Flickering pans

B

Brendan

Member
Hi all

I recently bought a DVX100 pal version. I’m fairly new to 25p shooting and I’m experimenting with the scene file settings trying out different looks. I love the rich tones achievable with 25p mode, static shots and wide-angle slow pans look beautiful. However, I’ve been using the cine-like pre-set F6 & any shot with significant motion {zoomed in pans, faster stedicam work} causes a huge amount of flicker when viewed on a pal monitor. I know that progressive formats are more ‘flickery’ than interlaced but these images are unusable and give me motion sickness! Can anybody suggest any camera settings that reduce this motion flicker or is this something that’s altered in post. Any advice would be appreciated.
 
Re: Flickering pans

I just wrote a huge, eloquent response with lots of tips & when I tried to preview it, it said my name wasn't entered & erased everything. So I'll give you the cliff notes version:

24p shooting requires thinking in terms of film shooting, not video. If you're used to 60i videography, you have to put yourself in a new mindset. With the advantage of a cool, film-like look, 24p does have it's limitations--no quick pans, no quick zooms, and certainly not the two together.

Don't shoot in F6 mode unless you plan to go out to film. The Advanced mode is for film output & looks weird on a video monitor if the pulldown isn't removed.

Try shooting in F5 (Normal) mode instead, as long as you don't plan to output to film. The normal mode adds standard pulldown in camera so you can edit at 29.97 (25 for PAL?) and view your footage on a standard interlaced monitor.

Also, check to ensure the OIS is set to off and that the shutter is set to off or above 1/48. 1/24 is tempting in low-light situations, but you'll regret using it if you're not locked down to a tripod, shooting something moving VERY slowly.

My advice--why not shoot at 30P? It's a great mode, and often overlooked because of the hip, uniqueness of 24p. But it will allow you a film-like look along with a bit more freedom of movement. It also cuts together with standard 60i footage better than 24p.
 
Re: Flickering pans

Sorry about that--completely forgot you're using PAL. So most of what I said probably won't help. Any PAL users that can advise?
 
Re: Flickering pans

F6 mode on PAL-version is not advanced mode. Since the PAL version uses 25p there is no need for it. The PAL version only got 50i or 25p as options. Everything else on the dial is only changes in the scene files, and no real mode. Besides that everything Jay wrote is also true for your camera. Progressive footage naturally looks more choppy than interlaced on a regular TV.
 
Re: Flickering pans

Jay, Thanks for the advice. tried using F5 and that smoothed the pans out considerably. In this setting the ‘V detail frequency’ is set to ‘thick’ which means {I think} that it merges pixels or something like that so you don’t get bits of different frames in each of the fields A and B on a PAL monitor. {could be completely wrong because this is all a new learning curve to me!}Because I’ve got the pal cam I don’t have the 30P option but I think some experimentation with F5 might be rewarding. So as I understand it, F6 {V detail frequency thin}is only used when the final output is to be an optical film print? For anything that’s going to be viewed on a PAL interlaced display, stick to F5 or an interlaced cine file? I think some more playtime with the new baby needs scheduling!! :)
 
Re: Flickering pans

Brendan--

Wish I could help you out more, but I'm a dunce when it comes to PAL. In terms of your question regarding detail frequency, you are correct about "thin" being used for film outs, and "thick" should always be used for video. it greatly reduces the flicker, but unfortunately, it also reduces the resolution as i understand it because you're losing 25% of the vertical scan lines.

hope this all works out for you. experimentation is definitely necessary for this camera--i don't think anyone has it completely figured out yet! Play around with the detail levels, shutter speeds, etc. and hopefully you can find the look you're desiring.

and remember-keep the pans slow! :)
 
Re: Flickering pans

You are correct about the Thin and Thick choices. However I wouldn't say F6 is for film blowup only. If i remember it correctly F5 is basically 25P while F6 is 25P with cinegamma. Thin and Thick may vary between the modes as well, which probably is the reason why you like F5 better than F6. The cinegamma on F6 should have nothing to do with the flickering.

Anyway, you can set up all the presets on the dial exactly the way you like. If you dont like the F6 preset, change it to something you like! That's one of the many great things with this camera.
 
Re: Flickering pans

johan, as i already stated above, most of the info given for the shooting modes was incorrect because it was based on the NTSC version of the DVX100.

The reason why F6 should be used for film out and not F5 (on the NTSC version) is because the two shooting modes each use a different type of pulldown--F5 using standard pulldown for an NTSC transfer, and F6 using an Advanced pulldown method, which needs to be removed via FCP4/Vegas in order to create a true 24P output for film.

If you do not remove the pulldown on F6, it will look strange because of the added frames from the pulldown.

I really don't know how the PAL camera works, but if F5 is working for Brendan, I say go with it.
 
Re: Flickering pans

Thin mode is also great for web viewing.

The flickering you're describing is most likely caused by your fast pans and is an issue with ALL 24/25p filming (including real film). The usual way to avoid it is to keep something steady and centered in the foreground, where most people's eyes will be focused and won't notice the flicker/stuttering in the background. Of course, you need to do very smooth fluid pans too just like the pros do. Smooth camera movements is actually probably the biggest part in pulling it off successfully if you have to do a fast pan (preferably try and avoid them at all costs).

You know, it's funny. For the last 6 months or so I pay close attention to any fast pan in any movie I watch. It's always stutter/flicker city yet nobody else notices them, because of smooth, fluid motion or an object in the foreground.

Another thing you can do while shooting is to lower your shutter, this will introduce a lot of motion blurring but may seem less jerky. As far as what to do in post, you could try using AE or something to stabilize the footage for your pans but it'd most likely be a tough thing to do.
 
Re: Flickering pans

:) its hard to just sit and enjoy a film after you start making them isnt it?
just got to see what techniuqes theyre using, and the color correctoin, and framing, and movement..blah blah.. a reall good example of a 35mm feature with a bad fast pan that flickers/strobes with no followed focal point in the frame is in "S.W.A.T." when the swat team is stiing next to a swimming pool and the camera pans to the left i think. its really bad because they moved the cam too fast. they are all just sitting there and the cam pans over the pool making an image motion about as smooth as a halrey davidson engine at idle.
 
Re: Flickering pans

Hi,

I have another strange result with DVX100 PAL version. Besides the flickering pan, I noticed that the image has many interlaced line (even captured in progressive mode) during the pan. This interlace line is very visible when I tried analyse frame by frame with Virtualdub regardless recorded in interlace or progressive mode. Is this only happen to me ? I can show these frame grab however I need free space to upload those pictures. Someone can help me ? :D
 
Re: Flickering pans

That looks like a lower/upper field order issue. I've never captured anything with VirtualDub, is there a lower/upper setting somewhere? It should set on lower first.

Sounds like something funky w/ VD, try using another capture program, like scenalyzer - you can download a trial version if you don't have anything else to capture with.
 
Re: Flickering pans

I use Vegas capture utility to capture and it properly recognize the clip as progressive, however from the preview window it looks interlaced during panning. From Vegas project I set the video field order to be none (progressive scan). The still/frame grab that I posted was from the save snapshot of Vegas preview.
 
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