80mm vs 90mm vs 100mm - visual use only

[digitaldave]

Can anyone with experience with these sizes of refractors describe what sort of difference one would expect to see between these different sizes, for purely visual use. I know aperture rules, but how much difference will there be, realistically, between an 80mm, 90mm and 100mm scope? Faint fuzzies will still be faint, right...?

Thanks,

Dave.

[John]

I've owned all 3 sizes of refractor and all were good scopes in their own right. Most DSO's are pretty faint even with 100mm but it's suprising what you can see if you keep at it. Having tried a number of 80mm's (APO and Achro) I eventually came to the conclusion that it was not really enough aperture for visual and likewise 90mm so I've settled on a 102mm now and would be unlikely to downsize again.

TBH of DSO's are your main interest you might want to consider a newtonian.

John

[Merlin66]

I regularly (!!??) use the ED80 and the 4" Genesis refractors.

Although the Genesis ALWAYS gives clear tight images, the ED80 is more "fun" - you can push it to the limits and have some challenging observing...

I agree with John, if DSO's are your visual targets, aperture does count and a good 8" or 10" reflector is far more satisfying.

[digitaldave]

Thanks for the replies. My mention of faint fuzzies may be a bit of a red herring - I realise that these sizes of refractors aren't going to be good with the faint stuff, I was trying to get an idea of how they would compare against each other, i.e. will 100mm show noticeably more than 80mm. I currently also have a Celestron 9.25" SCT for when larger aperture is needed.

Dave.

[gliderpilot]

I thoroughly enjoy my 102 Skywatcher. Small enough to setup and pack away easily but powerful enough to show considerable detail. It also has a good, wide field of view for framing bigger sights (Orion's sword, Veil nebula, double cluster etc) but can take high magnification well (globs, moon, planets etc).

As I have not used 80 or 90mm scopes - (I also have an 8" newt) I know this only gives you one point on your graph.

Mark

[beetlejuice]

Thanks for the replies. My mention of faint fuzzies may be a bit of a red herring - I realise that these sizes of refractors aren't going to be good with the faint stuff, I was trying to get an idea of how they would compare against each other, i.e. will 100mm show noticeably more than 80mm. I currently also have a Celestron 9.25" SCT for when larger aperture is needed.

Dave.

There is really is no substitute for size. On Saturday night I was using my C9.25 at f6.3 to pick up some fuzzies, even though sky transparency was not so good, I could easily make out the brighter parts of M51 the Whirlpool Galaxy. Trying to repeat the same trick last night with my C6 merely showed it as a fuzzy blob, despite the sky transparency being pretty good for a change. My M90 is disappointing with fuzzies, at least from my back yard with moderate light pollution. But I bought it more or imaging (when I get round to it) than visual stuff. That said it gives wonderful low power views.