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Categorized | Articles, Paul Burwell

Digital Chat — Micro focus lens adjustments (full story)

Story and photography by Paul Burwell

One of the things that the digital revolution forever changed about photography is the insatiable search for sharpness. And not just sharp images, but tack sharp images. Now that it’s easy to view our images on our giant home monitors and to zoom in to the pixel level, a lot of photographers have become obsessed with image sharpness. Many newer cameras support a feature allowing the user to adjust the micro focus capabilities of their lenses and a software company Reikan Technology Ltd. has developed a program called FoCal to help with the process.

 

©Paul Burwell Image showing screen after micro focus adjustment has been applied to a 24-70mm f/2.8L lens.

©Paul Burwell
Image showing screen after micro focus adjustment has been applied to a 24-70mm f/2.8L lens.

©Paul Burwell Image showing the main screen of the FoCal software

©Paul Burwell
Image showing the main screen of the FoCal software

“…there is something extremely annoying to know that your camera should have been focused
on some subject, but the focus was just slightly missed.”

 

Before we go any further, I want to point out that sharpness is not the end-all when it comes to making a great photograph. Famed photographer Henri Cartier-Bresson stated in his book The Education of a Photographer that “I am constantly amused by the notion that some people have about photographic technique – a notion which reveals itself in an insatiable craving for sharpness of images. Is this the passion of an obsession? Or do these people hope … to get to closer grips with reality? In either case, they are just as far away from the real problem as those of that other generation which used to endow all its photographic anecdotes with an intentional unsharpness such as was deemed to be ‘artistic.'”

So, sharpness isn’t what makes a great photograph. But, there is something extremely annoying to know that your camera should have been focused on some subject, but the focus was just slightly missed. And that’s the problem FoCal aims to help you solve.

It’s an excellent question to wonder why the SLR camera and lenses you paid your hard-earned money for don’t focus perfectly to start with. Producing cameras and lenses that focus better than they generally do out of the box is certainly possible, but the price for these devices would have to sky-rocket because of the extra care, time and materials required to achieve perfection. And so to keep prices affordable, we are all forced to accept imperfection.

 

©Paul Burwell Juvenile merlin sitting on my back gate. Settings: 500mm f/4L IS lens, ƒ4.5@1/500 sec., ISO 800

©Paul Burwell
Juvenile merlin sitting on my back gate.
Settings: 500mm f/4L IS lens, ƒ4.5@1/500 sec., ISO 800

 

FoCal currently only works with digital SLR cameras from Nikon and Canon. If you’re a Canon owner (with the exception of the 5D Mark III or 1DX), you’re in luck because assuming you have a supported camera, the entire process of adjusting the focus of your lenses can be automated by FoCal’s software. Unfortunately, for the Nikon users and those Canon users indicated above, you’re in for a more laborious venture that requires a bit of intervention to move through the process.

After installing the FoCal software on your Mac or Windows computer, you’ll want to print one of the included PDF files to use as a target for the camera to focus on. Mount the target in a well-lit area, set your camera on a tripod, attach it to your computer via a USB cable and the process can begin. The FoCal website lists recommended distances for different lenses based on each lens’ focal length. Stay away from using fluorescent lights to illuminate the target as their flickering (usually invisible to the naked eye) can lead to inconsistent results.

Run the software’s Target Setup routine to make sure you’ve got your camera well aligned and focused on the target. Next, click on the Fully Automatic AF Microadjust button and the software starts to work. If your camera doesn’t allow the software to make all the necessary adjustments (and I have one of those) you’ll have to access the camera’s menu and manually adjust the micro focus adjustment setting until the camera finds the perfect focus adjustment. In my tests it usually takes three to five minutes to find the “sweet spot” for a lens’ micro focus adjustment and when you’re done, the FoCal software creates a nice little PDF report summarizing the results it achieved as it ran the tests.

 

©Paul Burwell Image showing the alignment necessary for the target and camera.

©Paul Burwell
Image showing the alignment necessary for the target and camera.

 

Other tests available with the FoCal software include the ability to test the focusing of more than just the center focus point, an auto focus consistency test, an aperture sharpness test (to determine what aperture setting your lens is sharpest at) and a dust analysis of your camera’s sensor so you can visualize just how dirty your sensor really is.

If you’re keen on ensuring your images are as sharp as possible, FoCal is an indispensable tool. Although it could be a bit more user friendly (I think this program could be improved by addition of a “wizard” to lead the user through all of the steps), FoCal worked well and I was able to adjust my camera’s focus from the ease of home. FoCal comes in Standard, Plus and Pro editions, with ease of use and features increasing with price. For me, the Plus version is the best option between features and pricing. FoCal can be purchased online directly from Reikan and is priced in British pounds. The Standard version sells for £19.95, the Plus version for £39.95 and the Pro version for £69.95. They also sell a commercial version, so your local camera guru may be able to provide this service for you for a price. The general recommendation is that you adjust the micro focus adjustment on your lenses at least once or year or anytime they’ve been given a big jolt.

Remember though that like Cartier-Bresson reminded us, just because your photos are tack sharp doesn’t necessarily mean they’re great photos. Great photos still take creativity and there isn’t software available that can fine-tune that yet.

For more great how-to tips on landscape, nature and wildlife photography, as well as gear reviews please pick up the October 2013 issue of OPC today!

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