PDA

View Full Version : Venus Transits the Sun



Doug L
06-08-2012, 08:00 AM
I had taken the day off work in case I had to travel to get clear skies, but as luck would have it, I was able to watch the transit from my balcony till the sun disappeared behind clouds about 10 minutes before sunset. My photo does not do justice to what the event looked like visually - so much more detail was visible looking through the scopes. Three layers were used in this image. One was taken with a Canon XT attached to a 1000mm (focal length) F9.8 filtered (Baader solarfilm - white light) refractor, and two layers - one optimized for surface detail & one for prominences (flame-like appendages) - from a single shot taken with a Nikon Coolpix 4300 camera shooting afocally through the eyepiece on a PST (Hydrogen-Alpha filtered scope). Note: These hydrogen-alpha solar filters are different from photographic HA filters. Don't use those to look at the sun! One more comment about the transit. I've heard many newcasters refer to how small Venus looked when compared to the size of the sun. Venus, though, is about halfway between the earth and sun. It would be a lot smaller if it were actually next to the sun. :)

15428

Marko
06-08-2012, 10:04 AM
Very cool DougL - it's very visually interesting!

AntZ
06-08-2012, 10:56 AM
Fantastic. The red outer ring is cool. Did you manage to get a other shots as it traversed the sun.

Doug L
06-09-2012, 01:31 AM
... Did you manage to get a other shots ...

Yup. Here's a few others. The first one's with the 4 inch refractor and Baader filter (original purplish white colour has been changed to a yellow tone). The second shot is two layers from a single image with the Hydrogen Alpha filtered scope.

15431

15430

AntZ
06-09-2012, 03:36 AM
These are cool images too. I didn't even bother to try. As I didn't have the equipment, and figured I just watch it on the internet.

Runmonty
06-09-2012, 03:40 AM
These are really cool. Please excuse my ignorance, but what are the other spots closer to the centre?

Hillbillygirl
06-09-2012, 06:09 AM
Very cool Doug. I find these type of shots quite interesting, as in something new, something learned. Very nicely done, thanks for sharing these.
Yes, that was the first thing that came to my mind was just how small Venus "really" is, in relation to the sun.

vyeko
06-09-2012, 07:30 AM
Doug are you sure that you clean sensor. Just kidding. Fantastic set.:clap:

Iguanasan
06-09-2012, 09:15 AM
Very cool... it was overcast in Halifax as seems to be the case whenever there's something interesting going on in the sky but I'm enjoying your results.

Matt K.
06-09-2012, 08:48 PM
Interesting, for sure. Amazing what one has to do to take images of the sun. Well done, and now you have given us some ideas about those filters .. much appreciated ...

Doug L
06-10-2012, 01:15 AM
... what are the other spots closer to the centre?
Actually, that's what these are called - 'sunspots'. If you google that word you'll get a huge amount of info, but basically they are holes in an outer layer of the sun caused by protruding magnetic field lines. Some small spots disappear after a few hours, but large ones can last for more than a month (longer than one complete rotation of the sun) and can be visible with no optical aid other than a filter in front of your eyes. It's fun watching them with filtered telescopes or binoculars, as they grow and change in shape. The cheapest safe sunspot filter for your eyes or small binoculars is a #14 welders filter. I looked through one of these during the Venus transit and it was thrilling to be able to easily see the dark disk against the sun with just my eyes. General hardware stores may not have filters that dark, so one option is to stack two #7 welding filters (or any combination that adds up to at least 14). The only slight problem with this is that welding filter glass is not precision optical quality and doubling the thickness means resolution will suffer more. Also, I must warn that if you put this, or any other solar filter on binoculars, scopes, etc., do not put it at the eyepiece end (where the sun's light and heat is focused). The filter must completely cover the front (closest to sky) lens before the light enters the optical system.

Doug L
06-10-2012, 01:32 AM
... Amazing what one has to do to take images of the sun...
Actually, if one purchases a relatively inexpensive solar filter to cover a 300mm - 500mm lens, anyone can take snapshots of large sunspots. But yes, it can get more complicated, and expensive, if you have to purchase a telescope or more specialized filter systems. Most of the highest resolution shots of the sun, moon and planets these days are shot using webcams instead of regular cameras on the scopes. Processing packages then take the sharpest video frames in the shooting sequence and stack them together into a single image.