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A quick search of the internet will find many an internet discussion about issues people have with their copy of a given lens not focusing as they'd like. In the past, getting this sorted meant sending your lens back to the manufacturer to get it calibrated, and even then it may not perform as you expect on your particular camera.
Over the past few years, camera manufacturers have started to incorporate lens adjustment features into their camera bodies, which goes some way to allowing a lens' performance to be fine tuned as you wish.
Sigma have now taken this idea a step further by launching their USB Dock accessory, which allows their latest lenses to be fine tuned, and even receive firmware updates from Sigma. The USB Dock has an RRP of £39.99, which seems quite a reasonable price, and is available for Canon, Nikon and Sigma mount. In this review we'll see how it performs.
Sigma Optimisation Pro needs to downloaded from www.sigma-global.com/download/en/ and the following minimum system requirements need to be met to run the software:
Once the software has been downloaded and installed, then the USB Dock can be connected up the computer via USB with a compatible lens attached.
For this review we used a Sigma 30mm f/1.4DC HSM lens, which had displayed some focusing issues during testing to see if these issues can be easily corrected.
The software picks up the USB doc almost immediately when connected via USB with a compatible lens attached.
Once the lens is detected, options for updating the firmware and customising the lens are available.
To see exactly how the lens was behaving before adjustment a tape measure was photographed at 45 degrees and maximum aperture, which showed the lens was focusing slightly closer than required. The software splits the focusing distance into four zones, which is especially useful for lenses that suffer focus errors at certain distances. For example, a lens may focus incorrectly close to the minimum focus distance, so only this zone could be adjusted if required. In the case of this lens, it consistently focused too close. By applying small adjustments and rechecking the lens, correcting the issue was relatively straightforward. As each adjustment is applied to the lens' firmware the software warns that disconnecting the lens before it is complete may result in damage, so some care may need to be taken to prevent this.
After making a few adjustments and rechecking how the lens focuses by examining images at 100% on a computer screen, I found that a +13 adjustment across the focusing range gave the most accurate results. The whole process of adjusting and checking the lens took around twenty minutes in total and was fairly easy to get to grips with. As a result the lens can now be used a maximum aperture with confidence.
Value for moneyThe RRP of £39.99 seems quite reasonable, especially as an optional lens hood for some lenses can cost more than this. Although many camera bodies now have focus adjustments built into them, they do not give the range of controls the USB dock does.
Applying adjustments is straightforward and there are plenty of options available, especially for the 'Sports' line-up of lenses. Having this accessory available also means that routine adjustments can be applied to lenses at home, saving money on lens servicing costs.
|The Sigma USB dock is good value for money and gives a wide range of adjustments.|
Sigma USB Dock ProsEasy to use
Wide range of adjustments available
Sigma USB Dock ConsPotential damage can be caused if disconnected when applying adjustments
Proprietary USB connection
|VALUE FOR MONEY|