Swap a SW ED120 Evostar for a 190MN Astrograph ?

[Catanonia]

As you know I am 90% an imager and so need opinions based on this.

Can someone give me some honest opinions on swapping out my SW ED120 EvoStar Pro diamond black refractor for a SW 190MN Astrograph Newtonian.

Sky-Watcher Evostar 120ED DS-PRO telescope.

versus

Maksutov Newtonian - Skywatcher Explorer 190MN Mak-Newt Astrograph

I have an SW ED80 Pro II Gold for guiding and imaging as well and will keep that.

Would the ED120 vs 190MN be a good swap out or am I just trading for the sake of trading ?

[Whippy]

Personally, I don't think you'd be gaining much by swapping. There's pros and cons to both scopes. The focal lengths are similar but...

The MN is faster and will have a flatter field but is much heaver is is more prone to the wind knocking it about expecially with dew shield you will have to buy.

The 'frac is slower but won't have any issues with collimation or cooldown, is lighter and less prone to wind movement.

To be honest, you've just started out. I'd stick with what you have and get used to it before you go chopping and changing for no real reason. Plenty of time to do that later

Tony..

[themos]

or -> and

[Catanonia]

or -> and

indeed or not chop and have both is another consideration.

[arad85]

Cat,

Some thinking from the physics:

• They are very similar focal lengths so the scale will be similar (the Mak-Newt will give approximately 10% smaller field of view)
  
• You'll get the same exposure twice as quickly with the Mak
  
• Theoretical resolution (smallest thing you can see) is upped by 50% on the Mak Newt (although it depends on the optics).
  

I'm off to bed now - honest

[Catanonia]

thanks Andy, you know how I think, simple.

Cheers guys. If the wifey wants to buy me a chrimbo present, then why not, might help her out a bit with the purchase since I have given up smoking.

[Tim]

If you want both, and can afford it, then do that. Thats pretty much what I have done I guess. But you have a long way to go before you have gotten the best out of the kit you have, and with the weather we have, it'll take you a year or more to do that, and to use the kit on all the regular targets.

Imaging with a newt is a whole new ball game, and can be a lot more complex than with a 'frac. The results from a fast astrograph can be astounding, but what is gained by a fast f ratio is often lost in setup time, fiddling with collimation, dew, wind. The faster the scope, the more accurate the guiding has to be, and any flex issues will be emphasised. Every time I image with my newt, I wish it was like my WO72, and every time I image with that, I wish it was like my newt.......

[Whippy]

Every time I image with my newt, I wish it was like my WO72, and every time I image with that, I wish it was like my newt.......

That pretty much sums it up ..

Tony..