113mm refractor vs 8inch sct - Forums

Topic starter

Feb 1, 2025

So I have an opportunity to buy an 8-in SCT, I'm not really much of a planet guy but it seems like when people want to look in the telescope they always want to see planets

I have a 113mm refractor, I understand that the light gathering of an 8 in is a lot more but there's also a theoretical limit on how much magnification I can actually have and get a visual good view.

Knowing that anytime I have someone looking my telescope it's usually in my backyard and that's a bortel 6-7.

I can get a solid 270 magnification with my refractor on a decent night. Am I really going to see much more in an 8 in SCT?

Really the only value I see in the SCT is for showing people planets. Anyone have any real life comparisons between the two?

Keep in mind this is 100% visual and 100% planets. I love helping people get excited about astronomy, but is the view that much more impressive?

Tony Gondola

Frequent contributor

Feb 1, 2025

That's a hard one because in a really good refractor in that size range views and Jupiter, Saturn, Venus and the Moon can be very impressive. It will deliver these images on all but the roughest nights and so can pretty much be depended on to give a small but high contrast, easy to see view. Under good conditions an 8" aperture can give impressive views but that won't be true on most nights. I would also be careful with SCTs as these can vary a lot in quality. I've looked through some that were rather good but I've also seen more than a few that I would call "mush dogs". I think what would really work for you would be a classic 4" F/16 refractor if you can find one, or, a 6" F/8 Newtonian, another classic.

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Clayton Ostler

Topic starter

Feb 1, 2025

Tony Gondola:
That's a hard one because in a really good refractor in that size range views and Jupiter, Saturn, Venus and the Moon can be very impressive. It will deliver these images on all but the roughest nights and so can pretty much be depended on to give a small but high contrast, easy to see view. Under good conditions an 8" aperture can give impressive views but that won't be true on most nights. I would also be careful with SCTs as these can vary a lot in quality. I've looked through some that were rather good but I've also seen more than a few that I would call "mush dogs". I think what would really work for you would be a classic 4" F/16 refractor if you can find one, or, a 6" F/8 Newtonian, another classic.

Thanks for the reply. After doing some reading I'm starting to agree that I on most nights and in most circumstances the view I'm going to get from an 8 sct , will not really be any better than what I have now. I get to do this hobby so little that I don't think buying equipment that might be more useful on one of the few nights that I get super good seeing and I get an opportunity to use it seems kind of silly. I think I'll play the law of averages and assume most nights are just OK seeing.

Thanks again.

Kay Ogetay

Feb 1, 2025

I have organized science fairs and participated in many events. Yes, people are indeed interested in seeing the planets, but that's usually because they mostly know about them. Planets are more popular than any nebula. But when you show them some nebulae, they are always amazed. Or some star clusters. Especially if you use a laser pointer to aim where the telescope is seeing, they will see nothing in the sky in B6-7 but from the telescope they can see a star cluster! That fascinates people.

It's the twist, it's the surprising fact of the knowledge that hits them the most. I'd go with the refractor because of that reason. Cause you can even only show the Galilean moons and if they stay they will even see them moving! From my experience, that is not so different than seeing Jupiter itself. There is always something to show. It's all about your presentation. Whichever you feel more comfortable presenting, you might decide on that one. I don't think one is better than the other in this case.

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Clayton Ostler

Topic starter

Feb 1, 2025

Thanks for the advice and thoughts. I agree. Truth be told galaxies and nebula arent super visible where I live due to lipo. But clusters are still exciting.

You can only look at Jupiter and Saturn so long.

I think my money is better spent on other things and the sct is probably not worth the investment.

I'm pretty happy with my refractor and it fits a lot of roles, including AP.

Thanks again