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Old January 5th, 2005, 01:30 PM   #1
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DV grain becoming a problem (Magic Bullet involved)

Ok so I shot some footage for my upcoming Thesis film.

I'm using AE and MB for post.

The problem is that I'm trying to blow out the scenes and make 'em hot (and B&W). Well when I blow them out the grain becomes totally noticeable to the point of being bad.

here are some examples:

http://www2.msstate.edu/~zwp1/3.mov is a close up showing the uncompressed capture from tape and how much grain it has in it.

http://www2.msstate.edu/~zwp1/2.mov is a 3 stage video showing the original to semi treated to fully treated and you can see the evident grain.

http://www2.msstate.edu/~zwp1/1.swf is the same as above but in smaller flash format. It's pretty crappy and has some jaggies but you get the point.

Anyways I think the grain is just inherent in DV and shows up when the footage gets blown out, but I'm wondering if anyone has any tips for me...from shooting to capturing to processing...anything to avoid this in the future. Thanks!
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Old January 5th, 2005, 02:15 PM   #2
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Try using diffusion effects, as that will mask/hide grain. Various ways to do it:
A- In MB, use white and black diffusion.
B- Duplicate video onto itself. Set top layer to around 50% opacity and apply a blur (such as gaussian blur, but that renders slow). You can unsharp mask the bottom layer to gain back perceived resolution.

2- I'll take a look at the clips.
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Old January 5th, 2005, 02:24 PM   #3
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Another suggestion:
To do the black and white effect, use a channel blend filter (selects red green or blue color channel to turn into black and white). One channel may have less noise than the others. It may also be that one channel looks better aesthetically than the others (i.e. the blue one).
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Old January 12th, 2005, 02:12 PM   #4
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Hey thanks...tried the MB black/white diffusion to no avail.

Duplicating the video on top of itself, while not reducing the grain, did have the added effect of giving me some sharper scenes..thanks!

And I'm not sure what you mean by the "channel blend" filter. I went to effect>channel>blend and it wasn't what you mentioned...

am I doing something wrong?
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Old January 12th, 2005, 02:17 PM   #5
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I'm not sure what the equivalent to the channel blend filter is in After Effects. Basically what you want to do is to turn just the blue, red, or green color channel into the black and white image instead of using all three channels for the black and white image (the normal way). I plan on playing around with After Effects eventually so I'll try to get back to you on that.

Another suggestion:
Don't brighten the road and the sky so much... it just brings out the noise and you may not want that look aesthetically.
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Old January 12th, 2005, 05:17 PM   #6
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Aesthetically that's the look I'm going for. It's supposed to be in the Mississippi Delta in the middle of the summer (and I'm shooting in the middle of the winter and these shots aren't shot in the Delta).

It's also kind of a supernatural (slighttttly) short story so I'm trying to give it a slightly disorienting feel to it...slightly surreal...not quite sure where you are.

Also the grain really pops out in the darker areas of vegetation and such.

Another note is that the grain is ONLY prominent in this shot of the truck pulling up. So I think I'm just going to reshoot it anyways (plus there's some grime on the lens). The rest of the shots are a-ok. I don't need the actor for that shot so I'll just get my brother to go drive the truck out...should just take an extra hour or so.

I'm still interested in AE's version of the channel blend though...thanks again!
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Old January 18th, 2005, 10:39 AM   #7
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For a channel blend effect in AE, you can go to Effects -> Channel -> Set Channels.

Pick the channel that looks the best or has the least grain. You can view each channel by clicking on the red, green or blue icons at the bottom of the composition window.

In the Set Channels parameters, set all the channels to the channel to want to use (i.e.: set all the channels to get their source from the blue channel). That will make the image B&W by using only the source from one channel.

You can also do the same thing with Effects -> Channel -> Shift Channels.
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Old January 18th, 2005, 11:00 AM   #8
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Have you tried Grain surgery?
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Old January 18th, 2005, 05:23 PM   #9
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downloaded the demo for Grain Surgery. Took me a bit to find because the initial site just says "for photoshop" I had to go back and do google for grain surgery after effects which took me to a spot on their site for the GS-DV plugin for AE. However when I went to click on the "download demo" part it took me to the demo for the photoshop thing.

However the PS plugin, like others, worked in AE. And while it helps a LITTLE bit. It hardly gets rid of it all...in fact it hardly does a suitable job. And the manual that comes with it doesn't give any pointers for AE or motion video...just still images (in which case it works great).


Anyways I went out this morning and reshot at a bunch of different f-stops and shutter speeds and now I have a grain free shot :)!
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