Sigma Optimization Pro and USB Dock

Published June 9, 2013

“Commerce makes progress. Fortune passes everywhere.” – Frank Herbert

A few years ago I was accused of being a Sigma hater. (For the record, I did hate their quality control and so-called repair service at that time, and I didn’t hesitate to say so in this blog.) For the third or fourth time in the last year, I’m about to be accused of being a Sigma fanboy.

I’m pretty certain I haven’t gone soft over the last 4 years. I am certain, though, that Sigma Photo, Inc. has changed a lot in that time. Truth is, they’re making serious waves in the photo industry these last few years. They’ve improved their repair service and quality assurance. They’ve released some world-class lenses at way less than world-class prices lately. And now they’ve released their USB dock and Optimization Pro software.

I’ve spent the weekend playing with it. Partly because I really think this is a revolutionary product and I wanted to see how it worked. Partly because I desperately need a ‘Honey, I’ve really got to do this for work’ excuse or I’d have been restaining the deck.

My conclusion, as usual, first: if anything is going to get the attention of those who like to disable features in firmware, overprice lenses, and limit our ability to customize, this might be it. I did some adjustments this weekend, in about 10 minutes, which would have required a trip to factory service on a Canon or Nikon lens. And let me stop the Fanboy stuff before it starts: you may never have needed to make this adjustment on your 10 or 20 Canon or Nikon lenses, but I’ve sent dozens of them to factory service adjustments for exactly the issue I’m going to demonstrate today.

Quick Overview of the USB Dock and Optimization Pro software

The directions are pretty simple:

  • Make sure you buy the dock in the proper mount (Canon, Nikon, or Sigma).
  • Download the Optimization Pro Software HERE. It’s about 3.4 Mb in a zip file, available for Windows or Mac.
  • Open the software, put the lens in the USB dock, and plug the USB port in your computer.

Once you hook things up the program the program opens to a nice, straightforward main page.


The firmware update button reads the lens’ firmware and lets you know if you need a firmware update. Push yes and it updates in about 20 seconds.

Adjusting a Lens

First of all, there’s a nice 10-minute video that Sigma made that shows you the use of the device very clearly HERE. If you’re like me, though, you might prefer a 30 second blog read. It really is that simple. Actually, 10 minutes is more time than it took me to do my first adjustment on the 35mm f/1.4 (of course, without reading any manuals).

I should be clear, I don’t do a full-ballistic, OCD, 600-shot microfocus adjustment. I’m too aware that phase detection AF is a shotgun, not a sniper’s rifle. I’ll take nearly perfect in 10 minutes rather than perfect in 4 hours every time. Plus, like I said, I’ve got a deck to stain. Unless I can put it off so long that my wife gets frustrated and does it herself.

I chose a lens that is perfect for this software. This copy of the 35mm f/1.4 is perfect on my Canon 6D at close and intermediate distances, but at long distances it backfocuses badly. I can do a microfocus adjustment to correct long-distance focus, but then the lens is frontfocusing at near distances. Without the Sigma dock and software, the only option was a trip to the factory service center to change the lens parameters.

Since I was at home instead of the office, I didn’t have Focal, LensAlign charts, or any of the other things that seem to be considered necessary tools for autofocus adjustment these days. So I made do with a placemat and my back yard.

Since I plan on using this lens outdoors in daylight I wanted to adjust it in daylight (autofocus can change slightly in different lighting conditions, if you aren’t aware). I started with a placemat set in front of a picture window.

Spot focusing on the tip of the green leaf, I took several shots each at minimum focusing distance, 3 feet, and 6 feet. They all showed focus was accurate, as in the samples below.


Focusing at longer distances, however, showed the lens backfocused quite dramatically. In this image the focus point was on the small yellow leaf in the foreground (I’ve cropped the image to show the area behind the focus point).

Opening up the Sigma adjustment window shows I can make adjustments at 4 distances. With the 35mm, 3 of those are close: roughly 0.3, 0.4 and 0.7 meters. The other is infinity.

I left the close adjustments at zero and gave infinity adjustment a -12. You just click on the area you want to adjust, move the slider the amount you want adjusted, and then click the “Rewriting” button. (The “Rewriting” button is the only part of the software that isn’t totally intuitive; it isn’t highlighted until after you click on it.)

A repeat shot outside showed -12 was way too much adjustment so I went back and reset the infinity adjustment to -8. That was spot on as shown in the image below. I rechecked AF at closer distances and it had not changed a bit.

Total elapsed time for firmware update, focus checks, focus adjustments, and final check was just about 10 minutes. Obviously a zoom lens, which can be adjusted both at different focal lengths for different focusing distances at each focal length, will take longer.


