Author Topic: What do I buy after an 8 inch dob?  (Read 1079 times)

ulpehaco

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Re: What do I buy after an 8 inch dob?
« Reply #30 on: February 02, 2018, 06:50:03 PM »
Buy the optimal scope for you. A huge myth is that you should buy your next scope based on 1.5x your current scope. I recommend the 10". You'll notice the difference.
I've used an 8". The views were better than my 114mm. M13 was an averted vision target. I then looked in a 10". Everything looked brighter. It was not a huge improvement, but noticeable. It did not hurt my back like the 12" ota I lifted.
And bigger aperture has a smaller field of view, unless you pay for 2" eyepieces and balance the weight. It becomes harder to find stuff, and some larger stuff no longer fits in view. You also need an ajustible height chair or to just stand.
10" is a comfortable size.

xenjavabve

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Re: What do I buy after an 8 inch dob?
« Reply #31 on: February 08, 2018, 05:47:16 PM »
Quote
Seems you have some conflicting needs listed

The one i will address is the 4" increase to get a 'wow' factor. Not true. Standard advice is you double your aperture for that... so to answer your desire for a 'wow'-noticeable difference you should be looking at something around 16"

I don't agree. A 50% increase in aperture is definitely "wow" -- I speak from experience. Going from an 8-inch to a 12-inch scope will change your views dramatically across the spectrum.

Ironically, the one possible exception is the one the OP mentions in the base notes -- planets. Because views of the planets are limited primarily by atmospheric steadiness, a 12-inch scope will often give views of the planets that are only marginally better than the ones through an 8-inch scope. But going to even bigger apertures wouldn't help that.

Measuring this in absolute terms -- 4 inches -- rather than relative terms like 50% makes no sense at all. Going from 2 to 6 inches is a truly vast change. But going from 20 to 24 inches only perceptible if you compare both scopes carefully side by side.

Todd Kue

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Re: What do I buy after an 8 inch dob?
« Reply #32 on: February 09, 2018, 03:39:12 AM »
Going from 8" to 12" more than doubles light gathering and light gathering is what telescopes are all about. We look to increase light gathering and 2.25X (8 to 12) is a very significant jump.

incojukam

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Re: What do I buy after an 8 inch dob?
« Reply #33 on: February 09, 2018, 10:39:50 AM »
If you like to stand, a 12" won't require stooping. But your kids may need a step.
The weight and size difference between 150mm and 130mm is very significant, and is proportionally less than the difference between 10" and 12". Think about bulk, not just weight.