Stuck on Next Steps for My Astrophotography Setup – Need Input! Generic equipment discussions · akshay87kumar · ... · 22 · 837 · 3

This topic contains a poll.
What upgrade would you choose in the given context? Please do suggest your reasons!
Option 1: Invest in SO and broadband Filters
Option 2: Switch to a Mono Camera with filter set
Option 3: Higher Focal Length Telescope - Newtonian 8" f/5
Option 4: Higher Focal Length Telescope - Cassegrain 8" f/12
Option 5: Other
akshay87kumar 3.01
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Hi everyone, I’m looking to upgrade my astrophotography setup, but I’m torn between several options and would love to get your expert opinions!
PS: I dont intend to turn this into a yet-another OSC vs mono debate Just a recommendation on options, along with any anecdotes that the experts may provide 

Current Setup
  • Telescope: William Optics 71GT APO with a 0.8x focal reducer
  • Camera: ASI 294MC Pro OSC
  • Mount: iOptron CEM40
  • Accessories: Optolong L-eXtreme filter, ASI EAF, ASIAIR, 2" filter wheel, and a WO 50mm f/4 guidescope with ASI 120MM for guiding

I live in Bortle 8-9 skies, which has limited me to narrowband imaging for bright targets like Orion, Heart, Rosette, and Horsehead Nebulae (images in my profile). My guiding performance ranges from 0.5-0.7" RMS on good nights to 0.7-0.9" on poor nights. With my current 335mm focal length, I can manage 5-minute guided exposures (passeable if not peeping into pixels, and corrected well with BlurXTerminator). However, 10-minute exposures sstart to show trails, even though some can be corrected.Broadband ExperimentsRecently, I attempted broadband imaging (2-hour integrations) with mixed results:
  • M101 (Pinwheel Galaxy): Some galaxy detail was visible.
  • Seagull Nebula: Completely washed out compared to L-extreme; only stars visible.

Given the challenges of imaging under heavy light pollution, I’m unsure whether to continue down the broadband path or stick with narrowband imaging for now.

Upgrade Options I’m Considering

Option 1: Invest in SO and broadband Filters
  • Add a dual-band SO narrowband filter for capturing SHO data.
  • Add a broadband light pollution filter for galaxies and RGB star capture.

Option 2: Switch to a Mono Camera with filter set
  • Upgrade to a mono camera with an RGB+SHO filter set for higher-quality imaging.
  • This would significantly stretch my budget but could improve flexibility and image quality.

Option 3: Higher Focal Length Telescope
  • Newtonians (f/5): GSO or Sky-Watcher 6-8" models f/5 (~750-1000mm focal length).
  • Cassegrains (f/12): GSO 6-8" models (1800-2400mm focal length). Could use a reducer (~f/6) for DSOs and barlows for lunar/planetary imaging.
  • While I’ve only used refractors, I’m concerned about collimation challenges with Newtonians (f/4) or Ritchey-Chrétiens.
  • But what is the point of higher focal lengths if I cannot do galaxies or f/6 happens to be very slow. I currently do about f/5 (with reducer) and it occasionally seems slow to me!
  • Unfortunately, RASAs and Celestron EDGEs are out of my budget.


Alternatives I am exploring:
  • Broadband vs. Narrowband: Should I focus on narrowband targets under my light-polluted skies, or is broadband imaging of galaxies/planetary nebulae worth pursuing?
  • Mono vs. OSC: Is switching to a mono camera worth the added complexity and cost? Do RGB filters work well as light pollution filters for broadband imaging?
  • Telescope Upgrade: Is the "dual-purpose" potential of a Cassegrain (lunar/planetary + DSOs) realistic, or would a Newtonian be a better step forward for DSOs?


