Mesa Arch

Hey All, I just got back from a trip to Canyonlands and Arches National Parks in Moab Utah. I was able to get a fairly good image of Mesa Arch, which is one of the most spectacularly photographed natural arches, period. Here is one of my first developed images, click on image for larger view:

In order to get this shot I had to get up at 03:30 in the morning, drive an hour from Moab, hike ten minutes, and then setup in the dark well over an hour before sunrise. I figured that I would be the first to arrive, I figured wrong. These people were there before me:

The man on the extreme right and his wife were attempting to make a time-lapse video and had set up in a position that prevented anyone else the ability to setup in the ideal positions, close and wide angle. I tried to explain to him that keeping people out of his view would become increasingly impossible but there was a language barrier, I believe they were from France.

As more photographers showed up his perspective was completely blocked and they packed up and left the area, and not in a very good mood. Sorry but no photographer who makes a pilgrimage to this site this early in the morning is going to stand by and be preemted by any single person. Even if it were Steven Spielberg taking the video he would have had a difficult time and would have needed deep pockets to keep the other photogs at bay. Here is a shot as I left the area, the French couple were set up near the backpack in the foreground:

Here is a long exposure of the arch when I arrived a little over an hour before sunrise, the arch was light painted with my LED headlight:

This photo was somewhat inspired by a chosen National Geographic “Photo of the Day” image which was most likely chosen because it was a medium format film image rather than it being a well composed and executed image. The photographer is actually quite talented and has a very good portfolio of medium format images on his own website.

Why National Geographic chose this one is somewhat beyond me. Note the overexposure of the Sun and its surroundings, the lens flare overpowers the arch, the brightness of the Sun draws attention away from the subject which, presumably, was the arch itself. Not a very good composition or technically executed exposure, the photographer obviously knew this since he diverted the attention of the viewer, in the description, to the lens flare. Here is a link to NG’s site: Photo of the Day; Mesa Arch, Canyonlands

You do the comparison. The only over exposed area in my photo above is the Sun disk itself, the clouds and mountain areas around the Sun, as well as the near canyon features, have complete details, only able to be accomplished using multi-exposure HDR techniques.

I will be busy processing the rest of the images from this trip and will post new galleries in the near future, stay tuned…

HDR Math Revisited

To just add a few comments about yesterdays HDR Math post. One of the main reasons that photographers go to such great lengths to properly control and diffuse the lighting in their studios, is to reduce the dynamic range of their subjects. By using very bright lights and carefully controlling the amount of light that spills back into the shadows effectively reduces the dynamic range such that there are no losses of any details.

Secondly one of the reasons that the time periods around sunset and sunrise is called the golden hour is that, in addition to being a warmer color light, it is also a lower dynamic range of light which allows for the camera medium to capture most all of the details in such a scene. Also midday sunlight is often described as harsh light and it is often blamed for washing out colors when in fact this light easily produces scenes that simply exceed the dynamic ranges of the digital sensors or film chemistry mediums available.

This is also the same reason why most professional photographers will head for the shade in order to get their money shots and also why they will often use reflectors to back fill the shadows, even in the shade. This is also why scrims or neutrally colored opaque screens are often used to diffuse the direct harsh sunlight. Have you ever noticed that huge white screen above the morning show anchors as the cameras back off for a commercial on a brightly sunshine lit morning? They are simply reducing the dynamic range of the scene.

Also the reason many photographers and videographers use neutral density gradient filters is for artificially reducing the dynamic range of the scene by simply reducing the amount of light reaching the sensor or film from the sky portion of the composition. While I am a big fan of corrections in camera I think multiple exposure HDR is one area that, in the right hands, is potentially superior in post processing corrections.

HDR Math

OK, it seems as if there is some confusion as to the math involved with HDR and its intended original purpose. I’m speaking of realistic HDR as opposed to artistic HDR where the HDR program algorithms are used to produce surreal or artistic effects. First we must explain the term Dynamic Range. Dynamic range is defined as the ratio between the largest and smallest possible values of a changeable quantity.

