DV Resolution in Close Up vs. Long Shot
 

I was watching a documentary shot with an XL1S and consistently noticed that closeups seemed to be much sharper and in higher resolution than long shots. This was a documentary about hawks, so some of the long shots were done with serious telephoto lenses. Anyway, does this make any sense? Is there a reason in general why there would be such a difference between close ups and long shots?

I'm not talking about shots that are more grainy. I'm talking about edges that are more jagged. Just a lot less definition.

Thanks.

Yes sir, there is indeed a reason. Keep in mind that a digital image is made up of pixels. The number of pixels on screen is constant. When you have a closeup of something, there are more pixels to represent it, and therefore it will be more detailed. The reverse is true for long shots. This goes for any medium (film, analogue video) but it is more noticable with miniDV, because its resolution is lower than that of a Betacam SP, or the "resolution" of film. Take a still picture with a film camera. If you have someone very far away, you just won't see much detail in their face, or anywhere that takes up a small area of the frame.. You can magnify that picture as much as you want, and no more detail will surface. Take a much closer picture. Now you can possibly see their pores!

Resolution (number of pixels per frame) remains basically constant, far or close. Details in an object of course become less pronounced when the objects gets smaller. B.t.w. max (luma) resolution for Betacam SP is about 450 TVL while the max DV resolution is 540 TVL

The number of pixels in the CCD remains constant. The size of the subject plane (target) does not remain constant. In the close up, the target was maybe a couple of inches square. The number of pixels per subject plane is high. In distant subject planes the area covered is larger and results in less detail (less pixels per area). The Circle of Confusion (Cc) is larger in the more distant shot. Distant shots also suffer from other factors. Movement of tripod head to follow subject (movement reduces sharpness) and convection current of the air, pollution etc all affect the apparent sharpness and Cc.

Jeff