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First AP setup - does it look reasonable?

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#1 BillionsAndBillions

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Posted 04 July 2020 - 05:33 PM

Hi all,

 

I'm trying to build a basic but good AP setup, but with the numbers involved (~$3k) I don't want to make a newbie mistake.  The goal here is to get a simple but quality DSO AP setup that will last and I can extend without regret later.  I would like it to be reasonably portable, in a perfect world I could take it on a flight (assuming we ever get to fly again).

 

Mount - Sky-Watcher HEQ5 Pro EQ Mount - seems like the lightest high-quality goto mount

Telescope - Williams Optical ZenithStar 81 Doublet and Flattener (I might skip the flattener initially to save $200)

Camera - ZWO ASI183MC Pro (color) - I think this matches the resolution.  I don't have a DSLR nor do I need one day to day, so I thought I would just go straight for a dedicated camera

 

Eyepiece/Filters/Barlow (can you use a barlow in AP?)/etc - No ideas yet

 

The primary goal is AP, but any advice on getting great ooh/ahh visuals out of this for kids would also be appreciated. smile.gif.

Also, DSO is my primary objective, but how would this work for planetary or solar if I got the bug?

 

Thank you!  I appreciate your expertise.

-db-

 

 



#2 bjulihn

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Posted 04 July 2020 - 06:31 PM

Hi There;

 

I think your basically off to a good start. A couple of thoughts. First, if your goal is "simple but quality you can build on", I think you might want to consider a triplet scope. Someone else with more experience with that particular scope for imaging may have a different opinion but most advice would probably push you in that directions. The 80mm f6.9 optics is a good focal length to learn on though.

 

Regarding the flattener, you will definitely want one. You will spends hours taking an image and all the stars near the edge of the field will trail away. You will be frustrated and end up massively cropping the image to minimize the distortion. 

 

The 183MC Pro is indeed a great match for this focal length. I am using an ED80mm scope with the QHY 183c and they work well together. I have been aggressively learning and practicing AP for the last year and a half, after a long time in visual astronomy. One thing that surprised me was how many of the classic targets are too big to catch in a single frame with an 80mm scope and the small chip on the 183c. I have to use a .8 reducer and/or do difficult mosaics to get some things to fit. Stellarium allows me to project exactly what size frame I can capture with my scope and and camera combination.

 

I am using the similar weigh capacity Ioptron iEQ 30 Pro mount. The mount head weighs 15lbs which is pretty portable but not something I would want to fly with. Anyway, should be a similar class mount you might want to consider as an alternative.

 

Last thing, processing images is every bit as challenging as taking them and more. Learning processing will have a massive effect on the "kid appreciation factor". I was able to get good data fairly early in my AP journey, but I would say that only now are my processing skills catching up. I have taken to sending family copies of pictures I took last year next to images I am taking this year of the same object. They are often night and day different.

 

Good Luck;

 

Brad


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#3 bobzeq25

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Posted 04 July 2020 - 06:58 PM

Hi all,

 

I'm trying to build a basic but good AP setup, but with the numbers involved (~$3k) I don't want to make a newbie mistake.  The goal here is to get a simple but quality DSO AP setup that will last and I can extend without regret later.  I would like it to be reasonably portable, in a perfect world I could take it on a flight (assuming we ever get to fly again).

 

Mount - Sky-Watcher HEQ5 Pro EQ Mount - seems like the lightest high-quality goto mount

Telescope - Williams Optical ZenithStar 81 Doublet and Flattener (I might skip the flattener initially to save $200)

Camera - ZWO ASI183MC Pro (color) - I think this matches the resolution.  I don't have a DSLR nor do I need one day to day, so I thought I would just go straight for a dedicated camera

 

Eyepiece/Filters/Barlow (can you use a barlow in AP?)/etc - No ideas yet

 

The primary goal is AP, but any advice on getting great ooh/ahh visuals out of this for kids would also be appreciated. smile.gif.

Also, DSO is my primary objective, but how would this work for planetary or solar if I got the bug?

 

Thank you!  I appreciate your expertise.

-db-

Good stuff.  I agree the flattener can wait until you see how troubled you are by the stars at the edges.  No loss to omit that up front, that won't interfere with learning.  Very minor comments.

