Good scopes for ZWO 2600MC Pro

[Elp]

Hope it's not a Planewave... Or a more practical AP.

Edited 18 hours ago by Elp

[Mr Green]

I am really tempted to go for the Askar 107phq.

The option to image at 749mm at f7 or 524mm at f4.9 seems like a good option.

Just not sure if F7 is fast enough for the rare clear skies up here.

[Elp]

2 minutes ago, Mr Green said:

Just not sure if F7 is fast enough for the rare clear skies up here.

It is hideously slow if you've ever used fast optics. I generally don't use my Starfield for imaging at F7. Aperture is what you really need for speed.

Edited 18 hours ago by Elp

[Mr Green]

That's what I was worried about.

Another option would be the Askar FRA600 as that's kind of  in the middle of those focal lengths.

I could also look at the Esprit 120ED but that's getting pricey.

Or perhaps the Starfied Gear115....

So many options!! 

[Elp]

Depends on your expectations, what you want to image, the detail you want and how much time you want to spend on target.

From actual experience imaging the same target with different setups I found the shorter FL optics gave brighter signal in the same amount of time but with the loss of resolution. To me this makes sense and is exactly how reducers work, they condense a large area signal onto fewer pixel area hence increasing the pixel response in that smaller area, the result is a brighter image and/or in less time, you also see the opposite result with camera lenses by stopping aperture down and seeing the signal get dimmer (so going larger increases light gathering).

If I'm imaging over 500mm, for me a project is likely to take 10-20 hours at least to get reasonably low enough noise averaging, but some NR will still be needed.

The Esprit is the proven scope, you'll likely be happy with the 100 also. The other two are also okay I believe, Askar do sometimes have quality issues but most scopes you hear of someone has had an issue (even with premium brands). Maybe see if you can get a good one used, less depreciation.

[Mr Green]

Thanks Elp, you're always helpful when commenting on my threads.

I'm definitely considering the Esprit series, the 120 is just a little on the pricey side, especially after just ordering the AM5n.

After imaging with the 72ED, I've found myself feeling disappointed with the focal length as I seem to gravitate towards smaller targets.

I think 8-10 hours is realistic for me personally although I've had issues trying to stack images for multiple nights but that's a different conversation.

 

[Elp]

If you're talking this sort of budget for imaging quickly id consider a RASA 8 (a new one from a shop, some older 8's had an issue with star flaring issues and Celestron did a recall, if buying used ask to see unedited starfield images around bright stars taken with the scope). I know the FL will be similar to your existing scope, but the aperture is way larger and also the speed which helps with this weather.

The Edge HD also falls within this area, but will cost more if you consider the reducer (essential for imaging) and/or the Hyperstar. The added benefit is you can also use it natively for planets (you can technically image DSO native too) and visual.

Without some experience using other types of scopes other than refractors (IE collimating, it's not particularly difficult) the above recommendations are less applicable (IE expect a little bit of a challenge).

Note, long FL imaging needs good PA and guiding, an off axis guider is recommended though not essential, I used my 120mm guidescope when testing my 700mm SF102.

Id also add in the 103 and 120 Askar triplets (orange/white) into the mix, they were my narrowed down choice until I got a used SF102. Some people here already own and use them for imaging.

Edited 14 hours ago by Elp

[Clarkey]

I think you need to put 'speed' in perspective. I have images at F8 with my RC and for smaller targets it works well. You have to remember that a lot of galaxies may be small, but they have a relatively high surface brightness. Also, at the longer FL you do have the option to bin the data to improve SNR.

I image with my 115mm F7 triplet at native FL and the results are fine. The image I posted earlier on this thread was a single night (7 hours from memory). As a rule, you are not likely to be imaging diffuse nebula with a long FL scope so the 'speed' is slightly less critical.

If you want anything faster that about F5 you are really going to have to move away from refractors to get anything faster. I am a fan of RC scopes, but on SGL I am in a minority. They can be tricky to collimate, but you get a lot of scope for the money. I have just got a 10" carbon fibre Quattro (it was a bargain on flea bay so I couldn't resist). However, even though I will be getting F4 at 1000mm FL, I have had to modify it quite a bit and I expect it to be challenging. Not a plug and play refractor. At the end of the day you need to decide whether you want fast optics or an easy life!

[Clarkey]

7 hours ago, Elp said:

Note, long FL imaging needs good PA and guiding, an off axis guider is recommended though not essential, I used my 120mm guidescope when testing my 700mm SF102.

I use my RC8 at 1600mm with an ST80 guidescope without issue. Similarly, I use a 60mm guidescope with my 805mm triplet. No flex issues with either. I would point out, in both cases the guidescope was very well clamped in place. I am using an OAG for the F4 Newtonian as I expect this to flex. I find OAGs a right pain as every time you rotate the focuser to frame an object you need to recalibrate PHD2.

[Mr Green]

I am 100% set on a 4" - 5" refractor and an easy setup is definitely my preference.

I lost a couple of months at the beginning of the year trying to fix tilt issues that really took the enjoyment away for me personally.

 

[TiffsAndAstro]

15 hours ago, Clarkey said:

What scope? 🤣

Got lucky on eBay was just £x

[Clarkey]

3 hours ago, Mr Green said:

I am 100% set on a 4" - 5" refractor and an easy setup is definitely my preference

I guess your finances may need a top-up have purchased a new mount. But in case you are interested there is a 130mm Triplet on ABS for £1200.

U.K. Astronomy Buy & Sell (astrobuysell.com)

 

[Mr Green]

1 hour ago, Clarkey said:

I guess your finances may need a top-up have purchased a new mount. But in case you are interested there is a 130mm Triplet on ABS for £1200.

U.K. Astronomy Buy & Sell (astrobuysell.com)

 

Thanks for sharing, I'll likely buy new when the time comes though.

Probably sooner rather than later as I am impatient 😅