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HDR Expose 2 review
Standalone HDR creation and editing software
Keith has recently been looking at the HDR Expose 2 software package from Unified Color. This software package allows the creation and editing of High Dynamic Range (HDR) images.
As an aside, he also looks at the Float 32 plugin for Adobe Photoshop, which allows many of the HDR editing functions of HDR Expose to be carried out within Photoshop (CS5 in this instance). Detailed software package differences are outlined in the summary.
The functionality described below is also available for Windows PC users.
The software has versions that work as plugins for Lightroom and Aperture.
If you take a photo on a sunny day, and look at the range of brightness in the image, you'll see parts of the image very bright, and parts of it in shade.
Nothing surprising there, it's what you would see if you were looking at the scene yourself.
Getting the correct exposure for your photograph is a balance between losing detail in very dark shadows or losing detail in the highlights.
On a cloudy day, the difference between dark shadow and brighter areas is probably well within the range your camera can cope with, but on a sunny day it may be beyond what can be fully captured.
This is why you can end up with 'burnt out' white areas or solid black shadow areas - our eyes can adapt as we sweep our gaze over a scene, but current camera sensors may have difficulty.
This is a common problem in some of my interior photography work, where one single exposure can't capture the interior of a room -and- the view out of the window.
This is the view through a gap in the curtains from where I'm sitting. The inset is taken at 1/320th second exposure, whilst the curtains show a 1/6th second exposure.
What if you could combine the two (or more) exposures, getting the best of each? (OK, I'd likely want the curtains in focus).
Well, with multiple exposures you can combine images in a way that captures the full range of lighting from dark to light.
This is where the idea of 'High Dynamic Range' or HDR photography comes from.
What sounds quite straightforward is actually quite tricky to do, particularly if like me, you want images that look natural.
The image creation process consists of two parts.
One is the merging of photos to create an image that contains a full range of tones. This is represented in a different internal format to normal 8 or 16 bit images.
The second stage is to map this data into an image that you can use. It's this 'tone mapping' or conversion process that will give the final 'look' of the image (for better or worse ;-)
HDR Expose 2 can fuse your original images (ideally in RAW format) together, and then provide tools for you to control the mapping from HDR to a format you can display on the web, or print. It can be used as a standalone program or as a plugin for Aperture/Lightroom (I don't use either)
The Float 32 plugin for Photoshop allows existing HDR format images to be converted/mapped.
The software installs very easily, and you have 30 days of demo mode to see if it's something you like.
Note that the plugin is not the same as Float32, in that all it does is allow Photoshop to handle the proprietary .bef format for storing HDR images.
I'll show some examples of producing images with the software, but do remember that the mapping process is very much up to you.
There are many videos on the Unified Color web site that may be of help for you in finding out more about the interaction of all the various adjustments and controls. Just remember that there are a lot of adjustments you can make and that quite subtle changes often have a noticeable effect on how the image looks.
I'm going to start off with using these three shots of the interior of a room. This is the view from Adobe Bridge, where I've been sorting through some RAW camera files (taken with a TS-E24mm. shift lens on a Canon 1Ds3 camera)
The aperture was constant, but exposure varied with each shot
Unfortunately I can't directly export these files from Bridge, which means that I've no control over any of the RAW file processing parameters (I'll come back to this in the article conclusions)
I note the file names needed and open HDR Expose 2.
The main splash screen offers some links to tutorials and web information. The 'Help' menu item at the top of the screen (Mac) seemed somewhat somewhat inconsistent in what it did, with the suggested 'F1' key on my keyboard doing nothing at all. There is no context sensitive help.
There are links to video tutorials - not always much help if like me, you find video based help a pain to use (2m58s wasted to find that what you were after wasn't in the clip you looked at).
Read the quick start guide for an overview of all the various controls. Fortunately, most have an option to turn back to default values
When opening files, you can select how the software handles differences between the images caused by moving objects.
The only movement in this case would be the trees outside, and it wasn't a windy day.
Manual white balance is another option here, but if you go for a manual setting, be prepared for a rather daunting set of adjustment options.