Images for Reference (Only STF applied after WBPP)
Here are some to demonstrate what I am able to get in my skies:
  1. Seagull Nebula (No filters used with OSC) - 30s subs, 1 hr integration
  2. Pinwheel Galaxy (No filters used with OSC) - 30s subs, 1 hr integration
  3. Seagull Nebula (L-extreme) - 5 min subs, 7 hr integration

Looking forward to hearing your thoughts and advice! Thanks in advance for helping me navigate this decision.
Screenshot 2025-01-26 175117.jpg
Screenshot 2025-01-26 180103.jpg
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akshay87kumar 3.01
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Adding a screenshot of gradient corrected images for comparing Seagull Nebula, and what to expect out of galaxy (a mess!). Just Graxpert applied after WBPP, no other changes. I have experience mostly with Narrowband imaging, so quite possible the flats are an issue when I created them for RGB (no filters ) - They were only 0.0015ms exposure. I have only these 2 hour of experience on broadband targets.

First two images on top are without filters
Bottom single image is with L-extreme filterScreenshot 2025-01-26 182947.jpg
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sgthebert 2.81
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I'm still a newbie, so take what I say with a grain of salt, but newt collimation hasn't been much of an issue over the past year and a half for me and I'm imaging at (with reducer) f/3.54. I only have to check it once or twice a year and it's usually close if it moved at all.

One more thing to keep on mind if you get a new scope, will your current mount handle it?

With your amount of light pollution, I'd stick to narrow band.

Lastly, for the light pollution filter, it may not cut down on much depending of what's the source of the pollution. White LEDs for example will always go through.
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wesdon1 0.00
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Hi. In a Bortle8-9 I would suggest ( based on being told this by others for years and personal experience! ) you stick with NB. Broadband in 8-9 Bortle is incredibly difficult. Secondly, and this matters more than anything else…invest as much time as possible into post processing. A great post processed image using rubbish data will nearly always look better than great data post processed rubbishly! 

As a side note, you can always save up more money in the medium/long term and just buy that Newtonian, more filters, basically add to your existing gear over time, then you won't have to make difficult choices anymore my friend. I've been slowly building up my gear over 6 years and I'm STILL buying new gear!! LOL.

Clear Skies from Wes, Liverpool, England.
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akshay87kumar 3.01
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Médéric Hébert:
I'm imaging at (with reducer) f/3.54. I only have to check it once or twice a year and it's usually close if it moved at all.

Agreed, I am not as much concerned with Newtonian collimation as RC telescopes. I have seen videos, I think I should be able to do it. Just that some people have called out that collimating F/4 happens to be difficult. I am tempted to go F/4 for the faster scope, but want to stay away from issues that will demotivate the hobby. It depends how big of an issue it really is.
Médéric Hébert:
White LEDs for example will always go through.

True, and that is what the city is switching all over to. I have read some newer IDAS filters can cut down white LEDs to some extent, but IDAS dont sell in my location.
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akshay87kumar 3.01
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Wesley Robert Donnelly:
just buy that Newtonian, more filters, basically add to your existing gear over time

That is where I am most inclined towards. Just read about the cassegrains, how they can be F/12 at 2400mm focal lengths and you could use reducers to get them to F/6 at 1200mm. This got me tempted, but fiddling with the optical train with the reducer will certainly be something to keep in mind. F/6 is poorer than a F/5 Newtonian at 1000mm and if the planetary imaging at 2400mm isnt a great reach, then the F/6 also ends up with a compromise - both on planetary imaging as well as on DSO. Hence want to really hear it out from people who may have used it.
If it is a scope, I will get a dedicated astro-cam and set of filter/wheels (later over time, hopefully!) to avoid fiddling with the optical train every time. Ofcourse, there isnt a spare mount to keep both of them going through the night - that is where there is always limited finances to manage! Currently I have a iOptron CEM40 (18kg maximum load as per specs), I hope it will handle a 8kg Newtonian OTA with accessories.
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sgthebert 2.81
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An 8kg newt shouldn't be too bad.

