View Full Version here: : Venus Transit - Hi res white light
07-06-2012, 08:34 AM
Here’s a two-pane quickie from yesterday, showing some nice solar granulation and one of the sun spot groups. Venus is perched a little awkwardly in the corner due to the size limitation of the DMK31.
Taken at the prime focus of Tak Mewlon 180mm F12 with DMK31.
07-06-2012, 08:43 AM
Super sharp Dennis!
07-06-2012, 08:51 AM
That's incredible, what a great shot Dennis! I think you can even see the atmosphere of Venus, it's edge is more soft than the finest detail in the sunspots.
Did you get many images?
07-06-2012, 08:54 AM
really high res Dennis - excellent. regards Ray
07-06-2012, 09:01 AM
lovely work Dennis,I think Rolf is right,it does almost seem one can see the atmosphere of Venus,even on a few of my images towards the end of the event,I can see what looks like it could be the atmosphere.
07-06-2012, 09:10 AM
Great stuff Dennis. I was waiting to see what you produced. I checked the list a few times yesterday looking for your name to see your results. I really love how sunspots seem to take on a different appearance in white light compared to Ha. The granulation you have is awesome to say the least. Nice work.
07-06-2012, 09:12 AM
07-06-2012, 10:22 AM
Thanks for the comments. The “false” atmosphere around Venus is an alignment, stacking and processing artefact. This is not readily discernible when looking at the finished photo, but when you see the “Live View” images you can see the dramatic effects of the Earth’s atmosphere producing a “boiling” effect around the limb of Venus.
Although I have tried to minimise this effect in the processing workflow, it is quite difficult to eliminate it completely.
I spent most of the day with the Vixen 4” refractor collecting whole of disc photos, as the seeing didn’t really support the longer focal length of the Mewlon. We also had family and neighbours around, so we made it more of a social occasion than a hard core recording event. I had a few issues with clouds, trees and roof tops blocking the views at the opening and closing stages of the event.
Here is a single frame to show the boiling limb of Venus.
07-06-2012, 08:37 PM
Here’s a composite image where I grossly over-exposed the Sun, in an attempt to tease out the full disc of Venus as it crossed the limb. I added the solar granulation from another image, to replace the featureless, white, blown-out solar disc due to gross over exposure.
07-06-2012, 08:49 PM
That is cool!
07-06-2012, 10:13 PM
Superb Dennis . The atmosphere was certainly on the boil in the arvo
07-06-2012, 11:15 PM
08-06-2012, 08:04 AM
Cool images Dennis!
08-06-2012, 08:35 AM
Lovely work Dennis! I can certainly confirm the iffy & boiling seeing north of Brissy.
08-06-2012, 09:56 AM
Thanks guys, it certainly was an exciting event.
@John – in Brissie we appeared to be positioned towards the southern edge of the jet stream, whereas towards the north, the map was coloured with those horrible lime green/yellow contours that portend miserable seeing.
08-06-2012, 10:33 AM
Super resolution there Dennis, certainly a memorable day.
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