how to make everything in focus? at DVinfo.net

Nathan Quattrini · November 8th, 2007, 04:59 PM

I remember the flaw of old camera was no depth of field no matter what. You zoom in, everythings in focus, you zoom out, everything is in focus. Now with the A1 it seems something is always a little bit soft...maybe its just the LCD i`m not sure, which is why I`m asking, but how do you get a whole scene (indoor and outdoor) to be in focus?

Darrell Essex · November 8th, 2007, 06:02 PM

Panavision was supposed to have a lens like that a couple of years ago.
Check page 57.
http://www.panavision.com/media/Panavision_Camera.pdf
Darrell
FIRST CINEMA PICTURES

Sebastian Baron · November 8th, 2007, 08:29 PM

I usually just set my aperture pretty closed and avoid zooming too much. Originally I felt this was a complete pain, but the more I use the camera the more I realize its not as difficult to pull of as it seems.

Shiv Kumar · November 9th, 2007, 02:41 AM

Nathan,

I'm not sure I understand your question clearly. If "everything" is in focus you actually have a large DOF and not no DOF.

DOF is controlled by a couple of things (barring the size of the CCD since that's not something you can change/control).

When you stop down the aperture (a smaller apperture) (or iris) you get a larger DOF. That is, f/22 will give you a larger DOF than f/2.6

Telephoto (zooming in) tends to give you a shallow DOF and wide will give you a larger DOF.

So keep you lens zoomed out and your aperture small and you'll get a larger DOF.

Zoom in completely and keep your aperture wide open and you get a shallow depth of field.

Keep in mind also that the distance of the object in focus from the camera also changes the DOF for the given focal length of the lens and aperture settings. The further away the subject the larger the apparent DOF.

Richard Hunter · November 9th, 2007, 05:27 AM

Watch out for diffraction! The A1 image at small apertures is not sharp. Applies to other high res cams with small sensors too.

Richard

Jonathan Schwartz · November 9th, 2007, 08:41 AM

I have also found that shooting when shooting in 60i vs. 30p or 24p that the camera focuses much quicker. In 30p there would be times when the camera could not find a focal point. In 60i, never had that problem. You do loose a little of the DOF but the IAF is much more effective.

Jon Schwartz

Peter Jefferson · November 9th, 2007, 11:37 PM

The A1 doesn't go above f/11, so you have to make do with faster shutters, and tweaking focus to infinity.

November 8th, 2007, 04:59 PM	#1
Nathan Quattrini Major Player Join Date: Jan 2007 Location: Warwick, Rhode Island Posts: 740	how to make everything in focus? I remember the flaw of old camera was no depth of field no matter what. You zoom in, everythings in focus, you zoom out, everything is in focus. Now with the A1 it seems something is always a little bit soft...maybe its just the LCD i`m not sure, which is why I`m asking, but how do you get a whole scene (indoor and outdoor) to be in focus? __________________ Cinematography Site

November 8th, 2007, 06:02 PM	#2
Darrell Essex Regular Crew Join Date: Nov 2004 Location: kelseyville, ca Posts: 123	Panavision was supposed to have a lens like that a couple of years ago. Check page 57. http://www.panavision.com/media/Panavision_Camera.pdf Darrell FIRST CINEMA PICTURES __________________ darrell

November 9th, 2007, 02:41 AM	#4
Shiv Kumar Major Player Join Date: Jul 2007 Location: Gainesville, VA, USA Posts: 327	Nathan, I'm not sure I understand your question clearly. If "everything" is in focus you actually have a large DOF and not no DOF. DOF is controlled by a couple of things (barring the size of the CCD since that's not something you can change/control). When you stop down the aperture (a smaller apperture) (or iris) you get a larger DOF. That is, f/22 will give you a larger DOF than f/2.6 Telephoto (zooming in) tends to give you a shallow DOF and wide will give you a larger DOF. So keep you lens zoomed out and your aperture small and you'll get a larger DOF. Zoom in completely and keep your aperture wide open and you get a shallow depth of field. Keep in mind also that the distance of the object in focus from the camera also changes the DOF for the given focal length of the lens and aperture settings. The further away the subject the larger the apparent DOF. __________________ Canon XH-A1, Libec LS-55M, Letus Extreme, Steadicam Merlin, PPro CS3

November 9th, 2007, 08:41 AM	#6
Jonathan Schwartz Major Player Join Date: Nov 2006 Location: Ocean Springs, MS Posts: 211	DOF & Focus I have also found that shooting when shooting in 60i vs. 30p or 24p that the camera focuses much quicker. In 30p there would be times when the camera could not find a focal point. In 60i, never had that problem. You do loose a little of the DOF but the IAF is much more effective. Jon Schwartz

November 8th, 2007, 08:29 PM	#3
Sebastian Baron New Boot Join Date: May 2007 Location: Sarasota, FL Posts: 13	I usually just set my aperture pretty closed and avoid zooming too much. Originally I felt this was a complete pain, but the more I use the camera the more I realize its not as difficult to pull of as it seems.

November 9th, 2007, 05:27 AM	#5
Richard Hunter Trustee Join Date: Dec 2004 Location: Lipa City Batangas, Philippines Posts: 1,110	Watch out for diffraction! The A1 image at small apertures is not sharp. Applies to other high res cams with small sensors too. Richard

November 9th, 2007, 11:37 PM	#7
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	The A1 doesn't go above f/11, so you have to make do with faster shutters, and tweaking focus to infinity.