want bg out-of-focus: can I do this in 1080/24p? at DVinfo.net

Malcolm Hamilton · June 1st, 2008, 10:01 AM

Hi,
the reason for my question is that I just went through the Vortex 'How to Light' DVD, and Doug suggests shooting 1080/60i to get nice shallow depth of field for interviews (so the background is out-of-focus).
I pretty well have to shoot in 1080/24p, to get my stuff into Avid, so my question is, will this be o.k for getting shallow depth of field? Do I have to compensate somehow? (I think Doug's 'Lighting' DVD came out before the EX1 had been dreamed of, so for all I know 1080/24p will work just as well as 1080/60i. Thought I should check, though, since I'm shooting a few interviews this next week)
Thanks for any advice,
Malcolm

George Kroonder · June 1st, 2008, 10:04 AM

Framerate has no impact on DoF.

George/

Eric Pascarelli · June 1st, 2008, 10:09 AM

DOF is determined by the iris setting and lens focal length and not by the shooting mode/frame rate (except that they affect the exposure, which can be compensated for using the iris).

You'll have the shortest depth of field if you use the longest focal length (81.2mm) and the widest aperture (f/1.9).

You can engage the ND filters or reduce you lighting to allow you to shoot wide open. Or set your gain at -3dB (this subtracts a stop, allowing you to open the lens).

Or use a higher shutter speed. This is less desirable, because, like shooting 60i, it will noticeably affect the look of you video.

Malcolm Hamilton · June 1st, 2008, 10:15 AM

Thanks very much, George and Eric. I'll try to have the iris wide open, and I'll put some space between the camera and my subject so I can be zoomed in when I frame up the interview shot; my gain will be -3dB.
Cheers,
Malcolm

Alister Chapman · June 1st, 2008, 10:26 AM

Just be aware that some lenses can be a little soft when wide open. Most lenses are happiest between F8 and F4.

Having said that I often shoot wide open to get a shallow DOF. The EX1 lens is still reasonably sharp when fully open.

Malcolm Hamilton · June 1st, 2008, 10:43 AM

O.K.... maybe I'll try to err a bit to this side of wide open... between 2 and 4, for example (since you say the EX1 lens can handle it). Cheers Alister,
Malcolm

Craig Seeman · June 1st, 2008, 11:42 AM

Malcolm, maybe you should watch the DVD again. Doug says he never uses interlace at all. There's a DOF indicator on the LCD which can be a help. In many circumstance using the ND filters can help decrease the light as needed when iris is wide.

George Kroonder · June 1st, 2008, 12:14 PM

Although mathematically true that DoF is shallowest at the long end of the lens, artistically this will be quite a different look from a wide(r) shot because of compression.

This is not the data-compression-type: at tele the image looks "squeezed together" and the background will look "blown up" (even if it is out of focus). This can work just fine, just depends on what look you're after.

George/

Malcolm Hamilton · June 1st, 2008, 12:54 PM

Quote:

Originally Posted by Craig Seeman

Malcolm, maybe you should watch the DVD again. Doug says he never uses interlace at all

Hi Craig,
I'm referring not to Doug's EX-1 DVD (in which he talks up progressive), but his 'How to Setup, Light Great-Looking Interviews'... I think I heard him say 1080/60i as the way to go re DOF. Of course, as I mentioned, I think this particular DVD pre-dates the EX-1, and all the 'p' choices available with it. I might be wrong. This is what made me worry, because, as I say, for Avid, I seem to have to shoot 1080/24p... which wasn't Doug's choice in either video.
I hope this setting is a good one. I've got my shutter speed set to 1/48.
cheers, Malcolm

Rob Collins · June 2nd, 2008, 09:53 PM

In my experience even with the iris open, zoomed in, and your subject a good bit away from the background, you only get a subtle blurring of the background (and the EX1 is better than anything in its class in this regard). To get that film-like shallow DOF, you really need an adapter such as the Letus.

Having said that, Magic Bullet Looks can give you some decent approximation. My interviews in this piece: http://vimeo.com/887582 or http://exposureroom.com/members/robc...87f1e91c3fc99/ were shot EX1 without adapter, and I used MB Looks edge softening and vignetting to blur the "background" -- of course, it's not really the background, as the background near the subject is still in focus. But until I get my Letus (soon hopefully), it'll have to do.

Bob Grant · June 3rd, 2008, 01:57 AM

A black scrim between subject and background is one solution although care is needed. If the weave is too coarse you might get moire.

Ola Christoffersson · June 3rd, 2008, 03:38 PM

Quote:

Originally Posted by Malcolm Hamilton

Hi Craig,
This is what made me worry, because, as I say, for Avid, I seem to have to shoot 1080/24p...

