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IC1396: 9 hours worth of Ha


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What you've already got is beautiful :) Weather is dreadful - looks like we're back to one or two nights a fortnight :( Guess it gives time for a slow and lazy gear setup and improvement time :D

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Well, the weather has been glorious. Sunny all day (well, apart from the mornings) and clear by night, shame the nights are so short! But thats one of the reasons I use the twin shooter, at this time

Ok, (for the 1000th time...grrrr.) here is what ive been trying to post for most of the day. Ive given up with SGL and "IO error" messages when uploading, so ive had to host elsewhere for now. I manag

Thanks Paul I do hope to improve upon the HST version, I feel there should be more gold (Ha), towards the bottom of the frame, and the OIII isnt strong enough. Shame its going to be at least a few we

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Well done Rob, lovely image and I really like the HST too.

You said that each pane was 4.5 hours (x2) and since the scopes are pointing at exactly the same spot then that's 9 hours per pane right? (sorry for the stupid question).

As for the Baader Stronghold - I asked this question and I was told it was not recommended to use it for dual imaging to support a scope and camera but then I was close if not over the 7kgs limit. I use http://www.robincasady.com/Astro/ (I picked up on these from a thread Olly had posted in) and have the tandem bar plus a tgad so I can align the scopes. I upgrade my dovetails to losmandy too. It does add a lot more weight but I think you may be OK on the NEQ6 (which is what I have). I've not done any serious imaging yet with it due to weather and now summer but what I have done is confirmed that I do not have any flexure anymore from the mountings (I previously used the Sky-Watcher adjustable guidescope mount). I now need to drift align again which should get much more accurate PA. Drift aligning with a scope that has quite a bit of flexure is not good it seems :grin:

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Thanks Ian, ive taken a look at the TGAD assembly. It looks very solid, but the only problem is the price. Thats a lot of money for a bit of metal (import tax/fees wil be a lot too), its a shame nobody in this country produces a similar product - im sure somebody could knock one up (no matter how workman-like) for a bit less than that. If I had the time i'd design one myself and get it machined, how hard can it be? (haha... famous last words!).

But the setup I propose to use on the stronghold will weigh no more than 4.5kg (80ED, FF/FR, FW, Camera). Ive already weighed the individual parts of my setup so I can be quite accurate with staying under the payload limit for the stronghold (7kg). Actually, at the moment the stars in the 80ED held by the guidescope rings gives me better stars (work that one out!). The problem is that between sessions the placement of the 2nd 80ED always moves (a little) - so I have to recentre at the start of each session if I want to make full use of as many pixels as possible. And we all know what a finger shredding experience adjusting guidescope bolts can be!

Sorry for the confusion with the exposure details, what I did was to point both cameras at the same spot and shoot 2 1/4 hours worth of Ha (x2 gives me 4.5), the following night I did the same - except on the lower portion of the elephant trunk.

Capture details for the colour versions are:

HOO: 24x600 + 1x900 Ha_L, 10x600 Ha_R, 10x600 OIII_G&B (x2 panes)

HST: 24x600 +1x900 Ha_L, 10x600 SII_R, 10x600 Ha_G, 10x600 OIII_B (2 panes)

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Hi Rob - yes it is expensive and there are import duties making it even more expensive.

I found that I had the problem of a shifting secondary throughout an evening. It was quite a considerable shift and it was evident in my subs too. It's only takes fractions / tiny amounts of movement to impact subs and I was having difficulty getting over 10 mins. I still need to drift align to see what I can push the setup too. Hoping to do that one evening during the Summer.

Sounds like the Stronghold will do the job if the loaded OTA is only 4.5Kg. The Stronghold will be considerably lighter than the Cassidy kit. I do like the Cassidy kit, it is machined well and the TGAD is absolutely brilliant. It locks really nicely into place. The only movement I get now is when I walk into the scopes :eek: but the whole lot moves now.

Anyway, great work look forward to more. Maybe you could expand the Mosaic and capture more of that region? I've got an ambitious 25 frame mosaic lined up in SGP. I figure it might take me a few years given the clouds! I'm going to start on the middle and work outwards.

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You know, I sometimes cannot believe the quality of these images from amateurs with modest kit. I just showed these my dad who is visiting and he thought some of this stuff was from the HST!

Spectacular! Well done :)

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Hi Rob - yes it is expensive and there are import duties making it even more expensive.

I found that I had the problem of a shifting secondary throughout an evening. It was quite a considerable shift and it was evident in my subs too. It's only takes fractions / tiny amounts of movement to impact subs and I was having difficulty getting over 10 mins. I still need to drift align to see what I can push the setup too. Hoping to do that one evening during the Summer.

Sounds like the Stronghold will do the job if the loaded OTA is only 4.5Kg. The Stronghold will be considerably lighter than the Cassidy kit. I do like the Cassidy kit, it is machined well and the TGAD is absolutely brilliant. It locks really nicely into place. The only movement I get now is when I walk into the scopes :eek: but the whole lot moves now.

