Sigma USB Dock for Canon

This is equivalent to reviewing a movie. The details of the delivery media (say a DVD) is much less interesting than the movie itself. The hardware, in this case the USB Dock you're considering purchasing, just works as expected. You attach it to your supported lens and plug it in to your computer. Settings you make in the software is transferred to your lens. End of story.This review focuses on the entire solution, particularly the software - its design and how well it addresses the problem at hand.Top camera bodies from Nikon and Canon (and possibly others) support lens focus fine-tunning. Notice that, due to fabrication tolerances, this fine-tuning is necessary to match a particular lens to a particular camera body. I have tunned all my lenses and can attest that it does make noticeable difference in image quality.The problem is: You can only set one value per lens.Say your body/lens combination backfocuses. You set a negative value, essentially telling the camera to front focus a bit to compensate. That works well for a prime lens, but not for zooms. What if the zoom back focuses at the short end of the range but front focuses at the long end?Sigma had a brilliant idea: move the tuning process away from the constraints of the camera and into a computer where it can be done properly. Not only it allows fine-tuning the focus, it also allows one to customize a (supported) lens for different behaviors. In the case of my Sigma 120-300mm f/2.8 there are 2 variables, namelyAutofocus={speed priority (fast, a bit jumpy), accuracy priority (smooth but slower), default (somewhere in between)}andOptical Stabilization (OS)={heavy, light},for a total of 6 possible combinations. You'll need this dock and the accompanying software to set your preferred custom behavior into the lens.There is a third function: one can update the firmware in the lens using this dock. Firmware in a lens... that's a first for me. The fact that they had to put microprocessors in a lens to implement this in-lens customization (and thus needing firmware updates) should be transparent to the user. So I won't count this firmware update function as neither a pro nor a con.It must be noted that Sigma's solution surpasses the current state of the art (from Nikon/Canon/etc), in that you can set not only one but at least 4, and up to 16 values, depending on whether the lens is a prime or a zoom. The price for this much flexibility and control is the escalating amount of trial and error steps (set in computer, test on camera, repeat...). It's almost overwhelming and addictive. And I like it.The software (not supplied with the dock, but it's a free download) is well executed, with a simple and intuitive presentation.There are some defects here and there, mostly text that get truncated because they don't fit in a window panel that can't be resized. Fortunately, one can bring up the help and read the message in its entirety there. I'd say the software is so intuitive that there's really no need for help at all. Most of the text in the help is a copy of the text you see in the software anyways. It would've been nice if they elaborated/reworded what you see on the software panels. For example, when setting the OS customization, you can pick from Dynamic View Mode ("This mode offers a recognizable OS effect to the image in the viewfinder. This helps to ensure the composition of images quickly.") or Moderate View Mode ("This mode offers an excellent compensation of camera shake, and achieves very smooth transition of the image in the viewfinder. The composition of the image remains natural even when the angle of view keeps changing."). The explanation in the help is exactly the same as in the software. Can you tell which mode has more OS and which has less? I used the terms "heavy" and "light" above, which are more descriptive than "Dynamic" and "Moderate". If you want to know... Dynamic View=heavy and Moderate View=light.The one con that I can think of is this: while the software automatically recognizes which Sigma lens you docked, it has no knowledge of which camera you intend to use the lens on. The software stores only one setting for each lens. It would be nice if Sigma were to add the ability to memorize several settings for a particular lens (each corresponding to different cameras) so that they can be easily and quickly recalled and loaded into the lens.On the whole, I'd say this USB Dock is likely a must have item if you want to get the most out of your Sigma lens, especially a zoom lens (like the 120-300mm f/2.8).This is the best tutorial on how to use the Sigma Optimization Pro software that I know of.http://vimeo.com/64665246Update 4/01/2014: Sigma has since introduced 7 new lenses (including the 3 for mirrorless cameras) and none of them support/use this dock. I don't know why they've chosen that route, but the end result is that, at this time the value proposition of this dock isn't what Sigma suggested it would be.I'm changing my review from 5 to 4 stars until I see more lenses compatible with this device.Update 9/14/2014: Per Sigma's website[...] all 8 (A, C, S) lenses support this dock. Only the mirrorless series of lenses don't support this dock (I don't know why that must be the case; it seems like it'd be a good idea for all lenses to be focus fine tune-able, mirrorless or not).They must have forgotten to update that site last time I checked, which led me to my conclusion in the previous update. Their site has been corrected now.I'm changing my rating back to 5 stars.

As a Canon EOS 60D shooter who's fallen in love with the Sigma 18-35mm f/1.8 DC HSM Art lens for its razor-sharp wide-angle versatility and creamy bokeh in portraits and video, I always felt like there was untapped potential lurking in its autofocus performance. Enter the Sigma USB Dock for Canon – this little powerhouse has elevated my setup from great to exceptional, allowing me to fine-tune and update my lens like a pro without sending it off for service.The dock itself is compact and user-friendly: it connects via USB to my computer (Windows or Mac compatible), and the included Sigma Optimization Pro software is intuitive and free to download. Setup took minutes – just plug in the lens, launch the app, and you're ready to tweak autofocus microadjustments at multiple focal lengths and distances, update firmware for the latest improvements, and even customize features like focus speed or OS (Optical Stabilizer) behavior. For my 18-35mm, which can sometimes front-focus slightly on my 60D body, the AF calibration tool was a revelation; I dialed in precise adjustments across the zoom range, resulting in tack-sharp focus every time, especially at f/1.8 where depth of field is unforgiving.In real-world shooting, the difference is night and day. Whether capturing fast-paced street scenes or cinematic video footage, my hit rate on critical focus has skyrocketed, and firmware updates have smoothed out any minor quirks, like better compatibility with Canon's in-camera corrections. It's also future-proofed my investment – Sigma regularly releases updates for their Art lenses, and this dock ensures I'm always running the latest.At an affordable price point, this dock is a no-brainer for any Sigma lens owner, especially with the 18-35mm's reputation as a "crop sensor holy grail." It's built solidly, with a secure bayonet mount that holds the lens firmly during calibration. If you're serious about maximizing your gear's performance on a Canon body like the 60D, grab the Sigma USB Dock – it's an essential tool that pays dividends in image quality. 5 stars – highly recommended!

Works just as intended. Build quality is very nice. Price is decent for what it does and what you will use it for if you have one or more sigma lens and want to keep the updated and be able to adjust certain aspects of the lens or lens you have. Worked flawlessly with my sigma 18-35mm f1.8 Art