Something to consider: if you're gonna go with F/12 + reducer for F/6, why not got F/5 with a good barlow for F/10.
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Ricksastro 1.51
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I love my Skywatcher Quattro 10".  For your mount, the 8" should be OK and get you reasonable 1.1"/pixel which is good for average seeing.    I've not found collimation to be that challenging at all, and I also just bought a Nexus 0.75x coma corrector/reducer at f3 and didn't have to fuss with collimation at all for my first light several days ago (https://www.astrobin.com/wd3bxa/C/).  That was about the same pixel scale (>1"/pixel) and my guiding was just horrible (>1" rms) due to wind and horrible seeing. 
If it's windy where you are, a warning that larger newts will act as sails and guiding will suffer.  I usually check collimation if I bump it a lot, but it's usually good for months.  

Bortle 8-9 does mean narrowband for the most part or planetary.

Going mono will get you better spatial resolution, but that's a large investment from where you are.
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andreatax 9.89
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A good 8" f/4 newt is the way to go but I can't recommend the cheap ones in light of their poor mechanical features, notably their primary cell design/construction.
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akshay87kumar 3.01
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andrea tasselli:
A good 8" f/4 newt is the way to go but I can't recommend the cheap ones in light of their poor mechanical features, notably their primary cell design/construction.

Two follow-up questions please:
1. Is collimation of f/4 a big issue (compared to f/5) and how does it hold.
2. Any recommendations on good newtonians? What do you think about Sky-watcher tubes?
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WhooptieDo 10.40
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In your light pollution, upgrading to mono is a no brainer.   Spend the money and get yourself a set of 3nm filters.     Charles Hagen demonstrated just how effective this upgrade can be by imaging Veil from his Denver bortle 9 backyard.    See https://app.astrobin.com/u/jimmythechicken?i=h02ks4#gallery

Your efficiency is already extremely low in bortle 8 with OSC, a good mono camera like a 533/571 + 3nm filters will take you much farther and you'll wonder why the hell you listened to all the folks telling you OSC is fine.
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Rustyd100 5.76
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I’ve run a 925 on a CEM40 for 3 years now with terrific results. 

my traveler is the GT 71 on HAE29 and carbon fiber sticks. 

The entire 925 rig weighs 90lbs

The entire traveler rig weighs 25lbs, as you may know. 

This matters if the 925 is not in a permanent location. 

I love the 925!  I can’t imagine recommending a telescope more highly. It’s in a good sweet spot at 2350mm. You’ll get lots of utility out of it. But its rewards are diminished if you have to take it anywhere other than the end of the driveway.
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andreatax 9.89
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Two follow-up questions please:
1. Is collimation of f/4 a big issue (compared to f/5) and how does it hold.
2. Any recommendations on good newtonians? What do you think about Sky-watcher tubes?


1. Not really. Tools are the same, procedure is the same. Granted, your margins are tighter.
2. Good newtonians are harder to find than one might expects, as it turns out. SW have good optics but somewhat lacking in the mechanics side so think about upgrading stuff right off the bat. Potentially secondary holder/spider, focuser and primary cell would need to be upgraded. Luckily most stuff can be found on AliExpress and quite cheap. A quality newtonian is something like this:

Apertura CarbonStar 150 Imaging Newtonian | Free Shipping
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RideTheLiger 0.90
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Your biggest problem is light pollution, so Narrowband and lot of integration time…
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wesdon1 0.00
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Dave Rust:
I’ve run a 925 on a CEM40 for 3 years now with terrific results. 

my traveler is the GT 71 on HAE29 and carbon fiber sticks. 

The entire 925 rig weighs 90lbs

The entire traveler rig weighs 25lbs, as you may know. 

This matters if the 925 is not in a permanent location. 

I love the 925!  I can’t imagine recommending a telescope more highly. It’s in a good sweet spot at 2350mm. You’ll get lots of utility out of it. But its rewards are diminished if you have to take it anywhere other than the end of the driveway.

