Sigma 878101 USB Dock Mount for Canon Lens-Black

I bought this to calibrate the superb Sigma 50mm F1.4 DG HSM Art Lens for Canon. It's very easy to use and the software (at least on MacOS) is also straightforward. Having sampled the quality of Sigma Art lenses, I anticipate buying more, which makes the dock a really useful, cost-effective purchase.It's great to be able to fine tune your lens but also to update its firmware, as well as making other tweaks (configuring full-time manual focus and its sensitivity in the case of the 50mm).When I initially thought of acquiring this I wondered how much it would cost but was very pleasantly surprised; great value.Until consumer technology changes calibration is always going to be hit and miss (i.e. you have to keep tweaking via the dock and trying it on-camera) but that's the nature of the task. Tip, get one of these: DSLRKIT Lens Focus Calibration Tool Alignment Ruler Folding Card (pack of 2).

As described all good

Using this on a Sigma 150-600 sport. No software provided - has to be downloaded from Sigma's site (best way in my opinion for any new piece of software or drivers), but easy to download & install. Software for this is basic but usable (automatically checks for firmware updates for both dock & attached lens when lens connected) - hopefully new features will be added over time, software also provides information not provided on lens box or lens (needed the serial number for this lens for my camera insurance - nothing on box or lens, but showed up on the home page of the software). Device itself has a plastic (yet robust) feel to it, provided cable is reasonable length (have been able to use this on my desk without the need for an extension cable or replacing the cable with a longer 1 (unlike some other peripherals I have) and has a solid feel when connecting the lens. Overall a good addition if you have a compatible lens.

Sigma have upped their game in recent years, their lenses are on a par - if not surpassing - some original manufacturer's offerings. This USB dock is really easy to use and enables the user, through the Sigma app, to update firmware or change settings of their lenses to suit their needs, such as focus distance limiting or focus micro adjusting.For some lenses it's possible to change the focus speed/priority if required also.The app can be downloaded free from Sigma's website and, once the dock is attached to the lens mount and plugged into a usb socket, it will read the lens and enable adjustments to be made.Certainly worth having if you own a number of sigma lenses.

OK, so you will probably only use this a couple of times and then it will sit in a cupboard somewhere plus calibrating your lens is really tedious... but I've spent an hour and a half calibrating my 150-600 Contemporary and it's gone from a pretty good lens for the money to a real amazing lens for the money!If you are planning on buying a Sigma lens, especially a super telephoto where the Depth of Field is so shallow that focusing is absolutely critical, I would say you should definitely budget for the cost of the USB dock as well.Don't forget that you will also need a Lens Focus Calibration Tool - I bought the Maxsimafoto one as I couldn't see the point paying more than the price of the dock for the DataSpyder - it did the job. You also need two tripods (one for the camera and one for the calibration tool).There are lots of YouTube videos on how to do this but all you really need to know, and which doesn't seem very well documented, is that, for a given focal length at a given distance, if the lens is focusing behind where it should, you give it a negative number and if it is focusing in front of where it should, you give it a positive number. 4 focal lengths, 4 distances so 16 test shots. Adjust and repeat until you get it spot on - took me about 4 repetitions until it was right.My one tip is to do the calibration on a cloudy day (assuming you are doing it outside) as glare makes it harder to read the calibration scale in your shots and under-expose by a stop because that scale is very bright.Buy one (or borrow one).

Download the free Sigma Optimization Pro software unto your windows PC or Mac.Screw your lens into your mount and connect via USB and you're good to go.Run the software and you can easily update your lens to the latest software. I purchased it for use with the 150-600C which is incidentally remarkably sharp on the 7DII (sharper than my 400F5.6 and 300F4 - I must have got a good copy). With this lens I can calibrate for 4 different focal lengths 150, 250, 400 and 600mm over 4 different distances 3m, 6m, 15m and infinity. This allows you to make 16 separate adjustments!Using Micro Focus Adjustment (Canon) allows 2 adjustments, wide and tele.With this dock it's possible to make very specific adjustments indeed, for instance if everything works well, except 400mm @ infinity then you can dial in an adjustment for just that specific case, leaving the other 11 options at default.As it happened I didn't make any adjustments for my 150-600 as I felt it was sharp and well focused throughout the entire range straight out of the box but you can see the option to make 16 adjustments if necessary is very good.You can also set up custom profiles for the custom buttons on the lens so that you can have one profile set up for speed of focus and the other for accuracy at the cost of a little speed. I wish other manufacturers would follow Sigma's example here. A very handy product indeed.

Works perfectly, easy to use and great quality