On Jul 17, 8:24*am, bud-- wrote:
wrote:
On Thu, 16 Jul 2009 20:27:23 -0700 (PDT), harry k
wrote:

On Jul 16, 11:26 am, DerbyDad03 wrote:
On Jul 16, 12:57 pm, Smitty Two wrote:

In article
,
*DerbyDad03 wrote:
I have not been able to find an on-line copy of
the commercial.
snip
when I run my DVR in frame-by-frame mode, it still
appears that the drill and bit is rotating in reverse.
Step up to the plate in the name of science, and be the first to post
your clip online.
I don't have a "clip".

I rewound the DVR while watching the show and stepped through the
commercial to see what it looked like in slow motion. I did not record
the show.

That said, I'm still looking for an answer to my question: Would the
wagon wheel effect be captured while filming the commercial and thus
be captured by my DVR or is the wagon wheel effect "perception" in all
cases?

If it is "wagon wheel" effect it would be on your DVR. If it were mirror
image it would be on your DVR and you would have to have a reference,
like text, to tell the difference. If it were video played in reverse
direction it would be on your DVR and you would have to have a
reference, like unreasonable sequence, to tell the difference. TV and
film motion is "perception" from still pictures.

Now I wonder too. *It used to be common, especially in westerns. *I
can't recall seeing an example from other than old films.

Wagon wheels are large with a very visible pattern. Car hub caps are
small and don't have near as much pattern, if any. And anyone who shoots
now should be aware of the effect so they can avoid it. I have seen
modern car commercials with the wheels going backwards, or forwards at
the wrong speed. And I suspect we are aware of the effect and ignore it.

Once again... The film frame rate was different than the 60 cycle
timing used as the basis for television video. If something is
recorded originally on video rather than film, it won't exhibit the
effect, because the original recording will have used the same 60
cycle standard as the TV used to reproduce it.

The reason it used to be more common is that today, less TV production
work is done using photographic film as the media.

It can certainly be picked up in video recording. If a wagon wheel is
rotating clockwise and the 1st frame/field has a spoke at 12:00, the
next frame has a spoke at 11:30, the next frame has a spoke at 11:00...
the wheel will appear to go backwards. You are not viewing a rotating
wagon wheel. You are viewing a series of still pictures that are
perceived as rotation. It is a strobe effect.

--
bud--- Hide quoted text -

- Show quoted text -

Exactly! Some of thed posters seem to think they are view 'moving
pictures' rather than a series of still shots.

Harry K