Fast lenses, depth of field, and Photoshop CS6

[Sheiky]

Lol yes you're right about that. Even though pretty much everyone will be looking at 100% views of your photos, I doubt they will congratulate your photos for their beautiful bokeh
If Adobe comes out with a perfected version of the Iris Blur(It should recognize depth in a shot) before Lytro upgrades their product I foresee a small problem for Lytro

[Daniel Browning]

If Adobe comes out with a perfected version of the Iris Blur(It should recognize depth in a shot) before Lytro upgrades their product I foresee a small problem for Lytro

Forget Lytro. If Adobe can do that, then we should have them working on a cure for cancer, cold fusion, and warp drives. Unfortunately, it's just not physically possible.

[Sheiky]

Is it really? Isn't it possible that Adobe theoretically could recognize depth by analyzing the image for the amount of sharpness and contrast? Sort of like the Live-view AF mode? Or do I really need to do more homework?

[Daniel Browning]

Isn't it possible that Adobe theoretically could recognize depth by analyzing the image for the amount of sharpness and contrast?

In certain contrived circumstances, yes. But not for any (or even most) photos. The reason is that there are too many possible inputs (scenes) for the given output (a 2D image). For example, consider a test where you have two perfectly identical photos, but one was made using a large subject far away and the other was made using a small subject that is closer. The result is perfectly identical, so there is no possible way for Adobe to know which one is distant and which is close.

As another example, consider shooting through a chain-link fence. In the narrow f-number version, the fence obscures many details -- there is no way photoshop can get those back by blurring the fence with simulated thin DoF. If a wide f-number lens was used instead of software, the fence would be blurred into nothing and all the details would be visible on the subject (though overall contrast would be reduced, of course).

Hope that helps explain why it's impossible.

[Sean Setters]

Daniel, don't let facts get in the way of a good theory. Sheesh.

[Sheiky]

Hehe!(I had already started on writing a never seen before algorithm for it: Mission Impossible X) But thanks Daniel, that makes sense.

[btaylor]

I'm going to stick with fast lenses over a new trick in photoshop for two reasons:

1. The better low light usability
2. I like shiny toys with giant front elements.

There's no way photoshop or any other post production software can replace the performace of a high quality, wide aperture lens. I'll gut my 70-200mm f/2.8L IS II and use it as a water jug if Adobe can prove me otherwise.