Manual focus techniques for GS400

[Eric Chi]

I tried manual focus with my GS400. But it seems very hard to tell the best focus until I past the real focus point. And then turn back. Could some one share some tips for using manual focus with FS400?

[Joshua Provost]

I use a hybrid technique. Let's say I want to have a shot where the camera is pointed at a scene, and the actor will walk into view closer to the camera and be in focus. I set up the camera and get the framing I want. I have the actor stand on their mark where they will be once the walk in the frame. I allow the camera to auto-focus, then hit the manual focus button, but DO NOT change the focus. Now the focus is locked on that distance. Have the actor get out of the frame, hit record, and have him walk in. Boom, he's in focus.

Or, I want to have the talent on the left or right third of the frame, but be in focus. I get the camera set at the distance I am going to be. Have the actor on his mark. Center the actor in the frame, allow it to auto-focus, then hit the manual focus button to lock the focus. Then reframe (pan L or R, but don't change the distance from the camera to the actor) so the actor is on the side of the frame or the other. He'll still be in focus.

[Leigh Wanstead]

Hi Joshua Provost,

That is clever. 8 )

Regards
Leigh

[Kyle Ringin]

Good advice Joshua. I use the same method (with my MX500). It basically boils down to the viewfinder not being high enough resolution to focus with properly.

Just watch out using this method in low light as that can make the auto focus do strange things.

Cheers

[Andreas Winkler]

I agree with Kyle, that the viewfinder does not really have the needed resolution to focus manually. Same applies to the LCD, even though it's 3.5".
As I understand Eric's problem, he want's to change focus manually while shooting. In deed, that's not easy with the GS400. You need to practise a lot to get a feeling for the focus. Also try to shoot a scene several times, if possible.
Best solution would be to attach another external LCD screen with higher/full video resolution, but then an additional power source problem would appear, if it's "in-field" shooting.
So just keep on practising, Eric!

[Joshua Provost]

Here's another thought. Say you want one of the follow focus shots where something up close comes into focus. How about shooting it backwards? Start with the focus on the close up object, then manually focus it out of focus. Flip it backwards in post.

[Andreas Winkler]

Originally Posted by Joshua Provost

... Flip it backwards in post.

Interesting idea, but not really always possible... e.g. walking people, street traffic, smoke or ocean waves.

[Kyle Ringin]

I did a few test shots a while ago - it was a rack focus between two subjects. I framed it so one subject was taking up the left third of the frame and focussed on it, then I hit the focus button to switch to auto focus and the camera focussed on the far subject. It worked ok, both ends of the rack had perfect focus but the rack isn't very smooth, it 'snaps' to the second subject, also it means you have to frame in this particular way. I didn't end up using that method, but I can see it would be great in some situations.

The backwards idea is interesting, but I agree that movement would be a problem

[Kin Kwan]

To make sure you have something focused; you can zoom in onto the object, then focus it (or auto focus), lock the focus, and then zoom back out to frame your shot. This is just a way to go around the limited resolution of the LCD/viewfinder when focusing.

Oh, another thing. If you want to focus on a moving subject, use this method: First, focus on your subject at the place where he/she'll be moving from, then use a marker/pen to make a mark on one of those little indentions on your focus ring. (Place some tape around your focus ring so you won't actually be "marking" on it.) After that, tell your subject to move to wherever he/she'll be moving to, then adjust your focus again and make another mark. Now, you know where the two focusing spots are, just follow your subject and slowly turn the focus knob from one mark to the other. This method isn't perfect, but it works with a bit of practice. :)

[Mike Sun]

After reading what Kin Kwan and what Joshua Provost described, I got a question.

So going back to the technique where you zoom into the subject (to the further point they will be), lock the focus, and zoom out all the way, would there be a point where the subject would be out of focus if they started in front of the camera and walked to the furthest point where you set the focus? Assume that you also will be zooming in with the subject as they walk to the furthest point you've set. Do you have to zoom in proportionally to the speed they are walking away from the camera?

[Leigh Wanstead]

Originally Posted by Mike Sun

After reading what Kin Kwan and what Joshua Provost described, I got a question.

So going back to the technique where you zoom into the subject (to the further point they will be), lock the focus, and zoom out all the way, would there be a point where the subject would be out of focus if they started in front of the camera and walked to the furthest point where you set the focus? Assume that you also will be zooming in with the subject as they walk to the furthest point you've set. Do you have to zoom in proportionally to the speed they are walking away from the camera?

MINIDV has bigger depth of field than film, so I doubt that if you can manage to see out of focus in the video.

Regards
Leigh

[Andreas Winkler]

Originally Posted by Leigh Wanstead

MINIDV has bigger depth of field than film, so I doubt that if you can manage to see out of focus in the video.

When you use a lot of zoom, you can get some very nice depth of field effects! Try it, Leigh! I even saw it in some of the photos you posted.

[Leigh Wanstead]

Originally Posted by Andreas Winkler

When you use a lot of zoom, you can get some very nice depth of field effects! Try it, Leigh! I even saw it in some of the photos you posted.

Dear Andreas,

You are right that highly zoom minidv shot will show back ground out of focus. But in normal wide angle shot without zoom, minidv will have bigger depth of field and that is the area I am talking about. Actually that is a very hot subject related to mini35, micro35 sorts of device to use film lense and still lense to override normal default minidv lense.

Regards
Leigh

[Andreas Winkler]

Originally Posted by Leigh Wanstead

... in normal wide angle shot without zoom, minidv will have bigger depth of field ...

Yes, you are correct Leigh, in wide angle mode most MiniDV camcorders have a very high depth of field. But actually this is not related to the MiniDV format itself, it's the size of the CCD and focal length that matters here, afaik.
A mini35 is a good atempt to get shallower depth of field, but most of these (mostly selfmade) thingys are a bit terrible to handle or even fragile when shooting "on the road", imho. So I go with the "zoom-trick" for now.