Deep Omega Centauri with traces of interstellar dust

[tornado33]

Here is 2 deep Omega cantauri shots, I was not just after the cluster but wanted to see if i could reach the faint dust in the interstellar medium nearby.
I used the 6 inch f3.6 SN, 9x10 mins ISO 200 totally unfiltered, and the 300mm f2.8 lens from Bert, 7x10 mins ISO 400, with LPS filter. Both with modded 350D (clear AR coated glass over sensor)

Larger views here (http://d1355990.i49.quadrahosting.com.au/Scott/omegacen9x10minsiso200unfmod350d6in ch.jpg)
and
here (http://d1355990.i49.quadrahosting.com.au/Scott/omegacen7x10minsiso400lpsmod350d300 mmf2.8.jpg) (plane went through one sub)

The dust in the ISM is just there, on the 6 inch shot lower right, on the 300mm shot just right of upper middle.
Scott

[alan meehan]

FAINT dust in there scott alright something you wouldn,t generally notice well done.

[avandonk]

That is deep Scott to show the faint dust. You may do better if you put an aperture inside the lens hood. This has two effects it cuts off the outer part of the lens where the aberrations are greatest and stops any light not contributing to the image from scattering inside the lens. You do lose speed but the contrast goes up. I have used an 84mm diameter(f/3.5) and 56mm diameter (f/5) on my 300mm lens and the improvement was remarkable. The stars were pinpoint corner to corner and the images could also be stretched more as the contrast is far better. In fact the faint nebula data was better due to the increased contrast. Sky glow also seemed to be far less.

It is emotionally difficult to stop down a 104mm diameter clear aperture lens to something smaller but the gains far outweigh the losses.

I predict you will get even better images than the great ones you are getting now with your 300mm lens.

Bert

[gregbradley]

Wonderful images.

Greg.

[Miaplacidus]

Brilliant!

By the way, this obsession with finding dust in remote places... Are you related to my mother-in-law?

Cheers,

Brian.

[Tom Davis]

Nice shots!

Tom

[tornado33]

Thanks all
LOL, Miaplacidus, as my job as a cleaner I do need to find (and remove) dust, so , yep like finding it in the night sky too :)

Thanks Bert for the suggestion. The lens has a very nice iris with a large number of leaves, though, as you say I would be better putting an aperature stop in front of the lens so as to reduce light scattering. Its a fantastic idia and I will do it next time.
Scott