For instance the human eye can differentiate between the lightest areas to the darkest areas with a ratio of about 100,000:1. In other words we can see details in the darkest shadows that are 100,000 times darker than the brightest areas in a scene. Actually our eyes are not that sensitive, our vision is actually quite dynamic, our eyes will actually scan a scene and then our brains process the different areas and combine them into what we interpret as a complete scene.

This is also why it is in the literal sense when the claim is made that realistic HDR comes closer to what our eyes actually see than any single image from a any digital or film chemistry could possibly ever produce.

So what ratio can a typical digital image produce? Lets simplify things a bit and only consider the luminance or greyscale representation of all visible light using a digital sensor, current digital sensors are measurably more sensitive than any film chemistry available. The JPEG image format is an eight-bit per color channel format so the highest possible dynamic range is $2^8$ or only 256:1, that is roughly ${1}/{400}^{th}$ the dynamic range of our eyesight. With the best professional cameras that use a RAW image format the bit depth used is fourteen bits. This translates to $2^{14}$ or 16384:1 which is still less than $1/6^{th}$ the dynamic range of our eyesight.

I’ll repeat this very important fact: The best professional digital sensors have a dynamic range that is less than 1/6th that of our eyesight. So what bit depth would be needed to match our eyesight? Simple, a minimum bit depth would be seventeen coupled with a currently unavailable digital sensor would do the trick. $2^{16.61}=100,000$. For those of you who have been paying attention the powers of two translates directly into Stops or Exposure Values (EV’s) commonly used in photography.

Here is a table showing the dynamic ranges: (from Wikipedia)

Factor (power) Decibels Stops (EV’s)
1 0 0
2 3.01 1
3.16 5 1.66
4 6.02 2
5 6.99 2.32
8 9.03 3
10 10 3.32
16 12.0 4
20 13.0 4.32
31.6 15 4.98
32 15.1 5
50 17.0 5.64
100 20 6.64
1 000 30 9.97
1 024 30.1 10
10 000 40 13.3
100 000 50 16.6

In reality the actual sensitivity of a digital sensor is only about eleven or twelve stops under carefully controlled ideal laboratory conditions. Ansel Adams with his Zone system usually only includes ten stops or EV values for the maximum useable dynamic range between white and black.  Achieving this dynamic range in practice is very difficult and is what Ansel Adams, as well as the rest of the Group f/64 club, were best known for. And this, folks, is where practical HDR photography was born.

The ONLY way to include everything in a captured image that our eyes are capable of seeing is to bracket several images using several different exposures and somehow combine them into a single final image that contains as much of the original information possible.

So now we have an HDR image that is actually thirty-two bits wide so that it can fully encompass and surpass the the dynamic range of our eyesight, now what do we do with it? Since print or computer monitors can only display eight or possibly ten bits of information the thirty-two bit image must be compressed or Tone-Mapped so that it may be properly displayed in these lower bit-depth mediums. This is where a lot can actually go wrong, and where the “artistic” effects actually happen. Done as originally intended and the result is an image that more closely represents what the photographer originally saw, misdirected and overdone the results become “artistic.”

So anyone who tells you that they can get several “exposures” from a single RAW image is not right in the head. The image displayed from any RAW file has already been down-processed, compressed, or tone mapped to eight bits in order to see it on any display. They are only fooling themselves when they think they are gaining anything from this wasted effort. That is also why a RAW image converter is absolutely necessary. An HDR program is merely a special RAW image processor that allows for a wider level of processing than a simple RAW converter program, such as Adobe’s Camera RAW.

Afton State Park

Its great to get out and clear the cobwebs from the summer hiking boots and shore up the necessary calluses. These images are from Afton State Park hiking trails on the Minnesota side of the St Croix River.

Can anyone identify this snake? I think that it is a Timber Rattlesnake Bull snake, I damn near kneeled on it when taking the picture of the windmill blades. It had a rattle on its tail and it was shaking but was making no noise at all. I never saw its head and it retreated quickly back into its hole. It turns out that this sneaky devil uses the rattlesnake as its disguise for protection.

May Snowfall

May second snowfall, still waiting for global warming to kick in…..

Girl-Boy moves, Which one of you idiots had the idea to fly north?

