Dso & eyepieces

[Starlight 1]

I have seen lots on here for eyepieces but like every else I can not find them again so can you help,

hoping to try out some DSO so what is the best eyepiece I can use for this ,Here the list it may help or I go out and get a new one.

Meade series 5000 super wide angle 16mm

SW 2" 28MM

SW 5mm

Ts planetary hr 25mm

SmartAstronomy 40 mm

Celestron from 4mm to 32mm

Telesscope SW250 pds

[John]

Generally it's useful to have a low power eyepiece to find the DSO in the 1st place - you have a number of options there (ie: your 40mm, 32mm and 28mm eyepieces). Many DSO's then benefit from a bit more magnification to bring out their contrast and darken the background sky - the Meade SWA 16mm would be excellent for that.

I don't think you have any obvious "gaps" in your collection as fas as I can see.

[brantuk]

A 5mm ep will give you 240x magnification in good seeing conditions - probably around the maximum you want to limit yourself to due to UK average seeing conditions. You would go for planets with that.

For dso's you want to be looking at wide angle ep's of 20mm to 40mm and low magnification. Dso's are very large so you want to get the entire object in the field of view - especially galaxies and open clusters.

1.25" ep's will generally give you a narrower field of view than 2" which tend to be nice and wide. So I usually choose an ep diameter and a required magnification for any given object before choosing the make. Then I get the best within budget.

Use something like these to decide on the field of view you want (both free to use/download) :

http://www.12dstring.me.uk/fov.htm or

The New CCD Astronomy Home Page

You might also want to factor in use of any barlows that you currently use - hope that helps