Eyepieces - slight upgrade

[m37]

Trying to get my head round understanding the optics side of astronomy as was suggested to me by someone on here. Looking for one eyepiece that would not cost a lot but would be an improvement over the kit skywatcher ones.

First I was wondering what the shortest usable focal length eyepiece would be for my scope.

I read in one of the primers on the beginner's section that 'Under average seeing conditions, atmospheric turbulence limits the highest useful magnification to 25 to 30 times per inch (25mm) of aperture.' so I'm probably looking at 30x best mag x 4 inches = 120x mag under average conditions.

And if Magnification = Telescope focal length / Eyepiece focal length then 120 = 500 / 4.16

So am I right in thinking I should be able to get away with a 4 or 5mm eyepiece when seeing is average or better?

Would one of the following be a step up for picking out some planetary and lunar detail? I can probably go to about £40.

http://www.firstlightoptics.com/vixen-eyepieces/vixen-npl-eyepieces.html

http://www.firstlightoptics.com/celestron-eyepieces/celestron-omni-plossl-eyepiece.html

I was drawn to this one as I wear specs and it seems to be designed for the purpose

http://www.firstlightoptics.com/skywatcher-eyepieces/skywatcher-planetary-eyepieces.html

cheers

[paul mc c]

Hi, of the three you have listed,i can comment on the last one,i had a few of these eyepieces and they were very good,the 7mm gave me some of the best views of Saturn i ever had.

You wouldnt go wrong at the price they are.

[m37]

Cheers Paul, was hoping to get the opinion of someone who has used one.

[Eastridge]

Can't comment on the quality of any of them, but I also wear specs and the first 2 would be no good for me at all due to poor eye relief, usually people go for at least 16mm ER if they wear specs to observe.

[wookie1965]

One of the best cheapest and great for spec wearers eyepieces are the BST starguiders bought from here http://www.ebay.co.uk/itm/1-25-8mm-BST-Explorer-Dual-ED-eyepiece-Branded-Starguider-/380668399671 the 8mm is brilliant for Saturn im going to get the 5mm as well as Ive barlowed the 8 and had great views.

[mog3768]

I have to agree about the Starguider I wear glasses and brought a 12mm at the show and the eye relief is superb going to get some more.

[Chris]

Another vote for the BST starguider, I love mine

[faulksy]

were all different, I owned a few starguiders as they are now called they are good but I didn't like the yellow tint on planets, I sold them and bought the ts h-rs from modern astronomy, same price but a lot cleaner to look through

[ronl]

I too am a BST skyguider fan, these eyepieces would suit your scope

being an f/5 they are built for that focal length or greater, I have a 7mm

BST wide angle for viewing planets, and find it's really good along with my

Revelation astro Barlow for viewing the moon, they are easy on the eye,

and are well made and very good value for money, and the wide angle are

a little cheaper than the Starguider, I find that both are very good, but that

is my personal opinion I am sure there are many who disagree.

Clear Sky's

[Mattscar]

It never takes long in these kind of threads for the BST's to crop up...for good reason aswell. I have two of them and they are brilliant EP's and work great for people with glasses.

I have the 18mm for DSO hunting and the 8mm for use on abit of everything. I'm very happy to recommend them

[m37]

Thanks dudes, that's given me lots to look at!