Difficult Landscape HDR Scene

I thought that I would show a good example of when and why multiple exposure High Dynamic Range (HDR) imaging techniques are not only desirable and superior to traditional single image techniques, but are absolutely necessary in order to make an image rise above the level of simple snapshots that are probably taken tens-of-thousands of times each year from this very spot.

Last year, towards the end of summer on September 10, 2012, I visited Glacier National Park. My first day there it was raining almost continuously with numerous waves of heavy downpours. I had no expectations of getting any shots in that evening, I did not even plan on taking my camera out of their bags. After securing a bungalow, I really was not looking forward to setting up camp in the mud and rain, I set out to drive to the other end of the Going to the Sun road which is  arguably the most scenic drive in all of the lower 48 states.

I drove past Lake McDonald without so much as seeing past the shoreline. I found myself just above the hairpin turn and was blessed with incredible luck during a rare respite from the incessant rain that evening. The Sun actually broke through the storm clouds for a few moments so I pulled over in one of the many pull-offs to take it in. The long two-day drive from my home was, in an instant, very well worth it. I could have turned back and immediately returned home and the trip would have been well worth it.

I almost immediately turned to get my camera gear setup, the shots were taken just prior to the sunset at 7:25 pm local time. I knew that this would be a very difficult shot and that I would most definitely, without any doubt, have to do an HDR series of shots using several different exposures in order to capture all of the details in the entire scene. By this time there were numerous other people who saw the same thing as I did and were all out snapping pictures with everything from iPhones to hand-holding expensive DSLR cameras.

A presumably professional photog actually came up to me and said: “Good luck, you’re going to be disappointed.” I immediately knew that he was either ignorant or was one of many professional’s who discriminate against one of the major benefits of digital technology. That technology is HDR photography or blending the best areas from several different exposures into a final image that displays the entire dynamic range of a scene that normally would be passed by, especially by an experienced photographer who has not yet added this incredibly valuable tool into their workflow.

In this particular scene the subject was obviously the range of mountains, Logan Pass, and Bird-Woman Falls. These areas were, unfortunately, very dark while the Sun breaking through the clouds was very bright in areas. In fact just the sky alone contained a dynamic range that exceeded the best professional digital sensors or film chemistry mediums.

I set my Nikon D3s to bracket seven separate exposures separated by one full stop. I set my Nikon 17-35mm f/2.8 lens to 26mm and f/16 to make sure the field of view included the closest foliage in focus. ISO was set to 1600 for the shortest possible exposure times. The shortest exposure was 1/160th of a second and the longest exposure was 1/3 of a second. This would obviously require a tripod and a rapid succession of shots to prevent ghosting of the nearby wind-blown foliage as well as the fast-moving storm clouds. I set my D3S to Continuous High mode so when I pushed the cable release all of the images would be captured in the shortest time possible, in this case less than two seconds.

Without HDR techniques the knowledgeable photographer has a few choices:

1) Expose the foreground and subject properly and the sky and clouds would be completely clipped or burned out leaving absolutely no detail in about 2/3′s of the sky.

2) Expose the sky properly and the subject is then forced to be the storm clouds while the intended subjects and foreground becomes little more than a silhouette.

3) Expose the scene as the light meter suggests and then there would be some details in the subject, sky, and foreground. This is what almost all of the people will end up with if they shoot in Automatic mode. This will result in a compromised image that still has an enormous amount of loss of details in both the highlights as well as major losses in the shadows.

4) Pass up the urge to photograph it at all and just take in the scene while ridiculing everyone else for even trying to photograph such a difficult scene.

5) Use HDR techniques and capture the image as faithfully as possible using modern digital technology.

Here is the image in the first case:

Here is the image from the second case:

Here is the image for the third scenario:

Here is the result from the technique used in the fourth choice:

[                                                                           ]

And here is the final image HDR processed in Photomatix Pro software and fine-tuned in Photoshop, this technique was beyond my previously described technique of blending two images with layer masking since the dynamic range was so wide in this particular scene: (click on it for a larger image)

It is the drama of the storm clouds and the details readily available in the foreground which gives it scale and depth and ultimately makes this shot work. I used an unusually high level of contrast in order to burn through the mist and haze. I don’t know what you might feel when looking at the final image but it still makes me smile and pinch myself with the knowledge and satisfaction that there are still a great deal of professional photographers who are still passing up some of these incredible opportunities.