 

I'd consider the 533 camera instead of the 183 (and I own both of those).  You're sacrificing some theoretical resolution (that, frankly you're unlikely to realize, manyy other factors come into play) and getting improved signal to noise ratio, which you _will_ get.

 

Planetary is a different animal.  I did some with an 80mm, the results were OK, not good.

 

Barlows don't work well with DSOs.  Again, any gain in resolution is liable to be purely theoretical, while the loss in snr is certain.  Experienced imagers hardly ever use them, for a beginner, that should be 'never'. 

 

If you're going to do planetary with that scope, you will want one.  Planets are _very_ bright, the loss in snr is inconsequential, and the special "lucky imaging" technique will help you realize the increased resolution.


Edited by bobzeq25, 04 July 2020 - 07:00 PM.

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#4 BillionsAndBillions

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Posted 04 July 2020 - 06:58 PM

Thank you Brad!  So maybe the WO GT71 triplet?  Not a huge reduction in focal length - will the triplet really perform that much better?

 

Denny


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#5 Huangdi

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Posted 04 July 2020 - 07:31 PM

Thank you Brad!  So maybe the WO GT71 triplet?  Not a huge reduction in focal length - will the triplet really perform that much better?

 

Denny

A triplet is going to give you just a bit sharper images and no chromatic aberration. After using a doublet for two years I am very glad that I soon will finally upgrade to a triplet. Not because the images are so awful but because they're not optimal. 

 

My goal currently is to get gear that will enable me to acquire very good data. Data that can be reprocessed and combined with data from 3 years later.

 

A doublet will undoubtedly give you nice images, but it will lack some sharpness compared to a triplet and have some chromatic aberration.

 

Also, I think the ASI 183 is a great choice, it is my future small chip choice. If you want the best possible data, consider going mono.



#6 bjulihn

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Posted 04 July 2020 - 10:53 PM

Hi Billions;

 

I am leaning strongly on your statement about "extending without regret" in recommending you consider a triplet. The GT71 looks like a fine scope, but you may find some other options slightly cheaper if your budget is tight. I hope you realize that there is no perfect scope for all imaging. Everything is a compromise. Galaxies tend to need a longer focal length because they are mostly smaller. But it takes a really good mount to handle focal lengths above 1000mm. 70-80mm scopes are good general imaging scopes but trust me, at some point you will want to try something different as well. I went with an inexpensive 6" f4 imaging Newtonian for my second scope($350). It gives me about 600mm focal length which is a nice step up from my ES80mm f6. It is a significantly faster scope and it catches a lot more light. But it is heavier and on my mount, and I lose about 25% of my frames to poorer guiding and increased magnification which exposes guiding errors more. I heard a lot of anxiety on forums about maintaining collimation on a newtonian. I got a good collimator and cheshire eyepiece. I had to work at it a bit the first time after it arrived. But since then I check it each time and it is good.

 

Brad


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#7 BillionsAndBillions

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Posted 04 July 2020 - 11:35 PM

that's perfect, Brad, thank you.  I do mean it, even though it's difficult to not dream about something like an SCT with a longer focal length to get those amazing shots.  But that will be next, once I've done some basic stuff.  I will admit that I'm already planning that way, but... one step at a time.  The thing that gets me excited are the nebulae and such, so I'm trying to stay focused (buh dum bump) on those.



#8 BillionsAndBillions

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Posted 04 July 2020 - 11:45 PM

I'd consider the 533 camera instead of the 183 (and I own both of those).  You're sacrificing some theoretical resolution (that, frankly you're unlikely to realize, manyy other factors come into play) and getting improved signal to noise ratio, which you _will_ get.

...

 

Barlows don't work well with DSOs.  Again, any gain in resolution is liable to be purely theoretical, while the loss in snr is certain.  Experienced imagers hardly ever use them, for a beginner, that should be 'never'. 

@bobzeq25, can you talk more about the snr differences?  We just blew past the boundary of my knowledge...  thank you!



