Irish viewing conditions

I am just about to buy a 8" Newtonian, and wondering what the practical limitations on its performance would be under Irish conditions i.e. lots of moisture in the sky, even on clear nights! For example, how often is 300x or 400x (or even 200x) magnification actually useful or usable in our watery skies? What limiting magnitude would you get with a 8" Newtonian?
Likewise, what would the practical limit of resolution be for splitting doubles etc.

I know all the theoretical limits, interested in real world experience in Ireland.

We do get alot of moisture in the atmosphere here, one problem here is that when there is alot hazy it can catch light pollution from a fair distance away and make it seem you are nearer to the lights, but when you are at a dark sky site (in the west), it is really dark, milkyway horizon to horizon.

As for top magnification, I can easily get up to 357x using a 7mm and on a good night 500 with the 5mm, but this is with a 20" scope.
I can routinely split <2arc second double stars, so the seeing is not particularly bad in this part of the world, the real, issue here is cloud cover.

A good accessory to have for your telescope is a big umbrella

Hi Heebyjeeby,
I think it is also sometimes down to the luck of the draw. Last night was so cold and clear, we had heavy frost here (my car is STILL frozen as I type this). The night before, it was also clear, but foggy in parts. Last night is the kind of night you want, the kind where it will be so cold, that by 2am you will have to pack it in due to frost on your scope and eyepieces! It happens! But, those same crisp nights offer better seeing because the air is still.

That is key for high magnification viewing, especially of small distant objects like double stars, or seeing details on planets. Equally good are clear foggy nights - because the air is still, it means less currents to ripple your images (especially when viewed almost straight up (at the zenith)). Sounds weird, I know, but some of the best planetary images I have seen through 8" scopes were taken through fog.

Don't let the Irish clime put you off buying a large scope. You WILL get to use it, despite the law of averages in the past year stating otherwise. As a saying from one of my favourite movies (can you guess it?), "It can't rain all the time".

Seanie.

Sounds weird, I know, but some of the best planetary images I have seen through 8" scopes were taken through fog.

Seanie,

I am jumping up and down when it is foggy and/or very humid outside since I also have observed GREAT seeing under such conditions. In fact, one of the first things I check for each evening's forecast is the % humidity ... the higher, the better.