Luminous Landscape Forum

Equipment & Techniques => Motion & Video => Topic started by: montego51 on December 08, 2011, 09:15:48 am

Title: 1080 60P shutter speed
Post by: montego51 on December 08, 2011, 09:15:48 am
New here. First post.

I bought a Panasonic TM700 camcorder in May, 2010 and love the 1080 60P mode. I recently purchased a GH2,  mainly so I could shoot 24P at a higher bit rate. I've been reading as much as I can about the GH2 and have a question.

Per recommendation, when in 24P mode I set the shutter speed to 1/50 on the GH2. Now, on my TM700, before I started using manual mode I noticed that in automatic mode it defaults to 1/60 shutter speed in 1080 60P mode, so that's the speed I've been using in manual mode. Should I be using 1/125 instead?

I shoot landscape/cityscape stuff with fluid pan/tilt head, a slider, and sometimes a crane. With the purchase of the GH2, I plan to shoot 24P and use the TM700 1080 60P on a 24P timeline as well.

Thanks.
Title: Re: 1080 60P shutter speed
Post by: fredjeang on December 08, 2011, 12:53:07 pm
Hi and welcome,

I don't know were you are located, in a PAL region?

The recommendation you've been given, to shoot at 1/50, is correct if you are in Europe but if you are in the US it should be 1/60. It depends on the electrical standards of each country (frequency).

the 24P (and 23,98) is suitable for cine and the web, but if you broadcast in Pal region and DVD it will be 25P, in NTSC 30.

If you shoot 24P and you need to pulldown to NTSC (30), you would first slow the footage to 23,98 and then do the pulldown to match 29,98.
In fact the Canon shoots 23,98 and not 24.

I'm not in favor of this and think that the simpliest way is to accept a speed increment on display.

The shutter speed is important according to your "electrical standard" region, but also do not shoot too fast, (ideally a 24p project would be 1/48 shutter speed, 1/48 = 1/50 ).

But then, if your subjects are not action, you can perfectly shoot at 1/125, but beware if there are moving objects and do not go over that speed. It would remove the blur, and in motion we need blur if not it looks staccato. Your speed should match with the electrical frequency (or be close to). So you avoid banding-pulsing.

I generally use a range of 1/25 - 1/50 - 1/100, in the us 1/30 - 1/60 - 1/125

when you ingest footage in a 24p project, the footage whatever raw speed was, is motion adapted automatically to the project settings.


Some people may tell you to be aware of your main output and choose the frame-rate accordingly, (ex, if you broadcast PAL choose a 25P project) but indeed, more and more people just avoid the pull-down so IMO stick with 24p is ok.

ps: I forgot to mention that not pulldown is valuable only, of course, if lengh isn't an issue. But if you shoot a campaign that has to be 9 sec not more not less and in Europe and north America, you're obliged to do versions so your choice would have to be the most relevant output.(ex, if the american version will likely to be more important, then those settings are priorized)
 
Title: Re: 1080 60P shutter speed
Post by: hjulenissen on December 08, 2011, 01:18:16 pm
It is generally recommended that the shutter time is 1/2 the frame period. So for 60 fps, you might want to use something like 1/120 second. Videographers seems to refer to this as "180 degrees shutter", googling the term will give you some background.

It is also recommended to choose an integration time that is close to, or an integer multiple of the inverse of the distribution/display refresh rate. For PAL-countries, that is 50 fps. For NTSC-countries that is 60 fps. For the cinema that is 24 fps.

It is also recommended to choose a framerate that is a multiple of the power line frequency if you are going to have lights in the scene that flickers at the power line frequency. Again, this is usually 50Hz in "PAL-countries", and 60Hz in "NTSC-countries".

In short:
60 fps and 1/120s if you want maximum realistic video and target tv/pc monitors and have sufficient light and the light is non-flickering.

50 fps and 1/100s if you live in Europe and target tv/pc monitors.

24 fps and 1/48s if you want "cinema look" and target cinemas.

Shorter exposure times if you want a "stroboscopic" effect. Longer exposure times if that is the only way to avoid excessive noise.

-h