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-   -   Frame mode and panning (https://www.dvinfo.net/forum/canon-xl1s-xl1-watchdog/15510-frame-mode-panning.html)

G. Randy Brown October 8th, 2003 12:13 PM

Frame mode and panning
 
Hi all,
As you all know, we are capable of getting a great look using "frame mode"; however sometimes I forget to switch back to normal when panning something (and we all know what that looks like). My question is: does anyone have any suggestions on how to salvage this footage in post. I have Vegas 4 (very happy with it, so please don't try to convert me) and tried "super sampling" but it didn't seem to help. Vegas also automatically describes the clip as "progressive scan" under properties (as opposed to "lower field first" as it does with clips shot in "normal mode". Any thoughts?
TIA,
Randy

Rob Lohman October 8th, 2003 02:22 PM

I can't help you out because I've not really had this problem.
The higher shutter speed you'll use the less it stutters when
it pans. I always shoot in frame mode also when panning. I
shoot in PAL with a shutter of 1/50th. At what setting are you
shooting?

G. Randy Brown October 8th, 2003 02:58 PM

Thanks Rob,
I usually shoot between 1/30 to 1/60
Thanks again,
Randy

G. Randy Brown October 12th, 2003 08:02 AM

Maybe we DON'T all know what I'm talking about so please allow me to elaborate: When I pan in frame mode (with either of my XL1S') or there is fast movement in the shot, I get unusable "blocky" footage. Shutter speed doesn't seem to make a difference.
Can someone please just tell me what you do (when using frame mode) when panning, do you have to switch back to normal mode, do you treat it differently in post or what?
Thanks,
Randy

Dean Sensui October 12th, 2003 01:28 PM

Hi Randy....

The problem you're facing is what some people refer to as "stuttering" where pans look jittery.

I don't know what the formula was, but with frame mode (or productions shot on film) certain pan speeds are avoided. They'll go either faster or slower, but certain pan speeds look really bad.

I've seen this happen in major Hollywood productions. It's an effect of shooting at a slower frame rate -- with interlaced you're getting 50 fields per second or 50 half-resolution frames per second. With frame mode you're getting 25 frames per second. So movements such as pans and tilts aren't depicted as smoothly.

Not a whole lot you can do in production or post-production except avoid panning at certain speeds.

Dean Sensui
Base Two Productions

Rob Lohman October 12th, 2003 01:43 PM

Well, he said that changing the shutter speed didn't help.

Can you post 1 frame where this "blockyness" happens? Or if
you don't have a website e-mail me one picture please directly
from the movie.

As I said before, I just shoot pans in frame mode. Don't do
nothing with them before, while shooting or in post.

Barry Green October 12th, 2003 01:55 PM

There are detailed charts that spell out what panning rate you should use, to avoid stuttering with a film camera, based on the focal length of the lens and the FPS you're shooting at. You can find them in the American Cinematographer's Manual.

However, it can also be summed up with this rule of thumb: an object should take about 7 seconds to cross the screen. Any faster than that and there will be noticeable stuttering.

With an NTSC XL1 in frame mode, the faster 30fps capture rate would mean that you could pan a little quicker, so perhaps six seconds for an object to cross the screen...

Andre De Clercq October 12th, 2003 02:18 PM

Stuttering pans belong to the world of "film look". Some people aparently like thes artifacts... If the motion is slow enough the eye has learned to live with those shortcommings and film people have learned how to "hide" them. If you want to limit those temporal sampling effects and artifacts (like the reverse rotating stagecoach wheels) its important to use the longest possible shuttersetting (1/50 or 1/60).

G. Randy Brown October 13th, 2003 09:28 AM

Wow thanks everybody!
I've never seen this kind of response here. Anyway, Rob I e-mailed you a .jpg of the blockiness I was referring to....if anyone else is interested let me know (sorry, I have a website and I even uploaded the .jpg, but can't figure out how to link it where you guys can see it....maybe after I wake up)
Thanks again everyone,
Randy

Rob Lohman October 13th, 2003 01:11 PM

I looked at your picture. I'm not sure why you are calling it
blockyness because I don't see any. Your probably talking about
the blurry stuff that is going on? The lower the shutter speed
the more blurry it will get. The easiest resolution is to increase
shutter speed.

If I'm interpreting it wrong it might be time to put up a short
movie sample for everyone to see.

I'm basically out of suggestions for you...

G. Randy Brown October 13th, 2003 01:25 PM

Sorry, maybe I'm not clear on the terms, perhaps blocky means pixelated? Maybe stuttering is the term I should have used (or maybe just crappy); anyway, I apologize for my ignorance but perhaps I'll try to shoot some test footage at a higher speed; I just didn't think that could be the answer since the image in the viewfinder gets worse.
Thanks for everyones patience,
Randy

Joe Garnero October 13th, 2003 02:42 PM

Try turning off the image stabilization. I have had some luck with this approach; after all you are trying to use motion, while the cam is trying to cancel motion. Sometimes leaving this on with the cam locked down may cause the IS system to try and remove in-frame motion.

Just a thought ;)

Andre De Clercq October 13th, 2003 03:15 PM

Turning off EIS will partly solve the stutter visibility because of the shutter speed lowering. OIS will not change stutter behaviour when panning

G. Randy Brown October 13th, 2003 03:46 PM

Hmmm, makes sense Joe, I'll try it. Andre, what's the difference in OIS and EIS (while you're at it what does EIEI O mean : )
Thanks guys,
Randy

Andre De Clercq October 14th, 2003 03:04 AM

EIS is "Electronic Image stabilisation" wereby the image readout zone on the CCD is permanently adapted to the (shaking) image it gets. In order to get rid of motion blurr (because the image still moves on the CCD) the shutter speed is automatically set somewhat higher (1/100). Higher shutter speed makes stuttering more visible. OIS is "Optical Image Stabilisation" . Here the shaking image is made stable on the CCD using optical elements which adaptively bend the incomming images so that there is no longer motion on the CCD level, and no need for shorter shutter settings and thus no effect when being set "off"


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