movie with Canon A75 problem

Archived from groups: rec.photo.digital (More info?)

This is completely normal with CCDs when used at high frames rates such as
for video. I've noticed it years ago with my first camcorder. I see it in
the live previews of any digicam I've used. It even happens with
professional gear. Without getting technical, it is a flood over effect when
the CCD is over saturated from strong light.
John

"MB_" <mel@prodigy.invalid.net> wrote in message
news:Nz0xd.14334$N35.1359@fe06.lga...
> I am still a newbie to digital cameras. I really like my Canon A75.
>
> One question: when I use it to take a movie, sometimes I will get a pencil
> or two of vertical purple light. For example, the other day we had a
> birthday party and I took a movie which included a relative blowing out
the
> candles on a birthday cake. But when I looked at it, there were these thin
> pencil beams of purple light above (and below) each burning candle. (As
> each candle got blown out, the corresponding beam disappeared)
>
> Any idea what causes this and what to do about it?
>
> Mel
>
>

Archived from groups: rec.photo.digital (More info?)

"MB_" <mel@prodigy.invalid.net> writes:

> I am still a newbie to digital cameras. I really like my Canon A75.
>
> One question: when I use it to take a movie, sometimes I will get a pencil
> or two of vertical purple light. For example, the other day we had a
> birthday party and I took a movie which included a relative blowing out the
> candles on a birthday cake. But when I looked at it, there were these thin
> pencil beams of purple light above (and below) each burning candle. (As
> each candle got blown out, the corresponding beam disappeared)

I can reassure that it's not just your A75. without digging into the
details, when you have a relatively strong lightsource in a mostly
dark frame, you'll be prone to this. I believe it has to do with
sense amplifiers on that colum of image sensor pixels blowing out the
column, if I were a betting man.

> Any idea what causes this and what to do about it?

A proper videocamera. The bear may dance slowly, but one should be
impressed he can dance at all--sort of true for using these digicams
to do short videos as it were.

Best Regards,
--
Todd H.
http://www.toddh.net/