Fill in the gaps (help me spend my money) - OTA or something else?

[Shimrod]

I've received a recent gift of some FLO vouchers, and with the proceeds of some ebay sales I have £500-800ish to spend. I'm trying to decide what to buy. Current kits consists of:

• Celestron AVX
• Skywatcher AZ-GTI + wedge
• EdgeHD 8" + reducer
• Skywatcher 80ed (with Baader Steeltrak focuser) + reducer
• ZWO ASI533
• Eyepieces - mostly ES 4.5mm, 7mm, 14mm, 24mm, 40mm. The three middle ones are all 82 degrees.
• Various filters for visual and AP

I have to set up and tear down my kit for each session, so the AVX is a big as I want to go, and I am happy with the Edge and 80ed. The AZ GTI is a recent purchase so I have a truly portable set up to take further afield and on holiday. I've thought about a large dob, but I am not sure I would get the benefit in my light polluted skies, and my car is not suitable for transporting a large OTA.

I am only just getting started with imaging, and I find myself speinding a lot of time looking at the WO Zenithstar 61. I have been trying to use a Canon 300mm F4 lens with the ASI533, but I am finding for astro work the focuser is too coarse. The ZS61 would seem to be a good match for widefield, and from reading around it seems to be a good as a casual visual instrument as well.

I'm open to other suggestions for kit to consider, or whether given the above list you might suggest something else entirely.

[nfotis]

Another idea would be to enter the Ritchey-Cretien world, with imaging-focused reflectors?

https://www.firstlightoptics.com/telescopes-in-stock/stellalyra-6-f9-m-crf-ritchey-chrtien-telescope-ota.html

 

Focusing EF lenses doesn't have to be coarse. There's the Astromechanics adapter for this job:

https://www.firstlightoptics.com/adapters/astromechanics-ascom-aps-c-m42-to-canon-lens-controller-mark-ii.html

 

N.F.

 

[M40]

Interesting challenge 🤔

I must admit to being a fan of Baader eyepieces due to the flexibility of adapters enabling eyepiece projection. So how about a Baader Zoom and Barlow with an adapter allowing connection of your Canon?

Alternatively, binoviewers? or an ASI178? 

Good luck with your choices 

 

[Robindonne]

You have to take all of the list+1 extra item

[KP82]

What about guiding?

As far as I can see the OP has pretty much covered everything needed to begin imaging. 80ED is a good starting point to experiment with various techniques and gears. Guiding is a must if he wants to get serious with imaging (unless he plans to get one of those premium mounts with absolute encoders).

So I'd suggest he spends the money on a 50 - 60mm guidescope plus an ASI290MM (works better with an OAG than 120 if he images with the 8" SCT). The rest could be spent on some sort of remote control of the imaging rig (laptop, compute stick or pi).

[Astro Noodles]

Perhaps a plane ticket to somewhere dark at night.

[EntropyTango]

How about a quality EP between your 24 and 40mm

There are some great quality ultra wide angles around 30/31mm

[nephilim]

You seem to have answered your own question as the WO 61 has very good reviews.

You mention the Canon lens your not happy with, so I'll suggest another lens. The Samyang 135mm f2 (£445) This lens has fantastic reviews as one of the best affordable  lenses for AP. This forum has an entire continuous thread dedicated to it which is now running at 119 pages long, started in April 2019 & still going strong with regular updates even now. I'll link it at the bottom of this. 

