Tuesday, October 26, 2010

Tech Talk Tuesday / HDR Review

 What is HDR???

A technique referred to as HDR, or High Dynamic Range is taking the photography community by storm.  There seems to be two opinions;  it's either the best thing since sliced bread, or, it's so cheating it can't even be called photography!

Briefly and simply defined, an HDR image is the final product of taking several different exposures of the same scene, then aligning and merging them into a single image.

What's the Purpose???  

Why would you do that when our goal should be to get the right exposure for every shot?  The truth is, unless you are photographing a scene with a very limited tonal range, (which would be boring anyway), it's very difficult to get the right exposure for all parts of a scene.    Have you ever taken a shot of a beautiful, colorful, landscape, with your camera exposing for the whole scene, but then are disappointed when you view it on your monitor or in print?   It often seems dull and flat and not nearly as vibrant and dramatic as what you actually saw.  So then you adjust your exposure so the land looks perfect, but then the sky is all washed out.  Next you expose for the sky and clouds, but then the land is too dark.  While your camera can record only a limited tonal range, your eyes can see a great tonal range from white, to grays, to black.  So you can see the deep blue sky, puffy white clouds, as well as a nicely exposed ground.   For years photographers have tried to correct this problem by screwing split level neutral density filters on their lens, with varying degrees of success.  Then in the dark room there was dodging and burning to further correct the problem.  Now we live in a world of sophisticated digital cameras, computers, and programs that give photographers amazing tools to help us more easily correct the limitations of our cameras and help us create beautiful photographs.

Side Note:

Time for a side note.  For all of you who just want to pull out the point and shoot and take a snap and be done with it, you've probably already figured out this post is not for you.   Because the bottom line is that with rare exceptions, most beautiful photography still takes knowledge, planning, and especially time.  Even the photographer who does no post editing, has probably spent many trips and many hours on location until finally he's there when the lighting, sky and foliage are just right for that perfect shot.  Again, beautiful photography takes time even with our modern tools and techniques.

Maybe It Is Better Than Sliced Bread!

Like it or not, HDR is here to stay.....and I like it!  In fact I love it!  Why wouldn't anyone like to create and look at beautiful, vibrant photos and have the tools to do so?  When one is able to see a large spectrum of subtle color changes, and a large spectrum of tonal shades, a flat image (photograph) takes on a 3D effect, looks more real, and well, just looks more like what the eyes would see naturally.  I consistently get far more compliments on my HDR photos on the blog, in print and on other websites than I do on anything else.

A Few Helpful Hints: 

First of all, HDR does not work with all types of images.  It is good with subjects that don't move, because remember, you have to take several identical shots at different exposures.  If your subject moves, or your camera moves, your shots will not line up and your final HDR image will be blurred or have ghosting artifacts.  The current versions of HDR programs help in a limited way to correct slight movement, but to get a really sharp image you need a tripod, (or a rock steady grip),  and a stationary subject.  Also, naturally, HDR works best with scenes where there is a wide tonal range, with light, medium and dark tones and colors.

Next, it's best to shoot in Aperture Priority mode so your perspective does not change during the different exposures.

Another important note is that you will rarely be able to produce a beautiful HDR photo just by using an HDR program by itself.  This is because while creating an HDR image will make most of your scene look beautiful, it will most likely make parts of the scene look terrible.  Don't ask me why because I don't know, but it just does.  The sky, usually around clouds, can be particularly troublesome, with strange artifacts, halos, ghosting, noise, etc.  So here is the most important trick for me to tell you, so pay attention!!!...  After you identify the part of your merged HDR image that looks weird, you need to find one of the original images you used for the merge, where that weird part looks the best, then add that image as a layer to your newly created HDR image.  Then you need to 'erase' the weird portion of your HDR image so that part of the original image shows through.  Then you need to experiment with different ways to blend the visible portion of the original with the HDR image so it looks natural.  I know I've probably lost some of you here, because obviously you need to be able to work in Photoshop and have a basic understanding of how to use 'layers' and 'layer masks' to do this.

One more thing to remember, is after you have created your HDR image, you will probably still need to do some basic tweaking with levels, exposure, color casts, in Photoshop, Lightroom or whatever photo editing program you normally use.

Which Program Should You Use:

With the basics out of the way, you now have to decide which program you will use to help create your masterpiece.  Luckily there are now programs out there to make it easy for us normal folks so you don't need to be a techno geek to create HDRs.  I'll talk about the four I think are worth considering (IMHO); however, I will not give you all the specs, but you can click on the program names below and that will take you to their websites so you can easily get all the info you need :

    This program is endorsed by many HDR pioneers, including Trey Ratcliff, who is arguably the guru of HDR Photography.  If you are interested in learning how he produces his beautiful photographs, he provides an HDR tutorial on his blog HERE.  This is where I started.  He also has a fairly new book out.  This is an excellent program with an excellent interface and many controls giving you seemingly endless tweaks and options for unique looks.   It's a matter of moving sliders and other controls until you achieve the look you are after.  This is the program I am currently using.

