Shutter Off. at DVinfo.net

Paul Joy · December 30th, 2007, 06:40 AM

One thing that still puzzles me a little about the EX1 and that I can't find in the manual is what happens when the shutter switch is set to off.

Having used my XH-A1 for a while, I've gotten used to shutter speed just being a part of the general setup of a shot. I usually use a shutter speed of double the framerate.

So what does the EX1 do when the shutter is off? and also, if the shutter really is 'off' how does that effect the 'rolling shutter' side effect?

I'll do some experiments myself but just really wanted to put the questions out there.

Paul.

Paul Joy · December 30th, 2007, 07:24 AM

I've just done some initial tests by shooting a scene and firing the flash from my CX6. In 720/25p with the shutter on at 50 only the top half of the frame was exposing the effect of the flash - which is the effect that's been reported.

With the shutter off however, the flash always filled the frame, so it's definitely having an effect. If your shooting strobes etc and you're worried about getting half frames, wouldn't simply switching off the shutter give you usable footage?

Paul.

Piotr Wozniacki · December 30th, 2007, 07:52 AM

Paul,

It's been established here - with the help of the guys having experience with true pro cameras - that "Shutter OFF" simply disengages any additional electronic shutter, meaning you get one full exposure per frame. Which means it's equivalent to 1/25th if in 25fps mode, 1/24th if in 24fps mode, 1/50th in 720/50p etc. I am not sure about interlaced modes, is it 1/25 or 1/50th in 50i? I guess it should be 1/50th, to get the full temporal resolution.

So yes, it's possible that the side effect is getting rid of those partially exposed flashes... I'm using 1/25th in 1080/25p on my V1E and still do have partially exposed frames, though.

Greg Boston · December 30th, 2007, 09:56 AM

Piotr is correct. As for interlaced, if shooting 50i, your shutter would be 1/50th but you are only recording one field at that rate. Same for 60i.

For many years, video cameras didn't shoot alternate frame rates so the shutter switch was used only to achieve a certain look with 60i, or perhaps a clear scan function to sync with computer monitors that had a different refresh rate than 60hz. The same is pretty much true for 50i in a historical sense.

-gb-

December 30th, 2007, 06:40 AM	#1
Paul Joy Major Player Join Date: Mar 2007 Location: Norfolk, UK Posts: 627	Shutter Off. One thing that still puzzles me a little about the EX1 and that I can't find in the manual is what happens when the shutter switch is set to off. Having used my XH-A1 for a while, I've gotten used to shutter speed just being a part of the general setup of a shot. I usually use a shutter speed of double the framerate. So what does the EX1 do when the shutter is off? and also, if the shutter really is 'off' how does that effect the 'rolling shutter' side effect? I'll do some experiments myself but just really wanted to put the questions out there. Paul. __________________ Blog: www.pauljoy.com Company: www.videotrader.co.uk

December 30th, 2007, 07:24 AM	#2
Paul Joy Major Player Join Date: Mar 2007 Location: Norfolk, UK Posts: 627	I've just done some initial tests by shooting a scene and firing the flash from my CX6. In 720/25p with the shutter on at 50 only the top half of the frame was exposing the effect of the flash - which is the effect that's been reported. With the shutter off however, the flash always filled the frame, so it's definitely having an effect. If your shooting strobes etc and you're worried about getting half frames, wouldn't simply switching off the shutter give you usable footage? Paul. __________________ Blog: www.pauljoy.com Company: www.videotrader.co.uk

December 30th, 2007, 07:52 AM	#3
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Paul, It's been established here - with the help of the guys having experience with true pro cameras - that "Shutter OFF" simply disengages any additional electronic shutter, meaning you get one full exposure per frame. Which means it's equivalent to 1/25th if in 25fps mode, 1/24th if in 24fps mode, 1/50th in 720/50p etc. I am not sure about interlaced modes, is it 1/25 or 1/50th in 50i? I guess it should be 1/50th, to get the full temporal resolution. So yes, it's possible that the side effect is getting rid of those partially exposed flashes... I'm using 1/25th in 1080/25p on my V1E and still do have partially exposed frames, though. __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive Last edited by Piotr Wozniacki; December 30th, 2007 at 09:05 AM.

December 30th, 2007, 09:56 AM	#4
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	Piotr is correct. As for interlaced, if shooting 50i, your shutter would be 1/50th but you are only recording one field at that rate. Same for 60i. For many years, video cameras didn't shoot alternate frame rates so the shutter switch was used only to achieve a certain look with 60i, or perhaps a clear scan function to sync with computer monitors that had a different refresh rate than 60hz. The same is pretty much true for 50i in a historical sense. -gb-