ZWO to buy or not to buy?

[xelasnave]

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

[Atmos]

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 :)

[glend]

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.

[xelasnave]

Thank you Colin and Glen.
I really appreciate the input.
Alex

[glend]

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.

[Marke]

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.

[AstroApprentice]

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.

[xelasnave]

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

[Lognic04]

Go for it Alex! At high gain you should still be able to get reasonably short subs in narrowband.

[xelasnave]

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

[xelasnave]

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

[Atmos]

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.

[xelasnave]

Colin the various set ups to achieve something in this regard I have covered..but your idea is the most doable.
Alex

[ZeroID]

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 ?

[Marke]

You're correct and on a side note why not ditch the guide scope and go with the zwo OAG

[xelasnave]

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

[xelasnave]

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

[Marke]

Lrgb isn't considered narrow band Ha S2 O3 and N are NB

[xelasnave]

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

[Marke]

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

[xelasnave]

Thanks for your advice I am inclinded to think I should follow it.
Alex

[Marke]

Its better to have spare slots and motorized than wishing later you had :thumbsup:

[ZeroID]

Yes, I've considered that but with my LP'd sky I might struggle to find guide stars within the viewing. Most of my imaging is into the SCP area which can be a bit sparse sometimes. The 80F5 is setup with only one axis of adjustment so flexure is not a problem and I have had to move it only slightly once to get a star into a better position.
Having it all setup in an Observatory means I can keep it all locked down optically and mechanically which makes it a lot easier to get multiple night imaging done.

I still may go down the OAG path if I have to buy a SII filter from ZWO eventually but at present the RGBLHa imaging process is keeping me more than amused. And my slush fund is still recovering financially from the 1600mm-c buy but it was definitely worth it.

[Marke]

I'm in suburban Sydney and used an oag for the last 6 yrs with out ever an issue you can bin2x on the guider never not had a star I can use in the fov. If you are getting zwo nb filters don't get unmounted what ever you do .

[ZeroID]

I would still need another camera as one would have to be dedicated to the OAG. I'm not normally a 'planetary' imager but the current opportunity with Jupiter and Saturn to try for some better pix is worth having a go with my setup. The ASI 120mc is on the flip mirror with a 2x Barlow. Gives me f14 but really need a 3x or higher. Slightly smaller pixels on the 120 should improve the image. Having it on the flip mirror means the 1600mm-c is still setup for my usual DSO targets on f7, I just move the 120mc back to the guide scope and refocus everything..

My EFW is 1.25 so mounted is the only option AFAIK.

[kosborn]

I have the 31mm unmounted ZWO filters. What did I do wrong...?


Kevin

[Marke]

Nothing wrong but they have terrible large ring artifacts caused by reflections off the edge . I blacked out the edge on mine which helped a little but i ended up replacing them all due to the reflections they cause.

[xelasnave]

I have my money tied in the corner of my hanky (I wonder if there is anyone who lived in those days;)) and I would like you to write my note to take to the shop:DTell me exactly what I want:D
You recon the seven wheel but what size filters how do I avoid any problems?
Do I get the big ones or medium or small?
alex

[Marke]

The mounted 1.25 will be ok it's just the unnounted ones the mounted have cover around edge. Just get the 7 set you can always upgrade if you feel the need later.

[xelasnave]

If I get the camera in the 7 wheel kit I presume the right ones will be in that big or small..I would rather get big if there is an advantage.
alex

[Marke]

Your option is 2in filters but the wheel has less slots because they take up a lot more room. Unless you are using a very fast scope with a large chip camera 1.25 are fine and half the price.

[Benjamin]

I found these tables really useful for exposure times. https://www.cloudynights.com/topic/573886-sub-exposure-tables-for-asi-1600-and-maybe-qhy163/

I get some vignetting (maybe amp glow as well) with the 1.25” filters in both the ED80 (at f6.3 with flattener/reducer) and the 8” Newt (operating at f4.5 with coma corrector) but it is all easily processed out. However I knew I wanted some pricey filters (to best deal with LP) so anything larger than 1.25” mounted was unaffordable. Don’t regret the purchase at all. I’m using the 8 position EFW. Works like a charm. Using Sequence Generator Pro to control everything. Still not to the point of pushing “Run Sequence” and walking away but getting closer. I was amazed with the Results the Ha filter gave me (around 3 minute exposures at Gain 139).

Only other thing I remember reading was about matching pixel size to focal length for different seeing conditions. The ED80 could undersample in excellent seeing while the 8” Newt could over sample in bad seeing conditions. The bit that worries me was that oversampling seems to place more empahsis on the mount, which in my case is an HEQ5 which is already operating near to its weight capacity with the Newt. Thus I’m resolved to sticking to my ED80 and maybe using the rather slow f7.65 ED100 for a field of view comparable to the 8” Newt.

[ZeroID]

Alex, if you get the pro kit https://astronomy-imaging-camera.com/product/asi1600mm-kit
It comes with all the required filters, the 7 hole wheel and the camera, cables, adapters, spacers for almost any setup. I was impressed with what they provided to cover most setup requirements. Some bits have solved some of my other optical path problems.

The comment I'd make is will you do narrow band or just RGB + Ha ? If you don't anticipate going down the narrow band path eventually then just get the mini kit with 5 holes. Mine is awesome.

