50mm DS 'vs' 90mm SS Full Disks - 22nd July

[marktownley]

Monday started cloudy, cool and windy, but very quickly by mid morning the cloud broke and the sun came out, raising temperatures by 10c in about 5 minutes. Clouds were still scudding by and with the rising heat and cumulus peppered blue sky I knew I was going to have to take a lot of frames to get usable data.

I've been playing around so far this year with my ideal double stack setup for full disks; i'd tried my lovely flat LC50 etalon on my SM90 but was never pleased with the outcome, neither was I happy with the LC50 double stacked with another Lunt50 etalon, or with the LC50 stacked on the LS50 scope. I think I have found my answer; The Lunt50 etalon double stacked with the Daystar Quark, with the Baader 0.7x solar telecompressor I get a full disk on the chip of the FLIR GH3 ICX916M camera, giving a nice 2600px full disk. This is what took the disk below, no flats or anything, this is how it comes out.

Ha-FD-DS--bw by Mark Townley, on Flickr

Ha-FD-DS--colour by Mark Townley, on Flickr

The contrast is nice, highlighting the filament and both the active region well. The small proms came out well too! Be sure to double click for the full size view in Flickr.

Next up, compare this with a single stack full disk taken with the SM90, very similar image scale in terms of how much of the ICX916M chip it fills, the contrast isn't as great - which is what you would expect with the single stacked etalon. However I don't think the difference in resolution is quite as much as might be expected - the spicule ring shows some nice detail, but the surface isn't hugely different in terms of detail. Still a nice disk, just different! Again, double click to view full size in Flickr.

Ha-FD-SS-bw by Mark Townley, on Flickr

Ha-FD-SS-colour by Mark Townley, on Flickr

Next up it was time to put the Quark in the back of the SM90 for a bit of closeup double stacking, no telecompressor this time, but binning the ICX916M. I was struggling with the seeing as by now was getting close to midday. First up the filament in the north:

filament-bw by Mark Townley, on Flickr

filament-colour by Mark Townley, on Flickr

Next up the active region, which being on the equator is cycle 24.

ar-ds-bw by Mark Townley, on Flickr

ar-ds-colour by Mark Townley, on Flickr

It's clear now at dusk this evening, and i'm hoping it stays that way till first thing in the morning in which case I can get some more imaging in before the heat of the day builds too much.

Hope you like!

Mark

[xn44]

Very interesting, Mark. Great images.

[MAURITS]

Nice to hear Mark and beautiful results.

[Starry Jack]

Great compares.

[MapleRidge]

Great set of image Mark, and the DS with the Quark/LS50 turned out very well.

Brian

[MapleRidge]

Great set of image Mark, and the DS with the Quark/LS50 turned out very well.

Brian

[gabrieli]

Hi, Mark
Your SM90 really puts out some sharp detail at higher res.

I've just recently discovered where the binning option is in the FLIR Spinnaker software that runs all my Blackfly S cameras.
With a high pixel count camera the gain in brightness is very noticeable while the reduced pixel count is still useful.

Lou

[marktownley]

Thanks guys! A blue morning here in Brierley Hills, I think I will give the HaT a go first, see if the seeing will play ball for me.

[Montana]

These are excellent Mark, I think the resolution on the 90mm disc is far superior to the 50mm certainly around the little active region, you will notice more difference in years to come

Absolutely gorgeous blue skies here this morning and it would have been brilliant to test my CaK wedge on the little AR, why does this never happen at a weekend?

Alexandra

[pedro]

Very interesting results Mark. I never have good results with DS etalons

[marktownley]

Thanks Alexandra, thanks Pedro. Just playing with some pics I took earlier today.

[Astrophil]

Mark, that first image is very impressive from a small scope. That's the kind of full disk image I've been wanting and I don't think I can get it from my 40mm scope. Thanks to you I called Lunt Solar today and placed an order.

Phil

[marktownley]

Mark, that first image is very impressive from a small scope. That's the kind of full disk image I've been wanting and I don't think I can get it from my 40mm scope. Thanks to you I called Lunt Solar today and placed an order.

Phil

Thanks Phil, I hope the etalon you get is a good one!

Mark