Upgrading towards an astrophotographic equipment - Forums

Topic starter

Oct 23, 2023

Well, after having understood I'm still quite a terrestrial photographer (which, to be fair, holds some truth), I'd have another (perhaps) beginner's question.
Currently, I'm taking photos with my ordinary DSLR and its zoom lenses, to which over time I've added a guiding and goto system that are doing their job well and giving me good results (StarAdventurer GTI + ASIAR Plus + ZWO ASI 290mini). Apart from very good shots of the Moon, considering all the limitations of a DSLR+zoom, I'm doing quite decently with deep-sky astrophotography.

Should I step-by-step upgrade to a more advanced gear specific for astrophotography, putting the budget question aside for a moment and focusing primarily on deep-sky astrophotography rather than planetary, what would be better to focus on first to get appreciable improvements: purchase an astronomical camera to use with my regular lenses and think about buying a telescope later, or go the other way around, that is buy a telescope to use with my modded DSLR and postpone the purchase of the astronomical camera to a later time? Which of these two paths would be the more sensible choice allowing to make progress beyond an ordinary DSLR+zoom equipment?
Should I refer to ordinary photo, it would be perfectly clear to me where to invest my money and the path, but I understand in astrophotography different concepts rule to improve results quality, depending on targets.
Consider both the limits of my gear and the learning curve in dealing with astronomic camera vs. telescope for someone coming from ordinary photography.
(Is it a totally nonsense question and, in case, why?)

andrea tasselli

Frequent contributor

Oct 23, 2023

Your first limitation is in the optics you're using as the camera, per se, isn't the thing really holding you back. With your (other) current equipment you are (much) better served by getting the best, largest telescope/prime lens you can mount of the GTi while reliabily tracking the target, potentially something like a 500mm f/4-f/4.5 lens or a 3.5"/4" "short" fast APO. If it is not a matter of "pecuniam" there are a number of potential items to chose from.

Joe Linington

Oct 23, 2023

Telescope then Mount or Mount then Telescope. The weak spots in your rig aren't the camera, yet. Although you have done very well with that zoom lens, a telescope would likely improve your imaging more than a new camera paired with zoom optics. But your mount is light weight and limiting, so that restricts you to small, refractor telescopes.

So, mount first or telescope first. I guess it depends on what size telescope you want.

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Eric Gagne

Oct 23, 2023

I am just a beginner myself so anyone can correct me if I say something stupid here but it seems that Carlo is using a stock DSLR. I would think the best improvement he could get right now is to have that camera modified for astro.

Joe Linington

Oct 23, 2023

Eric Gagne:
I am just a beginner myself so anyone can correct me if I say something stupid here but it seems that Carlo is using a stock DSLR. I would think the best improvement he could get right now is to have that camera modified for astro.

He says the camera is modded in the original post and his gallery would seem to confirm that it is.

Carlo Paschetto

Topic starter

Oct 23, 2023 · Edited: Oct 23, 2023

Joe Linington:
Eric Gagne:
I am just a beginner myself so anyone can correct me if I say something stupid here but it seems that Carlo is using a stock DSLR. I would think the best improvement he could get right now is to have that camera modified for astro.

He says the camera is modded in the original post and his gallery would seem to confirm that it is.

Yes, confirmed, camera modded in super UV-IR cut

Sean Mc

Oct 23, 2023 · Edited: Oct 23, 2023

Ok I’m going to give a different take on an answer… but first, I have a question!

DSO covers a wide range of target sizes. The question is, what EXACTLY do you want to photograph?

I took a long and expensive route to figure out what I wanted to photograph. For *ME*, a 500-600 focal length doesn’t work to frame targets with the camera I have (micro 4/3). I ended up going wider for my telescope to fit more targets in the fov. Then I found out that my original telescope didn’t give me enough zoom for other targets. It’s not easy to zoom with a telescope like it is with a 150-600. On the flip side, a telescope will potentially give you a much cleaner shot than a zoom lens with a teleconverter. Zoom lenses aren’t the best, and teleconverters typically make them worse.

Now you add the catch-22. The weight of a telescope. Better is generally heavier. Which needs a better mount. You might pick your focal length and find out that your current mount can’t handle the scope you want.

So yeah, maybe telescope first but it might not be that easy.

edit: if you want super wide field, maybe grab a samyang 135?

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Carlo Paschetto

Topic starter

Oct 23, 2023 · Edited: Oct 23, 2023

Sean Mc:
Ok I’m going to give a different take on an answer… but first, I have a question!

