Wednesday, 30 September 2015

Sun Spots

With the long summer !! nights here in Shetland there has not been much chance for night photography.

So its all down to photographing the sun- Please use a special solar filter

Sunspots with a solar filter can be photographed  when its sunny of course. Setting up on a tripod, a 500 mm lens and using a cable release is all that is needed. Don't look through the viewfinder it is very dangerous but instead use live-view which is safe. If you did view the sun with your naked eye you will feel no pain because your retina has no nerve endings, you will become blinded almost instantly. Even after a short while the lens end temperature will reach 500 degrees, so as soon as you have finished photographing move the camera away from the sun

After focusing in live view you can fire away, the sun is always a superb target. With  a 500 mm zoom lens its best to go down to a 150 mm , find the sun then zoom in, the sun doesn't stay in view long but it can be easy to find. The solar filter cuts the light down so I use ISO 400 and shoot around f/8.

Sunspots add interest, these are small dark markings in the sun's photo sphere, large storms not of rain and wind but of intense magnetic activity. Because they are magnetic they always appear in pairs with opposite magnetic polarity.

The dark spots are in fact cool areas in a very hot mass. These move left to right across the suns surface (northern hemisphere) , normally lasting no more than 14 days. Some don't make it across the whole surface.

Every 11 years sunspots reach a peak and within a year 100's can be seen. But every 5.5 years after the peak very few or none will be visible. The peak activity for sunspots also occurs with other activity, which include mass ejections, called corona.

Some people also have concluded that in periods of little activity, very cold weather occurs on earth. Like wise in years of very active sunspots the sun temperature will rise could this be Global warming ??. The last peak activity was back in 2011, so you would expect less sunspots from mid 2017 on.

The other good thing is in periods of high activity there is a greater chance to see the Aurora (Northern Lights) .

Auroras can be superb colours but when they are around KP3-4 they look dark on the horizon and sometimes you have to use your camera to tell they are actually showing as the eye cannot detect low activity.

Saturday, 12 September 2015

Tingwall Aurora

`No colour and no brush is able to paint it;no words can describe it in all its grandeur' - Karl Weyprecht

If there is one thing people would like to see, its the aurora. These magical lights are very elusive but you can increase your chances of seeing the Northern Lights (Aurora) by living in an area that is as far north as you can go.

Shetland therefore has to be the best place, especially as a lot of auroras are dim even from Shetland, around KP4 and are therefore not normally seen further south.  These last few days however have been better with KP6.5 recorded, but as luck would have it we had been out and missed it. Just as we headed on holiday a KP8 hit and people in Shetland had some amazing colours- and clear skies.

On Thursday we went up to Asta to listen to some music and looking through the window about 9pm i could see stars and a clear sky. The temptation was too strong, especially as there was no moon (Light pollution) so we decided to go up to the boat shed further up the valley.

We pulled up beside another car where two other people stood watching the sky to see whether any aurora would be visible. Both these people were German and had the spot recommended by their B&B.

The glow in the sky revealed that the aurora was present, but weak. I took a photo which showed a green glow, visible to the sensor in the camera but not to the untrained eye. They seemed quite amazed that they had been looking at the sky for over an hour but didn't realise that they had been seeing the aurora.

They left soon after and missed a stronger aurora quickly developing , along with the green glow (the normal colour) a layer of purple sat on top, curtains and pillars of light began to form and moved across the sky. It was an amazing sight, the best aurora we had seen since moving to Shetland. You cannot witness such a beautiful phenomenon without the sense of awe.

It just confirmed to us how quickly the aurora can develop and then recede, easy to miss especially if you have to travel a distance

The location was reasonable, a dark site but with a steady stream of cars coming down the valley. The red glow coming down from the wind turbines looked spooky. The International space station and a meteor added to the scene.

When photographing the aurora you need to ensure you have a strong tripod, one that doesn't get blown about in the wind. Be prepared to change settings when the aurora starts to develop. I usually start with around ISO 800 - 1000, with 20sec exposure using a Nikon D7000, Tokina 11-16mm lens at 11mm, at f/2.8

On Friday aurora alerts kept coming through the day, no good for seeing anything in the night sky, and as darkness fell the strong winds F7 and cloudy skies did nothing to encourage me to go out