There are also plenty of entries to it regarding the Samyang coupled with the ASI 533, all with glowing reports There's no extra information I can really add about this lens (or the results from combining it with the ASI 533) as it's all in the thread, and some. I have the Samyang 135 & the ASI 533 (Photos added below of my set up, minus cables as I'm in the middle of stream lining those) but these are recent purchases & I've yet to see first light, this is due to a mixture of the curse of new gear & also getting my head around everything as I've recently saved for & built my first full AP set up & I'm slowly figuring out how everything works 😂 . I will say that the feel & quality of the lens is superb & the focussing feels very smooth indeed.  I also bought a 3D printed dedicated mount/ holder from Wega Telescopes for the lens (£85)https://www.wega-telescopes.de/shop/Rohrschellen-passend-für-Samyang-135mm-F2-Objektiv-inkl-Sucherbasis-3D-Druck-p258368766 , it works very well with the lens, ASI 533 & my guiding set up

My only other suggestion has been mentioned above & that's a guiding set up. I personally use the Skywatcher EvoGuide 50ED & ASI 120mm-s as the guide camera, this combination was recommended by quite a few SGL members (the cost for both is approx £370) 

Here's the SGL Samyang link 

 

 

Edited May 30, 2021 by nephilim
Adding forgotten images

[Shimrod]

10 hours ago, KP82 said:

What about guiding?

As far as I can see the OP has pretty much covered everything needed to begin imaging. 80ED is a good starting point to experiment with various techniques and gears. Guiding is a must if he wants to get serious with imaging (unless he plans to get one of those premium mounts with absolute encoders).

So I'd suggest he spends the money on a 50 - 60mm guidescope plus an ASI290MM (works better with an OAG than 120 if he images with the 8" SCT). The rest could be spent on some sort of remote control of the imaging rig (laptop, compute stick or pi).

Guiding is one of things I have thought about. I already have a guidescope and a Celestron Nexguide I bought when I got back into astronomy in 2019. The original intention was to try and have something that did not require a laptop (so Nexguide, AVX and DSLR), but things have taken a different tack since then. The AZ-GTI does not have an ST4 port so I have thought about selling the nexguide to pay for an ASI120 or similar to use as a guide camera.

The ZS61 and ASI290 combined would still be in budget though!

[Shimrod]

6 hours ago, nephilim said:

You seem to have answered your own question as the WO 61 has very good reviews.

You mention the Canon lens your not happy with, so I'll suggest another lens. The Samyang 135mm f2 (£445) This lens has fantastic reviews as one of the best affordable  lenses for AP. This forum has an entire continuous thread dedicated to it which is now running at 119 pages long, started in April 2019 & still going strong with regular updates even now. I'll link it at the bottom of this. 

There are also plenty of entries to it regarding the Samyang coupled with the ASI 533, all with glowing reports There's no extra information I can really add about this lens (or the results from combining it with the ASI 533) as it's all in the thread, and some. I have the Samyang 135 & the ASI 533 (Photos added below of my set up, minus cables as I'm in the middle of stream lining those) but these are recent purchases & I've yet to see first light, this is due to a mixture of the curse of new gear & also getting my head around everything as I've recently saved for & built my first full AP set up & I'm slowly figuring out how everything works 😂 . I will say that the feel & quality of the lens is superb & the focussing feels very smooth indeed.  I also bought a 3D printed dedicated mount/ holder from Wega Telescopes for the lens (£85)https://www.wega-telescopes.de/shop/Rohrschellen-passend-für-Samyang-135mm-F2-Objektiv-inkl-Sucherbasis-3D-Druck-p258368766 , it works very well with the lens, ASI 533 & my guiding set up

My only other suggestion has been mentioned above & that's a guiding set up. I personally use the Skywatcher EvoGuide 50ED & ASI 120mm-s as the guide camera, this combination was recommended by quite a few SGL members (the cost for both is approx £370) 

Here's the SGL Samyang link 

 

 

Most of the funds are in the form of FLO vouchers,  so the Samyang is not an option. From a focal length perspective, it is quite close to my Canon 100mm F2.8L which is reportedly good for AP, although seems to be less commonly used. The astromechanics adapter (linked by @nfotis) for controlling aperture and focus looks interesting, and I will check compatibility across my other, wider lenses. That might be worth considering.

[Shimrod]

15 hours ago, nfotis said:

Another idea would be to enter the Ritchey-Cretien world, with imaging-focused reflectors?

https://www.firstlightoptics.com/telescopes-in-stock/stellalyra-6-f9-m-crf-ritchey-chrtien-telescope-ota.html

 

What are the advantages of this over the EdgeHD, which with the reducer has a similar focal length and is slightly faster than the linked telescope?

