just see if 1/30 or 1/60 sec. looks better

<<<-- Film is 24 fps, with 180 deg. shutter the speed is 1/48th. -->>>

The math is: 24fps allows an exposure of up to 1/24th S. With a 180 shutter the exposure is 1/48th S.


30fps allows an exposure of up to 1/30th S. So a shutter speed of 1/30th S is certainly OK.

But following the same relationship as film at a 180 shutter -- and the same relationship as the DVX100 at 30fps -- the appropriate exposure is 1/60th S.

So you have a choice: use 1/60th S which the camera defaults to AND follow the "rules" on panning and zooming

OR

set at 1/30th which will let you not worry about the rules but which will have two side effects:

1. The image will lose detail on movement because of blur

2. By setting the speed to 1/30th S you totally lose the ability to adjust exposure. This leaves you helpless to adjust exposure in high contrast situations.

It's your choice. But JVC and Panasonic cameras default to 1/60th S at 30fps for good reason.

Lastly, there is the real possibility that for some folks 30fps just won't work. And I'd bet many of those never shot film.

On the other hand, some folks (likely those who have shot film) will love the look of 30fps at 1/60th. I love 720p60, but was blown away looking at DVX100 material blown to 6 feet. It really did look like film!

I said that I liked the 1/30th shutter speed look on this camera purely based on my personal tastes, not on any technical basis. I enjoy the look of film very much, and to me this gives something that looks very close to film motion and film motion blur. I'm also familiar with the (supposed) 30p look of the XL1 and GL1 in 'frame mode", and I can tell you that the JVC's motion is much much more natural and smooth than "frame mode", which I found to give a very stroboscopic effect when I used it. In 1/30th shutter speed mode on the JVC I find I'm only losing detail (if that's what you call it) in the motion blurred parts of a scene, which is how it should be.
Steve, a quick note, in one of your last postings you seemed to suggest that you could use the "Exposure" control while in S/A mode, to dial down the exposure when having the iris or shutter locked. This may have been my misunderstanding, but just to clarify.....Adjustments to the "Exposure" control on the JVC are only available on this camera when it's in AE mode (which lets you select the "spotlight/snow...etc" modes)). It is NOT available in S/A mode, (which let's you lock EITHER the shutter OR the Iris, but not both at the same time). The S/A and AE modes are mutualy exclusive in all ways, so it is not possible to access the "Exposure" control in S/A mode.
As someone mentioned, in the camera menus there is an "AGC ON/OFF" control that can be set. I have tried this both on and off and it doesn't seem to effect the cameras automatic adjustment of Iris if it's either on or off, so I haven't a clue right now what it IS doing.
As far as testing under exactly what changes in lighting conditions the camera is programmed to make adjustmets to the shutter speed, someone needs to do some accurate/controlled tests on this, and I don't ahve time to do it right now unfortunately.
I would suggest emailing Ken Freed at JVC and ask him to get an accurate run-down from his engineers as to what exactly this camera is programmed to do in that regard, they surely must know right? Then you could use you could use your ND filters in a more informed way rather than guessing when the camera is going to change the shutter speed.
Personally I think this camera will be reasonably controllable using ND filters to control light input and locking the shutter speed (which DOES stay locked), or enough to do most tasks in bright lighting conditions, which is where you will encounter problems. I bought 3 ND filters for it which arrived today, and plan to use at least one at this wedding I'm filming, so I'll let you know how it goes.
One last thing, when I talked about the "Jitters" on this camera previously, I was not reffering to the natural motion of the video when the camera is locked down, but to the 'Stuttering" effect that was noticed by many when panning or tilting the camera...and this is what seems to be cured when you use 1/30th shutter speed. But again, I haven't had time to do any rigorous tests.

Thanks