View Full Version : Focusing Tip & Tricks Wanted Here.


Nelson Maldonado
June 18th, 2009, 12:36 PM
Hi all,

Like many of you, I discovered the hard way that setting and maintaining a sharp focus under various situations is important when shooting and critical when shooting in HD.

I and others would appreciate the knowledge and experience those of you have gained in setting and maintaining a sharp focus under various situations with the H1.

Dance Recitals - uncontrolled event / fast motion / uncontrolled low lighting:
- This is probably one of the hardest shoots to control in terms of keeping a proper aperture and focus while trying to keep the performance framed and centered.

-Focus: You just can't tell. Double check a lot. The zoom-in, focus, and zoom-out technique seems to work. The magnifying feature kind of works, though not as well as you'd think. Fortunately, the camera has such a large depth of field that you're probably in focus anyway. And in HD when you're just a little out of focus it's not a huge deal.

Gabriel's take of focus would not work here. With back to back performances, there is little if any time to re-focus, low light equals a larger aperture and very hallow DOF and being a little out of focus IS a big deal in HD. ALso, the H1 takes longer to autofocus in 30 or 24f mode, so that won't work well for fast motion performances and trying to manual focus during a performance is not an option unless your really out of focus and your using a large HD monitor.

0 - set your focus selector to manual.

1 - make sure your back focus is set properly.

2 - set your focus in medium low light conditions with peaking and/or a large HD monitor.
DOF is basically determined by the iris setting. The smaller the aperture, the greater the depth of field. The more light you have, the easier it is to focus but more difficult to determine where the focal point actually is. In very low-light situations where the aperture is wide open, the depth of field is reduced and focusing becomes harder but is easier to find the focal point.

So...
a - find a focus target card and put it at center stage (half way between the backdrop and the front of the stage or where you think the center of all the action will be).

b - zoom in on the focus card.

c - get the theater to lower the stage lights enough to be able to decrease the DOF and still see the focus card pattern clearly enough to get a sharp focus. That setting will be your focal point.

d - Save that focal point on the H1 by setting the Position Preset switch to Focus, focus the card, then set the ON/SET switch to SET. Now you can reset your focus if it drifts or get bumped by pushing the ON/SET switch to ON. Keep in mind that the preset settings reset to OFF when the camera is turned off or the lens is removed.

e - Get the theater lighting crew to keep enough base stage lighting to insure a reasonable depth of field and a sharp focus throughout the show.

f - Mount a 24" HD monitor with component input jacks next to the H1 that's connected to the H1's component output to use instead of the view finder during the show to keep track of your focus. Using a large HD monitor will allow you to have better control over minor aperture and focus adjustments while maintaining proper framing and centering of the performance.

g - having a focus puller (with a follow focus adapter - if you can afford one) helps by letting them keep the camera in focus while allowing you to concentrate on shooting.

Garrett Low
June 18th, 2009, 06:08 PM
Last week I shot a two days of dance recitals with my new SmallHD monitor. It was great. It allowed me to follow the dancers while adjusting focus. I also have a laser distance meter that I use to take measurements as various points on the stage. I pretty much break the stage into segments that I can remember distances to. I keep the focus distance readout turned on and use that as a double check for what I'm seeing in the monitor.

As for exposure it is a constant battle as most stages are not evenly light. I'm constantly adjusting the iris.

To maintain proper framing I've got the monitor attached to my tripod so it pans and moves in line with the camera. I have it positioned where I can see over which allows me to keep one eye on the stage and the other on the monitor. That way I make sure I don't leave out those dancers who move too far out of formation.

Garrett

Nelson Maldonado
June 18th, 2009, 07:51 PM
Garrett,

What size the the SmallHD monitor? I would think that any monitor even an HD monitor that is too small would be hard to focus with. Also, does your laser distance meter use an invisible beam?

Garrett Low
June 18th, 2009, 08:59 PM
The SmallHD monitor is 8.9" which is just about the right size. It's native 1280x720 and takes a 1920x1080 signal. focusing with it is actually really easy.

The laser meter I have is actually for construction so it has the typical red laser which I like. I do all my set up ahead of time and have an assistant stand at different points on the stage. Then I shot them to get a distance reading. Once I typically find about 8 to 10 different locations depending on the size of the stage. I usually create a cheat sheet in case I forget but after a couple of minutes I can usually remember the distances. The readout on my XL H1A is really accurate so it's pretty easy to maintain focus.

Exposure is the bigger issue. For this last recital I did, they lost a center spot after Saturday nights show, they didn't have another bulb so Sundays show's had a dead spot in the middle of the stage where most of the solo dances were done. I'm editing it now and I can already tell post is gonna be hell.

Garrett

Doug Bennett
June 29th, 2009, 09:59 AM
Garrett: If you are confident in the readout of the cam why use a laser?

Garrett Low
June 29th, 2009, 10:23 AM
Doug, I got the laser range finder before I had the SmallHD Monitor. Without the larger monitor I was never confident I focus correct. Now it's just more of a habit. Also, with the laser it's a lot faster to get the distance than zooming in and reading the distance. All I do is push one button and the distances can either readout a spot or do a continuous readout as I pan across an area.

I suppose I could use the the camera to do the measuring ahead of time but the way I am I'd still double check with some other measuring device. I always hear my grandfather the carpenter saying, measure twice, cut once.

In this case I can't go out and buy another performance like I could buy more wood when I screwed up.

Garrett