A wonderfully detailed image of AR 1476 (Brisbane 10th May 2012)
I was delighted to obtain a wonderfully detailed image of AR 1476 from our back garden in Brisbane, recorded on 10th May 2012 at 10:56am AEST (GMT+10). I used a Takahashi Mewlon 180 F12 ‘scope with a Tak x1.6 Extender and the camera used was an Imaging Source DMK31AF04.AS industrial webcam.
To obtain this breathtaking detail, I recorded an AVI of 2500 frames and then let AVIStack select the best 154 frames whilst I had a cup of tea.
The skies were sparkling and although I was just inside the edge of a turbulent jet stream pattern, there were sufficient moments of excellent seeing for the details to pop through.
Thanks for all the nice comments everyone, I’ll pass them on to the “gods of seeing”...
I was using a full aperture solar filter made from Baader astro solar film, the photographic density type. In addition, for the 1st time, I also used a 1 ¼” Baader Solar Continuum Filter (BSCF) fitted to the DMK31, ahead of the standard IR block filter.
With just the IR cut filter, the DMK31 settings were 1/2000 sec with a Gain of around 295. With the addition of the BSCF, these changed to around 1/120 sec with a gain of around 450, quite a significant loss of light.
As the seeing was quite variable, I was pausing/re-starting the 2500 frame avi’s whilst eyeballing the screen and I think that the BSCF definitely revealed finer detail and seemed to cut through the seeing, although this effect was quite subtle – you still very good seeing to harvest this level of detail.
Outstanding work Dennis, such amazing structure and wonderful depth of detail. You certainly have quite diverse interests, regarding the objects that you image but regardless of what you post it is always of the highest quality.
A few people have asked me about the solar filter used on my Mewlon 180 F12 ‘scope, so here are some details.
The full aperture solar filter that I use on my telescope for high magnification astrophotography is made from Baader AstroSolar ™ Photo Film which has an Optical Density of OD = 3.8. The Baader website writes that:
“AstroSolar™ PhotoFilm is not intended for visual observation. PhotoFilm is only for use with telescopes for high magnification photographic work. Do not use it for producing solar eclipse viewers, do not mount it onto DSLR camera lenses.”
For visual use, Baader also produce AstroSolar ™ Safety Film which has an Optical Density of OD = 5.
WARNING: Never look at the Sun through an optical instrument without a specialised, full aperture, astronomy filter – otherwise you will destroy your eyes.
To make my filter cell, I used high density, closed cell foam. This is the tough stuff that is hard to compress, not the soft, floppy stuff which offers little support.
The following photos provide some details on how I made the filter and importantly, how I secure it to the front end of the telescope so that a gust of wind will not blow it off.
After cutting the correct length of foam strip, I joined the ends of the strip to form the cell body, using contact adhesive, staples and gaffer tape. I used contact adhesive to glue the solar film onto the cell body and contact adhesive for gluing the foam ring to the solar film at the top of the cell.
I drilled 1/8 inch pilot holes spaced at 120 degree intervals around the circumference of the cell body and fitted x3 off ¼-20” nylon bolts (trimmed to length) to act as retaining lugs for a rubber retaining band.
The large rubber retaining band was purchased from Bunning’s in their electrical cable section – I removed a plastic slider so the band fits nicely around my OTA.
The Finderscope filter was made using the visual use Baader AstroSolar ™ Safety Film which has an Optical Density of OD = 5.
I used 1 inch thick closed cell foam and glued the Safety Film to the foam using contact adhesive.
My finder is close to the OTA so I had to cut a flat side on the finder scope filter cell, to fit it to the finder scope – it is a tight fit and will not blow off.
If you do not know what you are doing, do not risk your precious sight – purchase an approved, ready made filter suitable for your particular ‘scope.
Thanks Derek & Rolf, I appreciate your comments, although I’m mulling whether or not just to kick back and enjoy the whole spectacle at a more leisurely pace, as a visual experience only.
No doubt there will be a plethora of wonderful images and animations soon available, globally; it hardly seems worth the effort in adding my 2c worth.
Just think, no PC’s , no cameras, no processing, etc., just a leisurely peek into the (full aperture solar filtered) eyepiece in between refreshing cups of tea, with lashings of hot buttered toast, Danish pastries or toasted English muffins!
I sometimes wonder if the majesty of these events can become a little marred by the dominance of the technical side of our minds rather than appreciating the more aesthetic value with the artistic side?
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wow
