FoCal Lens Calibration Software

[Editor’s Note.  We hope everyone had an enjoyable three day weekend, and making sure to remember the men and women who gave their lives in service of our country.  Here’s another great piece by Ben Hendel, this time talking about an interesting bit of software used for calibrating your lenses.  You need to be following Ben on Instagram.  He got a chance to take two big lenses into Animal Kingdom recently and got some GREAT photos.  So jealous of the opportunity Ben had.  Thanks again Ben for the article! ].

 

High-end cameras cost a lot of money and you get a great product for them. Same thing goes with lenses. But what if I told you that if you just bolt your new-and-shiny lens to your new-and-shiny camera, that you aren’t getting everything you’ve paid for? Because of production variables and tolerances, not every camera and lens leaves the factory “perfect.” The camera body manufacturers know this, and they build in a way to fine-tune your camera body to your lenses. On my Nikon, this is called AF Fine-Tune, and is usually called AF Microadjustment (AFMA) on a Canon.

Disclaimer: NOT ALL CAMERAS SUPPORT THIS FEATURE. It is usually found in higher end models. My D7000 had it, my D60 did not. [Editor’s note, my Canon 60D does NOT have this feature. Guess that saves me from getting the FoCal software myself. Will keep this in mind for the next camera I get.]

Modern cameras can hold multiple lens profiles. As you can see, my camera can hold 12 different adjustment values in memory, each one tied to a particular lens. If you have more than 12 lenses, well, you’re richer than I am. Spread the wealth, eh? I accept PayPal. If you rent a lot of lenses, you may want to keep half an eye on how many values you’re storing and clear them out occasionally. I know I need to do that with the values from tuning the Sigma 150-600mm.

Photo May 26, 8 38 13 PM

In the past, this has been a manual process. You’d set up a target, take a picture, and decide whether you were back-focusing (your actual focus-point is behind where you wanted it to be) or front-focusing (just the opposite of back-focusing). Then, you’d dial in a setting that reflected this, and compare the images to see if it was better or worse. Repeat until you found a value you liked, or until you gouged out both of your eyes with a used grapefruit spoon.

However, there is now a company in the UK called Reikan who makes a wonderful piece of software called FoCal.

Double disclaimer: Reikan did not contact any member of the Disney Photography Blog and ask us to write this review. We were not provided with a free piece of software, and we are not compensated in any manner by Reikan or any company because of this review. Got it? Good.

FoCal is a piece of software that makes automatically calibrating your camera body to your camera lenses, so long as you shoot Nikon or Canon. And even then, not all cameras are supported by FoCal. To see if your body is supported, please visit this website: http://www.reikan.co.uk/focalweb/index.php/why/camera-compatibility/ . Even then, if you shoot Nikon, automatic calibration mode is not supported. This shouldn’t steer you away from the software, but it may save you a couple bucks not buying the super powerful full-featured edition when some of those fancy features don’t work for your camera.
First, you’ll need to set up a target. FoCal provides you with a PDF to print out, and recommends you print it on good card stock instead of plain white office paper. They say that ink bleeds into office paper too much, and this prevents FoCal from getting sharpness readings right. Once you’ve set up your target an appropriate distance away, you set your camera up on a tripod and go through the most frustrating process for me. When choosing where to place your target (mine is on the back of the front door of my house so I can use the long hallway to calibrate long lenses), you’ll want to choose an area with a lot of light. Alternatively, you can just have a 3 D-cell MagLight hanging around and point it at the target while FoCal is doing its thing. Don’t judge me. It works.
Screen Shot 2016-05-26 at 8.34.55 PM

I hate aiming the camera at the target. It must be aimed just-so, and I always tend to overshoot when adjusting the ballhead on my tripod. It also likely doesn’t help that most of the lenses I’ve calibrated recently are super-telephotos, and so I’m halfway across my house, trying to aim at a 2.5 inch center, with a heavy lens-and-camera combination.

That’s the hardest bit. FoCal will tell you when it is happy about your aim, and from there, does the vast majority of the work for you. Frankly, on a Canon, it likely does all the work for you. It takes pictures, changes the AFMA automatically, compares the shots, and repeats until it dials in the sharpest, most accurate possible autofocus value. If you’re shooting a Nikon, it’s a little bit more user-interactive. FoCal still takes pictures for you, and it still compares them for you, but you’ll have to adjust the AF Fine-Tune value on your own. Be gentle when you do, because if you nudge the camera off the target-point, your comparison data will be useless and you’ll have to start over.

Screen Shot 2016-05-26 at 8.40.02 PM
There is a fantastic amount of data that FoCal gives you while it is working. This particular lens required very little adjustment. It only required a +1 Fine Tune in order to be considered sharp and accurate. I’ve had other lenses that live in the +17 to +19 realm like my Nikon 80-200mm f/2.8. Before FoCal, I could focus on the nose of a Princess during a parade and “miss” focus because the lens was back-focusing so much. Adjusting that lens made a world of difference.
Screen Shot 2016-05-26 at 8.44.44 PM

After about 5 minutes of actual work, FoCal said it was done. It gave me a new value, and a lovely set of charts to go with them. I set that value in my AF Fine-Tune menu, and was ready to go for a day of shooting. There is also the option to Save Reports of what your lens correction looked like. I’ve attached, via links at the bottom of this review, those reports from the Sigma 150-600mm and the Nikon 200-500mm so you can see a little bit more of the data that FoCal can produce for you.

This is software I highly recommend, for anybody who is serious about getting the absolute most out of their camera and lenses. Whenever I get a new lens, the first thing I do is calibrate it. I’ll never miss another shot because my lens doesn’t understand what my camera body means by “in focus.”

Here are is a link to what the report looks like that FoCal generates.
Sigma 150-600:  150-600mm f_5-6.3_600mm
Nikon 200-500: 200-500mm f_5.6_500mm

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5 Comments

Joanie Eddis-Koch

about 10 months ago Reply

Thanks for taking the time to share your experience with lens calibration. I understand that focus tuning prime lenses is relatively straight forward but how can you tune the focus of zoom lenses that have such a wide range of focal length? I'm thinking that you would just have to pick a certain focal length and work from that. Wouldn't that mean however that the other focal ranges would not be focus tuned to their optimum setting? And since the camera body generally only allows one focus adjustment per lens, the ZOOM lens would only be correctly adjusted at the millimeter setting that you used for the focusing test. So I'm wondering if a particular lens calibration, at a set point in the zoom lens's range would be beneficial all across the zoom range. Thanks for taking the time to answer this question.

Keith

about 10 months ago Reply

Thank you for taking the time to write in! I've alerted Ben, so look for answer soon.

Ben

about 10 months ago Reply

Luckily, FoCal has an FAQ about it you can read here: http://www.reikan.co.uk/focalweb/index.php/faqs/ An excerpt (they go into way more detail), "Well, focus errors have a greater impact at the telephoto end of a zoom lens as the depth-of-field is more shallow, it’s therefore better to bias the calibration value toward the telephoto end result."

Travis Belton

about 10 months ago Reply

My understanding is that mirrorless cameras, such as Sony a7Rii, do not need this calibration since they focus using pixels on image sensor.

Keith

about 10 months ago Reply

Thanks for your comment Travis. I did a little digging online and it appears you are correct. Multiple websites report that mirrorless cameras like the Sony model you mention above do not need lens calibration.

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