Camera and Lens Calibration with the Sigma USB Dock – Mike Palmer – Sabi Sabi
I’ve had the opportunity to shoot exclusively with some of Sigma’s new Global Vision range of lenses over the last few months and I’ve been hugely impressed with every product I’ve used thus far, including the extremely handy Sigma USB Dock.
As a working Field Guide at Sabi Sabi Private Game Reserve, my gear gets tested to its limits and the three lenses in my possession, namely the 150-600 Sports (My favorite), the 120-300 f2.8 Sports and the 20mm f1.4 Art, have undergone the same treatment as the rest of my Nikon gear. Needless to say the build quality is second to none and in fact far superior in some cases to my native kit, but you’ve heard this all before. We know the Sigma products are great quality and the results speak for themselves, but being a perfectionist, I did notice a compatibility issue with the telephoto lenses and my Nikon cameras. An issue that I have not heard about from any of the Canon users.
I found that the lenses attached to my cameras were forward focusing quite a lot and there were moments of sharpness, but not in every image. I investigated further, played around with focus techniques, focus modes and studied the images to figure out why my images were not tack sharp and that is where I noticed the issue. Now I know that these lenses are sharp and in many cases I was using a beanbag on stationary subjects where I couldn’t have messed up the focus. Shutter speeds, stabilization and everything else in favor. I have also seen the results from some of my colleagues using their Canon equivalents and I myself had seen some of my images being really sharp too, so I was determined to get to the bottom of this. I did some research on the ‘School of Google’ and found it to be a fairly common problem experienced across all brands of cameras and lenses, so I felt it quite important to share this with anyone who may be experiencing the same thing. Do not be discouraged with the purchase of your brand new lens if it’s not tack sharp out the box. It happens…what you need to do is calibrate camera body and lens so that they speak fluently with each other and you will see a dramatic improvement to your images.
You can take your gear to professionals and have this done in-store, but if you are like me and live in a remote area or just like to tinker with your gear on your own then this is how you can go about it:
On the Nikon camera bodies there is a “AF Fine Tune” tab under the Settings menu and this can be adjusted accordingly. It is simple to do and all it takes is a bit of time, patience and a lot of sample shots. I used a ‘Spyder LensCal’ calibration chart and a tripod to simulate a more controlled and accurate reading. The aim here was to get the focus plane as close to the zero line as possible across all ranges of the particular lens.
On the Nikon D750 & Sigma 150-600mm Sport combo, I only had to use the camera’s AF Fine Tune function, setting it forward by 12 points to achieve a consistent sharp focus across the range of the lens especially at wider apertures. It has made a massive difference to my images and I am thankful that the camera has this function built in.
With the D800 & Sigma 120-300 f2.8 Sport combo, it wasn’t so simple and I found the focus plane quite far out so I used the AF Fine Tune function in conjunction with Sigma’s USB Dock.
The Sigma USB Dock is a wonderful addition to to the Global Vision range of lenses and I found it incredibly useful in sorting out my focus issues. This is not however, the only function of the Dock and by attaching your lenses to the Dock via your computer, you can customize focus settings like accuracy and speed, Optical Stabilization settings and also update the lenses Firmware. It’s a very useful tool indeed and allows the user to customize each lens to their particular style of shooting.
In conclusion, once I managed to iron out the focus communication between my cameras and lenses, the photography experience with the Sigma products has been even more amazing and I am so impressed at the colour reproduction, image quality and versatility of these lenses.
I hope this short tip has helped some of you out there that may have experienced similar issues. Maybe mine is an isolated case, but perhaps for most users the thought hasn’t occurred to them to check. It seems as though there is definitely less communication when paired with the Nikon line of bodies, but again I may have just been unlucky.
All the best and happy shooting.
Assistant Head Ranger
Sabi Sabi Private Game Reserve