Reikan has announced a major update to its AF tuning software, FoCal. FoCal automates the process of calibrating your lens to your DSLR camera body, important - if not absolutely necessary - for critical focus when using fast lenses that yield shallow depth-of-field. Calibration options are typically available under 'AF microadjustment' (or AFMA for Canon and Sony bodies) or 'AF Fine Tune' (AFFT for Nikon bodies) menu items, with the process being pretty laborious and relying on the user to shoot many shots, throwing off focus in between each shot, to determine the optimal AFMA or AFFT for any camera/lens combination. Further frustrating things is the fact that the optimal value can change due to conditions like temperature and humidity, as well as subject distance, making it rather difficult to nail down the optimal settings. Sigma's USB dock takes care of one of these problems, allowing you to program in the best calibration value for four different subject distances into their lenses, but no camera manufacturer makes it easy to actually determine these values.

That's where FoCal comes in. By automating the process, FoCal allows you test multiple combinations, subject distances, and on different days, easily. This allows you to 'tune-in' the best calibration values for your shooting day/scenario. FoCal even allows you to test each individual AF point on your camera body, which can tell you (1) if your camera body has problems (a la Nikon D800 left AF issues), and (2) which AF points you may wish to avoid. Although manufacturers try to calibrate all AF points in camera bodies, sometimes some points are off relative to one another. AFMA and AFFT only globally affect all focus points, so you'll typically want to optimize for the center AF point. Therefore, it's useful to know when other AF points may be problematic.

We'll warn you that this can be a bit of a rabbit hole - when you look for problems, you'll find them. That said, performing this sort of calibration on just your center AF point will typically lead to drastically better results with fast lenses, such as F1.4 primes. We'll take this opportunity to stress that you cannot expect accurate focus results 'out of the box' for a F1.4 prime on your camera body, no matter what brand of camera and lens is in question. This is because of the limitations of tolerances.

Version 2 of FoCal introduces the ability to check your copy of a lens against other users' test results. FoCal has been collecting massive amounts of data from users, which can prove very useful in comparing your copy of a lens to an average of samples. This can be particularly useful in conjunction with the AF consistency test (shown above) - wouldn't it be fantastic to know how your camera/lens combo performs in terms of repeatability of focus compared to others with the same combo, to know if you've gotten good copies? Or how repeatability of focus of a Canon 35L F1.4 prime compares to a Sigma 35mm F1.4 Art on your camera body? Or AF precision differences between various AF points in your camera body? We certainly think so.

Other enhancements include an improved user interface, the ability to compare current test results against previous results, more concise reporting and voice prompts for hands-free camera adjustments. For now the update is available as a test release for Windows users with a FoCal Pro License, but will be offered as a free upgrade in its full version to all FoCal 1 license holders.


Press release:

Reikan has released a major update to its fully automated autofocus tuning software FoCal which provides autofocus fine tuning for both Nikon and Canon digital SLR cameras. Version 2 includes a unique ability for users to compare test results directly against results from other FoCal users around the world, helping to answer the age old question, "Is my camera/lens a good copy?".

Other highlighted features for Version 2 are routines to determine lens optical performance with an astigmatism metric and a large number of changes to the user interface to make calibration faster and FoCal easier to use.

Links:

FoCal Main Website:

http://www.fo-cal.co.uk

Blog Entry Version 2 Release:

http://www.reikan.co.uk/focalweb/index.php/2015/03/reikan-focal-2-test-release-1-is-here/