Had another go at processing the Andromeda frames, here's another version:
Andromeda Galaxy (M31).
(Nikon D50 at prime-focus on C8-N, ISO 200, no filters, 22 x 30s colour exposures stacked with DSS, reprocessed in PS CS3)
Archive for September 2008
Andromeda reworked #1
Observing Report 26th-27th September 2008 (Andromeda)
After what seems to be many weeks of overcast skies, Friday evening was clear enough to get out and test the new focuser setup. After a delayed start due to a mucky secondary mirror, the scope was recollimated and set up in the back yard. I did a few visual checks of random bright stars to confirm that all was OK, then decided that it was time to grab a few images for analysis later.
I slewed the scope around to the faint blur that is the Andromeda Galaxy (Messier 31), then slapped on the D50 for some prime-focus shots. This was to be my first semi-serious foray into taking this sort of shot, and I just wanted to get a few images to stack and play with, nothing too difficult.
Anyway, focusing was a lot better with the new setup. After transferring a few shots from the SD-card to the laptop to confirm image acceptability, I rattled off a series of raw files (NEFs), all at 30s, just to see what could be achieved at such relatively short exposures.
After a quick look around to see a few double-stars, the dreaded dew started to form and it was time to pack away and start photo-processing.
The individual frames didn't seem too bad - focus was just a tad out on the later pics, it looks like there was some minor focus-drift over time. The stars at the corners of the pics are distorted due to coma (typical of Newtonian optics - correctable with optical hardware, at a price) but the central stars are hardly trailed at all, which means that the initial polar-alignment of the mount was either very good, or just plain lucky!
Anyway, I plugged them all into various bits of software and , much later on, it spat out the following pic. There's a definite hint of spiral structure there, and the centre's not burned-out too much due to over-exposure or drastic levels/curves adjustments. Not bad for a first attempt with a basic set of frames, and I reckon I could drag more detail out of the data, given enough time. That said, I'm quite chuffed with it as it is at this stage in the processing.
Next time I'll go for much longer exposures, and more of them.
Andromeda Galaxy (M31).
(Nikon D50 at prime-focus on C8-N, ISO 200, no filters, 22 x 30s colour exposures + 1 dark frame stacked with DSS, processed in PS CS3)
Hinckley ablaze
There's a big fire in town, and rumour has it that the town-centre's been closed off. Luckily for us, the huge column of black smoke is going north-westwards. The helicopters from the emergency services are dwarfed by it. This roving-reporter has decided to stay at home and watch from the garden.
It's been burning for well over an hour now, and it's showing no signs of going out. The neighbour reckons that it's either B&Q or a tyre-fitting yard that's burning. If that's the case, they're about 50m from the fire-station.
Swabbin’ the decks
Been doing a bit of tidying up:
- All unused tags (created by an auto-tagging plugin that I used for a while) have been deleted;
- Quite a few new links have been added to the blogroll dropdowns;
- Some other bits and bobs have been added to the sidebar;
- All dead links in posts have been repaired or deleted;
- Hell, I've even cleaned the screen and removed all of the cookie-crumbs from under the keys!
See you tomorrow, fellow pirates, but only through me one good eye!
Yaaarrr!
Extended coverage
Spurred on by our efforts to use a tarp to extend the comfy space around our tents while site-camping on holiday, and frustrated by the scarcity of Exped Arc Tarps on the market, yesterday saw the acquisition of a new bit of kit - a Khyam Atrium, which is in the current Yeomans sale at £20 below RRP.
It's a tent extension/porch/canopy affair with webbing straps and an elasticated and toggled drawcord to allow a neat and secure fit over the openings of most small/medium tents, and the poles are adjusted for height/width by means of a tension-band system between the pole-ends. If that's not enough versatility, the "middle" pole is adjustable in length so that you can get the height/width just as you want it. There are plenty of guying and pegging options, and, as you can see, there's plenty of room under it:
2 pics above: width = 3.5m, height = 1.5m
2 pics above: width = 2.8m, height = 1.8m
Above: pole-end spacing = 1.5m
Above: elasticated and toggled drawcord etc..
Above: length-adjustable pole.
Specs from the Khyam website:
Poles: Fibreglass - 9.5mm
Flysheet: Polyester 185T - 68D / 5000mm - Flame-Retardant - Taped seams
Height: Adjustable
Weight: 3.9kg
Dimensions: As the Atrium is fully adjustable it is not possible to list or show all dimensions.
Packed size: 64x12x12cms
Colour Options: Castle Rock / Paloma
