Lightly toasted Lagoon ;-)

Hi all, I have this single shot of both the Lagoon (M8) and Trifid (M20) nebulae that I had took last month, It's only ok, but it was a test of a zoom lens that I had bought last christmas. This is a 75 second exposure using a 150mm lens at f4.5, ISO 800 with a Canon 400D. Just slight adjustment in curves to bring out the detail, you can see also two lovely bright globular clusters bottom left of the lagoon, these are NGC's 6544 and 6553. Star cluster M21 is also visible above M20, and the lovely star cluster embedded in the Lagoon - NGC 6530.

This lens is only ok, I'll get many more shots of this nebula hopefully soon...
Keith...

Sweet

Hi Keith,
A nice image there, can you elaborate as to why the lens is only ok, I don't see anything wrong with the image caused by the lens ? nothing obvious anyway.

That lens only "ok" Keith?
I'll buy it off you if you like!

Peter.

Yes, the lens looks pretty "OK" to me - sharp stars even into the corners! Great shot too!

Clear skies,

Paul.

Well, I'm out voted here so The reason why I say that it is only ok is that the lens is a sigma lens, a 70-300mm zoom and sigma claim it is an 'APO' lens which I can tell you it's not, I'd love a canon zoom lens, but I did get it for 200 Euro brand new last christmas, and I have rarely used it since. I forgot to mention that this shot is a slight crop of the original, at about 75%, but the stars in the corners are still reasonable on the original.

At best this lens will work at f4, but at 150mm it works at f4.5, but it's hard to get a bright exposure out of it since I can only go for 90seconds max piggyback - then the stars will start to trail and I have to use a High ISO to get some detail, but at the expense of noise...

Keith..