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-   Canon XL and GL Series DV Camcorders (https://www.dvinfo.net/forum/canon-xl-gl-series-dv-camcorders/)
-   -   24p questions (https://www.dvinfo.net/forum/canon-xl-gl-series-dv-camcorders/34265-24p-questions.html)

Chris Hurd February 26th, 2005 01:05 PM

Unless you're intending to transfer your video to 35mm film, I would recommend shooting in the basic 24P mode, with 2:3 pulldown. The "advanced" 2:3:3:2 option is better suited for 35mm film transfer, but is not ideal for distributing on video.

That said, any number of other factors could be contributing to your problem. Don't shoot in the Green Box (easy recording) program mode, and make sure you have Gain set to +0db and not Auto. Other considerations are your shutter speed and any Custom Presets you're using. Welcome to DV Info Net,

Andrew Oh February 26th, 2005 01:14 PM

Also, do you mean noise or aliasing on edges? If that's what you mean, you may want to turn down the sharpness a bit.

Michael Galvan February 26th, 2005 07:25 PM

Hi Scot,

I don't know about Avid as I work with Final Cut Pro, but I would recommend always shooting in 2:3:3:2 as it gives you more options than regular 3:2 pulldown. True, 3:2 pulldown allows you to edit on a 29.97 timeline and is meant for final viewing on NTSC but by using 2:3:3:2, you can revert the footage back to true 23.98fps and edit in that timeline. When finished with your edit, you can simply reapply the 3:2 pulldown to conform it back to 29.97 NTSC or make a progressive scan DVD.

As for your footage, check all obvious things like gain and iris levels. It could also be due to your multiple exporting ... make sure you use the appropriate DV codecs throughout your conversions.

Hope this helps,

Richard Hunter February 26th, 2005 08:51 PM

Hi Scot. When you shoot in progressive scan mode, and then view the results on an interlaced monitor, you will often see flickering of the fine details. You can try setting the Vertical Detail to Low (in custom preset) to reduce this effect.


Scot Hampton February 26th, 2005 08:58 PM

Thanks Richard, Chris and Michael...I've been reviewing some of Adam Wilts materials on the subject...and I found some really good help files (pdfs) on 24p.com.

I think the problem was the interlaced monitor, as well as perhaps my gain settings, I think i had them set on auto for my prelim tests...Am going to go back next week and do some more thorough tests, with better settings.

Joseph Andolina February 28th, 2005 08:11 PM

Adam Wilts
Where do I find the PDF files by Adam Wilts?

Any help would be appreciated.

Chris Hurd February 28th, 2005 08:23 PM

Two separate things...

Adam Wilt (a DV guru) is at www.adamwilt.com.

Various 24P docs in PDF format are at www.24p.com.

Hope this helps,

Nico van Tonder March 1st, 2005 04:47 AM

Hi Scott,

I am shooting with a PAL XL2 and in the beginning I had bugs crawling all over my footage - to such an extend that I thought something was wrong with the XL2. I removed the UV filter, etc., but nothing helped.

I captured the footage on an old Compaq laptop while I was building a proper XT PC.

I gave that laptop to my grandson and bought a new HP Compaq nw800 Mobile Workstation with much faster RAM and a very fast 60GB hard drive - and quess what? The bugs dissapeared like magic.

I'm not saying that is your problem - but the PC plays a very important role when capturing. Ask me!!

Alvaro Duran March 24th, 2005 10:31 PM

XL2 ISO value at 24p
Hello everyone

I read this info in one of yoir messages:

If I have 60i, 16:9 Mode, 1/60th second shutter speed, 0db Gain the effective ASA of the XL2 is 400.

Considering this info may I assume that 24p, 16:9, 1/24th shutter speed, 0db gain is equal to an effective ISO of 160?

Mike Minor April 2nd, 2005 08:23 PM

Motion lines on 24p 16:9 Footage
Hello. When looking at some footage i shot on FCP (and also when i export it to DVD and watch it on a tv) i notice a lot of "motion lines" for lack of a better term. When theres moving on screen little lines occur around whatevers moving. Anyone experienced this/know a fix? thanks.

if you guys dont know what i'm talking about, i could post a short clip if need be.

Douglas Robbins April 3rd, 2005 02:06 AM

You will only see them in the browser and the viewer. They go away when you export the project.


Richard Hunter April 3rd, 2005 02:56 AM

Hi Mike. I'm not sure whether you are seeing motion blur due to slow shutter or some other effect. Posting a sample clip would be the best bet.


Rob Lohman April 3rd, 2005 03:16 AM

Hello Alvaro, welcome aboard DVInfo.net!

ISO is very difficult "thing" in the world of digital video. You cannot
really compare it to film. I have no idea if your numbers are sound
or not. May I ask why you would need the ISO info?

Mike Minor April 3rd, 2005 04:12 AM

Hey, they still existed when I exported them...so i uploaded a VERY short clip to show what i'm dealing with. It's short, but its full resolution so you can see the lines around any motion.


A. J. deLange April 3rd, 2005 08:10 AM

When you shoot 24p the camera takes 24 complete pictures per second and splits each into two fields. Calling the fields from the first picture A and A', from the second B and B' and so on the camera writes them to tape as AA' BB' B'C CC' DD' EE' FF' F'G GG' HH' and so on if 2:3:3:2 pulldown is selected. If 2:3 pulldown is selected the sequence is AA' BB' B'C CD' D'D EE' FF' FG. Each pair defines a TV frame with the two fields as given by the letters. Thus in 2:3:3:2 the first and second frames as seen on the TV are composed of the two fields from the first and second pictures taken by the camera but the third has its first field taken from picture B and its second from picture C. The next four frames are "pure" but the fifth is mixed and so on. Thus in 2:3:3:2 every 5th frame is a combination of fields from 2 different pictures. If you look at this on a progressive device (such as a computer monitor) you are shown both fields simultaneously with two pictures superposed in the mixed frames and that is what you are seeing except that in the sequence you posted you have 2 pure frames followed by 2 mixed. This, as the second sequence above shows, is to be expected with 2:3 pulldown which is what I assume you used.

The way around this problem is to shoot 30p. Only use 24p if you are definitely going to film and then use 2:3:3:2 pulldown because, as you can see from the sequences above, the individual original frames are easily recovered from 2:3:3:2 whereas they are not from 2:3. If you feel you must shoot 24p (I think the biggest beneficiaries of 24p are Canon's marketing department) then use 2:3:3:2 because only 1 in 5 frames is mixed as opposed to 2 in 4. Another solution is to view the footage on an interlaced monitor.

At http://homepage.mac.com/ajdel/FileSharing7.html you can download a sequence, "Fan" illustrating the points made above. Be sure to set high quality mode if viewing with QT (because if you dont only half the fields are shown) and look at the clip on both a computer monitor and an interlaced monitor if you possibly can. Step through 1 frame at a time to see what's happening.

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