Stars, Waterfalls and Long Exposures

Well this week’s WIIW seems to have stumped people.

 I thought this image would be easy, but neither Linda G’s guess of : “Raindrops (or water drops, anyway) on a pane of glass in the dark?”; or Old Kitty’s “I'll say padding/insulation stuff!”;  were close.
I can see the water drops by the way…
So what was the image? Well the answer is kind of related to a question that Michael asked about this piccie of the day. 
Michael asked “I wonder if they used an overexposure to capture the look of the water like that?”
First up my inner child has to stamp his feet and say “MY PHOTO” – like 99.9% of piccies on this blog the Mackenzie Falls piccie is one I have taken. :-)

Now I have my tantrum out of the way  I will say, you are kind of right Michael, but it is more a case of “long exposure” rather than “over exposure”.  For a normal photograph (if there is such a thing) a camera is set for a fairly fast exposure with the shutter open for about 1/250 of a second.

If you use a shutter speed like that on a waterfall you get an image like this one I took recently of the Upper Ebor Falls. It was raining (you can see the rain on the lens) and I didn’t have a tripod so I just snapped a quick piccie.

The short exposure “freezes” the water.
 And on this piccie of the Lower Ebor Falls

SO to catch the look of motion I mount the camera on a tripod, narrow the aperture to limit the light coming in the lens and use a long exposure sometimes as long as a full second.
With a long exposure the water blurs due to its motion which generates an illusion of movement.  The only problem is sometimes the vegetation around blurs too as it moves in the wind. Like in this piccie of the Hopetoun Falls.

The trick is to get enough light reflected from the water without actually overexposing the piccie like this piccie of the lower Ebor Falls.

So what about the WIIW image?

Well other than aiming to blur motion, the other thing a long exposure is used for is when there is very low light. My WIIW piccie was taken outside here in the crystal clear skies we get in the mountains (when it isn’t raining). For this image the objects blurred a bit due to the camera moving in a breeze and in the extremely long ten second exposure the objects moved a little them selves.
I give you the Southern Cross and the “Coal Sack”

When one thing leads to another.

My piccie of the day has a story attached to it. If I hadn’t taken the piccie I am about to share the image I used for this week’s What is it Wednesday

would never have been.

Back in May last year Deb and I were down on holiday in Tasmania. One day we went across to Bruny Island which lies just off shore of Tasmania’s south-east coast. We drove from the northern point of the island down to the southern tip.
On the way back across the island I just had to pause to take my piccie of the day…

The strip of water reflecting the sunset colours is the D'Entrecasteaux Channel which separates Bruny Island from the Tasmanian mainland (which sounds absurd to an Aussie ear because Tasmania is an Island off the coast of the Oz mainland).

Anyway, because I stopped for the piccie we just missed the 5:30pm ferry back to the mainland.
Now after the 5:30 ferry there is only the 7:00 ferry. Miss that and you are on the island until the following morning. So we waited by the ferry terminal to make sure.

In the dark.

Now what is a boy with a near new camera going to do?
He’s going to experiment.

So I set up my camera on my tripod, pointed it at the ferry terminal and took a long exposure of 4 seconds.

“Nice”, I think, “but I could get a bit more light in the piccie.”
So I double the exposure time to 8 seconds, a long, long exposure.
This time while the shutter is open a fisherman in a powerboat shoots through the shot.
His navigation light draws an almost straight line 2/3 of the way across the frame before the shutter closes.
Bingo a WIIW puzzle is born!