Three years ago, in July 2014, I wrote a 2 part article (Part 1 is here and Part 2 is here) about how to calibrate lenses with a DSLR camera body using a lens calibration system known as LensAlign. Since then, a lot has changed and those posts I made are now mostly outdated. As a result, I have fully rewritten my techniques for auto focus calibration in order to share them with you.
In addition, I had gotten a new Canon 5D Mark IV DSLR camera body late last year. So I needed to recalibrate all of my own existing lenses with the new camera body to make sure auto focusing will be as accurate as possible. That’s when I decided to change my workflow and use Speedlight flashes (instead of using ambient light) so that I could use a fast shutter speed of up to 1/250th for my own calibration test shots. Using flash instead of ambient light resulted in much more evenly lit test shots, and without any blurriness from camera shake or noise that often occurrs when shooting with longer exposures and a high ISO.
I also started using a software called FocusTune (also part of the same LensAlign system I was using before). FocusTune automatically analyzes your lens calibration test photos to help you pinpoint your sharpest test shots and make a more accurate auto focus adjustment to your camera settings. As a result, my entire calibration and testing workflow has now changed and the new workflow I will be showing you in the coming week employs these newer methods and technology.
So this is again going to be a two part post. In this first part I will show you a video below that I complied from three short videos made by Michael Tapes (the creator of both the LensAlign and FocusTune systems). The video will provide a good introduction to the products and the general auto focus testing workflow he uses. Then I will provide you with an equipment list of what I use so you can replicate my lens calibration test workflow if you want to. Lastly, I will show you a diagram of my calibration test setup.
In part two (to be published next week), I will provide you with my own step by step lens testing workflow in fine detail. I will then show you some of my own test result graphs from the FocusTune software, and explain how to interpret them when performing lens calibration tests and making auto focus adjustments to a DSLR camera.
First, I want to answer the most important question: Why Do We Need To Calibrate Our Lenses? – In the video below (around the 03:50 mark) Michael Tapes also explains that, since cameras and lenses are manufactured separately, there will usually be some inconsistencies with their ability to perform accurately together. Therefore, by testing each of one of your lenses and camera body together (using LensAlign and FocusTune), you are able to pinpoint the faults and compensate by making adjustments to your camera settings via its own in-camera software. In the end, this will ensure that you get the sharpest possible auto focusing performance when shooting with your own camera and lenses.
Please watch the 17 minute video from Michael Tapes here below:
As for equipment, I use the following:
1 – My own camera, lenses, and memory cards
2 – LensAlign & FocusTune – Buy Them Here As A Bundle
3 – 2 Speedlight Flashes – I use these inexpensive high-quality flashes from Yongnuo
4 – 2 Speedlight Light Stand Mount Adapters
5 – Wireless Flash Triggers – I am using inexpensive ones from Yongnuo designed for their flash system which you can get here for Canon and here for Nikon
6 – 1 Tripod and Tripod Head for the Camera – I use this Manfrotto tripod and this Manfrotto tripod head
7 – 1 Inexpensive Battery Powered LED Video Light – Used to illuminate the LensAlign tool
8 – 4 Inexpensive Light Stands – 1 to Mount LensAlign, 1 to mount the video light, and 2 to mount the Speedlights.
9- 1 Hot Shoe Double Axis Level (In case your camera body does not have a built in electronic level)
10 – Remote Camera Trigger – If you buy a pair of the inexpensive Yongnuo flash triggers I mentioned above you can also use one of them with a shutter release cable they provide to trigger your camera’s shutter. That is what I use.
If you decide to purchase any of the equipment I am using above, I would appreciate it if you would kindly use the links I provided above to make your purchases so that a small percentage of your order may go to help support this blog.
Here is a photo of my auto focus testing setup:
Next week’s forthcoming post will take you through my testing workflow in finer detail, analyze my auto focus test results, etc.
If you have any questions or comments at this point please feel free to post them below.