Canon patent to increase dynamic range with use of Neutral Density filter (using Dual Pixel AF)

p

Canon filed  patent to increase dynamic range by using a Neutral Density (ND) filter on half of the measured field. This is a pretty complex one and I am not 100% sure I got it right (any help welcome).

The described system works by getting different degrees of light intensity from the Dual Pixel auto-focus (DPAF) points (i.e. split pixels) on the sensor. The patent says the ND filter is placed on 50% of the measured field: different amounts of light hit the split AF pixels needed for DPAF (this means both of the split pixels are used to measure the DR). The result is an output that’s able to render an increased dynamic range to the sensor, and a easier to measure differential signal from the DPAF points. It is not as easy as I am trying to put it :-) To learn more about Canon’s Dual Pixel Auto-Focus technology have a look here.

  • Patent Publication No. 2015-87401
    • Published 2015.5.7
    • Filing date 2013.10.28
  • Canon patents
    • Dual Pixel AF
    • And set up a half-ND filter at the pupil position of the lens
    • Half ND filter can be switched
[via Egami]

Yet another Yongnuo 35mm f/2 review

Another review of Yongnuo’s budget lens, the 35mm f/2, by Shooting on a Budget. In the conclusion:

The autofocus in video has improved since the YongNuo 50/1.8. With that lens, the autofocus would hunt, but fail to catch. In this, it’s slower than the Canon, but it works somewhat. It will zip close pretty quickly, but then takes a handful of zips back and forth to finally catch, about 2 seconds worth.

Read the review at Shooting on a Budget.

The Yongnuo EF 35mm f/2 is [shoplink 28529 ebay]available on eBay by Yongnuo itself for $116/€107[/shoplink]. The Yongnuo 35mm isalso available on Amazon.

Yongnuo 35mm f/2