Black Tern in flight alongside Hwy. 49, Horicon National Wildlife Refuge, Mayville, Wis. | Canon 7D and 400mm f/4 DO IS lens | Exposed 1/1600 sec. @ f/4, ISO 400 (neutral EV)

A Brief History of “Back-focus”

Last weekend I was at Horicon National Wildlife Refuge and experienced some focus problems with my Canon 7D heretofore non-existent, or so I thought.  Upon reviewing photographs from the 7D from the past several months, I noticed that none of them were actually as sharp as they could have been.  I attributed the softness to the lack of acutance in the files, and while I continue to believe that is an inherent property of cramming 18 megapixels into an APS-C format sensor, there was a real problem in play.

I didn’t want to believe that it could be a question of the camera “back-focusing” (or front-focusing) because I’ve grown to distrust people’s claims that their camera, and not their own inabilities, are to blame for their out-of-focus photographs.  I don’t remember these claims from the film days.  Perhaps I was just oblivious to the complaints, but I tend to believe that the instant feedback of the digital camera is partly to blame for the knee-jerk reaction that anything wrong with the pictures must be camera, not operator, error.

I will not mince words: ever since the Canon 10D and the Nikon D70, there’s been a lot of bitching and moaning in online forums about back-focused images, and I did not believe them.  At all.  Until now.

Now, I will argue that there is definitely operator error to blame in most many cases of complaints about back-focusing.  Last weekend I was convinced that I must have chosen the wrong focus point or didn’t have the AF locked by holding in the rear button–some prefer AF to only be activated by using the back button, I prefer AF to only be turned off if I hold in the back–and allowed AI Servo (Continuous AF for Nikonians) to screw up the focus.  To confirm my assumption, the next day I took test photographs in the garden around my parents house in Racine, Wis. and was shocked to discover that none of them were sharp.  Sure, the wind was to blame in a couple cases, but even when conditions were perfectly still the results were poor, so I rented a LensAlign from Lensrentals.com to investigate whether front or back-focus was to blame.

And what did I find after I unpacked and set up the LensAlign?  The 7D and the 5D Mark II both back-focused with the 400mm DO IS lens.  Well, there goes the neighborhood.  And a lot of preconceived ideas, with it.

Post continues after the jump!(...)
Read the rest of Horicon after LensAlign and Focus Tweaks (905 words)

Content © 2010 David Kennedy | Permalink | 2 comments | Reviews: birds, EOS 5D Mark II, EOS 7D, equipment, LensAlign, nature, Reviews, wildlife

Abandoned barn in late-afternoon light on Hwy. 146, Gilman, Iowa, in November 2004. | Canon 10D and Sigma 12-24mm f/4.5-5.6 EX HSM lens @ 12mm; exposed 1/100 sec. @ f/20, ISO 200.

A couple of months ago, a friend of mine from my days as a student at Grinnell College asked me if I had any landscapes of Iowa that she might frame up for her apartment.  For one reason or another it took me a while to get back to her–sometimes, my e-mail inbox gets a bit clogged.

Original capture of the barn

While going through my landscapes from Iowa, which were less abundant than I expected, truth me told, I found this image of a barn near Gilman, Iowa, which was just a stone’s throw from Grinnell on state Highway 146.  I remembered this image when I saw it: I remembered that I never had the right tools to process it, even though it had a perfect exposure (the histogram went “to the right”).  It’s sharp, too–that Sigma 12-24mm was a strange but surprisingly sharp piece of glass.  At least, my copy of the lens was.  As with anything from Sigma, your mileage may vary.  I purchased it early in 2004, back when it was first introduced for about $500, and there were not many options for getting a truly wide perspective on the APS-C cropped cameras.  Interestingly, the Sigma 12-24mm is now sells for $800.  Crazy little world!

At the time I made this image, I was using Capture ONE from Phase ONE as my primary RAW converter, and found this image to be far too difficult to tone properly.  But here it was, sitting in my Lightroom database, long-since converted to a DNG file (the universal RAW format that all manufacturers should be using, but that’s a topic for another day).

