LensAlign from Michael Tapes Design
This is a lens calibration device. Your camera auto focus system combined with the lens being used will not necessarily be "spot on" due to manufacturing error tolerances. This can result in pictures that lack sharpness and look out of focus. This is specially critical with high aperture lenses where the depth of field can be minimal. Remember that depth of field is a factor of "camera's sensor size", "focal length", "distance to subject", and "aperture". See the problem I am talking about below. Click on any image to see a larger version:
135mm f/2 at normal magnification
The procedure for calibrating your lenses consists on taking a picture of the calibration device and making sure the in-focus region is evenly distributed around the "0" mark. On the first picture, I started by taking a picture of the device using my Canon 135mm set at f/2 (you always use the widest aperture):
On a first look, it looks fine. But zoom in at 100% and you will see that pretty much all the numbers on the ruler behind the "0" mark are out-of-focus while the numbers in front are significantly sharper. This lens in this particular camera used is front focusing (badly). See below:
135mm f/2 at 100% magnification
Fortunately, this camera provides focus adjustment and, after some try and error, using an adjustment of +19 and taking another picture, I get the image below, which is clearly much better than the first picture (with unadjusted focus).
135mm f/2 after calibration
So, you should do this with all your cameras and lenses (with auto-focus) combinations. It can be time consuming and a lot of try-and-error is involved. But it is well worth it, especially if you shoot a lot with very wide apertures. I will cover this topic more in depth, including all the steps I did, in an upcoming article.
PhotoVision Calibration Target
The second tool I have started using this year is the "Digital Calibration Target" by PhotoVision. It is a "disc" split in 3 colors: white, neutral gray, and black. It helps you set the correct exposure and white balance so that your subjects are lit properly (not too dark and not too bright) and no undesirable color casts are upon them.
This product comes in different sizes. And the best thing is the Instructional DVD that comes with it. Really well done and worth watching over and over again.
If you are into collages, this is the program for you. Just select the pictures you want to be in a collage, set parameters like the overall shape, final image size, and background color and click "Preview". Watch as the program creates your collage and that's it. Really well done. Much easier than doing this in Photoshop for example. There is also an Advanced tab to select other parameters like randomness and image angles. The overall shape of the collage could by anything you want to be. Just draw a smiley face and have a collage in that shape. Really cool. This app is available for Windows and Mac. You can buy it from the App Store for $25. More advanced versions of this program allow you to save as a PSD for editing later in Photoshop. Each image in the collage turns into a layer for individual manipulation. Really well done!
That's what I have playing with recently. I feel much more confident now knowing that my equipment is well calibrated. The calibration target really helps on those tricky situations like shooting against a bright or dark background, and also under tungsten light for example. And collages are always fun to do and a different way to deliver an image.