reduce depth of field on Canon HV20
 

Any way to reduce depth of field on the Canon HV20 without breaking the bank? (I.e., getting a 35mm adapter and 35mm lens?)

You just need to zoom-in all the time to your subject. About 80% when using the normal lens and about 30-50% when using an ND filter in front of it. There's no other way to get background blur on most shots with these consumer cameras without modifications/adapters/etc. Also, using manual focus in some situations might help. That's it.

Not tried this but.....

You'll get the shallowest depth of field if the aperture is fully open.
In a brightly lit scene, I guess adding some neutral density filters could allow this to happen.

Of course you don't want to lose so much light that the electronic gain kicks in.

I prefer polarizing filters - you get a variable ND that way:

http://hv20.com/showthread.php?t=1132

Zoom
 

It's all abot zoom and 'enlarging out of focus areas'.

If you have a subject, make sure the background is 10 feet or so behind them, then you take the HV20 and make sure you're 10-15 feet away from the subject. Then zoom in and focus on the subject.

Ta da. The HV20's sensor is large enough that if you use this technique, you'll be able to yield great results!

The question was how to make that 'DOF' effect. Answer remains: open aperture, and/or zoom and focus maually if you need to make the effect the most apparent.

Green screen the actors in a very quiet place, then go shoot your background out of focus. This also does beautiful things for your audio. There's also a plug in for After Effects that claims it can do this for you. I'm just assuming it's a mask technique.

You know...I've actually thought about doing this. My question is....does big budget movies do this also? I know they would have the cams that can do this naturally...but I wonder if some are using this method.

"300" is shot fully greenscreen in a studio... well, in an empty hangar, except one scene with horseback riding. Then about year and a half in post.

The camera I want is the one captures scene with deepest dof and 'somehow' generates greyscale depthmap so that I can add custom and precise dof in the post ;-)

Yes 300. Less than recently, Sin City.

There's a romantic sunset balcony scene in Heat where Di Nero is talking with a woman, LA sunset in the background. I'm almost sure normal productions are never scheduled to include a green screen shot. Maybe a second unit "oops we missed this" or a prod co's funding cuts might make some of these types of things necessary but I don't think anyone starts out thinking this is a good idea.

...on the green screen "solution": blurring is NOT the same as having low DOF. It's so synthetic!
A calculated gaussian or other blur delivers a totally different light scatter than a lense. The HV20 proves this in a peculiar way by delivering a weird blur effect I have never seen before in a cam: I would call it square blur. Bright objects that are out of focus blur like this:

<>

Not round, but a 45degrees rotated square (actually, a little bit squashed). Maybe you can even see it on Wes' shots in this thread (thanks Wes)

To tell you the truth: once I started to notice this HV20 square blur, I diminished my low DOF shots. It looks somewhat artificial...

Pieter

I've been looking for a plug-in that would simulate bokeh after some rotoscoping. I know SDOF is not desirable in all situations, but I have one interview with a famous author, in front of a bookcase. Everyone wants to see what books he has! Maybe my After Effects wizard can figure this one out. Pieter, I know what you mean by the <> blur of the HV-20.

It's the shape of the camcorder's iris. Lock your aperture fully open at the widest zoom setting, and you'll get a nice circle.

Even then Steve, Pieter is right. The fully open Iris on the HV20 is still shaped like a diamond - it only consists of four-blades. So Pieter, that's the best you'll get! And, it's not bad, really.

This principle applies for any camera.. in the right situations, you can 'see' the shape of the Iris in the bokeh.

And Dennis, right on: the question was HOW to get the DOF look without the cost, not the merits of DOF. So, again, wide open with the iris, and if you're in the right situation, zoom and focus on subject (with foreground and background out of focus).

Like I said, the trick is to lock the aperture with the camera zoomed out fully. If you lock the aperture with the camera zoomed in at all, you can't get a fully open iris. This is straight out of my camera (it's the Num Lock light on my keyboard):

I stand corrected! Now that I think of it, I've gotten an image similar to that too, but the focus was so far out that it was just pretty colours (shot at night, street lights, etc).

Hi Steve&Robert,
thanks voor 'zooming in' on my relatively OT statement there. Helps me a lot!
Pieter
(ps - and I learned a new word: bokeh ;)

I too would love to be able to do DOF effects more naturally, but it costs so dang much. In a short movie I made (before buying my HV20) I did the green screen trick. I think it looks alright.

Here's a link, not to my movie but a short demo of some of the effects in my movie. You'll see one is a DOF effect using green screen. I don't think it looks half bad.

http://youtube.com/watch?v=AXec4XjmtHE

For anyone who gets hung up on depth of field, I urge you to see Orson Welles's Touch of Evil.

Zooming in does not produce shallower DOF if the subject takes up the same portion of the screen.

Actually yes, technically this is indeed true. Zooming in will in fact produce a shallower depth of field. However this technique for decreasing depth of field is not all that useful because the subject size obviously changes as focal length changes. For a full explanation, see our definitive article "The Ultimate Depth-of-Field Skinny" by Jeff Donald, located at http://www.dvinfo.net/articles/optics/dofskinny.php -- hope this helps,

You are both correct.

Michael, you're saying that DoF does not change if the operator moves the camera so that the framing is the same, no matter the focal length.

Chris, you're saying that the DoF will change if the operateor does not move the camera.

It's important to note the difference, because if a shot is framed the same way at wide angle and telephoto, the telephoto shot will yeild more diffuse background blur due to magnification, even though the DoF is the same.

DOF Test
 

I did a quick test on DOF for the HV 20. You can view it here:

http://www.vimeo.com/393169

Make sure to select Full Screen to see detail.

Hope it helps.

Brad

Hey, Brad, thanks for the DOF test on the HV20. The image is gorgeous.

I'm curious -- are you the same Brad Mirman who wrote Resurrection? One of the creepiest serial killer movies of all time.

rgb