Skywatcher Evostatr 80ED vs Evostar 120

[cathouse42]

I currently have a EvoStar 120 and want a better scope for photography, is the 80ED better than a Evostar 120, and if so, how much better?

What would I lose out on and what would I gain by swapping?

[carastro]

You'd get a larger FOV.  

Carole 

[David Smith]

ED80 = Less CA, wider field of view, weighs less, easier to mount but reduced aperture in theory means reduced ability to resolve fine detail. What that means in real terms is difficult to say. I have both 80 and 120 achromatic refractors and the step up from the 80 to the 120 is massive in terms of what I can see visually and image (although my imaging is limited to solar and lunar).

[xtreemchaos]

i got a 80ED from FLO 2 days ago and im well impressed, good contrast and no ca but lve only had a small play with it due to weather but what ive seen is good as for the 120 a mate of mine had one but sold it and got a 80 for portability and FOV, all the best.charl.

[cathouse42]

SO, so far

Pros:

FOV

CA

Form factor

Cons:

Light gathering

Does this sum it up accurately?

How much is this loss of light gathering really negative? In laymans terms, how much extra time is required for subs? Or is there any other laymans term metric we can use.

[RafalT73]

Hi, I am a user of big Schmidt-Cassegrain telescope (11") and definitely I am not expert from refractor scope. Nevertheless I think that aperture of refractor in astrophotography is not a crucial point. Deep space object are so far away from Earth that difference between 80 or 120 mm does not so important - still you can not see more with 120mm then through 80 mm. But there are some advantages of smaller scopes, an example bigger field of view and less light noise. Generally smaller aperture scopes are faster than bigger one.

Now I also wait for delivery of my freshly ordered refractor: TS APO 90/600 with Atik 383L+. I hope it has been good choice. I will see soon

Best regards

[cathouse42]

So overall it would make sense switching from a 120 to a 80ED due to wider FoV, faster optics, better glass, shorter tube for astrophotography.

The image should be brighter and clearer due to better glass and faster optics.

120 is f/8

80ED is f/7.5

is f/0.5 a noticeable difference?

[rob0971]

The 120ed is also f7.5 not f8

[cathouse42]

The 120ed is also f7.5 not f8

I am referring to the Evostar 120 not the 120 ED, the 120 is f/8.33.

1000mm / 120mm = f/8.33

The Evostar 120 is 1000mm focal length.