On Sun, 16 Mar 2003 20:15:25 -0800, pete <a@a.a> wrote:

 

>A review of the DVX100 at :

>http://www.cineshare.com/columns/reviews/AG-DVX100_2.htm

>states:

>"For some reason when set to Manual, the iris automatically closes

>down when you zoom in or out. I was told that was by design. I do not

>know why."

>Is this statement correct?

 

I don't know - but it would be useful, if true...

 

>What does this actually mean?

 

Most zooms for small video cameras do not remain constant in

"speed" as they are zoomed (an "f1.6" lens may be f1.6 at

its widest zoom, but may become f2.8 at its longest zoom,

more than a stop "slower". If you are in manual (fixed)

exposure mode (shutter-speed, aperture, and gain locked),

then this lens speed change with zooming becomes important,

since an exposure set at the zoom wide end (and correct)

would cause underexposure near the tele end of the zoom...

 

>In what manual modes does this apply?

 

Exposure...;-)

 

>As I read this statement it would mean that your picture becomes

>greatly underexposed during a manual shot after a zoom is initiated

>during the shot.  How could you possibly work around that?  I must not

>understand this statement correctly.  Does that mean you effectively

>should not zoom while in manual mode?  Please help.

 

See above...

It would correct a problem that exists, not introduce one...