I wish that I could go back and tell that photographer: “No it is you, sir, that will be the disappointed one.”

I also realize that a common technique to overcome similar problems is to use neutral density gradient filters. While these are normally the only option for videographers, I personally find them even more obtrusive and offensive as HDR processing by ham handed individuals who abuse HDR tone-maping techniques for “artistic” purposes which, by the way, is the major reason why so many professionals have shunned HDR photography to this day.

National Geographic Photo of the Day

National Geographic “Photo of the Day” April 22, 2013:

Thanks everyone,

My picture drew 9000 Facebook likes (6th place so far for April) and drew 54 comments (3rd place so far for April) which is pretty good since I have absolutely no social media following or presence. There were some very excellent photos this month so I’m probably not in the running for “Photo of the Month” but I’m very happy with the response.

Its still not too late to “Like” or place a comment.

This photo is the clear front runner for April, 33,000 Facebook likes and 126 comments. An amazing shot.
http://photography.nationalgeographic.com/photography/photo-of-the-day/gray-owl-mouse/

Update; It appears as if the mouse was placed as bait for the owl by the photographer. This has resulted in a huge controversy and may result in this front running image being disqualified.

Manfrotto Spherical Panorama Mount Vibrations

In my previous vibration testing of photographic supporting mounts and tripods I exposed a few weak areas of my equipment. I’ll show you the fixes to the vibrational nightmare of the Manfrotto 303SPH spherical panorama mount as well as stiffening the Manfrotto 055XPROB tripod.

The panorama mount has basically two weak areas that require beefing up, the vertical post, which acts like a spring, and the lower horizontal post. I chose to replace the 1/4″ x 1 3/4″ vertical post with a 1 1/4″ x 1 3/4 Aluminum bar. This added about two pounds to the mount. It also eliminated the ability to fold the mount for easy backpacking. Here is a photo of the new vertical bar along side the original plate:

I also added a 1 1 /4″ x 1 3/4″ aluminum bar to  beef up the lower horizontal dovetail plate. This added an additional two pounds to the mount but the lower bar could be replaced by simply mounting the old vertical bar to the dovetail, this would save a few ponds of extra weight. Additionally keeping the old bar handy would allow the mount to be put back to its original state for lightweight backpacking, and of course leaving the new aluminum bars behind.

I also beefed up the Manfrotto tripod by building a simple spreader brace with a center column support using off the shelf 1″ copper sweat fittings that can be found at nearly any hardware store. This modification also added a few pounds to the tripod, but the support is easily removed and the tripod was left completely unaltered. Here is a photo of the support before painting:

The ends can be clamped to the tripod legs and the center post fits into the center coupling. The center coupling is snug but can also be clamped for further rigidity.

Let me tell you that this is a huge advantage from the original setup. The original setup had lower frequency vibrations that are now transferred into higher frequencies. These frequencies can now be easily dampened by using the sandbags or hand hold methods described in earlier posts as well as sandbags on the tripod itself. (engineers – think of the  spring dampener system, the more rigid tripod now has a higher spring constant and the sandbags increase the dampening)

Here is the complete setup:

One last thing, I shopped around for sandbags and was disappointed, the quality was either very poor or the bags themselves were more designed for weighting down light stands, or other equipment, and were subsequently too big and too expensive. Instead I simply used some 7″ x 7″ ziplock freezer bags and duct taped them. The bags each weigh 2 1/2 pounds. (Red-Green approval pending; If she doesn’t find you handsome, she should at least find you handy.)

These bags allow for there to be sand on top of the lens and camera, the typical sandbags are designed as saddlebags and as such there is no sand that remains on top of the lens reducing their dampening effectiveness. In addition the bags that I found were not water proof or disposable and these can be easily fabricated on site. (think packing in and out)

The total cost of all three of the above projects was less that \$100 US dollars, not including labor.