Hey Dave! I recently purchased a 9.25" SCT and I was actually surprised how SMALL and LIGHWEIGHT it was compared to what I imagined it would be?? Isn't it strange how we can experience the exact same equipment so differently?? That anomaly aside, I have mounted the 9.25" on my SW HEQ5 Pro mount and the guiding is 0.8-1.1 which I find absolutely fine for me personally. It's a fantastic 'scope and definitely a keeper for sure!

Clear Skies from Wes, Liverpool, England.
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JamesR 6.35
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For narrowband, shooting mono is superior, so if you will be shooting mostly from a bortle 8.  If I were in your shoes.. I would go mono..   In fact, I was in your shoes.. my first astronomy camera was a mono.  Then I moved to a darker location.
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RemcoNL 1.43
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Hi @akshay87kumar ,
I think the advise above is excellent.

If you want to invest time instead of money, I would investigate the limitations of your sub-length. I don't own a CEM40 but it's payload capacity is a lot higher than my HEQ5pro,  and your RMS is a lot better than mine to. Yet with my wide-field setup I can easily get longer subtimes. (I go to 1200 seconds for my L! EXtreme filter)

You might not need that long of exposuretimes, but as soon as you add a bigger scope to your set, the performance will drop a bit. (I went back from 1200 to 300 seconds when I added my RC) And I with narrowband I think you'd like to be able to atleadt keep the 300seconds you do now.

So have you looked into that? Is your area particularly windy? Is the setup balanced well enough? I'd definitely ask CEM40 users to see what's realistic and if they have suggestions.
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RemcoNL 1.43
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So have you looked into that? Is your area particularly windy? Is the setup balanced well enough? I'd definitely ask CEM40 users to see what's realistic and if they have suggestions.


I forgot to add Periodic Error Correction (PEC)  to that list to investigate.
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AstraPharma 7.43
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Hot take!!

Invest in some camping gear and a portable power station and get out there every once in a while.

Nothing improved my astrophotography more than finally giving up on the City in favour of darker skies!!

good luck regardless of what you choose,

CS!
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MaxFork 0.90
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If your main issue is light pollution, and you are looking at one major upgrade, a different scope is irrelevant of course.  Narrowband filters are the best solution.

You have a high quality 294MC camera - fine pixel size that probably is an excellent fit with your APO.  Now the choice becomes whether:

1) a decent set of SO and HO filters with your OSC camera (perpaps add an electronic filter wheel)-
it's the simplest upgrade, and if you choose wrongly and later opt for mono, you're only out of the cost of the filter (sounds like you already have HO?).
2) mono camera with L R G B (when you go to dark skies) and S H O. 

If you are critical about color mapping your S H and O channels from the OSC, there's a lot of postprocessing (so I hear, I haven't touched that yet with my OSC setup) to account for color channel cross-talk (H and S showing up on your green and blue O data, for example). But if you get enjoyment out of the result of  your efforts, even though it may not be technically correct, you will enjoy the OSC option.

I'll let the more experienced get into the fine points of postprocessing NB OSC vs mono
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akp88 2.11
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For me, under these circumstances the biggest issue would be light pollution. Instead of getting a large focal length scope, i would go mono route with good filters. 
with your current FL of 335mm paired with a mono (say 533mm pro) you can capture lot of nebula targets which good details. Staying the same FL you can do 5mins exposures.

you can later on go for the larger FL telescope and use the mono + narrow filter setup.
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CosmicCoder 0.00
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With the light pollution you are forced to deal with going to anything over F/6 will cause you more stress. I shoot at  F/10 in Bortle 5 and deal with light polluted images. 

Have you looked into moving your scope to a remote observatory?  $30 a month in Bortle 1 skies has me thinking.
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akp88 2.11
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=16px  $30 a month in Bortle 1 skies has me thinking.


which remote Observatory is this? 30 a month?
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