First light with BD ED100 on eta Carina

[Robert9]

Got my new (for me - thanks Peter) ED100 last week and beat the bad weather curse. Sunday night was great; no moon, no cloud, no wind. Wow!

Attached is 10 x 1 min. exposures at 1000 ISO on my Nikon D90. Should have had longer exposure times but polar alignment on the HEQ5Pro was only rough. I'm sure my Orion mini-guider worked very hard.

Images were stacked and processed in PS.
Robert
https://picasaweb.google.com/103066228142024831623/19May201502?authkey=Gv1sRgCNr9jt3H7 9nokQE#6150462175736621810
https://picasaweb.google.com/103066228142024831623/19May201502?authkey=Gv1sRgCNr9jt3H7 9nokQE#6150462175736621810

[jjz]

Looks good to me, are you going to add more data in the future?

I am going to have a crack at eta Carina next clear night.

[Robert9]

I'll certainly have another go at this target Joe. My polar alignment wasn't good enough on this occasion to take longer exposures and I didn't take any darks either. I guess I was just too busy exploring the universe with my new toy.
Like you, I'm waiting for our next cloudless, moonless, windless night. (Did I hear someone mention flying pigs?)
Robert

[cometcatcher]

Nice one Robert. The BD ED100 is a fine scope, a pleasure to use. You will have much fun with it.

[Robert9]

Thanks for the comment Kevin. I've only had the one night out with the scope but I'm sure it will give me a lot of pleasure.
I have just uploaded the image to Astrobin and have now uploaded a second which comes from Registax plus PS processing. Be interested in comments on differences.
Robert

http://astrob.in/181555/0/
http://astrob.in/181560/0/

[PeterSEllis]

Your welcome, enjoy.

Cheers
Peter

[andyc]

Hey Robert, nice start! To my eye (being wary that colour is a tricky and often subjective topic), they appear to have a fair bit of blue in them, as highlighted by the histogram in Astrobin. Eta is bright enough that the reds and pinks often show up pretty well in DSLRs despite the H-alpha line being in a lower sensitivity region for the sensor.

A first question is whether the white balance was set to Daylight? Sometimes other white balances alter the colours unexpectedly. If you have the raw DSLR files this can be altered before stacking. Otherwise, you could maybe try fiddling with the channels to bring out a little more red (using Curves), though that can lead to unintended consequences in colour balance of the rest of the image.

But you'll see all kinds of colour renditions of objects, and it leads to arguments as to whether there is a 'right' colour balance (and that's more complicated than many would think as the 'right' colour depends on the differing balance of colour sensitivity in your eye, DSLR or CCD sensor) ... so go with what you find pleasing for whatever reason!

Enjoy your new toys :thumbsup:

[Robert9]

Hi again and thanks Andy for your very useful comments. :thanx:
I do agree that my first image was decidedly too blue. The second I think was rather too red and a bit overcooked! White balance on the camera was definitely set to daylight, so I don't think that was my problem.
Last night I took my camera out to cool and then took a series of black frames which I have now incorporated into the image with Registax. It certainly has cleaned up the image. I reprocessed in PS and the result, which is perhaps still a little too blue, is on display here:
http://astrob.in/181694/0/
I found that bringing up the red level seemed to bring up too much noise, or perhaps its real?? Anyway, I think this is probably as good as I can get with the images I have. I'll have another crack at it when Hughy decides to give us another good night - something he seems loathe to do these days - and go for a longer exposure time, perhaps frames of 10 minutes rather than 1 min. (depends on how good my polar alignment is.:D)
Robert

[andyc]

Yep, I reckon that's an improvement on the two - the colour is better than your first one, and the stars are tighter than your 'red' version. But gawd it's a fiddly process, so delicate to get a colour that feels right! I've spent way too long carefully getting images terribly wrong in the past :P.

You should get a better result with longer exposures, 2 mins, 5 mins, whatever your skies, camera, alignment and tracking can handle (I'm not sure of 10mins from Mt Waverley at ISO1000 though without the skyglow washing out the picture? but you can always try!). Longer subs should get you more signal, particularly getting the reds above the noise threshold to play with as well.

If you're passing the Fish Inn on High Street Road, have one for me - I miss his tasty bluey and minimum chips on a Friday, used to live round the corner from there!

[Robert9]

Thanks again for your feedback Andy; greatly appreciated. Last weekend I felt that the nights were exceptionally clear. As the camera was clicking away I recall lying back in my chair admiring the stars which have for so long eluded me - I could even make out the Milky Way. I think I was just lucky, especially with a new scope.
Way back in the '60s when my wife and I first bought a house (in Glen Waverley) the stars shone so very, very brightly. Ah, those were the days.

Apropos fish and chips, we tend to use the shop on Huntingdale Rd, near Waverley Rd. A bit closer to home. However, just for you, next time we'll try Fish Inn. :lol:

Meanwhile, I sits back and waits. I hear on the news Sydney is rather wet.
Cheers,
Robert

[andyc]

:thumbsup: And a treat for you to get a good winter clear sky in Melbourne! A bit wet here, but hoping for better in the next few days before the moon dominates again...

[rmcpb]

Nice shot of one of my favourite visual targets.

[Robert9]

Thanks chaps. :thanx: