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Monday, October 30, 2006

The Definitive Guide to Realistic High Dynamic Range Images





We have all seen them. The alien worlds. The velvet paintings. The collision of photography and flamboyant computer graphics effects.

This tutorial is none of those things.

This tutorial will attempt to demonstrate how to make a realistic HDR, one that is virtually indistinguishable from a single exposure. The biggest goal is producing a tutorial that can stand as a standard by which anyone can learn to create a balanced HDR. Ultimately, the processing choices are yours. These are the building blocks.

Before we start, some background about high dynamic range (HDR) that are often misunderstood or misconstrued. HDR is two or more exposures, and in many cases, more is not necessarily merrier. For simplicity's sake (Occam's Razor), use only the minimum number of exposures to cover the dynamic range of the scene. Today's auto-bracketing features allow for a neutral image, plus an exposure on either side of the neutral image (±1/3 stop to ±2 stops). A proper exposure on a decent digital camera covers about six stops of information; bracketing at ±2 renders approximately twelve stops of information. That is enough to cover all but the most extreme circumstances, like shooting into the sun, or interiors with wild lighting.

HDR is not a new fad in media--HDR has been used in cinematography since the days of Westerns. Any time the cowboy rides off into the [perfectly exposed] sunset where all the foreground is also perfectly exposed, that was HDR. Including artists of paint and pen, HDR techniques have been around for centuries.

Terminology with respect to HDR, while minimal, can be rather touchy. The two biggest issues are high dynamic range imaging and contrast. High dynamic range imaging is a technique to bring out the details in both light and dark extremes of an image. Contrast is more confusing. Local contrast is the contrast between adjacent components within the photo. A high local contrast will increase the perceived contrast of the entire image. A common complaint is that HDR images have less contrast than single exposures. Of course they do! The shadows and highlights are being expanded, then compressed into the same eight bit dynamic range as any other RGB image. However, with skillful processing, increasing local contrasts in the image will go a long way towards making the HDR merge amiable.

Enough rambling. On with the tutorial!

Materials

Canon 20D;
Three auto-bracketed exposures: -2 EV, ±0 EV, +2 EV;
Adobe Photoshop CS2 (Photoshop 9.0.x).

Outline and Procedure

I pondered long on how best to demonstrate this technique. First, I thought that just a run-of-the-mill, step-by-step tutorial would be easiest. Then I realized that my plug-and-chug tutorial would not offer any more insight than any other plug-and-chug tutorial. So I decided that I would take the three-exposure bracketing of the Canyon de Chelly (pictured at top), and make the plus and minus two exposure value frames, respectively, look "exactly" like the perfectly-exposed middle exposure. So, basically, I am taking the -2 EV and +2 EV frames, and merging them to look like the 0 EV frame.

"But, Mr. Leviathor!", you say, "You just said that HDR images can't look like single exposures and you said that you were going to make them look 'exactly' like one another!" Well, through the magic of Photoshop, I will get it pretty darn close. Noticeable in the HDR will be extra details in the shadows, and some richening of the highlights. Spending a lot of time to make an HDR look realistic is not always required--I just had an original to "copy". Now would be a good time to mention that I used both a circular polarizer and a two-stop graduated neutral density filter. Did I need to process this as an HDR? No, and I typically would not--in fact, I would advise against it. However, this is purely for demonstration. For posterity, if I did not have a GND filter, I would have had to use HDR.

First, navigate to File > Automate > Merge to HDR.



This will open a dialogue box which looks similar to:



1 & 2. "Use" files allows you to browse for the RAW files you want to use. "Folder" looks for a folder (surprise!) with RAW files to merge. "Open Files" uses the RAW files already opened in CS2.

3. I only use "Automatically Align" when merging handheld images. Aligning the images takes significantly longer than merging without alignment.

4. OK! Which will bring up this window:



I used a smaller zoom and cropped out some of the dead space to make the image a more manageable size. Visible here are:

1. The source images. Prep work in Adobe Bridge: I ensure that the temperature and tint values for all the to-be-merged images are the same. I uncheck all the auto-correction boxes. I never use Bridge's sharpening algorithm. Now, you will notice that PSCS2 made the darker image 0 EV and the lighter image +4 EV. You will notice, however, that one is overexposed, and one is underexposed. For whatever reason, Photoshop will always put the darker image of a pair at 0 EV. It does not do this for three exposures.

