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Old 23-05-2018, 11:05 AM
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ZWO to buy or not to buy?

In Sydney I get an hour on an object because of the trees.
So I wonder if there is any point to going narrow band.
I am thinking of a ZWO with the mini wheel. This comes with R B G L and Ha.
If I can get a manual wheel I would be happier with one less thing that can play up.
My question I guess really boils down to how short can I make exposures...particularly Ha ...
I have been surprised how well 30 second exposures turn out with the nikon dslr and although I have auto guiding working I find that the 30 second method is great for managing seeing.
I have two scopes a 8 inch f5 and a 80mm skywatcher and ask which scope would be best for the ZWO 1600 cooled pro camera and mini wheel.

Alex
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Old 23-05-2018, 11:33 AM
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Atmos (Colin)
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With the ASI1600 you can bump the Gain up to 200 and run with 30-60s Ha exposures and get a pretty good result. At 30s you’ll probably be a little below optimal BUT still perfectly fine too
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Old 23-05-2018, 11:41 AM
glend (Glen)
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Alex, I usually use 5 min narrowband subs (at Unity Gain, 139) on fairly faint targets, with my ASI1600mm-c. So you can get 12 of those in your available hour, if trees etc permit. Depending on the narrowband luminance of your target that maybe too much, or may not be enough. Certainly for M42 Orion, you can run 60 -90 sec narrowband subs and still be swamped because of the signal strength. For fainter nebula more time, or Gain, will be needed. As Colin indicated Gain is a good thing. You can always come back over three nights to get three hours of signal too.
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Old 23-05-2018, 11:51 AM
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Thank you Colin and Glen.
I really appreciate the input.
Alex
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Old 23-05-2018, 12:13 PM
glend (Glen)
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Alex, as to your question about which scope would be better suited, really it could be used on both. Obviously at f5 your going to be able to run shorter subs than an f7 refractor. However, if your refractor has a reducer/corrector and can give you f5 then they will both be great. Image scale is to be considered. With the 1600s pixel size, the reduced refractor is a good match, but your f5 Newt at 1000mm focal length will still get good results.
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Old 23-05-2018, 01:44 PM
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5min with Ha and NB in general for me in Sydney with the 1600 . I did a series of exposures and got noticeable improvements up to around 300s and little improvement past that at unity gain . I would suggest you consider the powered filter wheel tho it runs off the usb hub on the 1600 and is a time saver if you want to get as much as you can in a limited time without the need to keep moving the wheel its simple ascom driver.
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Old 23-05-2018, 04:20 PM
AstroApprentice (Jason)
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Hi Alex,
I agree with Mark - go the EFW over the manual wheel if you can. I've not had any communications issues with the EFW through the 1600 hub using SGP. Works well as a team.
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Old 23-05-2018, 04:23 PM
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Hi Glen
I feel as if I am getting ahead of myself particularly given I have yet to get pixinsite...but I am very happy with what I get fiddling in gimp and photo shop... I figure get it and work out what I can do ... I like the 8 inch and I havent tweeked it yet and the little 80 mm surprises me again and again.
Ideally the 80 mm as it is transportable with the zwo for up North...I just wonder how short an exposure you could do which not great could be say useable but maybe 75% below what you could get with longer exposures.
I also think I have to stop this age realisation get to me...and the legs...I mean if I was fit and young I would do it so why let what now has to be seen as minor problems enter your world.
Alex
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Old 23-05-2018, 04:26 PM
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Go for it Alex! At high gain you should still be able to get reasonably short subs in narrowband.
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Old 23-05-2018, 04:43 PM
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Hi Alex,
I agree with Mark - go the EFW over the manual wheel if you can. I've not had any communications issues with the EFW through the 1600 hub using SGP. Works well as a team.
Thanks for the reassurance.
I used to think I was old fashion but when I look back at the things I have bought that dont work or stop working etc I have come to a realisation that the simpler the better...but I guess even a manuel wheel could stuff up☺
I still want a dragon fly set up mainly not to have to change filters...one scope one filter and one camera...that would be so cool...in an hour here I could have seven...or more even.
But what an investment...say 7 80mm plus zwo 1600 on each one guide scope ..probably 7 computers...yes I like to keep it simple.
As I said to Glen get it and see what I can do .. give a monkey a gun and he can shoot something.
I feel driven to accept the challenge. ..
Thanks.
Alex
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Old 23-05-2018, 04:47 PM
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Originally Posted by Lognic04 View Post
Go for it Alex! At high gain you should still be able to get reasonably short subs in narrowband.
Thank Login.
Really after what I have been getting thru the dslr in Sydney is beyond what I could do at my dark site where I used to live it 24/7 ...those were the days...weeks on end just photos...but now that was ten years more...ago...so I have high hopes.

