View Full Version : Matte Box for JVC HD GY-200u


Jason McCormy
September 25th, 2008, 08:43 AM
Does anyone make a matte box for the JVC 200u that is similar to the ones Sony uses where you don't need to remove the lens cover, just flip a switch and it opens? I've already lost one and well... there yah go. I'm thinking I need one that stays on.

Jason McCormy
September 25th, 2008, 08:52 AM
Also,

If you had to leave one filter on for very rapid movements to different shoots through out the day, what would it be? I've been keeping UV haze on but really like the Black Diffusion for interviews. But, I hate they way it looks for scenery. Or, should I just find more time?

Werner Wesp
September 29th, 2008, 05:24 AM
A Mattebox with french flag connected that you can flip down perhaps? It's not ideal but it might work.

Keep the UV filter on, it's the most neutral. If you have enough light everywhere, I'd even keep the pola on (I have a pola filter in one stage of the mattebox all the time). If you shoot regularly with limited light, that will obviously no option.

Bottom line : more time for shooting is usually the best recipe to get better shots...

Jason McCormy
September 29th, 2008, 07:42 AM
Thank you Werner. Yes, it does seem that more time is the best, otherwise you just have to hope it is interesting enough you will be forgiven. Hmm.

Werner Wesp
October 1st, 2008, 01:00 AM
That IS the key indeed - keep the content that interesting, so regular viewers will forgive you for just about everything. Might still get a hard time from professional colleagues though.

Stuart Nimmo
October 1st, 2008, 11:47 AM
Apart from inevitably better audio it's also why getting rid of Sound Recordists and handing their job to the cameraman is such a false economy, but mention that and under-trained PM's think you must be a dud.

I'm thinking about your polar' idea Werner, it would certainly keep the iris opened up.

Jason McCormy
October 1st, 2008, 12:44 PM
So keeping a Polarizing filter on will help keep the iris open and the depth of field under control? What about an ND filter? Or is a polarizer better? Which is the best for moving indoors and outdoors with people in the shot?

Thank you for your help, this is very informative.

Werner Wesp
October 3rd, 2008, 12:26 PM
Pola is more versatile then just the ND of course - for one, you can reduce contrast a bit in scenery and saturate the colour of the sky, but, indeed, you need to have enough light to work with pola.

Shaun Roemich
October 4th, 2008, 08:15 AM
Jason: a polarizer (in addition to all of it's wonderful light-aligning properties that MAKE it a polarizer) has a transmission factor of less than one, meaning that it "robs" you of light passing through it, just like a neutral density would, although, in my experience 1.5 to 2 stops on the polarizers I've used versus a set number printed on a neutral density filter (ie. .3, .6 .9 etc.)

It's that transmission factor that requires the lens to be opened up further to compensate for light loss, not any other "magical" property.

Terry Lee
October 4th, 2008, 09:16 AM
I was under the impression that the lens is set manually and has no external factors that determin your focus... But I suppose there is alot I do not understand about the lens.

Shaun Roemich
October 4th, 2008, 12:18 PM
Terry: Focus is a result of a number of factors.

Distance to subject coupled with Depth of Field and focus distance = (Perceptually) In or Out of Focus.

With a large depth of field more of your image will be in focus, regardless of where the focus distance ring is set on the lens. It is possible to have a subject at 20 feet be in tack sharp focus with the lens focus distance set to 3 feet if the depth of field is great enough. Conversely, with a shallow depth of field, it is possible to have just a person's eyes in tack sharp focus and the back of their head and the tip of their nose going soft.

Depth of field is controlled by 3 factors:
-Distance to subject (the further from the lens, the LESS additional distance affects in or out of focus)
-Focal length of lens (the longer the focal length in mm, the less the depth of field)
-Iris (the lower the f or T number, the lower the depth of field)

A number of other factors can affect the amount of light striking the imager, thus affecting the correct Iris setting for proper exposure. Decreasing imager sensitivity results in the Iris being forced open further, thus lowering depth of field. Increasing shutter speed results again in a more open Iris and less DOF. Neutral density filters and other light "robbing" filters, same thing. Lowering camera gain again forces the Iris open (some pro cameras allow you to choose -3dB of video gain instead of 0). If you have less light falling upon your subject, the iris is open more, less DOF.