What Avid software are you using? Media Composer 2.8.3 accepts all EX1-resolutions and previous versions that can deal with HDV accepts 1080i.

June 1st, 2008, 10:01 AM	#1
Malcolm Hamilton Major Player Join Date: Jan 2007 Location: Ottawa, Canada Posts: 844	want bg out-of-focus: can I do this in 1080/24p? Hi, the reason for my question is that I just went through the Vortex 'How to Light' DVD, and Doug suggests shooting 1080/60i to get nice shallow depth of field for interviews (so the background is out-of-focus). I pretty well have to shoot in 1080/24p, to get my stuff into Avid, so my question is, will this be o.k for getting shallow depth of field? Do I have to compensate somehow? (I think Doug's 'Lighting' DVD came out before the EX1 had been dreamed of, so for all I know 1080/24p will work just as well as 1080/60i. Thought I should check, though, since I'm shooting a few interviews this next week) Thanks for any advice, Malcolm

June 1st, 2008, 10:26 AM	#5
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Just be aware that some lenses can be a little soft when wide open. Most lenses are happiest between F8 and F4. Having said that I often shoot wide open to get a shallow DOF. The EX1 lens is still reasonably sharp when fully open. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

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June 1st, 2008, 10:04 AM	#2
George Kroonder Major Player Join Date: Jan 2008 Location: Utrecht, NL \| Europe 3rd Rock from the Sun Posts: 612	Framerate has no impact on DoF. George/

June 1st, 2008, 10:09 AM	#3
Eric Pascarelli Major Player Join Date: Nov 2007 Location: Los Angeles, CA Posts: 498	DOF is determined by the iris setting and lens focal length and not by the shooting mode/frame rate (except that they affect the exposure, which can be compensated for using the iris). You'll have the shortest depth of field if you use the longest focal length (81.2mm) and the widest aperture (f/1.9). You can engage the ND filters or reduce you lighting to allow you to shoot wide open. Or set your gain at -3dB (this subtracts a stop, allowing you to open the lens). Or use a higher shutter speed. This is less desirable, because, like shooting 60i, it will noticeably affect the look of you video.

June 1st, 2008, 10:15 AM	#4
Malcolm Hamilton Major Player Join Date: Jan 2007 Location: Ottawa, Canada Posts: 844	Thanks very much, George and Eric. I'll try to have the iris wide open, and I'll put some space between the camera and my subject so I can be zoomed in when I frame up the interview shot; my gain will be -3dB. Cheers, Malcolm

June 1st, 2008, 10:43 AM	#6
Malcolm Hamilton Major Player Join Date: Jan 2007 Location: Ottawa, Canada Posts: 844	O.K.... maybe I'll try to err a bit to this side of wide open... between 2 and 4, for example (since you say the EX1 lens can handle it). Cheers Alister, Malcolm

June 1st, 2008, 11:42 AM	#7
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	Malcolm, maybe you should watch the DVD again. Doug says he never uses interlace at all. There's a DOF indicator on the LCD which can be a help. In many circumstance using the ND filters can help decrease the light as needed when iris is wide.

June 1st, 2008, 12:14 PM	#8
George Kroonder Major Player Join Date: Jan 2008 Location: Utrecht, NL \| Europe 3rd Rock from the Sun Posts: 612	Although mathematically true that DoF is shallowest at the long end of the lens, artistically this will be quite a different look from a wide(r) shot because of compression. This is not the data-compression-type: at tele the image looks "squeezed together" and the background will look "blown up" (even if it is out of focus). This can work just fine, just depends on what look you're after. George/

June 2nd, 2008, 09:53 PM	#10
Rob Collins Major Player Join Date: Jul 2007 Location: Richmond, VA Posts: 229	In my experience even with the iris open, zoomed in, and your subject a good bit away from the background, you only get a subtle blurring of the background (and the EX1 is better than anything in its class in this regard). To get that film-like shallow DOF, you really need an adapter such as the Letus. Having said that, Magic Bullet Looks can give you some decent approximation. My interviews in this piece: http://vimeo.com/887582 or http://exposureroom.com/members/robc...87f1e91c3fc99/ were shot EX1 without adapter, and I used MB Looks edge softening and vignetting to blur the "background" -- of course, it's not really the background, as the background near the subject is still in focus. But until I get my Letus (soon hopefully), it'll have to do.

June 3rd, 2008, 01:57 AM	#11
Bob Grant Trustee Join Date: Nov 2005 Location: Sydney Australia Posts: 1,570	A black scrim between subject and background is one solution although care is needed. If the weave is too coarse you might get moire.