I have a feeling it will work.
I have to make it work with what I can assemble.

And I should read Tui below more often.
Alex
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Old 23-05-2018, 05:19 PM
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Quote:
Originally Posted by xelasnave View Post
Thanks for the reassurance.
I used to think I was old fashion but when I look back at the things I have bought that dont work or stop working etc I have come to a realisation that the simpler the better...but I guess even a manuel wheel could stuff up☺
I still want a dragon fly set up mainly not to have to change filters...one scope one filter and one camera...that would be so cool...in an hour here I could have seven...or more even.
But what an investment...say 7 80mm plus zwo 1600 on each one guide scope ..probably 7 computers...yes I like to keep it simple.
As I said to Glen get it and see what I can do .. give a monkey a gun and he can shoot something.
I feel driven to accept the challenge. ..
Thanks.
Alex
Why not just get 10 DSLRs and 10 Large lensí or small telescopes and then you can just use external intervalometers with one laptop for guiding.
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Old 23-05-2018, 07:10 PM
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Why not just get 10 DSLRs and 10 Large lens’ or small telescopes and then you can just use external intervalometers with one laptop for guiding.
Colin the various set ups to achieve something in this regard I have covered..but your idea is the most doable.
Alex
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Old 24-05-2018, 12:32 PM
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ZeroID (Brent)
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1600mm-c and the EFW is the way to go. I only wish I'd gotten the 7 position wheel so I could go R G B, L, Ha, OIII & SII. Guiding is the 120mc and 80F5. Contemplating a 290mm Mini for guiding so I can dedicate the 120 to planetary. More than happy with all the ZWO cameras.

Correct me if I'm wrong but I understood Narrow band to be the OIII, SII & Ha imaging setup. RGB is just mono. Am I missing something ?
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Old 24-05-2018, 03:22 PM
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Originally Posted by ZeroID View Post
1600mm-c and the EFW is the way to go. I only wish I'd gotten the 7 position wheel so I could go R G B, L, Ha, OIII & SII. Guiding is the 120mc and 80F5. Contemplating a 290mm Mini for guiding so I can dedicate the 120 to planetary. More than happy with all the ZWO cameras.

Correct me if I'm wrong but I understood Narrow band to be the OIII, SII & Ha imaging setup. RGB is just mono. Am I missing something ?
You're correct and on a side note why not ditch the guide scope and go with the zwo OAG
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Old 25-05-2018, 10:42 AM
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The unit I feel will suit me best has a "mini" wheel and R B G L and Ha filters would one not call such and approach narrow band imaging?
Alex
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Old 25-05-2018, 11:24 AM
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I had to go but wanted to say my main hope is that having a cooled camera will take me forward and test if going up to a seven wheel is something I can manage.
Also I expect I could get a second "mini" wheel to inter change that holds additional filters...changing wheels for the next night should not be a big deal if I make it that far.
Alex
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Old 25-05-2018, 11:24 AM
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Originally Posted by xelasnave View Post
The unit I feel will suit me best has a "mini" wheel and R B G L and Ha filters would one not call such and approach narrow band imaging?
Alex
Lrgb isn't considered narrow band Ha S2 O3 and N are NB
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Old 25-05-2018, 11:34 AM
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So R B G L and Ha are narrow band.
All I wanted to add is Ha really.
Maybe I should go for the seven and save myself the effort later.
Any views?
Alex
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Old 25-05-2018, 11:38 AM
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No just Ha is narrow band not LRGB I would suggest getting the bigger wheel then you are covered if you want to add O and S or anything else
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