Luminance Depth Render Pass

For a personal tutorial, I decided to do this tutorial about creating a luminance depth render pass to use in an alpha channel to get a realistic depth of field effect in Photoshop (a similar technique could probably be used for After Effects, too). Also, I used this forum post to figure out how to make an alpha channel in Photoshop, because I wasn't sure how to make one. Anyway, the tutorial was not too difficult to follow once I figured out what I was doing. Below, I included images with the two techniques, the Maya Software method and the mental ray method.

Maya Software method luminance alpha channel pass thing

Maya Software method luminance alpha channel thing applied to the image.

Mental ray method luminance alpha channel thing.

Mental ray method luminance alpha channel thing applied to image.

In the end I ended up using the mental ray method, because I felt like the software method did not blur the background enough (ie. the sink and the paper towels). However, I'm sure there is a way to get the Maya Software method to have a darker background on the alpha channel. Anyway, this tutorial was definitely helpful because it enables a realistic depth of field effect sans super long renders and lower quality with the Maya built-in depth of field on the camera.