Focus Tips

[Patrick Surace]

Hey Everyone!

I have some quick focusing questions. I am a dSLR user, I can say I understand my 5D well enough to get by. That said I think those controls relate across to the XHA1 pretty well, obviously there are alot of differences also. I do alot of motion tracking and cg compositing with my XHA1 and I have to say after many tries and tests I'm not getting the sharpest footage.

I've seen some sample gallery stuff in the forums and I am blown away by the quality they're getting. I also know there's things like the redrock letting people use their FD lenses and whatnot, but I'm sure I can get a sharper shot without that equipment.

I use the magnify button during focus, I also learned from a friend to zoom all the way in on the farthest subject, focus on that and when you pull out all will be in focus. Knowing aperture information a little better than he might, I assume this doesn't hold true if you are shooting 2.8? Is this incorrect information to begin with?

Lastly when I use auto focusing features on the camera, my shots are way sharper, but I can see it tweaking out in the footage, "skipping, fast motion blur-ish imagery". The motion tracking software doesn't get along with the AF stuff and it always does better with sharper footage. Of course the sharper the footage the less grain and blur I have to apply to the cg.

I guess basically I need most stuff to be in focus, I can add DOF later if I have too, since it's for CG anyway. Any tips on A. focusing well, (on the little LCD it looks sharp as a tac to me). and B. keeping the whole frame in focus all the time, would be super helpful. Everyone on here usually is!

Thanks in advance!

-Pat

[Richard Hunter]

Hi Pat. I would guess that what you should do is avoid having the aperture too small. Unlike on your 5D, the A1 image goes soft when you close down the lens, due to diffraction. This is common with cameras that have small sensors. Try to shoot around f5.6 for the sharpest images. Of course, you will have to get the focus correct as well, but you should have reasonable DOF unless you are zoomed in quite far.

Richard

[Paolo Ciccone]

Hi Pat.

Originally Posted by Patrick Surace

Knowing aperture information a little better than he might, I assume this doesn't hold true if you are shooting 2.8? Is this incorrect information to begin with?

Not really. The way cine/video lenses and still lenses work is different. In fact when you use an HD camera with removable lenses you have to do frequent backfocus adjustment. This procedure is performed with the lens *wide open* and zooming in and out on a specially designed focus chart. The best way to get sharp focus is to zoom in, use peeking at about 60-70% and see when the image "pops" and the adjust you focal length for the shot. If you can, use a monitor so that you can judge focus on something that has sharper resolution than the little LCD, you will see how much improved your shots will be. If you have a Windows laptop handy you can use Adobe OnLocation to monitor the camera in the field just by using the FW port.