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-   -   Help With Depth of Field on GL2... (https://www.dvinfo.net/forum/canon-gl-series-dv-camcorders/115368-help-depth-field-gl2.html)

Ash Varma February 21st, 2008 07:45 AM

Help With Depth of Field on GL2...
 
Hi All,

I have recently purchased a GL2 and having trouble getting a proper DOF shot. I have a talent at the front and a talent in the background. I'd like to move focus from the subject in the background to the subject in the front and vice versa.

This vid has acheived it nicely without any other equipment:

http://www.youtube.com/watch?v=UXbTo6b_bxs

Can someone please guide me step by step on how I can acheive this effect?

Thanks so much in advance.

Todd Clark February 21st, 2008 09:18 AM

It is tough with video but the best thing you can do is move the camera back as far as possible and zoom in all the way. Open the iris up as far as it will go. You might need to use the ND filter to keep the shutter speed at 1/60.

Use Manual Focus to change the focus from front to back. It takes practice.

Don Palomaki February 21st, 2008 03:36 PM

Also you may have to "over focus" a bit; i.e., focus a bit past the far subject and in front of the near subject so each is just barely within the DOF range for their distance and the other is out of it.

Mike Barber February 22nd, 2008 01:02 AM

Quote:

Originally Posted by Todd Clark (Post 830175)
the best thing you can do is move the camera back as far as possible and zoom in all the way.

One issue with zooming "all the way" is the spatial compression that occurs. Be sure to look at your blocking through the camera. You may need to cheat a bit and have the actors farther away on the Z axis in order to maintain a realistic looking distance between them.

Sadly, the G2 does not have witness marks on the lense -- but then, why would it? That abomination servo focus defeats the possibility of using them. However, get yourself a roll of white paper tape (aka, artist tape... NOT masking tape!) and wrap some around the focus ring and the lens barrel in order to give you a place to add some reference markers for whoever will do the focus pulling.

Chris Coulson February 22nd, 2008 02:49 AM

the technical answers above are all correct, I believe, but just for the dummies (like me) reading this, here's the non-technical answer... (I think)

Low F numbers - F1.8, F2
Maximum zoom

will produce the smallest depth of field. Anything different will make the DOF larger, but you still might find it's good enough for you.

good luck!

Don Palomaki February 22nd, 2008 07:40 AM

If you want to spend some more money (~$1000), consider the LETUS product as a way to obtain 35mm film-like DOF with a video camera using 35mm still lenses. see: http://www.letusdirect.com/

Search the forums for "LETUS" for comments by others on this product. And there ares some instructions around on the web for do-it-yourself versions that will cost as little as $15 in materials if you have a reasonable amount of spare/junk stuff around the house and are handy.

Mike Barber February 23rd, 2008 12:40 PM

Quote:

Originally Posted by Chris Coulson (Post 830724)
Low F numbers - F1.8, F2
Maximum zoom

will produce the smallest depth of field. Anything different will make the DOF larger

That is correct. The two factors involved in DOF are 1)iris diameter and 2) focal length. The issue with automatically jumping to maximum zoom is the spatial compression along the Z-axis that comes with it. You have to balance depth of field with depth perception, so to speak. It's one of those subtle details that tends to get missed.


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