2. Preview of the 32-bit merge of the 16-bit originals.

3. Gamma-adjustable histogram. CS2 does a very good job of picking a proper gamma. If you desire to change it, you may. In fact, I encourage that you play around with it just to see what happens. If you want to reset it, just press the ALT key (PC) and press the Cancel/Reset button.

4. Whee! Next, convert the image to a modifiable 16-bit image:



Image > Mode > 16 Bits/Channel.

This is where the magic happens. Getting this part right will go a long way towards making your image shine. If you made mild mistakes earlier in the process, they can be partially recouped in this step. But, like photography, starting with a better image will make processing easier and the end results more stunning.



1. Method. The algorithm by which the image will be processed.
a. Exposure and Gamma: This will allow you to adjust the brightness and perceived contrast.
b. Highlight Compression: This is a one-click algorithm which compressed the highlights into a 16-bit range (or 8-bit).
c. Equalize Histogram: Equalize histogram compresses the highlights and shadows while preserving contrast--the quickest and easiest way to create realistic high dynamic range images. I am using it in this example for ease.
d. Local Adaptation: My favorite. Manually adjust the tonal range of the HDR image via a curves-like algorithm over the image's histogram. Also has threshold and radius adjustments.

2. Toning Curve & Histogram is only usable in Local Adaptation. I keep it open, because I typically use Local Adaptation, and I like to see what sort of information I am dealing with.

3. Zing!

Somewhere between processing and making screenshots I lost the original processing of my single exposure, so I had to reprocess it. I'm not quite as happy with these results, but they get the point across.

Single-exposure:



HDR composite:



Conclusions

Mastery of Photoshop is not required. First and foremost, master your camera. Understand that exposing correctly is important. Expose such that your 0 EV exposure is exposed right, then include the highlights and shadows (±2 EV, typically).

The second thing to keep in mind is self control. Often time the difference between a great HDR and a flop is too much: Too much saturation. Too much contrast. Too many highlights or shadows. Don't work hard to save detail in the extremes, only to erase it again with heavy-handed curves or shadow/highlight adjustments.

Understanding that HDR does not save failed images. A failure is a failure. Period. It is harsh, but it is also reality. Additionally, HDR, when used improperly, can ruin successful images. It happens all the time.

Finally, it is possible to create rather spectacular HDR images that look like a single exposure.

Leviathor's Photostream

Leviathor's Group

Magic Donkey Group

PS. If wanting to duplicate or reproduce any part of this, please contact me (through Flickr, preferably). I consider this a body work, much like the photographs before you.


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Saturday, October 21, 2006

Awesome Flickr Pictures.

If you see a picture you really like, and want to see more of that artist, just click the picture and you will be taken to their photo stream

Enjoy.


There is no doubt that the slide show above has some of the best photographers in the world. I challenge you to click the picture and sit back and relax, for one of the most awesome shows on the internet.


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Colorful


Colorful
Originally uploaded by Perikita.
This wonderful bird photo was take at the Hamburg Zoo in Germany, by Irma, (Perikita).
She is originally from Mexico and now resides with her husband in Germany.

Her photography is next to spectacular and I have been following her contribution to her photo stream for quite sometime. We are very honored to have her as a part of group, MagicDonkey


From her profile:
---------------------- September, 2006


So... I think it is time to upgrade my profile, again... :)

With a bit or a lot of luck I had the chance in September this year to upgrade my photography gear...

I got a beatiful Canon 5D and three Canon lenses: 24-105 mm f4 EF-L, 100-400mm F4.5-5.6 L, and 180mm f3.5 L Macro...

All my pictures are taken in RAW format and I use RawShooter and CS2 for my post processing...

Photomatix is one of my programs to work with HDR images and NeatImage my program to reduce noise and give the final touch to my pictures when it is needed...

Still learning how to take beautiful pictures, so if you have any comment to improve my photography, feel free to comment... I would appreciate it much...


---------------------- August, 2005.

My husband wanted to upgrade his camera gear and he gifted me what he was working with... A D70!! Can you imagine how happy I am now!

I want to learn more and more and take beautiful pictures... after all a good camera doesn't give you beautiful pictures...


