White Light Sun 2011-08-21

[lepton3]

Some nice clear skies in Adelaide this morning, so I spent a little time looking at the sun. Here are a couple of shots.

Both taken through a C6SE (150mm SCT) at f/5 + Baader full aperture solar filter + solar continuum filter.

The full disc is with a Canon 400D, 42 frames stacked with registax 6.

Detail on the sunspot group is at f/20, with a DMK21 camera, 3000 frames stacked with Registax 6.

-Ivan

[Derek Klepp]

Thanks for the update Ivan we're rained out up here

[asimov]

Cheers for the nice view.

[lepton3]

Derek, John, thanks for looking.

[asimov]

I'm only a babe in the woods right now with WL solar imaging, but could you tell me what difference a solar continuum filter does? I'm using a full aperture thousand oaks 2+ on my 11" SCT. & using an Astronomik R filter on the DMK camera.

I've read descriptions of what the filter supposedly does (by retailers) but in your opinion, do you benefit from it? Thanks.

[Merlin66]

John,
I use a Baader Solar Film for white light observing.
I've trialed may different coloured filters as well a the usual DSO and narrow band filters to "improve" the image
Nothing, IMHO, worked as well as the Baader continuum in improving the contrast. A pale green filter was the second best.....none of the othere did much....
HTH
(I now have both the 1.25 and 2" Continuum filters fitted to the diagonals I use for white light observing on both a 4" refractor and the 12" Lx)

[lepton3]

John,

I have only had the continuum filter a short time, so am still experimenting with it. But so far, I can say

1. For visual, it improves contrast, and makes it easier to see the light regions around sunspots. Definitely worth it for visual.

2. For the DSLR, it requires a longer exposure, therefore it can actually make things WORSE if the seeing is poor. I only used it this time because at f/5, I was overexposed at 1/2500 and ISO 400!

3. For the DMK21, the exposure time is so fast either way, I'm not sure whether it really improves things or not. It seems to (and it should in theory), but I'm still experimenting with this.

-Ivan

[asimov]

Thanks for that Merlin. I'm wondering if my attempt at using the R filter out of my Astronomiks set is actually doing anything or not. Studying each AVI with filter & no filter, I can't see a lot of difference..I'll look into one of those continuum filters though I think!

And thank you Ivan! In the little time I've been doing it, the seeing really dictates as to whether or not you get good data I think..

[El Paso Eric]

Interesting shots, Ivan. Thanks for sharing.