I set a custom white balance, and then established a black point and white point.  Then I adjusted the curves to make the black a little richer–I don’t find going beyond about 9 on the black slider in either Lightroom or Adobe Camera RAW is very effective.  Three brush strokes and a gradient later, the image was ready to go into Photoshop for some final tweaks–normally unnecessary, as I find the global adjustments with the brush and gradient tools for localized toning to be sufficient for my images.

Amazing what you can do with your images now that you couldn’t–or, at least, didn’t know how to–do a few years ago.

What gems are gathering dust in your archive?

Content © 2010 David Kennedy | Permalink | Comment! | Updates: Canon 10D, landscapes, nature

Entrance to the Devil's Ice Box, Rock Bridge Memorial State Park, Columbia, Mo. | Canon 5D Mark II and 16-35mm f/2.8L II lens @ 20mm; exposed 87 seconds @ f/11, ISO 400.

When I first looked into the opening of the Devil’s Ice Box, I wasn’t sure what would happen with a time exposure.  There was barely enough light to focus on the rocks–I was lucky that all of the mist above caused by the hot, humid air hitting the cool air from the cave was creating a giant diffuser.  Essentially, localized cloudy conditions on a sunny evening.  I was surprised at the colors that were revealed in the first time exposure–I started at 30 seconds at ISO 800.  I re-adjusted for a bulb exposure at ISO 400 for less noise.  You can see this same sliver of stream passing underground through the cave system in the photo below:

Looking down into the Devil's Ice Box, Rock Bridge Memorial State Park, Columbia, Mo. | Canon 5D Mark II and 16-35mm f/2.8L II lens @ 16mm; exposed 13 seconds @ f/16, ISO 400.

Content © 2010 David Kennedy | Permalink | One comment | Updates: EOS 5D Mark II, landscapes, nature, Rock Bridge Memorial State Park

Rock Bridge Memorial State Park boardwalk to the Devil's Ice Box, Columbia, Mo. | Canon 5D Mark II and 24-70mm f/2.8L lens @ 34mm; exposed 1/2 second @ f/16, ISO 400.

I took an excursion–albeit brief–to Rock Bridge Memorial State Park in the early evening hours tonight.  A sudden thunderstorm that passed through Columbia this afternoon had left the colors saturated, and the boardwalk to the Devil’s Ice Box (an extensive cave in the park) was slippery.  As I turned back to see the way I came–taking a cue from Dewitt Jones’ sappy, but helpful mantra “Look around, Dewitt”–I saw the sun bursting through the tree canopy.  Normally, for a scene like this, I wouldn’t worry about stopping down beyond f/9, possibly f/11, but for maximum sunburst without risk of image deterioration due to diffraction, I chose f/16.  I prefer to avoid a lens’s minimum aperture–you can test the theory yourself, and you will find that your lens becomes less sharp, not more-so, at its smallest aperture.

Content © 2010 David Kennedy | Permalink | One comment | Updates: EOS 5D Mark II, nature, pictorial, Rock Bridge Memorial State Park

Lightning over Discovery Lake, Columbia, Mo. | Canon 5D Mark II and 24-70mm f/2.8L lens @ 30mm; exposed 6 seconds @ f/8, ISO 800.

Last week, my friends Jakob, Calin, and Jamie called me up to join them on a small lake near Discovery Parkway in Columbia, Mo. to fish.  Well, they fished.  I fished for lightning photographs.

Unfortunately, while the picture above is tack sharp, it’s not quite satisfying.  Later in the evening, I made another image that is far more pleasing–great color, great lightning strikes, including one on a cell phone tower–but is way, way out of focus when viewed at 100%.  Interestingly, when sized for this blog, it’s hard to tell that it’s soft, so I’ll share it here:

Lightning strike on the cell tower, Discovery Lake, Columbia, Mo. | Canon 5D Mark II and 24-70mm f/2.8L lens @ 43mm; exposed 2 minutes, 36 seconds @ f/8, ISO 100.

Content © 2010 David Kennedy | Permalink | 2 comments | Updates: EOS 5D Mark II, landscapes, lightning, nature, pictorial

Storm over the water tower, Columbia, Mo. | Canon 5D Mark II and 70-200mm f/4L IS lens @ 135mm; exposed 10 seconds @ f/7.1, ISO 800.

