Getting the background out of focus.
 

I'm working with the Canon xl1s and I need to film a shot where the foreground is in focus (obviously) but I need the background to be heavily out of focus, not just a little of focus. Are there any special settings / techniques to achive this using the xl1s?

Besides what you probably already know about DOF and 1/3" CCD miniDV cameras, here are two options that will work. The first one is cheaper, and garuanteed to give you as much as you want.

1) Buy or rent a giant diffuser screen and place it behind your subject. There is a specific name for this but I can't remember it.

2) Rent a Mini35 for the day.

Hi Warren,

You need to create depth of field by adjusting the aperture and shutter. I can't remember whether the aperture should be bigger or smaller though???

Another thing that affects depth of field for camcorders is the type of lens used, and how far away from your subject.

If you are using the standard 16x lens then you will need to be quite a distance away from your subject, and then zoom into frame.

Please provide us with more info...

The item that Dylan mentions is called Softscreen. This will work great for a closeup to a medium shot that doesn't require panning. A more elaborate shot will require the use of a Mini35 as Dylan also mentioned.

Regarding Ed's notes, a larger aperture is required for minimal depth of field, along with a long focal length and short distance to the subject. The shutter is not a factor in the equation except that it can be used as the exposure control since you are keeping your aperture open. However, a "heavily" out-of-focus background is a bit of a challenge with a DV camera. There have been endless discussions on this subject here at the DV Info Net, try a search.

I have used the Mini 35 in the past. Together with a good Prime lense you can obtain great DOF effects. They rent for aproximatelly $600 a day

Thanks guys for all your replies. This forum is great.

I think I will try messing around with the aperture a bit and see how it turns out.

This can also be done in post. As long as the subject in the foreground doesn't move much, a matte can be created in photoshop and then used as a reveal track or a track matte in your nle suite. The amount of feather when creating the black and white track matte will dictate how many pixels are used during the computerized camera blur. Simply duplicate the clip and place it above the clip in the timeline. Apply much blur to this second or duplicate clip. Then, the track matte shows only the portion of the clip you require to be blurred. This is very useful when you need to blur a section out like a face or license plate à la COPS on Fox.
The above refers to editing with premiere.

hmm, how heavily are you talking here? When I open the aparture all the way then crank up the shutter speed OR use a neutral density filter, that seems to make the background indistinguishable (sp?) ND filters are good for giving shallow depth of field as explained in this article
the reason being it helps keep your scene from looking like you're shooting on the surface of the sun. basically just the aparture on the camera itself throws everything out of focus except the plane of focus...someone already said that but I thought I would elaborate since Im not one to throw away $600.00 for one day, im not so lucky to have pockets bulging with cash

Yeah, I've been messing around with the aperture and exposure settings a bit and it looks like I'll be able to get the effect I'm looking for. Thanks for all the advice :)

look at options in post. If it's a static shot a feathered mask could work in a pinch...
complex masks are made easy by adding color to the area that will end up being blurry... then combining a quick bezier mask and a color selection will give you potentially a better mask.

Warren,
 

You can also add an extender to your lens. With the Canon, not only will you increase your focal length by 1 1/2 times, you will also lose approximately 1 1/2 - 2 stops in light, thus aiding you in losing depth of field.

The closer you get to your subject, the closer you have to focus...as you focus closer, the more your background goes soft, so, once you get all of your ducks in a row, aperture, nd filters, lens size, etc., a little experimentation should give you what you want.

RB

<<basically just the aparture on the camera itself throws everything out of focus except the plane of focus...someone already said that but I thought I would elaborate since Im not one to throw away $600.00 for one day, im not so lucky to have pockets bulging with cash>>

Christopher, I know you are being facetious here, but I should point out that the method you describe will result in more than four times the depth of field than is achievable with the Mini35 given the same field of view, so it's hardly throwing away money to use such a device if the budget can handle it and a very shallow depth of field is desired at less-than-telephoto focal lengths.

This may be pretty obvious, but no one mentioned it. If you want the background really out of focus, then once you have opened the aperture as much as you can, it becomes important that the distance between you and your subject is much shorter than the distance to the background. If you are 10 feet from your subject and the background is 30 feet, you will never get the blur you want.

Good note Steve. The closer to the camera the subject is, the shorter the depth of focus (that is, the entire plane that is in focus from front to back) and thus the softer the background. The tricky part is that if you have the exact image size you seek at 10 ft (say, a medium shot), to move the subject to 5 ft and keep that size will require zooming out the camera to a wider focal length, and you are right back where you started!

<<<-- Originally posted by Charles Papert : Christopher, I know you are being facetious here, but I should point out that the method you describe will result in more than four times the depth of field than is achievable with the Mini35 given the same field of view, so it's hardly throwing away money to use such a device if the budget can handle it and a very shallow depth of field is desired at less-than-telephoto focal lengths. -->>>

Charles, sorry I came off that way but I was being serious. I understand your reasoning very much and I agree with you completely. I just wanted to be sure there were other, cheaper (although not as powerful) alternatives out on the table. I am new to this and you definately know what you're doing here so I in no way meant to offend you and apologize if I came off prudent. My choice of words was obviously at fault there.