Solar Photography: But beware, stay safe!

Seanie M

A topic I find is hardly touched on here on boards.ie's Astronomy forum is that of solar photography. There are lots of ways to go about photographing the Sun: narrowband filter imaging (for colour contrasts), whitelight (but still filtered), and projection. I, and other members of IFAS and the club I am a member in (Midlands Astronomy Club) have been asked about some of these by those who want to use astronomy for passing the time during the day. Here are some photos of a recent project I did that took less than an hour of my time (probably because I knew what I was doing!)


Materials:
Baader solar filter.
Something you can use to make a tube ring to go over the aperture*.
Sticky tape.

*The Baader Planetarium filter pack shown in the first photo below comes with detailed instructions on how to build a cardboard ring filter over your telescope, not specific to size. It comes as A4 size and is quite cheap to buy in Ireland (I'll let the stockists chirp in here!).

The photos below are quite self-explanatory:









Instrument:
Atlas Explorer 150mm refractor (focal length 1,200mm) on a CG5 mount.
Canon 350D T-mounted at the focuser (instead of an eyepiece). The telescope thus becomes a 1,200mm lens for the camera.







Method and result:
Through experimenting with the alignment (I didn't use the motors, I did it all manually), I found that the best setting was at 1/3200th second exposure at ISO 800 in RAW mode. I took a series of photos, adjusting the camera's setting in Bulb (or manual) mode and making a note of each photo's characteristics. The photo here was captured on January 7th, a single shot exposure, mild sharpening in Photoshop.



Safety Notes
- Remove the finderscope on your telescope before aligning it to the Sun.
- NEVER view through the eyepiece or the camera's own reflex viewfinder without the filter of choice covering the objective lens (or the tube opening before the mirror in the case of a reflector).
- Children MUST be supervised at all times.
- Always check your non-glass filters for pin holes, and if the filter (like mine used here) allows to much pin hole light through, do not use.


The final image shows Earth to scale (tiny dot centre-right). You can see this photo in all its glory among the tens of excellent shots from amateur astrophotographers around Ireland at the Images of Starlight exhibition, currently on view in the National Botanical Gardens until February 21st.


Clear Skies,

Seanie.

Flying Abruptly

This is something I'm definitely going to try out. Have been meaning to order the filter for awhile.

There's a transit of Mercury across the Sun this year on the 9th May which is a perfect opportunity to have a go. Last one was 10 years ago.

_Tombstone_

Great post.

Flying Abruptly

The Sun (23/04/2016)

Got the baader filter safety film and tested it out today. This was taken with 300mm telephoto lens and cropped. Can see one small sunspot. Happy enough with the results. I'll try again another day when there are more sunspots.

Seanie M

Well done, that's a nice capture! Now you're a solar astrophotographer.

Seanie M

By the way, my above post is ideal for preparing for the Transit of Mercury on Monday May 9th. You can also find out a little more from the Irish Federation of Astronomical Societies website here:

http://www.irishastronomy.org/index.php?option=com_kunena&view=topic&catid=42&id=100894&Itemid=211

Seanie.

bogman

Good to see you promoting IFAS Seanie, Baader products also, they work really well, take care....
Charles

Jan_de_Bakker

I took this a few months back ... nice spots there

Seanie M

That's a really nice triplet Jan, well done.


Mods: is it just me or have the photos disappeared from my original post at the top?

Seanie.

Jan_de_Bakker

I don't see them either, I guess wherever you have hosted them from is down or the photos removed ..

edit seems so, I get :

URL signature expired

When I try and access ...