OTA Recommendation purely for AP?

[Quetzalcoatl72]

23 minutes ago, vlaiv said:

Ok, that now makes much more sense.

Your worst enemy is LP - you live in very high LP area - SQM around 18.5.

I know how that feels - as I also live in SQM 18.5 zone.

Fact of life is that you'll need a lot of exposure time. I mean a lot.

This is two hours with 80mm scope and cooled dedicated astro camera. With additional 1.5h, and some careful processing - I believe you would match or even surpass this result with your setup.

In order to get really good image - we would need to image, say 8h, or even more in SQM18.5

 

That looks right actually can notice similarities, 8 hours though, a clear night of 8 hours? What are the chances of that happening without interruptions? So what would I expect from nebula? Orion is easy any LP can image that because it's so large. Horses head, rosette, veil and other wispy gas is what I'd like to see. I tried to image the Pleiades and I've seen people get spectacular blue gas around the stars, which has never showed up n my camera. That is basically my goal in the long run to capture something like that. I do have an expensive optolong LP filter that I haven't used yet till I get my adaptor, I'm hoping that would help, was recommended from 345 astro site. In regards to making a choice for a new scope since I'm used to a SCT and the c925 having a large aperture I've seen people get reducers to take it down to a f6.3.

Edited March 15, 2021 by Quetzalcoatl72

[vlaiv]

1 minute ago, Quetzalcoatl72 said:

That looks right actually can notice similarities, 8 hours though, a clear night of 8 hours? What are the chances of that happening without interruptions? So what would I expect from nebula? Orion is easy any LP can image that because it's so large, horses head, rosette, veil and other wispy gas. I tried to image the Pleiades and I've seen people get spectacular blue gas around the stars, which has never showed up n my camera. That is basically my goal in the long run to capture something like that. I do have an expensive optolong LP filter that I haven't used yet till I get my adaptor, I'm hoping that would help, was recommended from 345 astro site. In regards to making a choice for a new scope since I'm used to a SCT and the c925 having a large aperture I've seen people get reducers to take it down to a f6.3.

8h does not happen in one night - you need multiple nights to get that much data. Yes, I know - that is a problem, but that is a cost of light pollution.

If you want to image emission type nebulae like Rosette, Veil or HH - use UHC type filter. It blocks most of the light pollution and passes light from these targets. Problem is that you won't be able to get proper star color with such filter. You can either shoot separate images just for star color and do some gymnastics in PS to blend that in or settle for strange color stars.

Do try LP filter - I've used Hutech IPS P2 and it helps quite a bit. With LED lighting - LPS filters are not as efficient.

SCT-s are not good imaging scopes, even reduced. Internal focusing is a problem even with focus lock. OAG is solution for that. But you really want EdgeHD instead of regular SCT if you want to do DSO AP.

Maybe take a look at this scope:

https://www.firstlightoptics.com/stellalyra-telescopes/stellalyra-8-f8-m-lrs-ritchey-chrtien-telescope-ota.html

You'll need a focuser upgrade if you are sensitive to focuser quality. I replaced focuser on mine with:

https://www.firstlightoptics.com/ts-focusers/ts-25-rack-and-pinion-focuser-m90.html

You can use this to reduce scope to F/6:

https://www.firstlightoptics.com/reducersflatteners/astro-essentials-075x-reducer-for-stellalyra-gso-ritchey-chretien-ota.html

 

 

[Quetzalcoatl72]

18 minutes ago, vlaiv said:

8h does not happen in one night - you need multiple nights to get that much data. Yes, I know - that is a problem, but that is a cost of light pollution.

If you want to image emission type nebulae like Rosette, Veil or HH - use UHC type filter. It blocks most of the light pollution and passes light from these targets. Problem is that you won't be able to get proper star color with such filter. You can either shoot separate images just for star color and do some gymnastics in PS to blend that in or settle for strange color stars.

Do try LP filter - I've used Hutech IPS P2 and it helps quite a bit. With LED lighting - LPS filters are not as efficient.

SCT-s are not good imaging scopes, even reduced. Internal focusing is a problem even with focus lock. OAG is solution for that. But you really want EdgeHD instead of regular SCT if you want to do DSO AP.

Maybe take a look at this scope:

https://www.firstlightoptics.com/stellalyra-telescopes/stellalyra-8-f8-m-lrs-ritchey-chrtien-telescope-ota.html

You'll need a focuser upgrade if you are sensitive to focuser quality. I replaced focuser on mine with:

https://www.firstlightoptics.com/ts-focusers/ts-25-rack-and-pinion-focuser-m90.html

You can use this to reduce scope to F/6:

https://www.firstlightoptics.com/reducersflatteners/astro-essentials-075x-reducer-for-stellalyra-gso-ritchey-chretien-ota.html

 

 

That scope looks really sturdy, and as for the focuser that should be ok because a typical newt has it on the side which I'm guessing is mainly why they need to be replaced with a sturdier one. I probably wont mind the diffraction spikes because it gives it a sparkly Christmassy feel to it :D. It does say it's primarily a lunar planetary scope, but I need big pixels? will the 600d be ok in that regard?