For the even slightly gear-head amongst us, this is an awesome tool, giving us the ability to fine-tune autofocus adjustment much more completely than simple camera microfocus adjustment. At $59, I consider it an amazing bargain for anyone who owns one of the Sigma Art, Contemporary, or Sports lenses (it does not work on older lenses).

I’ve already heard a couple of people complain that it should be included with the lenses but I disagree. First, the price is very reasonable and the software is free. Why would they include it with each lens (which probably means each lens costs $59 more) when you only need one for all of your lenses? Not to mention half the people who got it would never use it.

I’ve heard others state that only Sigma lenses need such a device. I’ll meet them part way: I think there is probably a more frequent need for such adjustment on third-party lenses, but I can absolutely guarantee you that the big-boy’s lenses do indeed have this same kind of problem, at least occasionally.

Whether they need it more frequently or not, now Sigma DOES have such a device. Which means, for example (just pulling a random lens out of my hat), the Sigma 35mm f/1.4 is now not only sharper and less expensive, but also more accurately adjustable than the manufacturer’s 35mm f/1.4. I wonder if anyone is hearing footsteps*?


Roger Cicala

June, 2013

* For my non U. S. readers, hearing footsteps is a term used to describe an American football player, who, thinking he is wide open and about to catch a pass, unexpectedly hears the footsteps of an unseen opposing player about to crush him.

Author: Roger Cicala

I’m Roger and I am the founder of Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Posted in Equipment
  • Waxy Parsnips

    After reading your article on AF calibration – The 35mm Art lens to be precise. I too own this incredible lens and up until a week ago, I was unfamiliar with this calibration issue. Reading through your article on this lens and calibrating it with the Sigma Cal.. dock, it seems to me that your only issue was the “infinity” setting on the lens. I just recently purchased the dock myself and like you, I prefer to use common items throughout the home to shoot and use as a guide to see if in fact that the lens is out of proper calibration. At what distances did you shoot the photos of the placemat on the table at? I assume you took one photo at each distance (4 photos) that the software program is set up for for this particular lens? (35mm 1.4 ART) Thanks in advance!

  • pete guaron

    Hi Roger – thanks for this article – I recently bought a couple of their ART lenses (24mm & 50mm), they’re lighter for traveling than the other lenses I use on my D810.

    From what I’ve read, you’re on the money suggesting that it’s not just Sigma lenses that need such a device. However, it seems to be “just Sigma” that is providing one.

    I definitely need it for the 24mm w/angle. Manual focus is always an alternative of course, but not necessarily the most practical choice. The 50mm needed a very slight tweak, and I have to say that even without, the results from the 50mm were outstanding on my first shoot with these two lenses. Not so with the 24mm, because it needs quite a substantial adjustment – and so I am picking up my USB hub next week.

    For those who manage to convince themselves that “this stuff doesn’t apply to my lenses – it only happens to other people”, that’s fine – soft focus lenses were all the rage back in the day, for portrait work especially, because it spared everyone the agonies of retouching and pared years off many people’s faces – LOL

  • Art M.

    Roger, did you develop a sense of what the plus or minus 20 steps actually correspond to, and whether their is a clear relationship to the plus or minus offered on Nikon D750 or D810.

    (That is, if I use Dot Tune and find I need +10 at a given FL/distance on the Nikon, will that correspond to +10 on the Sigma dock?)

    Thanks very much,

  • David Arkin

    I have been reading this thread about the dock. From the example above of BackFocusing you go to a negative side of the scale (-12) at the start.

    When I read the manual:

    When you adjust the value, click the ?? buttons in the spin box, or drag the ? button of the slider (Shifting focusing towards the front requires “-“ side, while back focusing orientation requires “+” side).

    I get confused by their syntax.

    My question is if the camera/lens shows Backfocusing then you go to which side of the scale? If you place a number into the Dock program for lens then do you turn of the AF Fine Tune of my D-810?

    Thanks for clarifying this.

    David Arkin

  • Jimmy C.

    My copy of the 35mm f1.4 also has focusing problem on longer focusing distance, and this device seems to be great. However I probably will use it for only once or twice, so I think it would be great if we can rent it. Will LensRental provide rental service for this in the near future? If so, I would love to get it and calibrate my lens at a lower cost.

  • Arthur

    Hi, is there any guide to estimates the value of adjustment for the 18-35 on a 550D? For a close range, both 18 and 35 are in focus, however the nightmare begins when I move 1m away. It has front focus.

  • Roger Cicala


    If I understand the question correctly, yes it will. Microfiches adjust and the Sigma dock only work on the phase system. The contrast detection system does no calibrate differently with adjustment.


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