6.6.12

Venus Transit 2012 images!

*
I rose at 3.30am and had plenty of time to get ready for the short drive to the hill I had chosen. 
There was a plate of dark cloud right where the Sun was supposed to rise!


The view not long after I arrived. 4:50am.
The cloud is slipping slowly over the horizon.


All set up: Vixen 90M f:11 refractor on my Bogen video tripod. Baader solar foil, full aperture filter. Home made, tubular camera adapter on 20mm no-name Plossl eyepiece. I was careful to balance the telescope and lock all the unwanted axes.


I practised on the gibbous moon while I waited for sunrise.
The sky was quite light but was lost to applied contrast. 


The teaser shot!
Will the cloud ever clear?!!?


The first clear view of Venus


The sun, now clear of cloud looks remarkably flattened.



Higher and brighter but still not round!


Venus is clearly headed for the limb here. 
Yet the transit is now half way through for Danish observers.
The majority of the transit was taking place below the local horizon.


Contact with tear drop effect bleeding into the solar limb.


Half and half on the limb.


The last few seconds.
The transit is almost over as thin cloud veils the sun.
Next Venus transit is in 2117. 

I really enjoyed my early morning on top of the hill. A farmer passed a couple of times in his pick-up but seemed totally uninterested in my activities. I would happily have shared the view of Venus crossing the face of the Sun.

Thin cloud was present most of the time but was lost in the glare as I clicked away with my camera. My arms were getting tired by the end from bracing the camera at the telescope. I used the telescope and my hands holding the camera to shield my eyes from the direct sun. This worked very well. The entire experience was very successful. Sadly I never thought to remove the camera to view the transit by eye power alone.


The adaptor worked perfectly. Centring the sun was very easy. Keeping the image quite still was certainly not! I just tried to be as steady as possible. Holding my breath, bracing my legs and gently squeezing the shutter button. How I wish I had made an adaptor like this years ago. Instead of continuing to use my hand-held camera method. This time I tried to keep the camera as horizontal as possible. Previous attempts at photography had all sorts of orientations.

The only real oddity was the buff colour of all my images. The Sun looks rather like a round, brown, hen's egg in most of them. This has never occurred with my other cameras. With the camera set to infinity, exposures started at 1/30 as the sun cleared low cloud. Reaching about 1/300 second towards the end. Despite trying to be disciplined I took several pictures, with a variety of zoom levels, at 5 minute intervals. I still managed 520 images. A load more with my hand-held TZ7 camera of the unspoilt, rural views.


It was rather odd to be alone on top of the low, rural hill so early in the morning. It was perfectly still. So the wildlife could be heard waking up all around me. Each taking their turn to greet the dawn. At first the traffic was solitary and sporadic on the distant main road. Becoming a fairly constant roar as the rush hour started. Thin mist lay in the hollows as I looked around my 360 degree view. The wind was non-existent. The turbines standing still.


I wore a down duvet jacket and fleece hat until quite late on. As it was cold and everything was covered in dew. Even the telescope was soon dripping wet. Though the foil filter stayed dry. My worries about the camera dewing were unfounded. It probably gained enough warmth from being handled at frequent intervals. I enjoyed an occasional sit down on a folding chair which I had brought with me. It was pleasant with the warmth of the blinding sun on my face. I left my eyrie shortly after 7am for the short drive home. But was far too excited to see what I had captured to go back to bed.


The effect of "bleaching" and rotating an image 180 degrees in PhotoFiltre.
This is the correct orientation as seen by the unaided human eye.

Please note that all the other solar and lunar images are inverted
While it would be easy to correct this,
the dates and times would then be inverted.
Inverting the camera would have made the shutter button inaccessible.
And, would still have inverted the date and time.
Purists may like to stand on their heads to better enjoy my images. ;ΓΈ)

Sky At Night Magazine emailed me telling me that they were going to use one of my Venus Transit images for the HotShots CD-Rom Cover Disk. (now confirmed as the September issue)


Click on any image for an enlargement
*

5.6.12

Venus transit 6th June 2012

*

Unlike the last Venus transit in 2004, tomorrow's transit will be almost over by the time the Sun rises here in Denmark. I shall have to set the alarm clock for 4am and drive to a local hill with all my equipment. This is the only place nearby, in our rolling landscape, where a clear view is possible of the North-East horizon. Where the sun will (hopefully) rise into a clear sky with the transit already well under way. The weather forecast is for high cloud. Thickest where I live!  

I decided not to bother using the Universal Digiscoping Adapter. While it has obvious potential, it is just too fiddly and prone to misalignment.

I knew I would want to use my no-name 20mm Plossl. This eyepiece focal length provides the ideal image size when used with a simple P&S digital camera in extra-focal mode. The rubber eye-shield cracked off soon after purchase. Leaving a nice, smooth rubber barrel.

Now I had to find a simple tube into which the eyepiece could slip. No plumbing or drainage tube matched my needs. Fortunately my wife had a collection of plastic ready for the recycling centre. Amongst her horde I found a measuring cap from a detergent bottle. It was thin, tough and a funny shape where it screwed onto the bottle neck. The eyepiece fitted perfectly and stopped naturally. Precisely where I needed it to.

