really only have to deal with it on my Sigma 15mm fisheye since the Nikon pro lenses I have are amazingly clear of CA problems) but most of the time it will be apparent if you zoom your image to 100% and take a look at the corners. If you are using Lightroom, correcting the problem is very simple. In the Develop module, look under “Lens Corrections”. If Lightroom knows about your particular lens (and it knows about a lot of lenses), you can click “Profile” then select “Enable Profile Corrections” and your CA problems will disappear immediately. Note that this also allows you to correct lens distortion and vignetting but I typically leave these set to 0 since I like the fisheye distortion and the vignette doesn’t worry me.
If Lightroom doesn’t know about your particular lens, click on “Manual” and fiddle with the sliders under “Chromatic Aberration” until the fringes you see in the image disappear (or get as small as you can make them). In both the manual and profile cases, make sure you apply exactly the same setting to all the images in your bracket then go ahead and export them to Photomatix.
I’ve added an example of before and after here so that you can see what I am talking about. The top image shows a 200% view of the top right corner of one of my brackets before CA correction and the bottom one shows the same section after automatic CA correction in Lightroom.
As any dedicated HDR photographer will tell you, you should be carrying a tripod with you at all times. Even if you are carrying your tripod, however, it’s not guaranteed that you will actually be able to use it. Many buildings prohibit tripod use and many security guards get all hot and bothered when anyone walks into their territory carrying one. Despite this (and I won’t get started on how annoying and pointless some of these situations can be in this post) you can often save the day if you are also carrying a small and pretty inexpensive piece of equipment.
I have two Joby Gorillapods – an SLR-Zoom model and the larger, sturdier Gorillapod Focus. Frequently the same people who complain loudly if you even think of setting up a tripod won’t bat an eye if you pull out a Gorillapod and use that instead.
The picture shown here was taken with my D90 on the Gorillapod SLR-Zoom in St. Patrick’s Cathedral, New York, a place where tripods are completely verboten. I had to remove the camera’s battery pack and restrict myself to a smallish lens (this was shot with the Sigma 10-20mm) since the SLR-Zoom model, from my experience at least, really isn’t sturdy enough for anything but the lightest body/lens combination. Regardless of only having this small tripod-replacement, I managed to get some great shots by clamping the bendy legs of the Gorillapod onto the top of one of the cathedral pews. In some places, the fact that you can attach the Gorillapod to posts, furniture, fences, etc. actually gives you better camera-positioning options than you would have with a traditional tripod.
The newer Gorillapod Focus model is intended for larger cameras and can handle the weight of a pro-body with battery pack and a decent sized lens. For even more flexibility, add a small ball head to allow easier adjustment of the camera position. I have Joby’s own ballhead for the Focus and a small, generic ballhead on the SLR-Zoom.
Next time you find yourself having to use your tripod as a walking stick because some officious security guard tells you you can’t use it, save the day by trying to use a “non-tripod” instead and see if you can get away with that. I expect you will be pleasantly surprised.
Continuing the week’s theme of HDR tips, here’s one that can help out in situations where you find yourself wanting to shoot a bracket for an HDR but you don’t have access to a tripod. I don’t shoot many handheld HDR brackets but sometimes I don’t have a choice – either tripods are banned or I don’t have one with me. In this case, here are a few tips that can allow you to get the shot even without your trusty tripod. For reference, the shot above is a 7 exposure, handheld HDR shot at EPCOT in Walt Disney World.
- If your camera allows you to shoot more than 3 shots in automatic bracketing mode, set it to bracket a couple of shots wider than you normally would. If you would normally set up for a bracket of 3 exposures, for example, set it for 5. You won’t get a chance to tweak exposures after shooting your handheld bracket if it’s not wide enough so this helps minimise the chances of you having to reshoot the whole thing if you don’t get it first time. If your camera only allows 3 shots in the sequence, stick with that.
- Set your camera to high speed continuous shooting mode. The idea here is that you want to hold the shutter down and have the camera rip through the whole bracket as quickly as possible. Even if you can’t shoot at 8fps, 3fps is still better than you are likely to do pressing the button once per shot so go with what you have.
- Set your aperture so that the longest shutter speed in your bracket will still be in the safe handholding zone (1/focal length). If you are taking a 5 shot bracket, your slowest shutter speed will be 4 times the center setting (+2EV). If you are taking a 7 shot bracket, the slowest will be 8 times the center (+3EV). Typically, I will shoot 5 or 7 shot brackets and try to get my initial shutter speed in the 1/750 to 1/1000 range with a standard lens. This ensures that you won’t have problems with camera shake at one end of the bracket.
- Put your feet apart, brace your elbows by your sides and hold the camera firmly against your eye. Frame the shot and then squeeze and hold the shutter trying to move as little as possible in the process. In continuous mode, my Nikon cameras will shoot the entire bracket then pause to allow me to take my finger off the shutter.