[vlaiv]

8 minutes ago, Quetzalcoatl72 said:

That scope looks really sturdy, and as for the focuser that should be ok because a typical newt has it on the side which I'm guessing is mainly why they need to be replaced with a sturdier one. I probably wont mind the diffraction spikes because it gives it a sparkly Christmassy feel to it :D. It does say it's primarily a lunar planetary scope, but I need big pixels? will the 600d be ok in that regard?

I replaced focuser on mine because stock focuser does not come with threaded connection and I had issues with tilt with all of my accessories. I think that threaded connection is a big plus for imaging rig.

I'm not sure where you read that it is primarily lunar scope - that must be CC (Classical Cassegrain) - or this one:

https://www.firstlightoptics.com/stellalyra-telescopes/stellalyra-8-f12-m-lrs-classical-cassegrain-telescope-ota.html

These are different scopes - first one that I linked is F/8 RC type scope. Second one, is F/12 CC type scope.

First one is better at DSO astrophotography, while latter is better suited to planetary / lunar imaging although it can work as DSO imaging scope - but with smaller field of view.

Do pay attention to exact model as the very much look alike and have the same price.

600D has 4.3µm pixel size and if you get that x0.75 Reducer, or maybe this one:

https://www.teleskop-express.de/shop/product_info.php/info/p8932_TS-Optics-Optics-2--CCD-Reducer-0-67x-for-RC---flatfield-telescopes-ab-F-8.html

for that one you can use with 61mm distance instead of 85mm to get x0.75 reduction. I don't recommend that you go with x0.67 reduction for APS-C sensor as you'll get strong astigmatism in corners. In either case

you'll get 1.45"/px if you use superpixel debayering - which I would recommend. That is very decent all around sampling rate. Close enough for small objects and with enough FOV to capture larger things. Some things may need mosaics.

In the end, I need to warn you about collimation of this scope. You mentioned that you don't like collimation - well this one has tricky collimation. I did not find it particularly demanding but people have struggled with it. Some seriously enough that they ended up letting go of the scope.

Here is some light read on that subject:

 

 

[Quetzalcoatl72]

18 minutes ago, vlaiv said:

I replaced focuser on mine because stock focuser does not come with threaded connection and I had issues with tilt with all of my accessories. I think that threaded connection is a big plus for imaging rig.

I'm not sure where you read that it is primarily lunar scope - that must be CC (Classical Cassegrain) - or this one:

https://www.firstlightoptics.com/stellalyra-telescopes/stellalyra-8-f12-m-lrs-classical-cassegrain-telescope-ota.html

These are different scopes - first one that I linked is F/8 RC type scope. Second one, is F/12 CC type scope.

First one is better at DSO astrophotography, while latter is better suited to planetary / lunar imaging although it can work as DSO imaging scope - but with smaller field of view.

Do pay attention to exact model as the very much look alike and have the same price.

600D has 4.3µm pixel size and if you get that x0.75 Reducer, or maybe this one:

https://www.teleskop-express.de/shop/product_info.php/info/p8932_TS-Optics-Optics-2--CCD-Reducer-0-67x-for-RC---flatfield-telescopes-ab-F-8.html

for that one you can use with 61mm distance instead of 85mm to get x0.75 reduction. I don't recommend that you go with x0.67 reduction for APS-C sensor as you'll get strong astigmatism in corners. In either case

you'll get 1.45"/px if you use superpixel debayering - which I would recommend. That is very decent all around sampling rate. Close enough for small objects and with enough FOV to capture larger things. Some things may need mosaics.

In the end, I need to warn you about collimation of this scope. You mentioned that you don't like collimation - well this one has tricky collimation. I did not find it particularly demanding but people have struggled with it. Some seriously enough that they ended up letting go of the scope.

Here is some light read on that subject:

 

 

I'll give this some thought, I'll most likely be keeping the 600d for quite some time, unless it breaks, then I'll get a CCD which I already need anyway as I don't have a planetary camera. The planets of late have been very poor in the past few years, however will change nicely in a couple more. As long as my new scope is better than the C5 in both deep sky and planetary I'll be happy.

[The Lazy Astronomer]

1 hour ago, Quetzalcoatl72 said:

That scope looks really sturdy, and as for the focuser that should be ok because a typical newt has it on the side which I'm guessing is mainly why they need to be replaced with a sturdier one. I probably wont mind the diffraction spikes because it gives it a sparkly Christmassy feel to it :D. It does say it's primarily a lunar planetary scope, but I need big pixels? will the 600d be ok in that regard?

Ritchey-Chretiens are definitely deep sky imaging scopes (hubble is a Ritchey-Chretien!). I was very tempted to get one because they seem very good value for their size, especially when compared to a comparable Edge HD from Celestron, but was put off by others bemoaning the constant need for collimation.

