The HDR debate goes on - how much is too much?

Reading through another debate on the HDR flickrgroup - I had to laugh - throughout history fear of change and anything new has always been prevalent.

Portrait painters thought photography wasn't real portrait work because a camera was used.

Fast forward to a generation of film photographers calling DSLR users "computer operators." I still get told I'm not doing photography. They may be right, but that has little to do with it being a digital camera.

Then what is and isn't an HDR. These type of debates will go on as long as someone is afraid of anything different.

Beauty is in the eye of the beholder. If it doesn't look good to you, go on to the next one.

Tonemapping is a dial we use to render an HDR so it can be viewed on an RGB monitor. How high and far we turn that dial is based on what looks good to the person tonemapping the image.

For those who want to rigidly define what is or isn't ... or how far you can turn the above dial, please go lock yourself in that cage and enjoy it.

Meanwhile if I see something I enjoy seeing, the last thing I'm going to do is relegate it to someone's defined subgroup.

I don't like some of my own HDR's but I post them to get feedback on them. The reviews have been mixed and thanks to a few I've made some improvements I believe in what I do.

Lastly someone who 'hates HDR's" is going to anyway no matter which one he or she is looking at. That's the thing about opinions - everyone has one - and they DO vary.

Enjoy what you see, life's too short not to.

My next posts will be on hand held tips and then tonemapping and or processing and may be broken into parts to keep it from being too lengthy.

The image at the start of this post was hand held using the car lot's fence as a pivot.

What is an HDR Part 2 - the shoot

How to take the pictures for an HDR



HDR Photography

HDR Photography Creating high dynamic range images involves a little planning and setup time, but the results can be wonderful. Here's a step-by-step approach to help you ease into creating HDR images.

1. Bracketing
Setup your camera to bracket 3 or more images. Ensure that your bracket covers the entire range of light that is present in the scene.

2. White Balance
Set your white balance to whatever the scene requires, but don't use auto.

3. Mount the camera on a tripod.
Having a stable base for your camera is very important and means less alignment issues in post productions. While hand-held HDR is very possible, and many people create very successful images with this technique, having a sturdy tripod will give you the best results. If you have a model in the scene, just ask them to hold as still as possible for a few seconds.

4. Cable Release
Attach the Cable release, or set the camera to use the self timer. You do not want to touch the camera at all. Even the slightest movement can cause alignment issues with your final images.

5. Switch the camera to aperture priority and make your aperture F8 This step is only to give you a direction in where to begin, let me add that some people prefer to actually shoot at smaller apertures, experiment, and adapt this step to your workflow.

6. Mirrior Lock-up
When bracketing your shutter speeds may get very slow and the mirrior can cause vibrations that blur the image. Mirrior lock-up helps you to avoid the mirrior slap that creates this.

7. Shoot
Now, just take your series of photographs! You have successfully just captured a set of images that will merge into an hdr picture

What is an HDR?

What is an HDR?

There is a debate on in the various HDR Flickr groups, in fact, all over the internet as to what an HDR is or is not. If you want to get into it you can the technical opinion and debate here:

discussion

Flickr photographer with a lot of links about HDR

I'm going to attempt my take on it based on my experience using HDR files at work and at home.

We probably should define it first - the following is from wikipedia - "In image processing, computer graphics, and photography, high dynamic range imaging (HDRI or just HDR) is a set of techniques that allows a greater dynamic range of luminances between light and dark areas of a scene than normal digital imaging techniques. The intention of HDRI is to accurately represent the wide range of intensity levels found in real scenes ranging from direct sunlight to shadows."

What?

Okay let's try this again from a photography point of view:

Photographers use "dynamic range" for the luminance range of a scene being photographed; or the limits of luminance range that a given digital camera or film can capture; or the opacity range of developed film images; or the reflectance range of images on photographic papers.

