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XDCAM EX 1 stutter and blur

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Hoku Uchiyama
XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 12:12:18 pm

Hey Folks,

I've seen this question posed a few times throughout this forum, but I haven't come across definitive answers on it (yet).

I'm prepping a documentary where we're shooting on the XDCAM EX1. In our test shoots in HQ 1080 24p, I am seeing a stuttery look in the movement (which is the most offensive thing to me) along with some blur.

When the camera moves the image blurs and when the camera settles, the focus returns.

The shutter is on and is open, either at 1/32 or 1/48. (closing it decreases the blur a bit, but it is still there and it does nothing for the stutter)

I've also tried HQ 1080 30p (shutter 1/40 or 1/50). 30p does not have the same stutter problem but it does have the blur (again, closing the shutter helps the blur a bit but doesn't kill it). I find 30p to be less distracting, but I'd REALLY love to shoot 24p because I like the image quality better.

I've worked with the HVX200 in 24p and did not have the same problem.

I've heard the issue may lie in the XDCAM EX1's compression.

Is there anything I can do about this so I can work with 24p with out the strong stutter? This is a doc that will be almost all handheld and will involve a lot of fast movement. I worked handheld with the same fast subjects using the HVX and had no problems. I'd really love to find a way to calm the XDCAM EX1's stutter in 24p (and maybe that blur to).

Any help would be greatly appreciated.

All the best!

-Hoku

http://www.hokuuchiyama.com



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Steve Connor
Re: XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 6:03:40 pm

You can try reducing the detail level - that will help with the blur in pans. Sony set their detail levels too high as standard anyway.

24P is not a great frame rate to use if you are handheld with fast movement anyway, 30P would be better.

Not sure why you think the image quality of 24P is better than 30P because there's no difference at all apart from the frame rate!

Steve Connor
Adrenalin Television

Have you tried "Search Posts"? Enlightenment may be there.


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Hoku Uchiyama
Re: XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 6:09:59 pm

Hey Steve,

Thank you.

When you say reduce the detail level, do you mean working in HQ 720 as opposed to HQ 1080?

Also, I guess in general what I meant is that I like the look of 24p motion, just not thus far on this camera and I was hoping to find a way to achieve the same fluidity that I found on the HVX200.

Thanks again for your response.

I am definitely also interested in hearing from others.

Best,
-Hoku

http://www.hokuuchiyama.com



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Craig Seeman
Re: XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 6:47:44 pm

In order to judge the 24p motion you may need look at the results on a monitor capable of playing 24p or doing a proper pull down to 29.97 (and some don't do this well at all).

Keep in mind the HVX200 does 24p and 24pn. Sony EX only does "true" 24p (23.98) with no pull down added.

EX has a Detail control in the Picture Profiles. Some find the Sony default creates edges that are over sharpened. Reduce Detail can help in creating a more "filmic" look.

BTW I'm also not a fan of 24p. The difference between 24p and 30p or 60i or 60p is that 24p has the least temporal resolution. Fewer frames means greater distance between a frame of motion captured. That means either you have more motion blur or more "stutter" one way or another.



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Hoku Uchiyama
Re: XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 8:06:59 pm

Hey Guys,

Thanks once again for taking the time to help!

Craig, in reference to the pulldown you said "some don't do this well at all". Can you explain further?

On the HVX200 we were working in 24pn and I was satisfied. Are there any settings that I can work with on the XDCAM EX1 that will calm the stutter down (save for the shutter setting cause it's already wide open)? 30p is just a bit too fluid for me.

All the best,
-Hoku

http://www.hokuuchiyama.com



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Craig Seeman
Re: XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 10:49:30 pm

[Hoku Uchiyama] "Craig, in reference to the pulldown you said "some don't do this well at all". Can you explain further? "

To put it simply they don't properly take the frames (fields) and split into additional frames to create new ones. Some may simply duplicate frames creating very bad stuttering.

It's really hard to compare unless you have the two cameras recording the same source and testing with the same monitoring setup.

23.98 is 23.98 regardless of the codec. The same can be said for shutter speed as well (although there's certainly a difference between CCD vs CMOS scanning). Certainly Long GOP is different than an all I frame codec but that isn't likely to impact motion, just allocation of bits and decoding etc. It's very hard (although not impossible) to break XDCAM 35mbps VBR Long GOP and you'd have have to do a pretty hard wipe pan to do that and, in that case, the image won't look wonderful on any codec given the motion blur.

If you have comparisons why not post to Youtube HD and post the links here. Granted it's going through some significant compression but YouTube will play back 720p24 as will Vimeo (if it's truly 24p and not in 29.97 which Vimeo will butcher mercilessly).




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Hoku Uchiyama
Re: XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 11:10:06 pm

Hey there. I will try to post the footage. At present, I'm on a very slow internet connection so it may take a while or not be possible.

I don't have side by side comparisons of the HVX200 and XDCAM EX1 shooting the same thing. But I do have footage from both cameras in true 24p, where subjects (and my handheld work) are doing the same kind of motion with different results.

I will post if I can.

Thank you very much!
-Hoku

http://www.hokuuchiyama.com



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Hoku Uchiyama
Re: XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 8:37:42 pm

By the way,

Would exporting a HQ 1080 24p clip to a 29.97 format constitute as a proper pull down test?

Or is their a simpler way?

Thanks!
-Hoku

http://www.hokuuchiyama.com



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Craig Seeman
Re: XDCAM EX 1 stutter and blur
on Jan 7, 2009 at 10:52:24 pm

[Hoku Uchiyama] "Would exporting a HQ 1080 24p clip to a 29.97 format constitute as a proper pull down test? "

Some software is better than others at adding pull down so that's not a good test. The whole point is you don't want to see it that way. You want to see EXACTLY what the camera recorded without the risk of something mucking at it the wrong way.

Show us an HVX and EX example in native 24p in HD. YouTube and Vimeo will do that.




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Hoku Uchiyama
Re: XDCAM EX 1 stutter and blur
on Jan 11, 2009 at 1:20:32 am

One other question:

I often find quicktime to be deceiving when viewing DV and DVCAM stuff, in particular when judging motion.

How is quicktime on a macbook screen for accurately judging HD footage shot on the XDCAM EX1 (with an eye for motion/frame rate)? How does it compare with viewing on an HD monitor? My guess is you're missing quite a bit viewing on quicktime as opposed to a monitor, but I wanted to see what others had to say.

This would be for footage in both 24p and 30p.

Thanks for any help you can provide.

-Hoku
http://www.hokuuchiyama.com



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