Thursday, January 29, 2015

Canon EOS 7D Mark II and the Canon EF 24-70mm f/2.8 II ISO and Resolution Tests

The first test I wanted to know the optimal ISO settings to use for recording video.  Turns out that they are no different than the previous 7D model.  With the lens cap on, I switch to the different ISO settings.  The test reveals the following ideal ISO settings for recording video:

160, 320, 640, 1250, 2500, 5000

As you can see, they are all multiples of 160.  Here is the video:

The second test was to determine the "sweet spot" of my lens.  When a lens is wide open (i.e. f2.8), the optics are not as sharp.  When a lens is closed (i.e. f22), diffraction is your enemy.  So, what exactly is the ideal f-stop for optimum optical sharpness?  The following image shows a portion of a resolution test chart shot with multiple f-stops.  You can read the f-stop in the filename at the top of each image.

Obviously, you will want to click on the image to see it at the native size.  What this test tells me is that if I stick to apertures between f5.6 and f11 I should be fine... with f8.0 being the most ideal.  As I am most interested in doing GigaPans, this test was done at the maximum 70mm focal length.

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