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View Full Version : Depth of Field advice


Troyan
05-15-2007, 02:55 PM
After attempting to use AR's DOF and finding several issues (such as a bug where when you use front blur you lose the alpha channel on objects in the background) I'm wondering what everyone else is using for a DOF solution, be it in rendering or for After Effects. I've looked at Lenscare for After Effects but since it requires a depth map from Cinema it kind of defeats the purpose. Any suggestions?

I'm asking this because i'm having a major flicker problem that seems to be with objects with a glow on them and DOF. You can see it here

TestDOF (http://www.thedanse.com/clients/hanahawk/approvals/celltestDOFflicker.mov)

Triker
05-15-2007, 03:22 PM
I can't speak for others, but ZBlur has been good to me.

basilisk
05-15-2007, 03:49 PM
you probably won't have much luck combine post effects like DOF an Glow - they are just not designed to go together. I think the general verdict last time this was discussed was that the best option is to use zBlur for your depth channel (it can handle transparency) and frischluft lenscare for the blur. AE lens blur is another option.

govinda
05-15-2007, 03:50 PM
Zblur rocks!

Troyan
05-15-2007, 04:00 PM
Hmm, I wonder if people like Zblur :).

Done. Thanks guys!

T

basilisk
05-15-2007, 05:33 PM
Zblur rocks!

Hey gov - do you use zBlur for blurring or just for generating the depth pass (do you use it with lenscare?)

JoelOtron
05-15-2007, 06:06 PM
I do all my dof in post via lenscare.

I have zblur -but have only used it to generate depth pass in scenes with transparency.

Troyan
05-15-2007, 06:12 PM
I do all my dof in post via lenscare.

I have zblur -but have only used it to generate depth pass in scenes with transparency.

I have both so I'll be trying that next.

govinda
05-15-2007, 07:00 PM
Yo Basilisk! I only just got zBlur two weeks ago. The thing I discovered is that my DOF and Blur needs are different. A tight DOF makes large objects look like toys, but atmospheric haze in my scenes needs to start close to cam. If you render out 16 or 32 bit, you can levels your depth pass until the cows come home, but it 'walls off' at your minimum point. Like for example if your depth distance starts at 4000m and goes to 25,000 meters, your gradient is between those distances, and no amount of levels or curves will get you a gradient start point at 500m. You get all white at 4,000m when you pull your gamma over.

There must be a better comping solution for this. So while it's almost an extravagant luxury, I almost wish there were two outputs, one for blur and one for depth. Using a separate Environment object loses the flexibility of doing fog adjustments in post. I could by smoking crack here however, as I haven't used depth all that much until lately.

Luckily with faster computers these days, pyrocluster works really nicely for light fog at like 2.5 minutes a frame on a 1.3 million poly scene on a quad g5. But no separate post render for it unless I'm missing something.

interactiveBoy
05-15-2007, 07:06 PM
govinda -

I don't have Cinema in front of me, but I seem to remember pyrocluster pass could be done with the Environment Ambience pass or something similar.

G

basilisk
05-15-2007, 09:47 PM
Yo Basilisk! I only just got zBlur two weeks ago. The thing I discovered is that my DOF and Blur needs are different. A tight DOF makes large objects look like toys, but atmospheric haze in my scenes needs to start close to cam. If you render out 16 or 32 bit, you can levels your depth pass until the cows come home, but it 'walls off' at your minimum point. Like for example if your depth distance starts at 4000m and goes to 25,000 meters, your gradient is between those distances, and no amount of levels or curves will get you a gradient start point at 500m. You get all white at 4,000m when you pull your gamma over.

There must be a better comping solution for this. So while it's almost an extravagant luxury, I almost wish there were two outputs, one for blur and one for depth. Using a separate Environment object loses the flexibility of doing fog adjustments in post. I could by smoking crack here however, as I haven't used depth all that much until lately.
Can't you get your depth pass to go from 0 to 25000 metres, and then use curves to adjust it to your requirements for use with lens blur/lenscare?


Luckily with faster computers these days, pyrocluster works really nicely for light fog at like 2.5 minutes a frame on a 1.3 million poly scene on a quad g5. But no separate post render for it unless I'm missing something.

Until my Octocore arrives, pyrocluster stays mainly in the box :(
Have you tried massive underground visible lights for fog - try wavy turbulence noise for smokey effects. You might need to enable dust. Works nicely for ghostly mist in churchyard scenarios, not so sure for ambient mist on a sunny day.

govinda
05-15-2007, 10:50 PM
Ah that's not a bad idea for fog, a trick I knew and then forgot. We don't have Lenscare and can't get it--we've used all our app/plugin budget. But that's the answer for having different distant hazes vs. blurs.

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