Interlace flicker

ccf

ccf

Member
How the hell do you get rid of this?? Ive tried the "reduce interlace flicker" plug in After Effects, but it just makes it a blurry flicker. It only happens on shots that are still, but wow is it bad. Anyone else have this problem?

oh yeah- dvx100a, detail: -4, vdetail level -1, detail coring +6. Should I alter these settings?
 
Are you shooting in 24fps? If so you need to remove the 3:2 pulldown in post production. I think there's a sticky on this somewhere.

This is my agony with Final Cut Express. It can't remove the 3:2 pulldown
 
nope, I mean when you slow down 60i footage. It seems to be really picky with little brances or lines...like powerlines....its seems like NOTHING can get rid of the flicker too? I masked a gaussien blur on there of something rediculous like 100 and it still came through. Oh, I'm slowing this down in after effects..."preserve edges" checked. I've also tried slowing it down in Final Cut but it does the same thing. ARG...
 
Are you viewing 60i interlaced on a computer monitor or TV? 24p has interlace artifacts on NTSC TV. 60I has interlaced artifacts on progressive scan unless you deinterlace (computer monitor, LCD or plasma TV). This is most noticeable in scenes with motion.

SCannon
 
I'm viewing this just on my monitor, but this shows up on an NTSC TV as well. I dont think you understand what Im talking about...instead of me trying to explain, I'll just post an example :)

http://www.cleancutfilms.ca/site/videos/flicker.mov

Please right click and save as. File size- 468 kbps (H.264 so Quicktime 7 is needed)

It's much more obvious if you make the movie bigger...but it's still evident at its compressed size (look at the tree branches if you dont know what Im talking about)

How in the world do I get rid of this?!
 
This looks like video noise not interlace flicker. Check you gain setting, Also from your first post you have detail set to -4 but detail coring set to +6. If you want to soften the image to make it film like then why bump up detail coring? Also detail coring sharpens the edges of the pixels like unsharp mask does in Photoshop. This artificially sharpens the edges. You will note that it is happening in the ares of fine detail and the overexposed sky. This can create the effect you see if the branches are moving in the wind. The pixels that represent this area is artificially sharpend and is fine detail that is accentuated.

I would turn down the detail coring to at least 0. Also use the zebra setting to help eliminate the overexposed areas. Your shot is a low angel looking up into the bright sky. Your front is under exposed and the sky is over. A good place for an ND grad filter.

SCannon
 
CineAlta said:
Why not just shoot in progressive?
Click to expand...

Well see, sometimes I like to use slowmotion. Doubling up progressive frames *usually* doesn't work to well. Thanks for the comment though.

scannon said:
This looks like video noise not interlace flicker. Check you gain setting, Also from your first post you have detail set to -4 but detail coring set to +6. If you want to soften the image to make it film like then why bump up detail coring? Also detail coring sharpens the edges of the pixels like unsharp mask does in Photoshop. This artificially sharpens the edges. You will note that it is happening in the ares of fine detail and the overexposed sky. This can create the effect you see if the branches are moving in the wind. The pixels that represent this area is artificially sharpend and is fine detail that is accentuated.

I would turn down the detail coring to at least 0. Also use the zebra setting to help eliminate the overexposed areas. Your shot is a low angel looking up into the bright sky. Your front is under exposed and the sky is over. A good place for an ND grad filter.

SCannon
Click to expand...

Trust me, this IS interlace flicker. I know what noise looks like. haha. I have my detail coring at +6 for a reason, to ELIMINATE noise. Turning your detail coring up towards +7 doesnt sharpen the edges, it softens noise in dark areas, making the picture SOFTER. In the negatives, you get a clearer picture, but more noise.

No, I do not need to use a Zebra setting to help eliminate overesposed areas. Have you ever shot in the woods under natural light? Well theres not a lot of it. If I were to expose for that sky, the image would be pitch black. I wasn't aware that the foreground is underexposed, because it looks fine playing on a properly calibrated monitor. Thanks for comin out though!
 
ccf said:
Well see, sometimes I like to use slowmotion. Doubling up progressive frames *usually* doesn't work to well. Thanks for the comment though.



Trust me, this IS interlace flicker. I know what noise looks like. haha. I have my detail coring at +6 for a reason, to ELIMINATE noise. Turning your detail coring up towards +7 doesnt sharpen the edges, it softens noise in dark areas, making the picture SOFTER. In the negatives, you get a clearer picture, but more noise.

No, I do not need to use a Zebra setting to help eliminate overesposed areas. Have you ever shot in the woods under natural light? Well theres not a lot of it. If I were to expose for that sky, the image would be pitch black. I wasn't aware that the foreground is underexposed, because it looks fine playing on a properly calibrated monitor. Thanks for comin out though!
Click to expand...

Sorry you are correct re the detail coring I was reading one thing an thinking the other in reverse, maybe too much wine. But the typo is still not a HAHA. HAHA is your exposure is shifted to overexposed in all of the areas where the "flicker" occurs. HAHA is there is no detail in the shadow areas of the rider's (your?) body in the clip. If its underexposed in the compressed video then the sky must be way over in the original footage if you say it looks good on a calibrated monitor.

I shoot a lot in wooded areas but not with the camera aimed from a shaded area at the the sky. Also I use ND grads which block the overexposure of the sky vs the landscape

Flickering is pixel dimension (1 pixel lines) and edge sharpening/edge enhancement affected. If this still flickers with detail coring set as you describe (I stand corrected in my prior e-mail) then think how bad it would be other wise.:love4:

This clip doesn't flicker in all of the fine detail areas only in the marginal areas around the sky/brightly light areas. BTW you don't offer info as to gamma?

The answer for this shot is that you need supplemental lighting (reflectors) to bring the shaded foreground in tight balance with the sky (inside 5 F stops more like 3 stops difference ) My taste your decision! THis is not as easy as it looks. In film the exposure settings don't generate flicker. But in this instance the underside of the fine branches retain detail as contrasted against the overexpose sky which blows detail away creating the flicker in some areas and not in others.

Good luck

S Cannon
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