1/30th And Slower, And Resolution
 

Do you really lose 50%? Or what are the facts?
Anyone know why this is?

It seems to be like that, indeed. Don't know if it is that much
though. Found some more information on this thread

Yes, you do lose half of your vertical resolution (horizontal resolution stays the same of course) because at shutter speeds slower than 1/60 (NTSC) the picture is composed of one field only.

It's easy enough to test out. Just set up your camera on a tripod and take two stills to memorystick - one at 1/60th, the other at 1/30th. Pull these frames into Photoshop and notice the stair-stepping on diagonal lines at 1/30th - the reason being the lack of the other field.

tom.

Tom,
My understanding was it's still two fields under 1/60th.
Are you saying it's not interlaced below 1/60th?
I thought the interlacing is what *causes* the stair stepping.

Yes, it's still two fields. Problem is it's the same field.