Rack focus at DVinfo.net

December 29th, 2001, 11:59 AM

Could someone please explain the term "rack focus." I've read the Michael Pappas article on the site; although the article describes how to attain rack focus, it really doesn't explain what it is.

I can only assume it is something akin to what still photographers do when trying to obtain the largest depth of focus -- ie, focusing on the subject, setting an f/stop and then sliding the focus ring indicator over to obtain a larger depth of field.

Can you obtain rack focus with the XL1S using the Optex Fujinon 14x lens?

Thanks for any help you might be able to give me!

-- Alan

Daniel H. Buchmann · December 29th, 2001, 04:01 PM

hey cheese,
I think rack focus is simply fixing the focus from one subject to another. Ex: Racking the focus from foreground object to background object. Hope that helps.

Ken Tanaka · December 29th, 2001, 04:43 PM

Daniel is correct. Rack-focus is, indeed, shifting the focus between a subject in the foreground and one in the background. Implicitly, the subjects are just outside the normal depth of field for the lens' settings in that shot.

Generally, as a practical matter, rack focusing is simpler to accomplish with a manual lens or an automatic lens that features a full-manual mode.

December 29th, 2001, 09:56 PM

Ken, Daniel:

Thanks for your reply.

However, just to clarify that I understand what you're saying, is the following a rack-focus kind of event:

Scene: You have two people, both included in the frame of the shot, talking to each other. You start out focusing on the character FARTHEST from the camera. At some predetermined time, you shift the focus to the character closest to the lens, which puts the first character out of focus?

Am I getting close?

If that isn't a viable example, please do this idiot a big favor and give me a scenario.

Thanks, brothers!!

Ken Tanaka · December 29th, 2001, 10:34 PM

Exactomunde. Bingo. You've got it. Very good example, Alan.

Often you'll see this technique used to induce "Oooh's" or "Aha's" by showing the viewer something new in the frame. Also it's handy for showing another character's reaction.

Chris Hurd · December 30th, 2001, 12:13 AM

It's also a way to get movement within the frame without moving the camera or the subject. Definitely one of my favorite cinematic tricks,

December 29th, 2001, 11:59 AM	#1
gratedcheese Posts: n/a	Rack focus Could someone please explain the term "rack focus." I've read the Michael Pappas article on the site; although the article describes how to attain rack focus, it really doesn't explain what it is. I can only assume it is something akin to what still photographers do when trying to obtain the largest depth of focus -- ie, focusing on the subject, setting an f/stop and then sliding the focus ring indicator over to obtain a larger depth of field. Can you obtain rack focus with the XL1S using the Optex Fujinon 14x lens? Thanks for any help you might be able to give me! -- Alan

December 29th, 2001, 04:43 PM	#3
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Daniel is correct. Rack-focus is, indeed, shifting the focus between a subject in the foreground and one in the background. Implicitly, the subjects are just outside the normal depth of field for the lens' settings in that shot. Generally, as a practical matter, rack focusing is simpler to accomplish with a manual lens or an automatic lens that features a full-manual mode. __________________ 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

December 29th, 2001, 10:34 PM	#5
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Exactomunde. Bingo. You've got it. Very good example, Alan. Often you'll see this technique used to induce "Oooh's" or "Aha's" by showing the viewer something new in the frame. Also it's handy for showing another character's reaction. __________________ 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

December 30th, 2001, 12:13 AM	#6
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	It's also a way to get movement within the frame without moving the camera or the subject. Definitely one of my favorite cinematic tricks, __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

December 29th, 2001, 04:01 PM	#2
Daniel H. Buchmann Regular Crew Join Date: Sep 2001 Location: Philadelphia, Pennsylvania Posts: 57	hey cheese, I think rack focus is simply fixing the focus from one subject to another. Ex: Racking the focus from foreground object to background object. Hope that helps.

December 29th, 2001, 09:56 PM	#4
gratedcheese Posts: n/a	Ken, Daniel: Thanks for your reply. However, just to clarify that I understand what you're saying, is the following a rack-focus kind of event: Scene: You have two people, both included in the frame of the shot, talking to each other. You start out focusing on the character FARTHEST from the camera. At some predetermined time, you shift the focus to the character closest to the lens, which puts the first character out of focus? Am I getting close? If that isn't a viable example, please do this idiot a big favor and give me a scenario. Thanks, brothers!!