DSO covers a wide range of target sizes. The question is, what EXACTLY do you want to photograph?

I took a long and expensive route to figure out what I wanted to photograph. For *ME*, a 500-600 focal length doesn’t work to frame targets with the camera I have (micro 4/3). I ended up going wider for my telescope to fit more targets in the fov. Then I found out that my original telescope didn’t give me enough zoom for other targets. It’s not easy to zoom with a telescope like it is with a 150-600. On the flip side, a telescope will potentially give you a much cleaner shot than a zoom lens with a teleconverter. Zoom lenses aren’t the best, and teleconverters typically make them worse.

Now you add the catch-22. The weight of a telescope. Better is generally heavier. Which needs a better mount. You might pick your focal length and find out that your current mount can’t handle the scope you want.

So yeah, maybe telescope first but it might not be that easy.

edit: if you want super wide field, maybe grab a samyang 135?

Well, that's actually THE question. Generally speaking, based on my current experience, I would like to have a better chance with all those typical DSOs which, with my current gear, now I typically catch from 600mm to 1200mm. At 600mm I can get close enough to many beautiful nebulae with decent result shooting at maximum f/6.3 aperture, but I would like to get a much better quality. Extending 1.4x, or 2x it gets an extreme pain, as I shoot at f/13 and quality of the lens decreases drastically, and I would like to gain a significant improve (ex. Tulip, Trifid, Eagle, Bubble, Helix, Thor's Helmet, etc, and typical galaxies as well like M33, M51, M10, M106).

Truth is that in some way I would like to keep the versatility I now have in framing and FOV: reading around, I presume I could orient myself towards a new set up based, for example, on something like a SkyWatcher N150/600 + Mount HEQ-5 Pro, and a pair of Barlow lenses to have two or three different options for magnification (choosing SkyWatcher would also allow me to remain in the comfort zone of my current experience, at least in terms of the mount logic).
A set up like this, if I have understood something, would give me more and less the same FOVs "portfolio" I have now, but with a f/4 aperture at 600mm and much better optical performance as e general perspective. I'm just exploring to understand.
(Don't know if, for example, with such a set up I could also get a real improvement in shooting at the Moon, so as to imagine a more extended use).

tjm8874

Oct 23, 2023

I saw Carlo's gallery and I think you are reaching on equipment limit,

His recent Veil Nebula and cropped area
https://astrob.in/5ezwf0/0/

My Veil Nebula, same area close up. more detail and faint areas showing up
https://astrob.in/1qlz4c/0/

What I recommend
(1) Telescope, with very high resolution. I can recommend Askar 80PHQx0.76 (455mm f/5.7) and FRA300 Pro (300mm f/5)
300mm + APS-C = FOV for whole Veil Nebula. 455mm + APS-C = FOV for whole M31.
(2) High sensitivity Monochrome Camera. ASI2600MM Pro + Antlia 36mm SHO LRGB filters
(3) If possible, ZWO AM5 mount. very stable and accurate, easy to setup.

You can keep DLSR and mount for wide field.
(4) Sigma Art lenses (105mm, 40mm)

(5) for small DSO and galaxy, Askar 130PHQ (1000mm and 700mm) can work on AM5 + counterweight.
(6) ?? if you add ASI2400MC full frame high sensitivity color camera, it can support ASI2600MM with x1.5 focal length scope.

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Sean Mc

Oct 23, 2023

The problem is that adding a barlow to a telescope degrades the telescope much the same way your zoom lens and telextener does. It’s best to pick a focal length that will work with a future astro cam that you’re going to buy (apsc 2600 for example)

The only telescope I can think of that will get you wide, medium far and far is an sct. But then you’re going to need an expensive mount, and expensive filters if you do f/2 widefield.

A newt will need a coma corrector. I don’t imagine that will work well with a barlow, and I’m thinking you’ll need a better mount for a newt ¯\_(ツ)_/¯

Claudio Parisi

Oct 23, 2023

To answer the first, simple question. The path I went a decade ago is the same I would recommend today (unless… See the end): first telescope then camera. Especially considering your DSLR is modded.

Going into a bit more detail, I made what I consider a couple of mistakes, that you can likely avoid.

The first is to consider the mount. The GTI is a good mount focused on portability, great with small refractors such as Redcat or FRA300. Definitely not good for the focal lengths you have in mind at 600mm or more.
You are considering an HEQ5. That is a solid one, maybe a bit bulky and with a limited but decent upgrade path. I had one myself. Loved it.