Anyway, great work look forward to more. Maybe you could expand the Mosaic and capture more of that region? I've got an ambitious 25 frame mosaic lined up in SGP. I figure it might take me a few years given the clouds! I'm going to start on the middle and work outwards.

Thanks Ian! My thinking is that if the setup is light, and the FL (fairly) short then the stronghold should cover it well enough. If it works out well, then it may open the gateway to having a triple shooter. However, I may reach the point where I might be better served by getting a single, bigger chipped camera on a sub F5 refractor or 130PDS with the ASA 0.73 reducer. Im pretty comfortable shooting at 500mm, well... apart from Feb to April becuase its all galaxies! (I have more interest in nebulae).

Inspecting the subs I took for this, there is no detectable flex between subs taken at the same time. Im sure any flex I do have is elsewhere becuase between one pair and the next - there is movement. Maybe I should find a way to mount the finderguider on the dual mount bar (in the middle), and not on top of the stock SW scope rings. Hmmmm... that would involve a drill & tap though.

I might return to it later in the year to expand it in Ha, once the darker nights return. At the moment its just a bit too late in the evening to set up (got no obsy), plus I would like to send one of the cameras off for a service and clean - so I may as well take it all apart and give everything a summer service to get it all cleaned and ready for the new season.

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Thanks Olly, Dave and Kirkster :)

With luck it will only get more interesting as the year wears on, when this setup will see some proper dark time. The thought of potentially capturing 12+ hours of data in a single session means mosaics are no longer such a problem, so the cygnus loop is a viable project this year (which would require another 10 panes to complete, 20 hours worth).

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amazing colour version :rolleyes:

i must be doing something wrong :huh: i have the same setup albeit single ed80/314L+ and this is way way way better than what i had for 6 hours of ha in 10 min subs.

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Just picked up the "coloured version." Fantastic as I would have imagined.

This aspires me to setup my dual imaging rig. Just a question do you run both your imaging cameras from the same PC?

cheers

Steve

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Just picked up the "coloured version." Fantastic as I would have imagined.

This aspires me to setup my dual imaging rig. Just a question do you run both your imaging cameras from the same PC?

cheers

Steve

Thanks Steve! Yes, you can run two (or more) instances of Artemis capture on a single computer - I use the tiny Acer aspire one. When you have two cameras connected, Artemis capture will ask you which camera you want to connect to (via serial number dropdown menu).

The only thing you need to keep an eye is the autosave location, as as the start of each session they will be the same. If its not changed then you will end up getting subs from different filters going into the same directory.

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amazing colour version :rolleyes:

i must be doing something wrong :huh: i have the same setup albeit single ed80/314L+ and this is way way way better than what i had for 6 hours of ha in 10 min subs.

Tony, are you using the 0.85x FF/FR? I'd say its a must for the 80ED, six hours worth of data at F7.5 can be collected in just 4hours and 20min at F6.38.

If you have a large amount of subs, its a good idea to inspect each sub closely and hand-pick the ones you want to keep (sometimes less is more!). My sorting routine isnt based so much on the quality/shape of the stars, but also the background level and focus.

This is especially important when doing mosaics, becuase differing background levels and focus changes between panes shot on different nights are quite noticeable when you put it all together. An example was my recent mosaic of NGC6914, I ended up having to re-shoot a load of it becuase of noise caused by a combination of dodgy sky, not waiting for the sun to set properly, and the best efforts of a neighbour to keep his flamin security light on all night (that last point will come to a head over the next couple of months).

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Tony, are you using the 0.85x FF/FR? I'd say its a must for the 80ED, six hours worth of data at F7.5 can be collected in just 4hours and 20min at F6.38.

If you have a large amount of subs, its a good idea to inspect each sub closely and hand-pick the ones you want to keep (sometimes less is more!). My sorting routine isnt based so much on the quality/shape of the stars, but also the background level and focus.

This is especially important when doing mosaics, becuase differing background levels and focus changes between panes shot on different nights are quite noticeable when you put it all together. An example was my recent mosaic of NGC6914, I ended up having to re-shoot a load of it becuase of noise caused by a combination of dodgy sky, not waiting for the sun to set properly, and the best efforts of a neighbour to keep his flamin security light on all night (that last point will come to a head over the next couple of months).

hand pick, they all look the same to me :laugh: i'm still learning all this, hadnt been using the dslr for long when i decided to jump in at the deep end.

but still a very enjoyable hobby though, getting that end result, even though it may be pants compared to some :grin: and learning all the time.

and yes i have the ff/fr, just havent got round to using it yet, when i finally get the obsy finished and i can leave everything set up ready to go, i may just finish it this century :laugh: working 6 days/nights alternate weeks and day off like today and its raining :embarrassed:

Edited by tony
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