Antares and Rho Ophiuchus Nebula

[JohnH]

I have found this object really tricky to image, this is my best effort so far and not that good, I guess a quarter moon is a no-no for this one as it is faint. I stacked 24*4 mins (got half histogram approx) at iso 1600 and still have not got enough signal. This was with the 135mm lens at f8 and my tracking and focus were both a bit off. MMmm got lots of excuses, looking for practical advice, is it down to my poor prctices or the moon/light polution. Other than going to a dark site what can I do to get a better result?

[Octane]

John,

That looks pretty good to me, considering your camera isn't modified.

Have you tried it at a faster F/ratio? Perhaps F/4.0?

Did you apply darks and flats?

I'm dying to image this region as a widefield. But, not as wide as my previous effort: Antares in Scorpius - Mk II (http://members.optusnet.com.au/octane2asphyx/Kulnura/Kulnura_20060429_Antares.html).

Regards,
Humayun

[JohnH]

Hi Octane,

Yes I did Darks, my flats turned out to be unusable (hence a few donuts are visible). The reason was the sky shot I used for the flat was not as flat as I thought and if I use them I get a background gradient introduced. I could open up the lens a little say f5.6 would be ok but I think at f4 I will get some bad SA however that would only mean I could reduce the exposure time (and hence trcking issues) - it would not do anything to reduce the impact of skyglow would it?

I re-processed with a bit of NR in NeatImage - better but you can see I have had to push to hard...not sure what is causing the purple glow to creep in - light polution or something else....

[tornado33]

nice image. Try again with no moon and see how you go, and yes its very good for f8.
Scott

[Lester]

Hi John,

that is a wonderful area of the sky. Really like your second process of this image.

[sheeny]

John,

I have to echo Scott and Lester's comments!:thumbsup: The second version looks great to me. I'd love to see what you could do on a new moon!

Al.

[JohnH]

Thanks for the feedback guys, I guess I need a dark site and no moon to get a better go at this with an unmodded camera - here is another view this time through the little WO66....

[ving]

that is a stunningly colourful piece of sky. thanks for the pic :)