There is no simple 'set all to a particular value' option and any numeric values seem to have little connection with any other software I regularly use. I'm left with the 'as shot' option, which, given the presence of daylight and an energy saving lightbulb in the lamp doesn't inspire confidence. No help options either...
This is the adjustment screen, from when I opened up a collection of night time shots.
Probably best left at 'default' for the time being.
The interface is mostly fairly clear and self explanatory, although it has some interesting foibles, with small buttons and icons that do things (note the eyedropper above).
It does something, but you'll have to use it to find out.
Software preferences are fairly straightforward, although with the .bef file format I've no idea what:
Many functions are available from the main menu bar, but the normal workflow would likely be to move from top to bottom of the various adjustments on the right hand side.
The default is for the freshly made HDR file to appear in Linear tone mapped mode. It's a tabbed interface, so you can have several images open at once.
Available conversion presets are along the bottom (you can save your own settings as presets) I'll show examples from several sets of images I tried with the software.
A full 32-bit histogram is shown at the top along with various indicators of pixel data.
The arrow under the histogram plays an interesting movie showing the full dynamic range of your image (think of a series of snapshots at varying exposures).
Or, as in this 180 degree fisheye shot, you can click on the 'S' and 'H' marks above the histogram.
The shot is looking up the inside of a church spire. The black area around the image should be completely black, but some light leakage shows from the bright light coming in through the lucarnes.
HDR Expose allows for some basic image geometry adjustment - since I use Photoshop for all my detailed image editing, this isn't a function I'd find any use for. In fact, unless you are using some pretty basic software for your other image editing, almost anything will have more functionality.
The adjustments for veiling glare and tone mapping are quite complex in the way they interact. There's no easy recipe for the 'correct' numbers for your images, so it really is a matter of experimenting, although it's worth looking at some of the presets and their settings for some starting points.
The veiling glare setting can be used to effectively set black points in images where glare and haze are problems (night shots for example).
As you'd expect, tone tuning is probably best tried after the basic tone mapping settings are OK - think of it as a version of Photoshop's curves adjustments.
The effects are quite subtle. Unfortunately you can't enter individual points on the curve and there are no sharp kinks allowed (sometimes of use where an image consists of distinct zones of brightness levels).
There is a degree of localised dodging and burning provided.
This is great in that it can be very finely tuned, but if, like me, you are used to using masked adjustments and layers, then it feels like going back to a very old version of Photoshop in some aspects - no history, no masking, no multiple layers.
If those features mean nothing to you, then maybe you're more in this software's target audience. I've used Photoshop for years and sometimes forget that others have not ;-)
Colour tuning and adjustment is something that HDR Expose 2 does in a very comprehensive way.
When working with HDR images, colour shifts and adjustments can easily introduce unwanted effects. The software is designed to minimise such problems and indeed does a good job.
However, a lack of detailed information on just what does what in the settings, and examples of why you might make particular changes, mean that once again you are left wondering 'what next?'.
The sharpening and noise reduction tools are both useful and limited at the same time. I'll come back to this later when looking at some aspects of image detail.
Once you find a set of adjustments you like, do save them as a preset - it could save a lot of time later, particularly if you want to batch process sets of images.
All the editing functions except geometry are available from within Photoshop, via the filters menu.
This particular image shows a typical use for HDR for myself.
I need to get the photo whilst I'm at the location, and can't wait until early evening, when exterior light will be much more similar to internal lighting levels.
So, two shots aiming for correct exposures at either end of the scene.
This is the sort of shot where I'd probably just blend two images together with a mask and graduated fill, but using HDR Expose 2 does offer different ways of approaching the problem.
Hopefully that gives a feel for the types of adjustments you can apply to HDR images, in order to turn them into images you can print or display in some way.
You don't have to do this for one scene at a time. There is a batch option in HDR Expose 2, for multiple builds of HDR files (Batch merging).
If you've got a preset that works for a particular set of images, then you can also process those files with it to produce a set of completed, ready to use files (Batch processing).
The tools are comprehensive and allow users to get a real feel for what is involved in mapping a 32-bit HDR file to a usable RGB image.
Perhaps it's because of my own personal tastes, but I found it difficult to produce a lot of images that I really liked - do bear that in mind, when reading some aspects of these conclusions. Some of what might be significant issues to me may be of no interest or concern in your own work.
Modern cameras do have a significant dynamic range coverage, which when coupled with the latest RAW conversion software, can give results that only a few years ago would have needed a multishot HDR approach.
A pair of images - one from three shots using HDR and one with very careful processing of just one RAW file.
I'll not say which was which - this is the sort of thing where tastes differ (and with a paying client, the customer is always right, even when they are not ;-)
Another example using a different RAW converter and single image vs an HDR approach. This is looking down the internal scaffolding inside a church spire.
Here I come up with what is a serious issue for myself.
If I use a particular RAW converter, I can apply geometric and lens aberration correction to my image. The converter is also using advanced demosaicing techniques to convert the Bayer filtered (R,G and B) pixels of my image into the pixel data.
I could use my converters of choice to produce TIFF files for merging to HDR, but that introduces other issues.
The problem is that I've no control whatsoever over how the RAW files I'm using are being processed in HDR Expose 2 - just what is processing those Canon files I'm using?
Look at this example 100% crop from the image above. The highlights are blown out somewhat, even in the shortest exposures, but this could easily happen if you have specular reflections. It's all those false colours that concern me.
With many of my files, I'm pushing to get a lot of fine detail out of my images. The sharpening and noise reduction features of the software are useful, but I feel that some of it should be available at the time that the data from the RAW files is being processed.
I know that HDR files are not actually displayable (it's why you do the tone mapping), but it would be nice if some default option could be used to produce an icon related to the image contents?
A folder full of files like this (produced by a batch process for example) is not easy to navigate - particularly since this lack of preview is extended to applications opening the .bef files. Adobe Bridge for example, won't even allow the files to open in PS, nor can you see what's in them.
There are quite a few minor usability related issues I noted throughout the program, but that's probably because usability research was one of my previous careers, and such stuff just jumps out at me (like the non standard progress bar behaviour - OS developers provide widgets for just this, designing your own isn't usually a good idea).
You might well ask... Compared with many other software packages I've looked at, the amount of useful help available in the program is relatively limited.
There are numerous online video clips available, but I know I'm not alone in finding most video based help a tad irksome when you are looking for a single bit of information about a feature. Sorry, but I want proper written guides, with proper indexes... The quick start guide is useful to get you started but not for detail.
If I save a tone mapped file as a JPEG, I don't get any quality or colour space settings reminders. All this is in the program preferences, so JPEGs default to maximum quality sRGB and TIFFs to 16 bit Adobe98. Whilst these are reasonable choices, it would be good to at least remind people what they are at save time.
The Unified Color web site mentions their 'BeyondRGB' colour space used to handle HDR imagery, but has very little hard information about it, and what there is, is to my mind bears rather too much of the imprimatur of marketing. As someone who does quite a bit of work related to colour management (I'm one of X-rite's 'Coloratti') I'm still at a loss to clearly explain what the real tangible benefits are. There is an interesting bit of technical detective work relating to this, in this forum thread at OPF [Warning - Maths alert]
It does work though... ;-)
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Even though I've some issues with the implementation of this software and lack of detailed explanation, it is capable of producing some excellent images which to my mind pass the test of looking real.
In particular, with good care about acquiring source images it's capable of reducing one of my major issues with 'HDR style' images ... halos around objects.
Be prepared to experiment a lot to find the best ways of getting images you like.
The software is relatively inexpensive ($149) and capable of a lot, but you do need to take care with the quality of your input images.
I should note that since I don't use Aperture or Lightroom, I'm unable to comment on how well the software works with these applications, and whether this has any effect on some of the issues I've found as a Photoshop user, using the standalone HDR Expose 2 software. The quick start guide suggests that some of my RAW processing concerns are addressed.
The software is available as a 30 day free trial from Unified Color, and if HDR is your thing (or you're not sure) then it's worth a try.
HDR creation and editing software, available in different versions from Unified Color.
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