Setting the SpyderLensCal up was easy
enough. The bubble level lets you know once you have the base of the device
level and from there the target locks into place. To ensure that the target and
camera's sensor are on the same plane, I mounted my camera on a tripod
alongside the SpyderLensCal and lined up the centre of the target and the
centre of my lens at the same height, before moving the camera into position. I
chose to first calibrate my Sigma 50mm f/1.4, which I use primarily for
portraits, and so positioned the camera at the typical distance that I would
shoot a portrait from using this lens.
I selected aperture-priority mode and my
lens's widest aperture, and focused on the target. I wanted to test the full
range of adjustment available, so started by setting the AF forward microadjustment
at it's maximum: -20.1 then changed the adjustment by five points after each
shot to record the full spectrum of adjustments. Before each shot, I set the
lens's focusing ring to infinity to ensure that the way the lens focused was
the same each time.
After loading in all nine shots to the
computer and zooming in to 100%, I eliminated the least accurate images. It
left me with what I felt were the two best shots that showed the zero indicator
on the SpyderLensCal's ruler in focus. In the case of the Sigma lens, these
shots were the ones taken with zero AF microadjustment and +5 backward
adjustment. With this in mind, I selected a middle ground of +3 backward
adjustment and took another shot. The image produced a sharper picture than the
shots taken at zero and +5, proving that a minor adjustment was needed.
I repeated the above on a Canon 135mm f/2L,
which I consider already to be a sharp lens. I was surprised to find that the
results showed that the lens required +7 backward microadjustment to produce
its most accurate results, making it even sharper.
Finally, I repeated the test with a Canon
24-70mm f/2.8L. I tested this lens twice, once at 24mm and again at 70mm. The
test revealed that at 70mm a zero microadjustment was the sharpest, whereas at
24mm a forward adjustment of -5 was needed. The Canon EOS 5D Mkll used for the
test does not allow for different microadjustments to be stored at different
focal lengths on a single lens (unlike the new Canon EOS-1D X), so I had to
take the average of the two, leaving me with -2 as my final setting.
Verdict
Once the SpyderLensCal was set up and in
place, it couldn't have been easier to use. The device feels well-built and
solid, and gives you the impression that you are going to get as close to
ideal test conditions in your own home as possible. The attached scale ruler
allows you to easily see how far forward or backward your lens is focusing -
however, this measuring scale doesn't correlate to the adjustment increments
on your camera, so some trial and error is necessary. If I had one complaint,
it would be that the supplied quick-start guide is overly brief and leaves
you guessing at some of the details in the steps taken. It does give you
enough to grasp the basics, though, and with a pinch of common sense you can
create a fair test environment for comparing each adjustment. At £50, it
isn’t the sort of thing you would rush out and buy if all you had in your kit
bag was your camera and kit lens. But if you have a collection of lenses, or
other photographers to split the cost with, then it is well worth the
investment.
Likes
Well-made, simple to set up and very easy to see the results from any
adjustments you make.
Dislikes
The instructions are on the concise side and leave a lot to be desired,
meaning research is needed before use.
Overall 