Newtonian, that's fine (i.e. not the second mistake). That's how I started and learned a lot of things the I wouldn't have otherwise known. But… Consider that depending on where you are when you take pictures, you might have to deal with light leaks, then you will need a coma corrector to have a flat field, and some collimation tool.
All of those add to the final cost. What about a good refractor instead? Just consider the option.

The second mistake was to really think that my DSLR (non modded, I recon) once paired with a good telescope would have satisfied me.
The improvement, both in pictures' quality and in usability, that I got with a cooled camera I wouldn't change it for the world.
Am I suggesting the other way around? Nope. But if I could go back I would opt for an all-at-once upgrade. Might be less of a problem for you since your DSLR is modded, still your are loosing on the advantage that cooling gives to both noise management and ease of use with dark frames.

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andrea tasselli

Frequent contributor

Oct 23, 2023

Sean Mc:
The problem is that adding a barlow to a telescope degrades the telescope much the same way your zoom lens and telextener does. It’s best to pick a focal length that will work with a future astro cam that you’re going to buy (apsc 2600 for example)

That's a myth which I thought has been long laid to rest. Barlows most definitely DO NOT decrease optical quality and have nothing to do with modern zoom lens. There are coma-correcting barlows that work well with APS-C sized sensor so that is another myth laid to rest.

Carlo Paschetto

Topic starter

Oct 23, 2023

Claudio Parisi:
To answer the first, simple question. The path I went a decade ago is the same I would recommend today (unless... See the end): first telescope then camera. Especially considering your DSLR is modded.

Grazie Claudio, very interesting experience. The main reason I'm considering a step-by-step approach is budget in any case, let's say around 2000-2200€ (well, I wrote "let's the budget question aside", but I have to keep an eye on it anyway!

). To go for a all-at-once solution I would have to stay on very low priced, or second-hand components, probably finding myself wanting to do a further upgrade on the short-medium term.
Given that after three years I now know that this is not just a passing whim, as my usual purchasing strategy (not only for astrophotography) I prefer to spend a little more for each component buying one piece at a time, thus investing more in quality and on the longer term. According to what I understand you all recommend, first mount+telescope, then the camera later, so this could actually be the path.
I started to take a look at some online stores, e.g. astroshop. So far, within the price range I have in mind, it seems that Newtonians have a better price/aperture/resolution ratio than refractors, this is the only reason so far, but of course I don't exclude any solution a priori.

Carlo Paschetto

Topic starter

Oct 23, 2023

andrea tasselli:
Sean Mc:
The problem is that adding a barlow to a telescope degrades the telescope much the same way your zoom lens and telextener does. It’s best to pick a focal length that will work with a future astro cam that you’re going to buy (apsc 2600 for example)

That's a myth which I thought has been long laid to rest. Barlows most definitely DO NOT decrease optical quality and have nothing to do with modern zoom lens. There are coma-correcting barlows that work well with APS-C sized sensor so that is another myth laid to rest.

Grazie Andrea you too, this could actually be another key point to consider when talking about versatility. As a first thought, I would have honestly taken into account that using Barlow lenses could lead to some loss of quality, but it must be said that I'm comparing with a 150-600mm ordinary cheap photo lens multiplied 2x which really loses drastically quality.

Sean Mc

Oct 23, 2023

andrea tasselli:
Sean Mc:
The problem is that adding a barlow to a telescope degrades the telescope much the same way your zoom lens and telextener does. It’s best to pick a focal length that will work with a future astro cam that you’re going to buy (apsc 2600 for example)

That's a myth which I thought has been long laid to rest. Barlows most definitely DO NOT decrease optical quality and have nothing to do with modern zoom lens. There are coma-correcting barlows that work well with APS-C sized sensor so that is another myth laid to rest.

Availability might be an issue. I can only seem to find 1.25” coma correcting barlows.

Well Written

andrea tasselli

Frequent contributor

Oct 23, 2023

Sean Mc:
Availability might be an issue. I can only seem to find 1.25” coma correcting barlows.

The APM coma-correcting 2.7x barlow is indeed 1.25" but it full illuminates the APS-C sensor. There is also a 2" 1.5x but it is pricey.

Sean Mc

Oct 23, 2023

Wow. That’s impressive. I would not have expected that.

Joe Linington

Oct 24, 2023

andrea tasselli:
Sean Mc:
Availability might be an issue. I can only seem to find 1.25” coma correcting barlows.

