shutter speed question. at DVinfo.net

September 10th, 2001, 01:34 PM

This may seem stupid, but why would you change to different shutter speeds when shooting video. I see that the cameras have variable shutter speed 1/500... etc. Any clarification would be appreciated.

Thanks.

Chris Hurd · September 11th, 2001, 12:37 AM

Howdy from Texas,

Most of the time, I leave my camera on the default 1/60th shutter speed. But there are times when you'll want to manipulate the electronic shutter to a much higher speed, depending on your shooting requirements.

Let's say, for instance, you're shooting a scene outdoors with a lot of natural sunlight. Let's say you have a shot where you want to have a very shallow depth of field... a person in the foreground in crisp focus, with the background in soft focus. A very common shooting requirement, but the sun is so bright, you have your aperture stopped all the way down to something like f/11 or so, keeping you from getting your shallow depth of field.

Now you set your XL1 to Tv (shutter priority) mode and crank up the shutter speed to something much higher than 1/60... probably 1/1,000 or so. This forces the aperture to automatically open up, which decreases depth of field. Now you're set for your beauty shot.

Oh, and those high-speed shutter settings can also prevent fast-moving objects from looking blurred in the frame, but you probably already knew that.

Hope this helps,

John Klein · January 4th, 2002, 01:33 PM

I would add that the lens is going to be less sharp at f/16 than at f/5.6. Yes , more depth of field, but the image can begin to get fuzzy with tiny apertures. The Auto cam is almost always going to go for 1/60th for a SS until it's too bright.

Therefore, by setting the cam at a higher shutter speed to force the lens to use more of it's glass, it will give you a sharper image.

Generally two stops from wide open is the "sweet spot."

Vic Owen · January 4th, 2002, 01:44 PM

As mentioned elsewhere, I've used the 1/30 speed on the XL-1 in very low light conditions -- as long as there isn't a lot of movement, it provides an effective simulated gain increase.

Vic

Ken Tanaka · January 4th, 2002, 02:14 PM

One way to consider the issue is to realize that for a given scene at a particular distance/zoom setting you basically can control only 2 factors; the camera's shutter speed and the lens' iris (the aperture). (Film photographers have a 3rd variable in the form of the film emusion's sensitivity to light or ISO rating.) If you're using one of the camera's exposure compensation programs (aperture priority or shutter speed priority) the camera will attempt to control the variable you're not controlling to achieve a correct exposure. Ex: The slower your shutter speed the more time the cam will have available to collect light from the scene in each "frame" and the tighter the cam will close-down the iris. Keep in mind also that the smaller the aperture (i.e. higher f-numbers) the greater your deph-of-field will be. That is, measuring from your lens to the back of the scene, more of the scene will be in focus.

Words probably fail me here. The best way to learn this is to just pick your cam up and experiment for yourself. It can certainly be alot more fun than reading about it. <g>

Don Palomaki · January 4th, 2002, 04:59 PM

You do have a third exposure control with the camcorder - GAIN. It is a bit like push processing of film. Six dB equals a stop. Ands as gain increases, the grain battern and noise of the CCD can become more apparent, knod of like film grain can become more apparent when film is push processed.

September 10th, 2001, 01:34 PM	#1
Guest Posts: n/a	shutter speed question. This may seem stupid, but why would you change to different shutter speeds when shooting video. I see that the cameras have variable shutter speed 1/500... etc. Any clarification would be appreciated. Thanks.

September 11th, 2001, 12:37 AM	#2
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Howdy from Texas, Most of the time, I leave my camera on the default 1/60th shutter speed. But there are times when you'll want to manipulate the electronic shutter to a much higher speed, depending on your shooting requirements. Let's say, for instance, you're shooting a scene outdoors with a lot of natural sunlight. Let's say you have a shot where you want to have a very shallow depth of field... a person in the foreground in crisp focus, with the background in soft focus. A very common shooting requirement, but the sun is so bright, you have your aperture stopped all the way down to something like f/11 or so, keeping you from getting your shallow depth of field. Now you set your XL1 to Tv (shutter priority) mode and crank up the shutter speed to something much higher than 1/60... probably 1/1,000 or so. This forces the aperture to automatically open up, which decreases depth of field. Now you're set for your beauty shot. Oh, and those high-speed shutter settings can also prevent fast-moving objects from looking blurred in the frame, but you probably already knew that. Hope this helps, __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

January 4th, 2002, 02:14 PM	#5
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	One way to consider the issue is to realize that for a given scene at a particular distance/zoom setting you basically can control only 2 factors; the camera's shutter speed and the lens' iris (the aperture). (Film photographers have a 3rd variable in the form of the film emusion's sensitivity to light or ISO rating.) If you're using one of the camera's exposure compensation programs (aperture priority or shutter speed priority) the camera will attempt to control the variable you're not controlling to achieve a correct exposure. Ex: The slower your shutter speed the more time the cam will have available to collect light from the scene in each "frame" and the tighter the cam will close-down the iris. Keep in mind also that the smaller the aperture (i.e. higher f-numbers) the greater your deph-of-field will be. That is, measuring from your lens to the back of the scene, more of the scene will be in focus. Words probably fail me here. The best way to learn this is to just pick your cam up and experiment for yourself. It can certainly be alot more fun than reading about it. <g> __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

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January 4th, 2002, 01:33 PM	#3
John Klein Regular Crew Join Date: Dec 2001 Location: Wisconsin, USA Posts: 182	I would add that the lens is going to be less sharp at f/16 than at f/5.6. Yes , more depth of field, but the image can begin to get fuzzy with tiny apertures. The Auto cam is almost always going to go for 1/60th for a SS until it's too bright. Therefore, by setting the cam at a higher shutter speed to force the lens to use more of it's glass, it will give you a sharper image. Generally two stops from wide open is the "sweet spot."

January 4th, 2002, 01:44 PM	#4
Vic Owen Major Player Join Date: Dec 2001 Location: Seattle, WA Posts: 540	As mentioned elsewhere, I've used the 1/30 speed on the XL-1 in very low light conditions -- as long as there isn't a lot of movement, it provides an effective simulated gain increase. Vic

January 4th, 2002, 04:59 PM	#6
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	You do have a third exposure control with the camcorder - GAIN. It is a bit like push processing of film. Six dB equals a stop. Ands as gain increases, the grain battern and noise of the CCD can become more apparent, knod of like film grain can become more apparent when film is push processed.