M27 Dumbell Nebula in Vulpecula

[Fay]

I though I should go outside & have a practice with my nre Orion Newtonian. I have realised that these are a pain in the butt. The primary & secondary mirror have to be collimated, a lot, with a laser collimator, to start with.

I set it up & the ZS66, which I had piggy backed on top, for guiding, nearly fell off due to a screw falling out. I wanted to test my Canon 350D, to see how images would come out.  Every image was full of mishapen stars. I changed the arrangement of the corroector, altering the distance which was between the camera lens and front of the corrector. It should be 55m exactly. Could not get it right, even took corrector away completely. It is the large chip in the camera that is the problem, but I had a larger secondary mirror put into the scope to help combat this.

I decided to change cameras, to the Atik, + Ha filter, no corrector & got a couple of reasonable 300 sec subs. I had problems with mis shapen stars & ended up deleting about 4 subs. Stacked the 5x300 secs that were ok. No darks or flats
Really needed, around 15x300secs, but gave up.

[MarkS]

Fay,

In what way were the stars mis-shapen?  Right across the image or only away from the centre?  If you don't get the spacing exact (I think you mean 55mm not 55m!) , then stars will be increasingly mis-shapen away from the centre.  Trouble is, you'll never get the Canon 350D sensor 55mm from the corrector because the distance of the CCD to the camera front is 45mm and then add 10mm for the T-ring.  This makes 55mm already, so the T-ring would have to be directly attached to the reducer to get the right spacing.

That's a nice M27, by the way, but the middle does look a bit burnt out - it ought to be possible to see a star right in the centre.

Mark

[Daniel]

Lovely image fay, you've really brought out those outer limbs, I agree with Mark though, a little burnt out in the middle, maybe a bit of layer masking on this would help.

Daniel
:O)

[Fay]

see you at dsc Mark, to discuss, thanks Daniel, I will reprocess to get rid of burnout

[RobertM]

Very nice Fay.  The faint outer envelope is starting to show and I think some subtle processing could tease out quite a bit of extra detail.

Robert

[Mac]

nice image.

have a word with Robert on how he processes his images.

[Fay]

Reprocessed. This is only 7x300 secs Ha no flats or darks with Orion/Atik

[RobertM]

Very nice Fay but the brighter nebulosity still looks a little burnt out.

[Tony G]

Lovely image Fay.

Tony G

[Fay]

well, this is not a serious image only 7x300, thanks Tony