View Full Version : 1/30 and lower


Ozan Biron
June 4th, 2009, 10:24 AM
I dunno if its me but i CANT seem to get lower then 1/30 shutter in the "new" manual mode. The wheel only turns soo far.... Is there a way to set the camera lower then 1/30 shutter?

o

Rick Casillas
June 4th, 2009, 10:44 AM
Ozan,

I am not an expert, but it seems to me that if the camera records at 30fps, then it would follow that it needs to shoot at 1/30 so that one frame can be coded 30 in one second. Any lower and you will be getting duplicates and partials, I guess.

Jon Fairhurst
June 4th, 2009, 11:50 AM
Rick is right. At 30 frames per second, the exposure of each frame cannot be longer than 1/30th of a second. The camera could simulate a longer exposure by adding in previous frames, but you can also do that in post.

One way to accomplish an interframe blur in most any NLE would be to duplicate your timeline, slide one of the timelines to the right by one frame, and then adjust the opacity of the top layer to taste. Various NLEs will likely have more specific motion blur effects and plugins; the above method is generic.

Ozan Biron
June 4th, 2009, 12:04 PM
Rick is right. At 30 frames per second, the exposure of each frame cannot be longer than 1/30th of a second. The camera could simulate a longer exposure by adding in previous frames, but you can also do that in post.

One way to accomplish an interframe blur in most any NLE would be to duplicate your timeline, slide one of the timelines to the right by one frame, and then adjust the opacity of the top layer to taste. Various NLEs will likely have more specific motion blur effects and plugins; the above method is generic.


hmmm, dats weird. I remember before the new firmware update.... i was able to hit lower then 1/30... The image would be super grainy but it totally helped in low light.

Noah Yuan-Vogel
June 4th, 2009, 01:25 PM
Yes, in non-manual mode or in the old firmware, shutter would read very slow settings in very dark shooting situations, slower than 1/30th, but they were never actually used. When it said 1/15th sec shutter it was actually just using iso 6400 etc. thats why it looked extra noisy when the shutter number went down below 30. if it was actually using slower shutters than 1/30th, it would get blurrier and choppier, not noisier. now you can just set your iso super high if you want, if i recall they go pretty high above 3200 if you use manual mode and you have extended iso modes turned on.

Bill Binder
June 4th, 2009, 02:08 PM
Rick is right. At 30 frames per second, the exposure of each frame cannot be longer than 1/30th of a second. The camera could simulate a longer exposure by adding in previous frames, but you can also do that in post.

One way to accomplish an interframe blur in most any NLE would be to duplicate your timeline, slide one of the timelines to the right by one frame, and then adjust the opacity of the top layer to taste. Various NLEs will likely have more specific motion blur effects and plugins; the above method is generic.

I believe it actually is possible to go to REAL shutter speeds (not simulated) below the framerate (not on the 5D) -- which is not possible in post. For example, if you shot at 1/15 with 30 fps, then the 1/15 frame would be repeated twice after the fact to fit into a 30 fps file. Kind of pointless at that point cause it'd be better to just put it into a 15 fps file, but I do believe there are cameras that do this very thing, it's obvious because the shutter drags really, really bad. People sometimes use it in doc work in extreme low light, no? Can't the DVX do this?

Jon Fairhurst
June 4th, 2009, 04:36 PM
Bill, if the camera slows it's framerate to 15fps to get 1/15, then it's not really shooting slower than its framerate, is it? ;)

Jay Bloomfield
June 4th, 2009, 06:15 PM
No video camera truly shoots at a lower shutter than the inverse of its frame rate. Most video cameras have what's called "frame accumulation mode", where you can stipulate the number of frames to pile on top of each other. It's interesting that there aren't too many threads on dvinfo.net about this topic. Here's one:

http://www.dvinfo.net/conf/sony-xdcam-hd-cinealta/82801-frame-accumulation-help-please.html

You see the standard kinds of slow shutter speed videos, the same way you see them for still cameras: nighttime shots of stationary objects, fireworks, smeary celestial bodies and blurred babbling brooks/waterfalls with stationary backgrounds (my favorite). But whats the advantage of such a video over a still shot?

Bill Binder
June 5th, 2009, 09:11 AM
No video camera truly shoots at a lower shutter than the inverse of its frame rate. Most video cameras have what's called "frame accumulation mode", where you can stipulate the number of frames to pile on top of each other. It's interesting that there aren't too many threads on dvinfo.net about this topic. Here's one:

http://www.dvinfo.net/conf/sony-xdcam-hd-cinealta/82801-frame-accumulation-help-please.html

You see the standard kinds of slow shutter speed videos, the same way you see them for still cameras: nighttime shots of stationary objects, fireworks, smeary celestial bodies and blurred babbling brooks/waterfalls with stationary backgrounds (my favorite). But whats the advantage of such a video over a still shot?

This is exactly what I was talking about. And yeah, Jon, agreed, your "effective" framerate is actually lower (e.g., in my example 15 fps), so yes, of course, your shutter can't be slower than your framerate, heh. Agreed! But, it can nonetheless place that effective framerate in a 30 fps video file. My main point is that some cameras can effectively shoot at much lower shutter speeds that 24 or 30 (actual slower shutter as opposed to simulating a slower shutter).