[Quetzalcoatl72]

26 minutes ago, The Lazy Astronomer said:

Ritchey-Chretiens are definitely deep sky imaging scopes (hubble is a Ritchey-Chretien!). I was very tempted to get one because they seem very good value for their size, especially when compared to a comparable Edge HD from Celestron, but was put off by others bemoaning the constant need for collimation.

Surely if you're just using it in the garden and being careful when picking it up, placing it on saddle and packing it up it should be fine right?

[The Lazy Astronomer]

46 minutes ago, Quetzalcoatl72 said:

Surely if you're just using it in the garden and being careful when picking it up, placing it on saddle and packing it up it should be fine right?

Well that's what I thought, but more than one person said they just don't hold collimation very well at all. I like to spend my limited imaging time actually imaging, rather than resolving problems (ha! An AP session without problems - imagine that! 🙃), so I was put off it for now.

[Quetzalcoatl72]

35 minutes ago, The Lazy Astronomer said:

Well that's what I thought, but more than one person said they just don't hold collimation very well at all. I like to spend my limited imaging time actually imaging, rather than resolving problems (ha! An AP session without problems - imagine that! 🙃), so I was put off it for now.

To be honest, collimation seems to be a thing to do for all newts and similar scopes, so we'll all have to go through it eventually I guess. Might get used to doing it too! I've spent countless hours working out what scope I want so I don't waste money and to be honest, every single scope has problems. I've made my decision, will probably be the TS Optics Ritchey-Chretien Pro RC 203/1624 OTA

Edited March 16, 2021 by Quetzalcoatl72

[lukebl]

10 hours ago, The Lazy Astronomer said:

Ritchey-Chretiens are definitely deep sky imaging scopes (hubble is a Ritchey-Chretien!). I was very tempted to get one... but was put off by others bemoaning the constant need for collimation.

I started that thread about my struggles with Ritchey Cretien collimation, which vlaiv referred to earlier. I would point out that one significant positive thing about them is that they hold their collimation extremely well, so I’m not sure where you got the idea that they need constant collimation.

Despite my trials and tribulations, I have now mastered RC collimation, which is easy once you get the hang of it! I take it on and off the mount frequently when swapping with other scopes, and it never needs re-collimation.

Edited March 16, 2021 by lukebl

[Quetzalcoatl72]

6 hours ago, lukebl said:

I started that thread about my struggles with Ritchey Cretien collimation, which vlaiv referred to earlier. I would point out that one significant positive thing about them is that they hold their collimation extremely well, so I’m not sure where you got the idea that they need constant collimation.

Despite my trials and tribulations, I have now mastered RC collimation, which is easy once you get the hang of it! I take it on and off the mount frequently when swapping with other scopes, and it never needs re-collimation.

What is the difference between that first RC you sent and this one I found https://www.astroshop.eu/telescopes/ts-optics-ritchey-chretien-pro-rc-203-1624-ota/p,46250?utm_medium=cpc&utm_term=46250&utm_campaign=2103&utm_source=froogle&utm_content= other than being 99£ cheaper, same specs

Edited March 16, 2021 by Quetzalcoatl72

[johninderby]

Same scope but don’t forget the import duties and taxes if ordering from Germany. 

[Quetzalcoatl72]

1 minute ago, johninderby said:

Same scope but don’t forget the import duties and taxes if ordering from Germany. 

Fair point especially with brexit now, there's a lot of sites like these where I'm not sure where it's shipping from.

[johninderby]

Some people have had a nasty shock on orders shipped from thr EU.

https://www.moneysavingexpert.com/shopping/buying-online-from-europe-post-brexit/

[lukebl]

33 minutes ago, johninderby said:

Some people have had a nasty shock on orders shipped from thr EU.

https://www.moneysavingexpert.com/shopping/buying-online-from-europe-post-brexit/

I bought mine a couple of years ago, in anticipation of prices going through the roof post-Brexit.

I think I'll be proved correct. I'd better shut up now before I stray into dangerous territory!

[The Lazy Astronomer]

11 hours ago, lukebl said:

I started that thread about my struggles with Ritchey Cretien collimation, which vlaiv referred to earlier. I would point out that one significant positive thing about them is that they hold their collimation extremely well, so I’m not sure where you got the idea that they need constant collimation.

Despite my trials and tribulations, I have now mastered RC collimation, which is easy once you get the hang of it! I take it on and off the mount frequently when swapping with other scopes, and it never needs re-collimation.

Ok, well that's good news, because an RC is still on my wishlist!

[Quetzalcoatl72]

5 hours ago, The Lazy Astronomer said:

Ok, well that's good news, because an RC is still on my wishlist!

I might have just "accidentally" bought one, I hate it when that happens lol.

Edited March 17, 2021 by Quetzalcoatl72