Graduated neutral density filters are used to increase the dynamic range of scene luminance that can be captured on photographic film (or on the image sensor of a digital camera). The filter is positioned in front of the lens at the time the exposure is made; the top half is dark and the bottom half is clear. The dark area is placed over a scene's high-intensity region; usually the sky. The result is more even exposure in the focal plane, with increased detail in the shadows and low-light areas. Though this doesn't increase the fixed dynamic range available at the film or sensor, it stretches usable dynamic range in practice.[14]

In the domain of digital imaging, algorithms have been developed to map the image differently in shadow and in highlight to better distribute the lighting range across the image. These techniques are known as high dynamic range imaging.

Whoa way too technical!

See this isn't easy - here's still another - no less obfuscating:

Dynamic range is a term used frequently in numerous fields to describe the ratio between the smallest and largest possible values of a changeable quantity, such as in sound and light.

On imaging it refers to the ratio of the highest and brightest color tone value to the lowest.

For example, a good quality LCD display has a dynamic range of around 1000:1 (commercially the dynamic range is often called the "contrast ratio" meaning the full-on/full-off luminance ratio), and some of the latest CMOS image sensors now have measured dynamic ranges of about 11,000:1 (reported as 13.5 stops, or doublings).[1] Paper reflectance can achieve a dynamic range of about 100:1.


The above comes closer to what I know - the ratio of the darkest part of an image to the lightest.

Cameras - film or digital - can typically provide a 6 f-stop range of light values accurately before it begins to peak at white or black. HDR's attempt to broaden that ratio of dark to light past the point of what your camera interprets.

The image above was a black car reflecting a very bright sky on mostly clear day with a few clouds in the sky. So there was a broad range to begin with. On the image below the afternoon sun lit up the boat while the restaurant and dock cast it's shadows on the water.



So this is a technical definition of what an HDR is - a tonal ratio covering the entire range of light in an image from darkest to lightest.

I'm going to publish this and then go on to how to shoot an HDR my way(s,) in a future post. In my next post I'm going to talk about tonemapping, HDR's, and Single Image RAW file processing.

Venice Pier Ortons and more ...

As some of you may have gathered, I like taking pictures at the Venice Pier. Especially sunsets!



This started out as 3 exposures from my point and shoot Canon G7. I've hacked this camera to produce RAW files by using CHDK or the Canon Hackers Development Kit. Other extras include expanding the F-stops to F11 (normally the smallest hole on this one is F8.)

CHDK also gives one the option of converting to a digital negative (DNG) in the camera. This raw file goes anywhere and I loaded the 3 exposures into Lightroom. In Lightroom I changed the white balance to Tungsten on all 3 and duped each of the RAW's. On the duplicates I changed the white balance to Florescent. I also added Clarity, Vibrance, and a little Saturation. I now have 6 16 bit files - 3 each of the autobracketed sets with two different white balances. I use Lightroom's export to photomatix plugin and combine all six into one HDR in photomatix.

Tonemapping is done there and I usually use strength, Saturation, Light Smoothing, Microcontrast and White Point adjustments only. On darker images I'll look at Luminosity and Gamma. Also large cloudless skies really benefit from microsmoothing.

Now I save out a .tif and I'm ready for photoshop. In photoshop I like to tweak the levels, and run a noise removal filter. I've often through the kitchen sink at a file in the way of filters and plugins but this time the Orton method mentioned in earlier posts was used. I've described that method here.

I went two ways with this one. First I like playing with Redfield's plugin Fractalius. I've still learning this software but if you reduce your image size before you experiment, it's much more interactive. I went with one of the glow presets on a duplicate layer. I then changed the blending mode for this layer to Screen and flattened the image. This resulted in:



Then I went back to the Orton shown at the top of this article and made bubbles out of the entire image and comped them on top. No special filters for this as it is straight photoshop out of the box distortion. I lined them up like I thought they would be floating in and altered the transparencies making them more transparent the farther they were "away." You might have seem this already here:



So I went overboard on this but it was fun. The sunset was one many great ones we had this winter on February 20, 2009. Any questions, let me know here or on Flickr.

Michael Orton's Sandwich Digital Style

Orton imagery, also called an Orton slide sandwich, is a photography technique which blends two completely different photos of the same scene, resulting in a distinctive mix of high and low detail areas within the same photo. It was originated by photographer Michael Orton. This is from a Wikipedia article about the Orton Technique.

