RASA 11 or Esprit 100 ?

[bluesilver]

Hi, I am not 100% on where i was suppose to post this question,, so thought here would be a good start, apologies if i have this in the wrong section.

 

So I have been imaging for a few years now,  just don't get much time to actually get out and do it,  so maybe once a month i get a chance to get out and image.

My area is around the Bortle 2 -3 

My current scope is the Skywatcher Esprit 150,  and the mount is a iOptron CEM 120  and the camera is asi2600mc ( color )

I also have a C14 XLT ( non Edge )

So i am looking at getting a second scope of the larger objects like M42, M45.  Even with a reducer, the objects won't fit with the Esprit 150

I was thinking about getting a RASA 11 or even a Hyperstar for the C14,  but after doing a bit of research,  it appears both a pretty fussy with collimation. ( I do have a Skywatcher 16" Dobsonian that i use for visual use and find collimating this is no dramas at all.)

I then started to look at the Esprit 100 as all these 3 have very close the same imaging filed of view.

So basically i am just hoping to get some advise on what way be the best way to go here?

Esprit 100, RASA 11 or possibly look at a Hyperstar for the C14 ?

 

 

 

 

 

 

[tomato]

I have an Esprit150/IMX571c set up, and was looking for a wider FOV scope to use with the same camera. I was mightily impressed with the images obtained by @gorann with a RASA8/ASI2600c setup and went for that scope. It holds collimation very well and on the one occasion when I had to collimate it when the secondary assembly came loose, it was a straightforward operation. 
 

Certainly no regrets with going with the RASA8.

[fwm891]

Why not go for a good make camera lens 300 f2.8 or similar. There are adapters to fit your 2600 MC...

[dark knight]

Another option would be to sell the esprit 150 and get an esprit 120 instead, that coupled with the 2600mc would frame m42 perfectly, just an idea.

[Elp]

I think the Rasa and the HS will both have collimation to do, but it's not necessarily difficult. I use a HS6 and generally leave it at it's default (closed) position. After weighing up all the options I chose this for my C6 as I can image native 1500mm, reduced 1000mm and HS 300mm. Can be used both visual and AP. You don't have that sort of flexibility with many scopes.

[gorann]

My vote is on the RASA. I have an Esprit 100 and it clearly needs many times more integration time to get to the same depth as a RASA8. Not sure why you want a RASA11. Your camera fits well with a RASA8 and to get an equally large FOV with a RASA11 you need a full frame (24x36) sensor (like ASI6200). The RASA 11 is also very heavy and difficult to handle alone, as evident from this scary thread 😱

Cheers, Göran

 

[Elp]

Are there still bad examples of Rasa 8s on the market though with the bad optics issue? It is however ideal for cost/size.

[gorann]

30 minutes ago, Elp said:

Are there still bad examples of Rasa 8s on the market though with the bad optics issue? It is however ideal for cost/size.

Yes, it would be worth finding out if there is still a quality issue with the mirror of RASA8. There has clearly been a bad batch produced as  @symmetaland others have been victims of.

Edited December 24, 2022 by gorann

[bluesilver]

Very much appreciate all the replies and advice.

I was mainly looking at the RASA 11 as it has the larger mirror for collecting more light and also matches the asi2600mc perfectly.

Never really though of the RASA 8,  but did here a few mirror issues with them.

Weight wise, it isn't an issue at all,  I have a pretty good setup to mount and dismount the C14 without and issues.

 

[ollypenrice]

The RASA choice involves a bit more fiddling at setup but, once you're running, it is phenomenally fast. Ours goes very deep on faint targets in three hours, which is astonishing.

Olly

[symmetal]

A new RASA 8 will most likely have the mirror edge flare issue if you get one that's still in stock anywhere. I had to return three of them as they all had the issue, and got a RASA 11 instead. Celestron returned their stock of RASA 8 scopes to China for the mirrors to be replaced or re-worked. FLO have stated 90-120 days delivery which effectively means when ever they start shipping again.

The RASA 11 is recommended if weight and cost isn't a problem, and you don't drop it like me. 😭 It doesn't have the limited backfocus issue of the RASA 8 so you can use mono cameras with a filter drawer, and gives very good stars out to the corners on full frame, although there is significant vignetting with the stock 48mm adapter.

Back focus spacing is critical to get good stars, which can be misinterpreted as tilt, if it's out by more than 0.2mm.

Alan

[bluesilver]

Appreciate all the advice and replies.

Lots to think about there now,  Would also be interesting to see how the HyperStar compares on the C14 compared to the RASA 11,  just another option.

A tad cheaper + larger aperture also.