I'm quite happy with the RGB + Ha ( the other filter is 'L' which is an IR/UV filter). It is letting me manage my LP issues much better and narrow band is a whole other ballpark in exposure times and colour processing and management. I'm only intrigued with it because the only filter I am missing is the SII and having a permanent setup makes it easier to try new things. And I am curious ..

The big thing I am seeing with the 1600mm-c is the incredible detail and depth as each channel adds to the picture and it is easier than I expected after an initial period of frustration and confusion.

And the supplied mounted 1.25 filters work just fine.

[xelasnave]

Hi Brent,
That was well timed I just got back in.
I think I will go the 8 wheel on the basis that I hopefully can manage the additional complexity and not have to upgrade...unfortunately the price is above what I wanted to invest, I have the cash but I dont like spending it on toys...however after my close call thinking I was dieing I am syarting to be a little more easy on myself.

My plan is to capture stuff and store it and learn pixinsite latter.

I am a mug and well aware of my limitations so I feel I may be expecting something that wont happen...still I am going to try.

And at least down here in Sydney I can now set up on a permanent basis in the cube that I built...not having to pack up has been a massive pay off and being able to just open the box and its all set up is great.
My only problem is where should I buy it...I like dealing with Bintel but would like to give the folk who sponsored Logan a go.
Any ideas there?
Alex

[JA]

Go with your gut / first thought!

Best
JA

[Lognic04]

I say Give Sidereal trading a go! :thumbsup:

[ZeroID]

I don't know the Aust market options Alex but I'd be prepared to give Logans people a go. They seemed pretty good to deal with. If you're dealing with a person you might like to mention that is why you are going through them.

Re the 'spending on toys' comment. A very close friend of mine passed away middle of last year. He had cancer, knew approximately when he would go and he just did everything he could while he could. He told me to 'do it now because you don't know when it's too late'.

I hedged and hummed over my 1600 buy, lot of money especially at our exchange rate at the time. But glad I did now, it's an investment in my own time and that is the most important thing of all.

Just go for it, tomorrow might be too late. :D

[xelasnave]

Hi Brent
Please explain to me why I should get a 100 mm espirt:D
Look I know what you will probably say so thanks for talking me into it:D
Finally got the pole master fitting sortted... I just used a polar plug and epoxy ...better than a bought one.
I may be back onto the motorised walking frame..I was given a golf cart, a club carrier, which has a great moter and gear box. So maybe.
Alex

[xelasnave]

So if you get the 8 position wheel what do you get to become the eighth filter?
Leave it empty or add something?
Alex

[lazjen]

Sometimes you can get a solid "filter" to go in there to do darks and not have to cover the scope. Personally, I'm a bit dubious of how good that would work.

[ZeroID]

Leave it empty so you get the full works ..no IR/UV cut.

[ZeroID]

Just been browsing the ZWO website with buying in mind. I have been tossing up to get an SII filter to complete the set but I see the new LRGB filter set has a wider band pass to include the SII wavelengths on the Red filter. My LRGB set is the earlier version which just clears the Ha wavelength. I think I'd be doing better (and a lot cheaper) to upgrade my LRGB set. It also improves on reflections, light transmission and better colour separation.
Alex, you may want to consider that option in your buy. Not sure if it would be available locally unless they only import on order.

Any comments on the new ASI filters anyone ?

[xelasnave]

I am still not sure.
So what do I get to avoid reflections?

I plan getting one of the kits...should it be the 1.25 or larger.

The seven or the eight?
Can I get mounted large?
Forget about the money which is the best to get to have the least problems.
I gather mounted?
What is the largest in mounted?
I dont want to change up later but I want what I get to have few problems.
Alex

[Lognic04]

Alex, if you want the least problems just go for simply mounted 1.25 filters. These are only screw in to the filter wheel, so least amount of fiddling and chance of flipping the filter accidentally. You shouldn't get vingetting until about F3 if I remember right. Also, any reason that you are switching to mono so fast? Doesn't hurt to practice more with the DSLR and perfect it :)

[xelasnave]

Thanks Logan.
Why the rush?
There is so much to do I need to get started.
Alex

[lazjen]

Personally I'd get the largest filters that I could afford - just for more options later on if you change scopes, etc.

[xelasnave]

As I understand it the larger filters have reflection issues.
I can afford anything I want but I do not feel like buying the most expensive if they have reflection issues.
From the feed back it seems the large filters have issues with reflection and that would drive me crazy I go to so much trouble to eliminate stray light it would be an enormous issue for me probably more than for others... some things I can accept or manage but there are certain things that I find most off putting...

If I buy any more scopes it would be a 100mm espirt and a f2 11 inch like David purchased but I have to buy a caravan and build another observatory before that...
But I like to have scopes set up with their own camera etc so whatever I buy will be for the 80mm but more likely mostly for the 8 inch...
I just want to get the best thing to suit my current needs or rather wants:)

Alex

[ZeroID]

Alex, get the 1600mm-c kit with the 1.25 filters ( and what ever filter wheel you prefer ). If you get it direct from ZWO it will come with the new filters. 1.25" mounted is their recommendation for any scope above f4 so f5 > f whatever is good to go. My scope is F7 and no problems.

I'm going to get the new LRGB filter set as it includes SII coverage in the red and I am only wanting that to try and get as many of those precious photons as possible. I won't bother with the 7 hole wheel or SII filter for now at least.