[Shimrod]

13 hours ago, M40 said:

Interesting challenge 🤔

I must admit to being a fan of Baader eyepieces due to the flexibility of adapters enabling eyepiece projection. So how about a Baader Zoom and Barlow with an adapter allowing connection of your Canon?

Alternatively, binoviewers? or an ASI178? 

Good luck with your choices 

 

I considered a zoom lens, but I think I will wait for some reviews of the APM 75 degree zoom. I have discovered with eyepieces that I have a preference for wide angle eyepieces and the current zooms get a bit narrower than I would like. I would like a zoom as part of my travel kit for simplicity - I've never had the opportunity to try one though, so maybe I should pick up one of the cheaper zooms first to try and sell it on if I don't get on with it.

[nfotis]

3 hours ago, Shimrod said:

What are the advantages of this over the EdgeHD, which with the reducer has a similar focal length and is slightly faster than the linked telescope?

 

It's all done with mirrors (and not smoke 🙂 ) .

The RC design is supposedly better for astrophotography , and you can add a 0.67 CDDT reducer for higher speed, as an intermediate between the Edge 8" (which can work nicely at its native focal length when hunting galaxies with the ASI533) - I am not sure that FLO offers it, though:

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p4955_Astro-Physics-0-67x-Focal-Reducer-for-astrophotography.html

The 6" RC would be nearly as fast as a refractor. Another extreme idea would be to buy the Hyperstar for the Edge 8", to get an ultra-fast astrophotography scope, at f/2, but it seems that FLO doesn't carry this 😞

The Astromechanics adapter is quite useful, I dare say, if you have alot of Canon EF lenses (I am tempted to order one, if I settle on a camera first). You may want to check their site (I think that you want the M42 version, which supports up to APS-C sensors like the IMX571 on the ASI2600):

https://www.astromechanics.org/ascom.html

N.F.

 

 

[nfotis]

(Another idea, go full hog and buy a RASA 8" 🙂 )

N.F.

 

[Shimrod]

2 hours ago, nfotis said:

(Another idea, go full hog and buy a RASA 8" 🙂 )

N.F.

 

A RASA is a little out of budget, but when buying the EdgeHD my thoughts were of getting the Hyperstar at some point in the future. At my current skill level for AP, that is a long way off, and from what I have read when that time comes, the RASA may be a more straightforward option.

[Shimrod]

21 hours ago, KP82 said:

What about guiding?

As far as I can see the OP has pretty much covered everything needed to begin imaging. 80ED is a good starting point to experiment with various techniques and gears. Guiding is a must if he wants to get serious with imaging (unless he plans to get one of those premium mounts with absolute encoders).

So I'd suggest he spends the money on a 50 - 60mm guidescope plus an ASI290MM (works better with an OAG than 120 if he images with the 8" SCT). The rest could be spent on some sort of remote control of the imaging rig (laptop, compute stick or pi).

Is there any difference between the USB2 and USB3 versions of the ASI290 if you are just using it for guiding?

[nfotis]

35 minutes ago, Shimrod said:

Is there any difference between the USB2 and USB3 versions of the ASI290 if you are just using it for guiding?

Guiding means rather infrequent exposures, not at all like in planetary imaging.

If you plan to use the ASI290 as a planetary camera too, USB3 is quite useful in order to keep high frame rates.

N.F.

 

[Shimrod]

I just thought I would provide an update on this thread - I've taken advantage of the ZWO sale at FLO to buy a guide camera along with the ZS61 and the WO 45 erecting diagonal for some casual terrestrial viewing. The Baader zoom also went in and out the basket a few times - I like the idea of the zoom to go with the ZS61 as part of a compact travel kit, but wasn't sure how well the two would go together although it would be a good fit for my other scopes.

 

Thanks for all the suggestions - it's taken me a while to come to a decision!

Edited July 17, 2021 by Shimrod