Barry,
First, - if you want to increase the size of the piece of the video, you
can decrease the resolution of the video.
However, with K-7, the maximum resolution is 720p (unlike with K-5 and
K-3), - so, decreasing it might not be practical.
I observed that with continuous recording of video, the
temperature warning was coming on within 30-40 minutes, depending on the
ambient temperature in the room.
As far as I understand the big reason for this heating in Pentax DSLRs is
the fact that the sensor is suspended (for the optical stabilization), and
that reduces the heat sink.
While I understand your thought that running at lower ISOs would require
lower signal amplification, and hence might potentially decrease the
currents (and heating).
I am not sure where the amplification process is happening: right on the
sensor chip, or away from it. If it is the latter, it wouldn't matter much
for the sensor heating.
But in any case, - I don't think there is a way to set the ISO that the
camera is using during recording video. AFAIK, the camera chooses the
parameters (including the effective ISO) based on the the aperture and the
available light. So, the only way to decrease the effective ISO would be
to open the aperture as wide as possible. And AFAIR, you can only change
the aperture _before_ you start recording the video.
In any case, with any tricks yuou might play, with K-7 (and K-5*), I don't
think you'd be able to record continuously (even with multiple files) over
a period longer than 40 minutes, 1 hour tops.
Sorry for the disappointment, but I hope this information helps.
Igor
Barry Rice Fri, 14 Nov 2014 10:08:14 -0800 wrote:
Hey guys,
Thanks for your help my recent questions regarding video cards and my K7.
I've gotten the cards and am experimenting with them.
So, I've been asked to video an event which is about 2 hours long. This
will
be in a dark theatre. I'll be able to experiment ahead of time, and
position
my camera where it is most convenient. I can see that I'm going to have to
video in snippets about 7.5 minutes each. That's a little tedious, but not
such a problem.
Doing some tests in my living room, I saw that after several minutes of
continuous video work, the camera starts warning about internal
temperature.
But after 30 minutes, it wasn't shutting down. So I guess the heat wasn't
so
bad...
But here's my question. Any advice on settings I should use that might
ease
this process? I suspect that potential overheating might be an issue, so
is
there any setting that would minimize this? I'd assume that using the
native
sensitivity setting of 100 would be best? Any other suggestions or tricks?
Look, I'm a scientific plant photographer, so this is out of my comfort
zone!!!!
Cheers
Barry
Barry Rice, Ph.D.
Sarracenia.com
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