#9 Stelios

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Posted 05 July 2020 - 03:20 AM

Hi all,

 

I'm trying to build a basic but good AP setup, but with the numbers involved (~$3k) I don't want to make a newbie mistake.  The goal here is to get a simple but quality DSO AP setup that will last and I can extend without regret later.  I would like it to be reasonably portable, in a perfect world I could take it on a flight (assuming we ever get to fly again).

 

Mount - Sky-Watcher HEQ5 Pro EQ Mount - seems like the lightest high-quality goto mount

Telescope - Williams Optical ZenithStar 81 Doublet and Flattener (I might skip the flattener initially to save $200)

Camera - ZWO ASI183MC Pro (color) - I think this matches the resolution.  I don't have a DSLR nor do I need one day to day, so I thought I would just go straight for a dedicated camera

 

Eyepiece/Filters/Barlow (can you use a barlow in AP?)/etc - No ideas yet

 

The primary goal is AP, but any advice on getting great ooh/ahh visuals out of this for kids would also be appreciated. smile.gif.

Also, DSO is my primary objective, but how would this work for planetary or solar if I got the bug?

 

Thank you!  I appreciate your expertise.

-db-

Good choice on the mount and the scope (although you can get less expensive doublets--Orion sells the HEQ5 in its Sirius incarnation with an ED-80 and mounting hardware for a significant savings. 

 

The ASI183MC Pro is a good camera limited only by its small FOV. Also if you are shooting from a high LP site (Bortle 7 and worse) you will be better off with a mono.

 

For photography you don't need EP's, filters or a barlow.

 

I've seen the Barlow question pop up a lot recently, and I don't want to just say that (true) practically no astrophotographer ever uses one for *DSO* imaging. What a Barlow will do is (assuming a 2X Barlow) increase the time required to get equivalent signal by a factor of 4 (square of the barlow power). In addition, in your case, a Barlow will mean you are significantly undersampled. Your normal image scale with the small-pixel ASI183MC and the WO 81 is 0.88 which is good but *slightly* on the oversampled size. A Barlow will render it to half of that, i.e. 0.44"/px which is very oversampled. What that means is that the extra resolution you are trading time for, will be lost because of seeing limitations--similar to how "empty magnification" works for visual. 

 

Visually an 81mm refractor is a very good scope and will yield powers up to around 180 or so with good seeing. You should ask at the eyepiece forum for recommendations.

 

For planetary, the scope will yield a very small image size, but the ASI183 and a 2X Barlow should yield some acceptable images. I know nothing about solar--you should ask at the Solar System imaging forum.

 

Finally, re doublet vs. triplet. IMO, it's silly to blow a lot of the budget on a triplet at this stage, as you will improve your images far more by adding guiding and auto-focus than upgrading from a doublet to a triplet. A beginning weightlifter doesn't need to start with an Olympic barbell set. It will be *years* before the doublet is a limitation, and when it is, you can sell it at a very high percentage of its original price (refractors lose very little of their value). By then you may want a longer F/L scope, or perhaps even an SCT or a reflector.

 

As long as you make a sound purchase today, future-proofing further is a poor strategy. 



#10 sg6

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Posted 05 July 2020 - 04:00 AM

Copied to this branch from Beginners.

 

Not the best idea.

 

The scope is basically wrong - it is a Mak and focal length is low, scope is defined as "slow" so any images would be excessivly long or you need lots and lots and lots. The long focal length would also mean you would lose a good percentage.

 

Then just to really end it the mount is the wrong typr - you need an Equitorial, not an Alt/Az.

 

The mount and scope will image planets - you obtain say a 90 second video. Catc is there are basically 3 planets (add in the moon).

 

Visual and any images both use a scope and a mount. problem is they are or need ti be different scopes and mounts.

 

The Az Gti has an Eq mode, you need a wedge thing. However the mount was not intended as an imaging setup. Sort of you can buy bits and get something but I guess you only ever get to 90-95%. Too many expect it to be perfect.

 

Starter would be more in the line of a small but good equitorial mount and a 72ED or 80ED as the scope, even one of the 60ED's would be good. Imaging tends to either be or get expensive as you want more. You have to set your limits as equipment. If you set limits by image standard you spend more and more.

 

Imaging is a good equitorial mount and a good small relatively fast scope. You have selected a Alt/Az mount and a slow scope. Sort of the opposite end.