    Photoshop CS5 has a merge to HDR function.  At times I can produce decent images, but not consistently.  A real disadvantage is that the merge process is extremely slow.  I rarely use this function, but if nothing else works, I'll give it a try.

    HYDRA 2.2 - $79.95

    This is a new program and claims to have an excellent alignment and anti ghosting algorithm so you do not need a tripod.  It also advertises one can merge up to 10 exposures.  It is common to merge 3 to 5 exposures, and in my opinion, that is plenty to get a good tonal range.  This is a much more simple program with not nearly as many 'bells and whistles' as Photomatix or HDR Efex Pro.  For me, it produced a noticeably different look, and more of an artificial look than the other programs.

    HDR EFEX Pro  - $159.95

    This is also a new program and has everything the above programs have and more.  In other words it has all the bells and whistles to allow you to create endless looks for your images.  It has a very intuitive interface, and an impressive number of visual presets.  One unique feature is selective editing where the other programs are all global editing.

    My Comparisons

    As I worked with each of these programs I tried to create the most natural looking photos I could, working 99% in each particular program.   I didn't do any major altering, like bringing in a layer of one of the original photos, although I did do a small amount of exposure correction on some in Lightroom.  Needless to say, all the programs will create a variety of psychedelic, abstract, artificial looking images, but I suspect most of you are like me, and want your photos to look real.

    Medium Exposure of Originals

    Hydra 2.2

    Photoshop CS5

    Photomatix 4.0

    HDR EFlex Pro

    The first set of photos above are of an extremely wide range of tones and colors.  I stood out on my deck in the morning and shot toward the east with the sun just out of the frame.  (Did you know that sometimes you can shoot directly into the sun and end up with a very interesting HDR shot?)  Anyway, I wanted to see how these programs handled extreme light and extreme dark.  Notice the differences in how these programs handle the sky, the color variations and the lens flare.

    Medium Exposure of Originals

    Hydra 2.2

    Photoshop CS5

    Photomatix 4.0

    HDR EFex Pro

    Clouds and 'ghosting' are particularly troublesome.  In the above set of shots, the wind was blowing and the clouds were moving fast, so they were not in the same place in all the exposures.  Notice the ghosting on the left side of the cloud in the Hydra and Photoshop photos.  Using the function to help eliminate ghosting in the Photomatix photo helped, but as you can see, made that portion of the cloud faded and dull.  The HDR EFex Pro shot altered the ghosting in a different way, but still noticeable. 

     Medium Exposure of Originals

    Hydra 2.2

    Photoshop CS5

      Photomatix 4.0

    HDR EFex Pro

    In this final group, the original is good.  This was taken in my great room with a fisheye lens.  As you can see, the left wall is covered with windows letting in really bright light.  I wanted to see if these programs would pick up any of the details on the deck in the bright morning light.  Also notice the color variations.


    Well, first of all, since I love HDR, any program that helps you create a beautiful image is better than none!!!!  Second, since my experimenting with Hydra and HDR EFex Pro is very limited, my opinion may or may not hold much weight.  But, in my humble opinion, the HDR EFex Pro was the most versatile, easy to use, and fun program.  The interface is easy to use and allows unlimited ways to tweak your image, and it is just fun to see how all the presets change the look and feel of your shots.  Maybe you'll find a look that really works that you didn't know you could achieve.  I may consider purchasing this one.   PHOTOMATIX 4.0 is still an excellent program and produces amazing images.  It has a new interface with 4.0 that is more user friendly and also comes with some visual presets as well.  HYDRA 2.2 does a passable job but I had to do lots more tweaking to come close to what I wanted my images to look like.  The interface is extremely simple and simple to use with fewer controls and sliders.  PHOTOSHOP CS5 will also produce passable images, but again, I had to work a lot harder to produce what I was looking for, and another real downside for me was that it takes forever to render or merge your originals into the HDR image.


    Sorry, I can't make that decision for you!  A start is to study the above examples to see if the images processed from one program look better to your eye than the others.   But just looking at my few examples is not enough.  You should also look on the internet for other reviews of these programs.  And cost may be a factor.  But how easy each program is for you to use and how you like the results are the most important factors; and, the really good news is that you can download HYDRA 2.2, PHOTOMATIX 4.0, and HDR EFEX PRO for free and give them all a test run before you decide.




    Hopefully this review has piqued, (thanks Rick), your interest in HDR.  The bottom line is that it is no longer a complicated, technical process reserved for a few techno geeks.  Anyone can achieve beautiful images with one of these programs and a little knowledge and some time.   This review has been 'bare bones' and only a beginning, but I hope you've learned something about HDR. 

    It would make my day if some of you are willing to download a free trial version of one of the above programs, create your first HDR image, and email it to me.  If there are any brave souls out there, I'll publish your images on my blog and link back to your blog!  (Deadline is November 10.)

    I'd really like your feedback.... has this post been useful and would you like me to continue doing similar posts (it is time consuming), or would you like less words and just more of my images??