Bit jealous of all these images so I'm trying to do some myself again !

[RobertM]

First post for a while primarily because of kit/software issues, lazyness, apathy, other interests etcetera etcetera !  I think must astronomers go through this at least once in their lives.

I've still got some equipment issues but after getting a request from Doug I thought I'd do something anyway (I felt better afterwards as well).  I know it could have been better framed and I've probably done it numerous times before but I wanted something relatively bright.

Anyway, this is the first for quite a while, details at the bottom:



Link to the full sized image: https://c1.staticflickr.com/1/935/43862390611_ff55231b3d_o.jpg



Taken over the nights of 2nd and 4th August 2018 with the following equipment

Mount: NEQ6, Rowan belt mod
Telescope: RH200 (f/3 600mm FL astrograph)
Camera: ASI 183mm PRO binned 2x2 (1.64 arcsec/pixel)
Filters: Astrodon 31mm 5nm Ha
Observing conditions: Poor - limiting magnitude approx 3.5 ( Bortle 9)

Image acquired in SGPro using 2m subs with gain 111, 77 subs in total (144 mins - 2hrs 24mins equivalent exposure time).
Image calibrated with matching dark frames and stacked in MaximDL.
Image processed in Pixinsight.

[Carole]

Nice to see an image from you Robert.  Very nice and smooth from Orpington, those Astrodon filters are the bees knees, but just can't justify the expense.  Such lovely pin point stars.

I see you have the same camera that Roger has just bought, and was interested that you did 2 x binning and 2m subs.  He's trying to get advice on this.  Just curious as to why you binned though, as I thought binning was supposed to be reserved for the colour elements of an image and not the Ha or Luminance.

Carole

[MarkS]

Lovely image!

It's good to see you back!

Mark

[RobertM]

Thank you.

Carole, Binning is not just reserved for RGB !  In this case I used bin 2x2 subs primarily to mask guiding issues - if you look very closely there is a very slight elongation even so.  In addition the seeing was very bad probably due to thermals (hence the bad guiding) so with 2.4 micron pixels it would have been pointless, far better to loose the resolution and gain on the photons/pixel front.  If the seeing had been better then I might have tried 1x1.

Regarding the Astrodons, they were the only make that did 3nm bandwidth filters blackened on the edges and totally anti-reflective - no contest (at the time) !

Robert

[ApophisAstros]

Thank you.

Carole, Binning is not just reserved for RGB !  In this case I used bin 2x2 subs primarily to mask guiding issues - if you look very closely there is a very slight elongation even so.  In addition the seeing was very bad probably due to thermals (hence the bad guiding) so with 2.4 micron pixels it would have been pointless, far better to loose the resolution and gain on the photons/pixel front.  If the seeing had been better then I might have tried 1x1.

Regarding the Astrodons, they were the only make that did 3nm bandwidth filters blackened on the edges and totally anti-reflective - no contest (at the time) !

Robert

Very much learning about this camera and after reading various bits of advice i thought i would try binning for the colour subs so can reduce these in number in order to have more Luminance detail subs.
"Astrodons" sounds like something you should go to the doctors for
Roger

[The Thing]

Good to see you making use of some of your kit at last Robert! The image is lovely and smooth, I would like to be able to stretch my pictures and keep them like that. And if my stars were as round as yours I'd be very happy. Blame it on ground vibration from traffic on the Orpington Bypass. I blame mine on the waves hitting the beach a mile away