Which APO?

[almoskosz]

Hi,

I am now buying an APO, which i will stick on to my existing Skywatcher EQ-5 that held a 200/100 Newton, but not anymore due to it's weight, and the fact that would always go away from home when observing, so a giant newton didn't cut it for me, albeit it was great for my needs. I am mainly a Deep-sky guy, mostly clusters and smaller nebulae ( such as: m57, m42), and I want an 80-100 mm APO for main use, but I am unsure of how worse it is going to perform, and foremost:

Is the Equinox 80/500 or the Black diamond 100/900 better for me? Which is the better for deep sky purposes? I am leaning heavily towards the Equinox now because of it's lower f number. Also, I would use it only for visual observing, no astrography.

Is there a big difference between the Equinox and the Black diamond versions, other than the looks, and the 100mm focus? 

[Peter Drew]

If you are ruling out photograpy then the F ratio is of less importance. I would consider the larger aperture longer focal length to be more of an allrounder.

[nmoushon]

I love my Equinox ED80 for both visual and AP. Great views and well corrected. But for visual only its going to be very underwhelming for you since you are comparing it to your 200mm newt. Both scopes will be just because of aperture loss. Have you looked at the new achros at all? The newer ones are very well corrected for the most part and offer a lot more aperture for the price. 

Are you replacing your Newt because you are tired of traveling with it because of how large it is or are you trying to lighten the weight on your mount? 

[Peter Drew]

The problem with Achros of a size to be not much of an aperture downgrade from a 200 Newtonian is that they are similar in weight to the 200.

[ecuador]

I bought an Evostar 80ED for photography and I was shocked at how enjoyable it was for visual. Ok, it can't replace an 8", but it doesn't feel that bad compared to 5"-6" newtonians especially in the city where you can't really take advantage of the large aperture and you mainly focus on planets where the little APOs higher contrast and better color are an asset.

I recently got the Equinox 80ED to make it even more portable and wider field. It is a much better construction than the Evostar, a beautiful scope, however it is disappointing when it comes to planets. Having the same optics basically as the longer focal length Evostar I expected some more CA, but it is a bit worse than I expected on planets. So for visual if you want it all-around, i.e. including planets I'd not recommend it, the Evostar 80ED would be better overall (and cheaper). The Evostar 100ED would be even better, especially for planets. But if you love your DSOs try to go for an 120ED

[ollypenrice]

Bang for buck in visual would point me towards the slow-ish ED100. I wouldn't tempt fate by going for a faster photographic apo unless you really wanted the wide field (as you might.) I have an Altair Astro 102 triplet which is exceptionally good optically, too. SO I agree with Peter Drew, really. (I tend to be worried when I don't!!)

Olly

[almoskosz]

21 hours ago, nmoushon said:

I love my Equinox ED80 for both visual and AP. Great views and well corrected. But for visual only its going to be very underwhelming for you since you are comparing it to your 200mm newt. Both scopes will be just because of aperture loss. Have you looked at the new achros at all? The newer ones are very well corrected for the most part and offer a lot more aperture for the price. 

Are you replacing your Newt because you are tired of traveling with it because of how large it is or are you trying to lighten the weight on your mount? 

Both!

[laser_jock99]

The only true APO is an all mirror system......

[John]

Really, 80mm or even 100mm is not enough for deep sky observing IMHO.

Have you thought about putting a smaller newtonian optical tube on the mount ?. I've had some wonderful deep sky views from a dark site with an 150mm F/5 newtonian. Plus it's an "apo" of course !