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-   -   Blurring background during interview (https://www.dvinfo.net/forum/documentary-techniques/143650-blurring-background-during-interview.html)

Cliff Etzel February 12th, 2009 03:11 PM

Blurring background during interview
 
Since I work with a pair of SONY HC7's, the depth of field even at the long end of zooming still keeps the background in focus during my lit interviews. I remember reading someplace on the net about a technique that utilizes some form of a diffusion material on a stretcher frame that can soften the background to give the appearance of using a shallow DOF adapter.

I can't remember off hand where I read it, but thought someone might know what the technique is and the kind of fabric used that provides the effect - I want to use something that's neutral so that it doesn't lend a color cast.

Make sense in what I'm asking???

Tripp Woelfel February 12th, 2009 08:50 PM

There has to be a simpler way. What's your shutter and iris settings? If you can keep the iris down in the 3-4 range you should get a shallow DOF. Faster shutter, or better, ND filters will help with this.

Vasco Dones February 12th, 2009 09:39 PM

... and/or apply some blur in post
(MB Looks might come in handy)

Best

Vasco

Bryan Daugherty February 12th, 2009 11:51 PM

Cliff I read the article you are referring to. I can fill in some of the blanks about the article but i can't remember what they used. it was an article in one of the videography trade magazines about the reality TV show on cable based on a tattoo parlor. For the interview portion of the show they set-up in a room without enough space to achieve the DOF they wanted so they stretched some sort of screen or fine cloth over a frame behind the talent. The effect was transparent enough to result in a blurred, toned done background. I have done a quick search of the DV magazine archive and videography archives but can't find the article. Does this ring a bell for anyone else? If anyone knows the name of the show that might help the google search too. My memory is that they used some sort of cutter for this but I can't remember what it was. I will dig through my old mags when I get a minute and see if I can find that article.

Corey Williams February 13th, 2009 12:05 PM

Here's a link to the article:

DV - Digital Video

Don Bloom February 13th, 2009 02:30 PM

A few years ago I had to do some outdoor interviews and needed to blur the background. I found a roll of mosquito netting that was about 5 feet wide IIRC and clamped it to to stands so it ran lengthwise. By doing this it 1) blurred the background out nicely and 2) toned it down to the degree that when I lit the talent they really popped nicely from the background.
Gotta remember to set the exposure to as shallow a DoF as possible to start with and again IIRC I had the netting about 6 or 8 feet backfrom the talent. Oh yeah, watch the framing. Don't need any stands and clamps in the shot ;-)

Bryan Daugherty February 13th, 2009 02:53 PM

Corey-thanks for the link! That is the article I was remembering. I had thought it was about Miami Ink but I wasn't sure and every search I ran with Maimi Ink in it turned back weird results. Thanks for hunting that down. Here is the excerpt from that article in DV magazine or found at DV - Digital Video

"After the High Voltage clients are inked, they proceed to an apartment next door and are interviewed on-camera by a segment producer. They are shot using a 1/3” CMOS sensor Sony HVR-V1U HDV camcorder in the HDV format at 24p. These pieces could look pretty bad given that they are shot inside a cramped 8’x8’ room, but to create the illusion that the interviews transpire inside the shop and to give them a feeling of depth beyond the limitations of the location, the wall behind the subject is painted and decorated like the walls of the shop. Even with the iris wide open on the V1U, the focal length (limited both by its small chip and the scant space between camera and subject) would not allow Krummel to limit his depth of field nearly enough to provide the selective focus he desired. The solution was to stretch a large sheet of Hampshire Frost on a frame and hang that between the subject and the wall, throwing the decorations behind the freshly inked person into soft focus. “The key,” Krummel says of the illusion, “is to hang the Frost as far from the background — or as close to the lens — as possible.”

There’s a fine line, he adds, between having a shot that looks like it has depth to it and having the big sheet of Frost become obvious. Stretching it in the frame properly is also a key, as the material will ripple in the slightest breeze."

Hope that helps!

Brian Drysdale February 14th, 2009 04:04 AM

Quote:

Originally Posted by Bryan Daugherty (Post 1011590)
The solution was to stretch a large sheet of Hampshire Frost on a frame and hang that between the subject and the wall, throwing the decorations behind the freshly inked person into soft focus. “The key,” Krummel says of the illusion, “is to hang the Frost as far from the background — or as close to the lens — as possible.”

There’s a fine line, he adds, between having a shot that looks like it has depth to it and having the big sheet of Frost become obvious. Stretching it in the frame properly is also a key, as the material will ripple in the slightest breeze."

Hope that helps!

The Hampshire Frost trick is used by quite a few DPs. As pointed out, it will require careful setting up, not one for the quick News & Current Affairs interview with the local politician.

Greg Quinn February 19th, 2009 10:08 PM

Softening backgrounds in post
 
I'll add my few cents worth....

I finished a project last year using a V1U (i.e. 1/4" chip, long DOF) and did 50% of the interviews against a green screen. After starting the project, I thought I'd made a serious error doing any green screen interviews, but it turns out to have been a good idea; I needed to do a lot of interviews at short notice, on my todd and in natural settings. To do properly, these require quite some setting up and lighting issues, particularly outdoor interviews i.e, setting up a Scrim Jim net behind the interviewee to cut down the brightness of the background and soften it, etc. If you're feeling brave (and frankly as a last resort), you can do some stuff in post that will help you out of a bind. In the blog about the project I've written about how I did this, but it's far easier if you do sort this out during the photography rather than afterwards...
Beyond Blue Eyes Film Production BLOG: The Perils of a 1/4 inch Chip Camera...

Marcus Martell February 21st, 2009 11:28 AM

Excuse me dear friends oversea,could you explain to an european what does it mean:The large sheet of Hampshire Frost on a frame and hang that between the subject and the wall?


sorry for my english but a lot of word are missingmy dictionary...

Bryan Daugherty February 21st, 2009 03:25 PM

Hampshire Frost is a specific type of diffusion material used for cutting lights. In this case a large sheet of it is stretched carefully over a frame so it can be hung behind the subject. It is semi-translucent so it softens the background but is not so dense that it will show up on the video if lit properly and set far enough back. Try searching for "Hampshire frost" in a search engine and you will find several links to various retailers some of which describe it better. As a disclaimer, i will state that personally I have never tried this technique but did recall the article in which it was mentioned. Hope that helps.

Marcus Martell February 24th, 2009 10:30 AM

Any example of this particular technique?Any link or stuff like that?

Bryan Daugherty February 24th, 2009 10:22 PM

Marcus, the technique referenced here is based on an article from DV magazine (link in previous post) where they used it on the TV show "LA ink" you might be able to find a clip of that show online... they used it during the interview portions according to the article. I am sure there are others that have used it too and maybe someone here might have a clip?

Marcus Martell February 28th, 2009 07:20 AM

sorry 4 the question:what does stand for IIRC?

Shaun Roemich February 28th, 2009 12:06 PM

IIRC = If I Remember Correctly
IMHO = In My Humble Opinion


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