Once you’ve done all this and have your handheld bracket back in the computer, probably the most important tip is to forget Photomatix for the first part of the process. If you have Photoshop, it does a far better job of realigning brackets that are not perfectly aligned so use the “Merge to HDR” feature in Photoshop and save the file it generates as a .HDR or .EXR file. Take this file and open it in Photomatix for tonemapping.
If you practice these steps, you can usually get a pretty decent HDR even if you don’t have a good way of stabilising your camera.
This week, HDR aficionados Rick Sammon and Trey Ratcliff are offering a week of HDR tips so I figured what better time to throw out a few tips of my own. I can’t promise to write one each day but I’ll try to get as close to this as possible. Without further ado, here’s tip number 1.
Most of us who do HDR find ourselves in a situation once in a while where we would love to produce an HDR image but only have a single raw image to start with. Common causes for this are that we didn’t bracket when we originally shot the image we want to process now or that we want to take a picture that contains a lot of movement. In these situations, we can, however, still make use of Photomatix to produce an HDR-like image from that single original exposure and the results can often be very appealing. The image above, for example, was generated from a single exposure I shot while on a tripod-less trip back to Scotland a four years ago.
Many people, including several photographer friends whose HDR work I respect enormously, produce HDRs from single raw files using a workflow that goes something like this:
- Create 3 virtual copies of the original image in Lightroom.
- In the develop module, pull the first image exposure up by 2 stops so that it is brighter.
- Again in the develop module, pull the last image’s exposure down by 2 stops so that it is darker.
- Export all 3 images to JPEGs (hence creating the bracketed set you need to create an HDR).
- Open Photomatix and merge the 3 JPEGs together to give an HDR image which you can then tonemap and process as normal.
This sounds reasonable, doesn’t it? To create an HDR, you need a set of brackets and this gives you that set of images so all is well.
What these folks don’t realise, however, is that they are wasting about 20 minutes per picture and likely ending up with an image that is not as good quality as it should be.
Why not try this instead?
- Open Photomatix.
- Choose “File/Open…” and point it at the single RAW file you want to work on.
- Process as if you just merged a bunch of brackets.
“That can’t be right – it’s far too easy!” you are likely shouting by now. The truth of the matter is that this is likely to give you a better result than the long and complex “generate your own fake brackets” approach described above. The original raw file has at least 2 stops and most likely at least 3 stops more information in it than the JPEGs you create in the awkward workflow. The JPEGs you export there throw away all but 8 stops (8 bits) of the data so by using exposure modification to generate your pseudo-bracket,all you are doing is deciding whether you throw the information away from the highlights or shadows in the different JPEGs. You then open these in Photomatix and have it try to reconstruct the very same data that you were so careful to throw away in the export step.
Photomatix is perfectly capable of extracting all the information from your single raw file so why not have it do the work instead of trying to help (but actually making Photomatix’s job more difficult)?
People who have heard me talk about this before may note that I’m breaking one of my golden rules here which is never to have Photomatix process my raw files. HDRSoft themselves admit that Adobe Camera Raw (the raw file processor inside Photoshop and Lightroom) does a far better job of rendering a raw file than their processor so I always use Lightroom to export my brackets to Photomatix. If you want the best possible quality, you can do the same thing here as long as you remember one very important choice. When you export your single image from Lightroom to send to Photomatix (which, incidentally, you can do via the standard Photomatix plug-in by just highlighting a single image rather than a whole bracketed set), make sure you select “TIFF 16-bit” as the output format. A 16 bit TIFF file allows you to save every bit of dynamic range information from your original raw file and pass it over to Photomatix. If you select JPEG at this point, Photomatix will only receive 8 bits of information and can’t, therefore, pull out any extra dynamic range since you’ve already thrown all that data away.
Next time you are tempted to muck with your exposures in Lightroom and create a fake bracket, give this a try and see what you think. I’m confident you will see that in this case the easiest approach can also be the best!
I’ll be giving a talk on HDR photography this coming Thursday evening at the Austin CapMac Advanced Photography SIG meeting. Come along to the parish hall of the Episcopal Church of the Resurrection at 6:30pm and join the fun.
My plan was to revamp the talk and update it so that anyone who had previously heard it at Hill Country Photography Club or Austin Shutterbugs would find new material to listen to and new pictures to see but my laptop hard disk decided to die yesterday so I may be dragging pictures from Flickr and winging it if Dell doesn’t come through on their “next business day” service promise or I don’t manage to get my backup restored in time. My fingers are crossed!
As another upshot of this failure, the photoblog is going to be quiet for the next few days. The failure occurred as I was exporting a batch of images for the next week’s posts so, unfortunately, they will be delayed until I get everything back up and running too.
I can’t help noticing the irony of me having a catastrophic PC hardware failure (in a 1 year old drive – I’ve never had a hard disk fail in less than 5 years before) the very week I’m supposed to be speaking to a Mac user group. Oh well…
A couple of months ago, New Jersey-based photographer and HDR aficionado Scott Wyden invited me to write an HDR tip for an ongoing series on his blog. The article was published today and you can find it here. I would love to hear what you think so please leave a comment over there and let me know.