---------------------- February, 2005

One day in late February I went to the garden and I broke my camera this is the last picture I took with my Olympus C-3000. Ah! How much I miss those colors... :(

My husband bought me as a birthday gift a Panasonic FZ20. It has been great to play with it.


---------------------- November, 2004.

I am Mexican, but I live in the northern part of Germany. I got interested in photography when I got as a gift a digital camera in September 2004. I am learning how to take beautiful pictures. So, if you have any comment to improve my pictures it will be very welcome.




To see Irma's photo stream.

To see a slide show of the best of flickr.

To go to the MagicDonkey home.


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Tuesday, October 17, 2006

Amur Leopard


Amur Leopard [2]
Originally uploaded by Edgar Thissen.

Edgar Thissen comes to the MagicDonkey group from Rotterdam, The Netherlands. While he is a new associate of mine in the craft of photography, his pictures portray a quality that is seldom equalled. His compositions are excellent, and many center on nature and landscapes. But he does not limit himself, throughout his photo stream can be found wonderful portraits, and spectacular creative efforts.

His photo Amur Leopard was recently promoted to the 25 percent MagicDonkey Solution and we are honored to have this best of the best photographs in that exclusive pool.

From Edgar Thissen's commentary:

The Amur leopard (Panthera pardus orientalis), whose habitat is currently confined to the Sikhote-Alin mountains, is the northernmost subspecies of leopard. It is also known as the Far-East leopard and the Siberian leopard. It is extremely close to extinction, with only about 35 still living in the wild. Habitat destruction and the fur trade have diminished its numbers dramatically.

Although their range overlaps with that of the Siberian tiger, their population is not as heavily affected as it is for other leopards and tigers in different regions. Amur leopards tend to avoid living or hunting too close to tiger territory to avoid direct competition for prey.
Like all leopards, they are very skillful and opportunistic hunters, though their usual diet consists of roe and sika deer, hares, badgers and smaller rodents. They are solitary animals with primarily nocturnal habits.

They stand apart from other leopards in their longer fur and legs, probably to better cope in the harsh, cold conditions of the taiga. They also have larger and more widely spaced rosettes. Their fur lightens to a pale cream during winter, but is more golden orange during summer. During the summer, their fur is usually about 2.5 cm long, but during winter, their fur is around 7 cm. Males are about fifty percent larger than females, and their weight ranges from 65 to 155 pounds.

While the Amur leopard inhabits the same area as the Siberian tiger, it has received far less attention from the media and from charities. The Amur leopard is the rarest of the big cats, and is in danger of dying out in the wild. They are suffering from habitat loss and are especially vulnerable to natural disasters, such as fire, because of their fragmented range. Amur leopards prefer to live in forested territory, but most of the forest in which they live is surrounded by farms and villages, making poaching easier.

from: Wikipedia
Taken @ Blijdorp Zoo, Rotterdam

To go to Edgar Thissen's photostream.

To see a slideshow of the best of Flickr.

To go to the home of MagicDonkey


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Sunday, October 15, 2006

Fall vs Sunset


Fall vs Sunset
Originally uploaded by Fort Photo.

I have appreciated the photography of Fort Photo for quite some time. Here is one of his efforts with HDR and we are pleased to say is part of the MagicDonkey Group.

One thing I have always appreciated from this master photographer is his commentary that can be found with each photo. Here you will learn about ecology and history about the photos he takes in the Midwest of the United States. Delve in to his photostream you will not be disappointed.


From his profile:

I find a large chunk of photography that I do could be labeled as nature photography and really it's no surprise. Conservation biology is a central area of interest for me, which is reflected in the subjects I chose. Photography can pair well with birding and botany, two other activities I also have a great time doing.

Often with my photography I hope to evoke the same sense of childhood wonder and appreciation for nature that experiencing it first-hand instills in me. I hope you find my images to be a fun diversion.

Fort Photo's photostream on Flickr

MagicDonkey Group Home where you can find the best photographers in the world.

Sit back and be awed with a slideshow presentation of the best of flickr presented by MagicDonkey.


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Saturday, October 14, 2006

Fluidness*


Fluidness*
Originally uploaded by imapix.
Gaëtan Bourque, (also know as Imapix), is one of the greatest photographers on Flickr. This is a deserved complement with reason. You only have to look through his photostream to see awesome picture after picture.