Wikipedia provides you with some examples and then goes on to say:

"Photography enthusiasts, such as groups on Flickr, have embraced the technique and used photo editing programs, like Adobe Photoshop, to replicate it. Some have modified the technique to selectively apply the technique, producing images that have regions of crisp focus and high detail and regions of intense blurriness."

I have written about Orton's before in this blog about Orton images. That article did go through the steps of making the image that article was referring to but I've adjusted it since then.

I've now reduced the Gaussian Blur step to a radius of 3 pixels.

Also I now have a photoshop action which automates the steps. When I figure out where to upload that action I will.

The image at the top had a serious hot spot above where the sun was setting. Any saturation of the image at all resulted in serious banding. Since this was the sky of course I didn't want that kind of sharpness.

So from my previous article here are my Orton steps again:

The digital version starts by duplicating layers in photoshop, then duplicating the top layer again. I then change the blending mode on the very top layer to Screen. I merge down and duplicate this layer again.

Now I take the top layer and sharpen and sharpen edges using those basic photoshop filters. (This step by the way was added thanks to the tip by Chris Anderson) I change the blending mode on this top layer to multiply. I then go down to the second layer and use a Gaussian blur.

This is where I've changed also on advice by Chris Anderson, as I wrote above I now use a much lower blur radius.


Dynamic Photo Hdr Orton Filter option



Mediachance has released Dynamic Photo HDR version 4 which includes an Orton color filter which you can use during the tonemapping your HDR step.

This is pretty much a push button and select method as there are no blur or sharpness controls, and no control over the sandwich layer blending. It does have Black and White, Sepia, Sky and Hard Light presets but they're all automated.

So you either like the result or you don't. In this case immediately above I did.

For me either method served the purpose of removing the serious color banding in the sky, however. It comes down to whether or not yoiu like what you see.

Maserati for sale

There's nothing like a black car for reflections in an HDR image.

This Maserati is for sale at the corner of Lincoln and Washington in Marina Del Rey at Platinum Motors. Only $70K and it's yours!



I made the HDR from 3 hand held exposures. Once again I had to use CS4 for alignment of the 3 frames. CS4 has good aligning tools for handheld shots.

I tonemapped the resulting HDR in photomatix. I usually use most of the top half of the enhance detail tab pulling the dials back and forth and seeing what looks best. This file was no different.

I used photoshop then to adjust color levels and even out the exposure. I also used noiseware to tone down the noise levels. After this I used Nik Color Effects to tonal adjust some more. This one probably has been processed over the top.

This image was uploaded and then I ran Fractalius on the result.



First I dup the layer. On the duplicated layer I run Fractalius, using the glow 80 preset.I select the canvas and copy it. I then create a mask for the layer and paste what I copied into the mask. This allows the original image to show through.

I flatten it and what you see above is the result,

Pink Skies In January.

Looking east over the Los Angeles basin during the last hours of daylight often shows a pink ambience to the sky and city beneath it.



It happens every winter in Los Angeles. It's caused by a combination of recurring events. The sun's position changes during the year as we all know and in the winter it is at its southern most position. The sun sets around 5pm in Los Angeles in January and still before 6 in February. That combined with the suns rays travelling through the atmosphere and the dirt in Los Angeles' atmosphere produces this pink color this time of year.

This is from January 10 of this year.



It is the same every year. This is college crew team rowing in the same area in January of 2007.



Actually it's not just January but early February as well. Here's one from February of 2008.



This was shot on the back of the Santa Monica Pier. The crosses on the beach are for the dead U.S. soldiers in Iraq. This is about the sky though and NOT intended as a political statement. There are other blogs for politics all over the internet. All I was intending here was to show the eastern Los Angeles sky as being pink in the winter.

White balance does come into play of course as I tend shoot on the blue side more often than not. However warming up the white balance only makes it appear more towards orange but pink just the same.

A little bit on processing - generally I use photomatix to generate HDR's unless the alignment is terribly off, then I use Photoshop CS4. In the last two I used lightroom to generate multiple EV's for the HDR as each was a single RAW file. All were tonemapped in photomatix and edited in photoshop for exposure, sharpness and noise removal.