The Sun 10-03-07

[UniPol]

Nice day here in the Lower Blue Mountains so it was time for some quick images of the sun. Quite a few prominences are visible, more so than a week ago although no sun spots were apparent.

I used my Coronado Solarmax40 with the BF10 filter mounted on the Vixen Porta mount. I used a GSO 20mm Superview (great EP) connected to a Scopetronix Digi-T/ T mount adaptor coupled to my 350D for imaging. The Digi-T is a great little device which is attached to the groove where the eyepiece rubber cup is attached and is held in place by three grub screws. The image below was taken at 1/15 sec and the camera was set at 100 ISO and the largest file format.

The Solarmax40 with the BF10 filter is well suited for photo imaging unlike the PST which is excellent for visual use. Of course the Solarmax40 is a little over three times the price so it should be better. I have a PST however it has been sent back to Meade/Coronado for a warranty repair on the front lens element. Quite a few of the PST's suffered from the dreaded "rust" problem which really means that the cement holding the doublet starts to break down and takes on a rust coloured appearance. I believe only a small loss of contrast is apparent with this problem, it has nothing to do with the Etalon filter.

Cheers, Steve

[iceman (Mike)]

Excellent image! Is it possible to change the settings for a capture which highlights the surface detail? You can them combine the exposures in post-processing to get the best of both worlds.

[mickoking]

Very nice image Steve

[UniPol]

Originally Posted by iceman

Excellent image! Is it possible to change the settings for a capture which highlights the surface detail? You can them combine the exposures in post-processing to get the best of both worlds.

Thanks Mike, I am basically a lazy photographer and like to get a pic in one. I used the Meade LPI/PST combination a while back with moderate success however the 350D seems to perform much better particularly for single images. I noticed if you under expose the image of the sun a small amount it will appear uniformly red all over. Over expose the image it will appear bright white/yellow, both showing little or no detail. The red rim seems to go hand in hand with a reasonable amount of yellow centre detail. Of course the prominences are quite spectacular when viewed visually, they are fine and filament like.

I'll keep experimenting with the images of course, that is the beauty of these new DSLR's, keep clicking away until you find the right combination.

Cheers, Steve

[UniPol]

Originally Posted by mickoking

Very nice image Steve

Thanks Mick, I think I fluked this one really. I'll try for some better flukes next weekend.

Cheers,

Steve