This one that he was so nice to share in our group has the caption:


n. *Fluidness1. the property of flowing easily.
Water & Color Fluidness, Petit Lac Cache, Mont-Tremblant National Park, Quebec, Canada.
Fixquote:"To take photographs is to hold one's breath when all faculties converge in the face of fleeing reality. It is at that moment that mastering an image becomes a physical and intellectual joy."-Henri Cartier-Bresson


His stylized descriptions conform to this format, and adds interest beyond the image itself. If you are new to Flickr one of your destinations should be right to his stream. I learn much by excellent use of composition and vividly vibrant photos.
Gaëtan is gifted in other ways also, and is excellent in his use of many languages. He is a true communicator of wonderfulness.

To see his photo stream go here.

To see the best of Flickr by other artists come to our group.

To be awed by a spectacular slideshow of the best come here.


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Friday, October 13, 2006

How to See the Best Photos from MagicDonkey





Welcome, we are determined to show you the best of the best photos on flickr. And we have made a great start by finding some of the best photographers in the world.


There are several ways to us this blog to find the best. One is to go to our slide show presentation. There you will be awed by the fantastic images by this excellent group of photographic artists. Just click the picture and you will be lead to all of the work of that individual photographic artist.

Another way to see the best is to go to the group pool itself. Here you can quickly go through the thumbs and check out some of the most amazing photographs in the world.

On our sidebar now is a constantly updating display see something you fancy, click the picture and you will also be lead to that persons wonderful photos.

Have fun exploring you are about to see the best of the best.

Photo displayed on slideshow is from Jeff Clow another outstanding photographic artist in the MagicDonkey group.


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Moonlight of Gold


Moonlight of Gold
Originally uploaded by `Bobesh.


Pete is one of best photographers on flickr, if you read his profile you can see he almost accidentally got started with photography. He has been featured on the Explore Front Page and his photography is amazingly, excellent.

His moon compositions are some of the first of his photos I saw of his on Flickr. Here is a pointer he left others on flickr about photographing the moon.


"There is a great website (Geoscience Australia) that computes the Moonrise and Moonset times at any specific location (as long as you know your latitude and longitude), it also computes Azimuth and Elevation of the Moon at any given time."

"That's how I knew the Moon would be falling just on the other side of the lake at 5:04 this morning. "

From his profile:
Nothing really interesting about me so I may as well just mention how I found my way to Flickr.

To cut the story rather short : just before my trip to Germany for the World Cup in Soccer (Football), I decided it was just about time to purchase some decent camera.

Nikon D200 just arrived to Australia hence it was easy to make up my mind. Unfortunatelly all shops were out of stock and I went overseas without a camera. I still enjoyed the World Cup and forgot all about the cam until I accidently bumped into it at the airport in Dubai on my way back home (in July '06). Well I bought it although I have to wait another 4 years for the next World Cup and I'm not sorry, 'coz in the meantime I'm having great time learning how to use my first DSLR.

Next, I found Flickr to be a great source of information and ideal Photo sharing enviroment.

Pete's Photostream on Flickr

Where to find the best photos on Flickr

Slideshow of the best of the best on Flickr


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Thursday, October 12, 2006

Encapsulated


Encapsulated
Originally uploaded by algo.
Alex is one of the best traditionalist photographers on flickr, and one of the ones that I am familiar from the start of my posting here myself.

He is truly talented, and with a quick wit. In my back and forth comments with him, we have had frank and playful debate if HDR is a graphic medium or not.

Please be sure to check his stream (by clicking the picture) for some of the most fantastic images on the Internet.


algo's photostream on Flickr

MagicDonkey's Home on Flickr

SlideShow of Flickr's best


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Wednesday, October 11, 2006

mirrors


mirrors
Originally uploaded by FreeMySoul.

Welcome to our new group blog, it is still under construction, but quickly developing as we move along. The photo you see is one of my favorites and one of the many fantastic images that can be found on our group page:

MagicMonkey

The photo is by Free my soul. Her caption reads:

Most people are mirrors, reflecting the moods and emotions of the times;
few are windows, bringing light to bear on the dark corners where troubles fester.
The whole purpose of education is to turn mirrors into windows.

Sidney J. Harris


To see more of the best of what flickr has to offer go to:

FreeMySoul's photostream on Flickr

MagicDonkey's Home on Flickr

SlideShow of Flickr's best


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