It’s a bit belated, but heck, I’ve been too busy with Christmas and New Year family stuff.
The last 2 weeks have been torture, with a very bright moon out preventing imaging, not to mention a strict curfew imposed by Wifey due to all the extravagant trips taken just before Xmas. We won’t be going out picture taking until mid-late this month, with a possible epic trip to deep-darkest Mount Beauty with a few friends, stay tuned! Mount Beauty is really out of the way and will be about as dark as you can get in Victoria, it’ll be a really highly anticipated trip. As the visit will be for at least two nights, I plan to bag the Witch Head nebula, an even wider field Orion, the California neb if the angle permits, as well as the Cone Nebula area.
MOST RECENT PICS
As ever, always click on the Flickr link to the right of the blog to keep up to date with my latest imaging attempts, as I don’t post here in a perfectly timely manner! Speaking of that, here are my latest images since the last update, all taken with the now permanently used Sony A7s, it’s definitely a long-term keeper!
First use of the Ha filter, Rosette – I purchased a 2 inch, 12nm Ha filter from Astronomik, Gird was most helpful with all my questions. The filter screws into the rear of my T-mount scope/camera adapter, saving me having to use a filter holder/wheel that might use up my precious tiny back focus allowance (only 55mm due to the fast F3.3 ratio!). Here I took a set of standard RGB shots of around 2 mins, then a set of 4 min Ha’s.
Alas I discovered that the relatively high/deep Astronomik filters stop my camera from being fully screwed into the focuser! It stops about half a turn less than without the filter, so I had to guess alignment with the RGB images. And I was waaaay off! So the star alignment in Pixinsight was pretty tough, but PI handled it with a breeze. I”m really pleased with this image, as it’s my very first Ha/RGB combined image. I used PI’s HA/RGB combination script to combine the colours, then did a heap of photoshop masking work to combine the nice pure RGB stars with the Ha/RGB combination image, getting a reasonable hybrid look.
Pleiades – NO HA FILTER USED – A pleasing result, of 12 shots at 4 min/1600 and 10 shots at 2 min/3200. Love all the dust and star colours, the camera has an excellent star colour retention.
As with much of the theory written, I am finding that it’s exposure time that is the main determinant in image detail, not ISO. Doing crazy short images at 12800 will not produce magic results, extending the time to over 4 mins WILL. Last time I only went up to 2 mins, this time I’ve gone up to 4, you can see the improvements. Next I’ll be trying 5-6, by then I suspect the sensor shot noise will start to reduce the returns. A COOLED version at 10 mins should prove to be spectacular:
Comet Lovejoy, my very first comet shot! – 13 shots of a minute, 3200. Taken pretty late in the am, so the background isn’t as dark as normal. Really pleased with how PI coped with the stacking of this one, though I only stacked for the general stars and not the comet.
A final ‘random’ shot, taken of the Beta Crucis area, to see what dark dust I could pick up – success! 22 shots of 80 seconds at 3200.
Here’s an idea from one of my astro-buddies Alistair. Go Barlow! My Focal length is only 430mm, but with a 2.5* Powermate, I can get to 1,075mm. It’s only a 1.25 inch adapter, so the image will be fairly closely cropped compared to the usual 2 inches, but it’ll be worth a try in the future. Funny, I’d totally forgotten about this handy setup, having only used it (successfully) for taking moon shots like the one below. Hmmm, I need to clean my fingernails!
moon, single shot taken with the 2.5x powermate and Tak, very early on in my astro-adventure: