Up went the spider...

[Camelopardalis]

Folks,

My first foray into narrowband...and by the looks of it, I could do with a narrower band! But still, given my proximity to the CBD I'm pleased with what can be pulled out (or filtered out!)

82x 60 second subs in Ha with Skywatcher Esprit 100 and ZWO ASI1600MM-Cool

The m4/3 sensor gives a decent FOV, it could just use a few more subs :D

Edit: added zoom-in around the spider and its nest, still "only" 50% though. You can start to see some streaking appearing...I'll try more aggressive dithering next time around.

Cheers,
Dunk

[strongmanmike]

Nice work Dunk...welcome to the dark side :D

Being able to image from a big city is pretty cool huh? :thumbsup:

Mike

[Camelopardalis]

Thanks Mike! It's a new adventure..given the number of clear new Moon nights I figured it was about time to stop wasting clear nights at home :D

I'm sure I'd get better contrast with a narrower filter, but it's a start :)

[Placidus]

That is looking scrumptious. Can you post a link to a higher resolution version?

[glend]

Dunk, what settings did you choose for those subs? At only 60 seconds, i would expect high gain. Narrowband is not going to sky glow you out of business, so 300 sec subs at Unity could work nicely. Play around abit with settings and exposure length. :thumbsup:

What filter width and brand were you using? Looks like Ha but there is alot of Oiii in that area.

[gregbradley]

Boy, very impressive for a first try. The standard of images continues to rise.An image like that not so long ago would only be possible with very expensive equipment. Well done.

Greg.

[RickS]

A fine result, Dunk! What's the bandwidth of your filter?

[Camelopardalis]

Thanks Mike & Trish! I'm working on a calibrated version that will hopefully calm the background down a bit...maybe then ;) the 200kb hides a multitude of sins :lol:



It's a Ha filter which IIRC I bought from Sirius on a whim after getting my 224 a year or so ago, in the end I didn't try it out and I'd almost forgotten I had it. Now I've got no excuse :lol: they say it's a 10nm bandpass.

Given my proximity to the CBD and with the Tarantula being low over south Brisbane, 60 seconds is about all it takes. This is with gain 200, and the background sky is about 400 ADU above bias. I know I said I'd never go (too) high (or low) with the gain, but it's fun to experiment :D I do want to give OIII a try at some point, and expect I'll have to settle for 2 minutes or many more subs.

[Camelopardalis]

Thanks Greg! I'm sure I could eek more contrast out of it with a narrower filter, but it's what I've got for the moment. Next decent night I want more subs...



Thanks Rick! I believe it's 10nm, so fairly broad for imaging from the city, but it'll do for now! I'm sure I'll want something narrower for fainter stuff...

[glend]

A nice set of parafocal Baader narrowband filters would do nicely ( $470 from Teleskop-Express in 36mm unmounted size).. Those 3nm Astrodon filters are too rich for me. The Baader Ha is 7nm.

[Camelopardalis]

Thanks Glen, I'll have to look into it. It's hard to quantify how much difference it'd make for the added expense.