Note the barrel distortion in the following image — there seems to be some strange gravitational effect, perhaps located behind those trees; it looks as if the water is draining toward the center of the image.

This type of distortion tends to occur with telephoto lenses, even good ones, at the widest end of their telephoto range.

In this case, the lens is a Nikkor 18-200mm f/3.5-5.6G DX VR; quite a nice lens within most of its range. This particular shot was taken at 18mm, which isn’t where the lens does its best work. The funhouse mirror effect is quite unpleasant, and without correction, this shot would be garbage.

This type of distortion can be manually corrected in Photoshop, but that’s tedious, and the results are inconsistent, which is annoying, since a given lens will have predictable distortion, so the distortion should be correctable in a systematic and calibrated manner, just as in this corrected image:

This image was corrected by PTLens, which at USD $15 must be the best value in image processing available. Your $15 obtains all of the following:

• Automatic, calibrated correction of pincushion and barrel distortion, vignetting, chromatic aberration, and perspective, with hundreds of lenses supported.
• A standalone Windows application.
• A standalone Mac application.
• A Photoshop plug-in for both Mac and Windows.
• An external editor for Lightroom on both Mac and Windows.
• A plug-in for Aperture 2.1 or later on the Mac.

Note that the Mac support is Intel-only; PowerPC isn’t supported.

Since I’m an Aperture user, the Aperture plug-in is my weapon of choice. The utility is fast, intuitive, and the results are excellent.

A trial download providing 10 corrections prior to requiring a purchase is available.

I don’t think there’s any better value out there in image processing; this thing is a steal at $15.

Tags: Photography

Pictured on the right is the Father of the Forest, a 2000-year old, 250-foot giant redwood, located in Big Basin State Park. The shot was taken about 20 feet from the base of the tree, which is 66 feet in circumference.

We are fortunate to live in an area with many of these magnificent trees, and I love to take pictures of them.

However, the incredible size of these trees poses some photographic challenges; in short, they’re just too big to take pictures of — even with a wide angle lens, it’s impossible to fit something so massive into a single picture.

In fact, using an 18mm lens, moving from top to bottom, it took 7 shots to capture the entire tree. Now, that’s neat and all, but the result is a number of disjointed shots; it’d be nice to be able to stitch them all together into a complete picture.

Fortunately, we can, using panorama creation software.

This is a surprisingly competitive segment, with a number of solutions available. Almost all vendors provide downloadable demo copies, typically enforcing the demo license via a prominent watermark in the resulting stitched image.

In my opinion, the preeminent product in this space is AutoPano Pro, from Kolor.

AutoPano uses SIFT, developed at UBC, to perform its magic, and magical it is — one simply hands AutoPano a series of images, and it does the rest; stitching, lens and camera correction, exposure blending, ghost removal, color correction, and cropping.

Basically, it’s a fully automated solution, very simple to use, and produces great results without any effort. Handles the 14-bit RAW files produced by my camera without problems.

The one downside to the program is the UI, which appears to be QT-based. This isn’t surprising, as a Windows and Linux versions of the program are also available, and Kolor isn’t a big shop; it makes sense for them to use a cross-platform toolkit. However, the result is that the UI looks a bit odd from the Mac perspective.

However, that’s but a small complaint in what is otherwise a fantastic utility.

AutoPano Pro is 99 Euros. A free, watermarking demo is available.

Highly recommended.

Tags: Photography

OS X comes with iPhoto, a much better photo management application than anything we had on the old PC. iPhoto has a very intuitive interface; moving our photo library over was a trivial task. Furthermore, it immediately understood what to do with our camera as soon as we plugged in the USB.

However, by default, iPhoto imports pictures into the personal library of the user running iPhoto. This wasn’t the way we wanted iPhoto to work; rather, we wanted to share the same library, with full access control, no matter which account was in use.

The definitive and most workable approach to this problem uses a shared directory and access control lists, and is outlined at macOSXhints:

10.4: Share an iPhoto library among multiple users

Finally, to keep the ‘Pictures’ quickpick in the finder view looking normal, I followed the following tip, also from macOSXhints, to link each account’s iPhoto Library folder to the new shared folder:

Share an iPhoto4 Library between two or more users

This all works as desired. Each account sees the shared library and has full access control to it; iPhoto itself will disallow other instances of iPhoto to run under another account simultaneously, so data integrity is assured.

Tags: Photography