Stephen Eastwood
June 21st, 2007, 09:53 PM
Is there a basic minimum shutter speed to use for given settings, like 24F, 30P, 60i ? Is there a disadvantage of faster shutter speeds as a means of reducing light over ND? Assuming of course no slow shutter effects are wanted when shooting. I am looking to maintain as much control over the depth by F stop and use the shutter to control that to an extent, but am not sure why people tell me to use ND when I have a lot of available speed left to cut down the light available first, also was curious of (in normal shooting circumstances) the lowest shutter speeds that can be used without adversely effecting the image quality, of course this is not for high speed slow motion effects, just normal avereage shooting conditions. Thanks for any help.
Stephen Eastwood
http://www.StephenEastwood.com
Don Palomaki
June 22nd, 2007, 06:44 AM
In general, for NTSC the slowest normal shutter is 1/60, for PAL 1/50. Below that one needs to understand how the camcorder internals function.
Except for possible hot pixel issues with very slow shutter speeds, the shutter speed issue is mainly with moving objects (or moving camera), thus it tends to vary with what is being shot.
Higher shutter speeds have a greater "stop motion" ability, resulting in less motion blur in the frame/field. This can give motion a bit of a different look, perhaps a bit more harsh or hard. It may look a bit more strobed to some eyes.
Best to run your own shutter speed tests to see what image effects you get and decide which best meets your artistic intent.
Trish Kerr
June 22nd, 2007, 06:53 AM
I'd start with a few of these threads
http://dvinfo.net/conf/showthread.php?t=90949
http://dvinfo.net/conf/showthread.php?t=74634
the idea is to stick with the standard shutter speeds as much as possible (I believe it is to emulate as close to how film behaves but I'm not 100% on that)
24p - 1/48
30p - 1/60 (though this is debated in one of those threads)
60i - 1/60
and for other effects go higher (for car racing, extreme sports as an example) or in low light situatons that make it unavoidable, go lower on the shutter speed
ie shooting 60i, normally standard would be 1/60 - but if you need more light 1/30 can work but you will start to see more blurring in fast movement - go down to 1/15 to see this effect or turn on the NIGHT shooting setting.
higher shutter speeds I can't speak to as much but I think in sports situations where movement is really fast the higher shutter speed will catch things better if you want to slow things down or need crisp full detailed frame by frame grabs
People suggest using the ND filters because this enables you to keep the F stop wide open as much as possible - best practice on this is somewhat in debate but most people say keep it ideally F1.x to 4.x and if possible don't go over F5.x as it produces less desirable footage
I'm still pretty green but this is what I've learned from the more experienced here
Trish
Bill Pryor
June 22nd, 2007, 04:51 PM
Stephen, it sounds as if you're coming from a still photography background, where for static objects you can use shutter speed for exposure control. With video, the standard shutter speed for interlaced 30fps is 1/60 in NTSCland, and 1/48 for shooting 24 fps (same as with a film camera). You can, on occasion, get by with a slower speed, but generally you'll get blurring and/or strobing. Faster shutter speeds can be used to a degree, but often you'll get some effects there too. Point your camera at a spinning fan blade and start changing the shutter speeds and see what happens when you get too fast.
Greg Boston
June 22nd, 2007, 05:28 PM
Point your camera at a spinning fan blade and start changing the shutter speeds and see what happens when you get too fast.
Or for more fun, use the clear scan shutter mode and dial the frequency until the blades appear motionless. (hehe)
-gb-