#11 FrankMill

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Posted 05 July 2020 - 07:27 AM

Like you, I’m just getting started with a similar budget. Initially, I was going to get a doublet but found an Explorer Scientific ED80 carbon fiber on classifieds here for $630. Very happy with the sharpness! Just received my HEQ-5 Mount from Astronomics. Practicing polar alignment now. Instead of a Zwo camera, I already had a Nikon D5500. I’m sure it will give decent images but I will get a Zwo next year. Guys on the forum tell me to get a guidescope and guide camera right away. So now I’m looking for mount adaptors. I’m finding that there is always something new to buy! Lol

#12 bobzeq25

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Posted 05 July 2020 - 02:53 PM

that's perfect, Brad, thank you.  I do mean it, even though it's difficult to not dream about something like an SCT with a longer focal length to get those amazing shots.  But that will be next, once I've done some basic stuff.  I will admit that I'm already planning that way, but... one step at a time.  The thing that gets me excited are the nebulae and such, so I'm trying to stay focused (buh dum bump) on those.

For some time, months, not weeks, this will be about learning, rather than what you're imaging.  And the small scope and big targets is better for that task.  Corollary.  For your first image, don't even bother with a nebula.  Try a cluster, or even a random star field.  You'll walk away from gathering the data, and processing it, with a significant "to do" list.  <smile>  So don't overly fuss about the target, simple is good.

 

@bobzeq25, can you talk more about the snr differences?  We just blew past the boundary of my knowledge...  thank you!

The key parameter is "image scale", the number of arc sec per pixel.  You calculate it by dividing the focal length by 200, then divide the pixel size by the result.  Closer to 1 could theoretically get you more resolution, but a number of things are likely to intervene, so you won't get much more resolution if any.  Closer to 2 puts more signal on each pixel, making noise less important.  Better signal to noise ratio, and the loss in resolution is unlikely to be a concern.  Closer to 2 is also more forgiving of beginner mistakes.

 

I was laid back about the recommendation, but, since you asked, I think the 533 is a better learning tool.  And well regarded here.

 

All much better described in this book that in a short post.  I pretty much guarantee you it will be the best $40 you ever spend in AP.  <smile>

 

https://www.amazon.c.../dp/0999470906/

 

I have a number of scopes and cameras, image between 1.0 and 2.7.  Below is 2.7.  Look OK?  Better quality, and a lot more details, here.

 

https://www.astrobin.com/367734/C/

 

Like you, I’m just getting started with a similar budget. Initially, I was going to get a doublet but found an Explorer Scientific ED80 carbon fiber on classifieds here for $630. Very happy with the sharpness! Just received my HEQ-5 Mount from Astronomics. Practicing polar alignment now. Instead of a Zwo camera, I already had a Nikon D5500. I’m sure it will give decent images but I will get a Zwo next year. Guys on the forum tell me to get a guidescope and guide camera right away. So now I’m looking for mount adaptors. I’m finding that there is always something new to buy! Lol

Good choices.  I have astro cameras, still use my D5500 sometimes.  If you an track well enough, the ideal ISO is 200.  Build data with exposure time.  Subexposure time is less critical, total imaging time is vital.  Shoot more subs.  <smile>.  Higher ISO just limits your dynamic range.  If you can track properly.

 

My rule of thumb is one hour total imaging time is minimal, 2 is better, 4 good.  The image below is 7.2 over 3 nights.  That (and some special filters) got me the dim stuff.

 

NGC6992 HaO(III)RGB V4.jpg
 


Edited by bobzeq25, 05 July 2020 - 03:00 PM.


#13 bjulihn

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Posted 05 July 2020 - 04:10 PM

Hey Billions - One more time!

 

One of the things that makes this a fun hobby is that there is always something new. A new target, a new camera, a new processing technique, a new software, a new imaging site, a better mount, a higher magnification, a wider field. It is endless. That is why people who hang in there in the hobby for any length of time tend to buy and sell equipment. They are trying different things and learning in the process. Early on in AP you are mostly just hoping for decent focus and something you can see. (focusing for imaging is more challenging than visual) When it happens it is thrilling. But then your eye get more discerning of what you are producing. You realize the focus is a little soft or you're frustrated trying to focus with a Baktinov mask. It doesn't take long for the bug for an autofocuser to kick in.

