Ta da! My first afocal image of the Sun using my little Sky-Watcher and DSLR:
This is as focused as I could get it and the best of the bunch - my mount was not tracking. I took 4 exposures in this 'range' but any stacking (which I attempted to do in Photoshop because I don't have access to stacking software on my Mac) messed up the granulation detail visible and it just looked like noise. Not sure that the granulation is visible in the Flickr image... It is in my tif - promise!
Does anyone have any tips on overcoming this? Or getting crisper shots with my current setup?
That's really good! I can see the granulation too. Sorry I am bit useless to advice on a Mac solution to overcome your stacking, I'm sure Mike can help here. But usually to get more detail you would need to take a lot more frames...preferably a laptop tethered "liveview" video recording, if your dslr offers it.
But if this was a practice run for the big day tomorrow, you're in great shape! Still take lots of frames, because you can always stack them in registax on a virtual PC or when an affordable or free stacking program is finally developed on the Mac, I guess.
I was observing the sun today at regents park (in between a day's set of cricket matches!). I am gutted I cant join you guys tomorrow because again, I have to be at Regents Park. I wonder what are the chances of Mercury transiting a sunspot....lets see, how many mercurys fit on the visible surface area of the sun divided by the probability of a Sunspot visible on the day divided, divided by the..oh never mind...no chance, lol.
Thanks, Tej for your kind words. I'm keen to do better - the image is not as crisp as I'd like but it's a start, for sure.
I hadn't intended this to be a test run for today's Mercury transit but as things have transpired, it is! The blanket of cloud has wrecked my plans for viewing Mercury in Greenwich but I intend to keep a close eye on the sky at home and dart outside should there be a break in the clouds.
If I get lucky with the weather, I'll be taking your advice and will shoot video as well as take photos to stack (I'll cross the stacking software problem later). I wonder whether taking shorter exposures would help with crispness... ? They were pretty short but I'll experiment if I get the chance. If anything, at least Mercury will perhaps make focusing easier...
Good luck today - hope the skies clear a little for you too! Look forward to seeing the results if they do.
Hey Christina, great to see you starting your solar imaging career!
For white light with a DSLR, you can get surprisingly good results without stacking. The two things to get right are focus and exposure. The only real way to get focus right is to use live view and zoom in to a feature like a sun spot. Exposure is always more than you think with white light solar, especially if your using the standard ND5 solar film. The photographic version is ND3.8 but that is not safe for visual use. Try to keep the exposure short because the SUn will drift quite quickly.
Were you using your Newtonian? If so, try to make sure it is well collimated as you will lose a lot of detail if its not. Your DSLR will be quite a load for its focuser so collimate first using a collimator then put the DSLR on and tune the collimation using that. Just aim at a star (or even Jupiter) and defocus a little so you get a big disc with a black hole in the middle. Then tweak the secondary screws to get the hole dead centre. You will need to be tracking to do this.
If you can get it tracking then you can start thinking about stacking but I would try and get the other things right first. For a list of Astronomy software for Apple see
http://www.primordial-light.com/macastronomer.html
Good luck!