Boris reviews Pentax K-7 (part 2)

Graydon oak at
Thu Aug 27 13:59:36 EDT 2009

On Thu, Aug 27, 2009 at 07:50:27PM +0200, Ralf R. Radermacher scripsit:
> Graydon <oak at> wrote:
> > I've never needed to turn the shake reduction off in the K20D.  If I
> > have the camera on a tripod on a really solid substrate -- bedrock,
> > concrete footings -- I don't get any benefit from it, but I haven't seen
> > any harm from it, either.  
> I've just recenty noticed a rather strange phenomenon with my K-7:
> I usually travel with two tripods. A heavy wooden Berlebach and a simple
> metal tripod that has the great advantage of being set-up literally
> within seconds as you only need to push three locking tabs to make each
> of the legs unfold by spring force. Surprisingly solid and steady, that
> little thing.

Sounds very handy!

> Put the K-7 with activated SR and Live View on the small tripod and
> within seconds the whole combination of camera and tripod will begin to
> strongly oscillate at around 10 Hertz. Obviously some resonance
> phenomenon triggered by the SR. Never seen anything like that before.

The reason I emphasized the "really solid substrate" part is that trying
to shoot from a wooden observation platform often outright fails; when
there's a bunch of other people trooping across the platform behind me,
the wooden surface bounces, and the relatively long-period oscillation
defeats the shake reduction.  Nothing for it but to wait until they've
all passed by and try again.

-- Graydon

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