The APM coma-correcting 2.7x barlow is indeed 1.25" but it full illuminates the APS-C sensor. There is also a 2" 1.5x but it is pricey.

That is interesting. I am surprised a 1.25" anything could illuminate an APSC sensor.

Carlo, I would look into an 8" (200mm) f/5 newt and an EQ6r or similar. You would have to purchase some correctors but with a standard coma corrector you would get 1000mm F/L and with the Starizona 0.75 corrector you would get 750mm at slightly faster than f/4. You could do the same with a 10" (250mm) f/4 scope but, it is heavier, needing a larger mount, and it would be at f/3 using the 0.75 reducer and then need expensive, specialized filters.

I think this is the cheapest road to 1000mm F/L but you should expect some bumps along they way. You will have to learn collimation and buy the tools. There is also a high chance of light leaks you would have to solve. But the end result should be quite good.

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Arun H

Frequent contributor

Oct 24, 2023

Joe Linington:
That is interesting. I am surprised a 1.25" anything could illuminate an APSC senso

I also would like to understand how this is possible. The diameter of an APS-C sensor is 28.4mm (Nikon DX) which is only marginally smaller than 1.25" (about 31.75 mm). I suppose it is possible, but the light rays coming out would have be almost parallel, which means slow effective optics.

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andrea tasselli

Frequent contributor

Oct 24, 2023

Arun H:
I also would like to understand how this is possible. The diameter of an APS-C sensor is 28.4mm (Nikon DX) which is only marginally smaller than 1.25" (about 31.75 mm). I suppose it is possible, but the light rays coming out would have be almost parallel, which means slow effective optics.

At 105mm distance between flange and sensor there is plenty of scope to diverge the beam to cover the required field, if I understand it right. Obviously is a much slower optcal assembly you have here, at a minimum (using a f/4 newt) ~f/11.

Arun H

Frequent contributor

Oct 24, 2023

andrea tasselli:
At 105mm distance between flange and sensor there is plenty of scope to diverge the beam to cover the required field, if I understand it right. Obviously is a much slower optcal assembly you have here, at a minimum (using a f/4 newt) ~f/11.

Hi Andrea, I don't believe this is correct. A basic marginal ray calculation shows that the diameter of the light cone would have to be 9.5mm larger than the sensor diagonal to avoid vignetting for an f/11 system at a distance of 105mm from the sensor. Obviously, a 31.75mm barlow would not satisfy this requirement to fully illuminate APS-C.

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andrea tasselli

Frequent contributor

Oct 24, 2023

Arun H:
Hi Andrea, I don't believe this is correct. A basic marginal ray calculation shows that the diameter of the light cone would have to be 9.5mm larger than the sensor diagonal to avoid vignetting for an f/11 system at a distance of 105mm from the sensor. Obviously, a 31.75mm barlow would not satisfy this requirement to fully illuminate APS-C.

APM Telescopes. APM Comacorrecting 1 1/4" ED Barlow 2.7 x (apm-telescopes.net)

Arun H

Frequent contributor

Oct 24, 2023

andrea tasselli:
APM Telescopes. APM Comacorrecting 1 1/4" ED Barlow 2.7 x (apm-telescopes.net)

Thanks, that diagram helps. The barlow has a diverging lens.

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Carlo Paschetto

Topic starter

Oct 25, 2023

Joe Linington:
andrea tasselli:
Sean Mc:
Availability might be an issue. I can only seem to find 1.25” coma correcting barlows.

The APM coma-correcting 2.7x barlow is indeed 1.25" but it full illuminates the APS-C sensor. There is also a 2" 1.5x but it is pricey.

That is interesting. I am surprised a 1.25" anything could illuminate an APSC sensor.

Carlo, I would look into an 8" (200mm) f/5 newt and an EQ6r or similar. You would have to purchase some correctors but with a standard coma corrector you would get 1000mm F/L and with the Starizona 0.75 corrector you would get 750mm at slightly faster than f/4. You could do the same with a 10" (250mm) f/4 scope but, it is heavier, needing a larger mount, and it would be at f/3 using the 0.75 reducer and then need expensive, specialized filters.

I think this is the cheapest road to 1000mm F/L but you should expect some bumps along they way. You will have to learn collimation and buy the tools. There is also a high chance of light leaks you would have to solve. But the end result should be quite good.

Thank you @Joe Linington , actually my first concern upgrading to a newt is to deal with collimation and maintenance issues, as I read around they are more sensible than refractor to dust, wind, displacements, light impacts, etc, but I suppose it might be worth it just to gain in terms of luminosity.