I cut off the outer screwed section in the lathe. Using a craft knife with only a tiny bit of blade showing. Then I smoothed the remains to produce a neat flange for a little more strength and rigidity in use. Though it's probably more decorative than anything else.

Now all I needed was to make a suitable section of tube for the camera nose to slide into without effort. First I had to cut off the closed, top end of the cap. This section had to be smooth and soft to avoid damage to the camera finish. So I used sportsman's injury binding tape to reduce and adapt the end of the tube to the size of the telescoping, camera lens barrel.

After some fiddling, with small pieces of tape, I found it much easier to just wrap it over the edge. Half inside and half out. The sticky tape is thin, fine cloth and matt black into the bargain. Absolutely Ideal! There was no need for internal blackening to reduce stray light reflection. The lens is very close to the black top of the eyepiece. I suppose I could have made the binding tape a bit neater but nobody else is going to see it. ;-)

Here is the blue, bottle-top adapter, 20mm eyepiece, Baader "Fringe Killer" filter and the simple P&S digital camera. Note the small camera lens aperture and short zoom are ideal for this purpose. The eyepiece fits in the far end of the blue adaptor. The camera into the soft, black taped end. The length of the adaptor is made to just bring the camera lens very close to the eye lens of the eyepiece without touching. Producing a smooth edged stop, central in the camera viewing screen. Though only at widest angle setting. Any zooming produces a clear field to the edge of the image frame.

Here, the eyepiece is inserted, friction tight, to very near the end of its rubber sleeve. The eyepiece barrel will be inserted and stop just as normal in the telescope focuser. 

The filter has been screwed to the eyepiece barrel. While the camera lens housing has been slid gently into the other end of the adapter. Perfect alignment is achieved without any effort or adjustment required.

The camera will not stay in place of its own accord unless pointing downwards. Particularly as there is always the risk of lens retraction. Though the lens will be deliberately set in the camera menus not to retract. Battery energy saving will also be cancelled. This should avoid auto shut-down.

When attached to a star diagonal the camera will rest naturally (nose down) on the adaptor. It is a snug fit but not remotely tight. One must avoid physical damage and fault reporting by the camera. The camera senses when it has been overloaded on the end of the lens barrel. It will report this fact then withdraw the lens and close down for a reset to avoid damage.

I will set the camera to focus on infinity in the Program menu. This is important. As I have discovered that on 'Auto' it will cycle between Normal distance and Macro. My first pictures of the Sun were actually Macro shots of the illuminated, eyepiece field lens. Ugly and worthless. Except to point out that I really ought to clean the lens properly before use! The distance between the top of the adapter and the eyepiece is just over 20mm. i.e. the length of the camera lens nose plus a little clearance. 

There is still the risk of camera movement when releasing the shutter. I can't take my massive stands and Fullerscopes mountings with me in the car. So inevitably the Vixen 90mm f:11 telescope will not be supported as well as usual.

I have a choice between the Bogen video tripod with heavy duty, pan and tilt head. Or the Bresser 70mm refractor mounting.  I shall probably use the Bogen with the Vixen dovetail screwed to the Bogen's quick release plate. This worked well for the partial solar eclipse which was also a low altitude, dawn event.

Wish me luck with the weather! If it is clouded over at 4am I shall still have to go in case it clears. At least I can sit in the car. The narrow lane goes right over the top of the hill I have chosen as my observing site. Traffic is almost non-existent at any time of day. The chances of anybody else choosing that hill are as remote as the hill itself. My partial solar eclipse on a popular hill was spoilt by noisy smokers!

THE BIG DAY:

I awoke naturally at 3.30am to find the sky clear except for a plate of cloud in the North-East. Precisely where I don't want any! The horizon is bloody red with dark clouds above very slowly moving away. The moon is low in the South. Rising so early allowed a leisurely bowl of muesli and a cup of coffee before setting off. With luck I shan't forget anything. The blackbirds have started singing (loudly) already. It was lucky my wife reminded me to charge the camera batteries last night! 


Click on any image for an enlargement.

*

2.6.12

Digiscoping the Sun.

*
I spent a couple of hours trying to image the sun this afternoon. I was using a Baader foil filter on the Vixen f:11 achromatic refractor. With 26mm and 20mm Plossl eyepieces with a Baader Fringe Killer filter attached. After a false start on the rather shaky 70mm Bresser mounting I put the Vixen telescope on the Fullerscopes MkIII mounting. My new synchronous drive was fitted but I made little attempt to align on the Pole. The telescope tracked but was well out of alignment.

The Ixus 117 camera was fitted to the Universal Digiscoping adapter. Then the adapter was clamped to whichever eyepiece barrel was being used at the time. The camera was set to Program and infinity. When set to Auto it insisted on switching to Macro as the shutter button was depressed. So I had quite a number of useless pictures of the eye lens of the eyepiece. Only then did I discover the ability to set the camera to infinity on the P setting.


There were quite a number of small sunspots but nothing very remarkable. The highest spot on the sun's image above was the largest and showed clear umbra and penumbra.  Visually the image was rather soft with lots of thermal effects. Not a bad effort for a first attempt on the sun with the new camera and fiddly adaptor.

I have found a suitable hill top to see the dawn Venus transit a only a few miles away. The weather forecast is looking cloudy with possible rain!

Click on any image for an enlargement.
*