Last night a line of thunderstorms tracked through Columbia, Mo., changing the hot and humid air for the better, leaving much cooler temperatures in their wake. Before the rain came, I set up my tripod on the balcony of my apartment to try to get some lightning strikes.

Lightning was plentiful, if far away–I counted out the seconds between the light and the sound, lest I be caught outside with my own personal lightning rod–but I had little to no success at capturing a bolt across the frame.

However, I did get one image that was almost surreal: the city’s water tower encircled by the light from the lightning strikes and the clouds as they sped past overhead.

I’ve added some contrast to the image, but the colors are how the camera saw them. A fun, if a bit surreal landscape.

Next time I’ll get lightning bolts.

That said, if anyone has a suggestion for how to capture them, I’m all ears!

Content © 2010 David Kennedy | Permalink | One comment | Updates: EOS 5D Mark II, landscapes, nature, pictorial, weather

Thunderstorms over the Water Tower from David Kennedy on Vimeo.

In the wee hours of the morning on June 2, 2010, a wave of thunderstorms swept through Columbia, Missouri.  I took it as an opportunity to make a “thunderstorm time-lapse,” and set up my tripod.  My apartment faces one of Columbia’s landmarks, the water tower, but to get a decent composition of it, I actually had to use a 300mm lens, several feet from the door to my balcony (no need to get wet, though!).  I was hoping for some lightning strikes, but the reflections of the lightning on the water tower, and the illumination of the clouds, was all I could get in the hour that I made these images.

I set the camera up on a remote trigger with an intervalometer, and exposed them all at 30 seconds @ f/9 using 200 ISO on the 5D Mark II and 300mm f/4 L lens.  The time lapse above is made of 57 such photographs.

I should note that part of the process of putting this time lapse together was discovering opsound.com, a resource of royalty-free music.

Overall, the thunderstorm presented a good opportunity and it was a lot of fun to put the time-lapse together; I hope you enjoy the final product.

Content © 2010 David Kennedy | Permalink | Comment! | Updates: multimedia, nature, thunderstorm, time lapse, video, weather

Since the explosion on a British Petroleum (oops, sorry, just “BP” as we wouldn’t want to pretend that this energy company works with oil, just as KFC doesn’t “fry” any food) oil rig on April 20, 2010, a tremendous amount of oil has been spewing from the seafloor a mile down and into the Gulf of Mexico.  The National Wildlife Federation, home to one of the more competitive nature photography contests in North America, has started a campaign to assist wildlife threatened by BP’s oil as it washes onto the shoreline.  I now have a link that will take you to their donation page on the top of the sidebar on the right side of my Blog.

Environmental Effects of Crude Oil on the Gulf Coast

I will soon be on Lake Michigan’s shoreline to work on a story about the potential effects on the tourism industry should Asian Silver and Bighead carp should they successfully colonize Lake Michigan, or the effects on people living in the Chicago area should they close the Sanitary and Ship Canal that forms the artificial connection between the Mississippi River basin and the Great Lakes basin.  However, just as I was finalizing my proposal, BP’s oil rig exploded.

Sarah Palin’s mantra during the 2008 presidential campaign, “Drill, baby, drill,” suddenly and perversely betrayed the cruel reality of offshore drilling: “Spill, baby, spill.” (There is always risk in oil exploration: even if you are a staunch supporter of increased energy exploration, you cannot deny that there is always some risk of a catastrophic event, even if you believe it to be unlikely.)

For a moment in time, I contemplated changing my proposed story altogether, and travel to Louisiana, Alabama, Georgia, Florida, Texas, and Mexico (should oil enter the Loop Current, all of the coastline will be covered).  Cuba would be a good place to go as well, but that would be difficult as an American.  However, I believed then, as the events of the past month have reinforced for me, that the environmental damage is incalculable and that the story of the effects could only begin when the spilling of oil has stopped.

Instead, I watch alongside everyone else as a commercial industry, which some proclaim hold the answers to all catastrophes, and should therefore be entrusted with the future of our natural environmental, fails to stop the worst oil still in United States history.

Content © 2010 David Kennedy | Permalink | Comment! | Advocacy: environmental advocacy, nature