 

Then you discover the miracle of plate solving! At least it seems that way to us old guys who never had it for the first 30 years. Click a button, it takes a pictures, syncs the mount and then slews to exactly the right position! Joy! You are up and running in no time! However, the next time out everything seems to fall apart. You can't sync the mount to anything. It's getting late and you are desperate to use the clear skies to capture something. Eventually you figure out that the software talking to your mount is telling it that your location is 0 long and 0 lat. when of course that is 5,000 miles from where you live. By the time you figure it out it's too late to do any imaging. GRRRR! This is the journey of learning astrophotography. It's fun, it's frustrating, but it isn't boring and there is always something new to learn or find.

 

Brad 


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#14 RogueZero

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Posted 05 July 2020 - 04:58 PM

I started AP back in April as my shutdown hobby and while I'm still a beginner my experience may be helpful: 

 

 

Started with an old DSLR (micro 4/3rds), a used 70mm triplet and a new AZ-EQ5 mount. Spent a couple of weeks taking 10s-30s images, just getting familiar with how to set up the rig, find targets in the sky and do basic processing in DeepSkyStacker. The final images were recognizable but poor.

 

Added a ZWO 30mm guide scope and ASI120MM guide camera plus an old laptop. Learned the basics of PHD2. This was a big step up in terms of consistency. Could now take 1m-2m images. Started doing additional processing in Photoshop. Final images were good enough to show but still pretty poor.

 

Replaced the DSLR with an ASI178MC. Big step up in terms of automation and easy of use. Could now use software such as SharpCap and later, Astrophotography Tool. Built a dark library and started including dark frames in DSS. Final images were more consistent and detailed, but more noisy.

 

 

^^^  This point is what I consider to be the minimum for reliable AP. 

 

 

Getting fed up with temperature matching the lights/bias/darks/flats I purchased a used cooled color camera with double the pixel size of the ASI178MC (2.4 vs 4.8) the ASI071MC-Pro, and a dual band nebula filter. Easily the largest single step up in capability to date. Could now fit the largest targets in the frame, emission nebula became not just viable but preferred targets and the effects of poor guiding and moon/city light pollution were reduced so much I could now image successfully on any cloudless night. And no more temperature related stacking issues or noise issues.

 

Actually, that's a lie. The single biggest improvement is the Automatic Background Extractor in PixInsight smile.gif. That blew my mind the first time I used it.

 

Doing it again I would skip the DSLR stage and get an ASI533MC-Pro plus a dual-band nebula filter (eg Optolong L-Enhance or L-Extreme). It has good sized pixels (3.75), temperature management and very low noise. Which will make everything easier.


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#15 bjulihn

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Posted 06 July 2020 - 12:58 AM

My list of big steps forward in AP over the last 18 months:

 

1) Discovering Sharpcap' polar alignment tools. Wow! Easy and accurate polar alignment in 10 minutes or less.

 

2) Plate Solving: Didn't even know what the term meant when I came back to astronomy after 10 years away. Perfect target finding without having to star hop.

 

3) Phd2 autoguiding. I tried autoguiding and some imaging 15-20 years ago. It was nothing like this!

 

4) Triad filter: (or L-enhance or other similar filters) Finally getting some contrast from my Bortle 7 location on nebula images. Fantastic!

 

5) PixInsight: Oh my goodness. The options available for taking raw data and bringing out details are staggering. The number of Youtube videos watched to try and learn it were also staggering!!!

 

6) Jon Rista's website on noise reduction in PixInsight. Jon's tutorials and explanations have made a massive difference in the quality of my image processing. Check it out if you want to learning how and why to apply noise reduction to your data.

    https://jonrista.com...de/pixinsights/

 

Brad


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#16 bobzeq25

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Posted 06 July 2020 - 02:39 PM

The single biggest improvement is the Automatic Background Extractor in PixInsight smile.gif. That blew my mind the first time I used it.

The gradient reduction tool in Astro Pixel Processor is very close.  I've used them both, sometimes APP has worked better, but that may be due to the fact that spending hundreds of hours on PI has not made me an expert.  <smile>
 




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