which eye piece

[dean w]

hi i have a 130p and was reading about how to spot dso someone said to get a wide angle low mag eye piece does anyone have any sugestions as to which one would be sutable for the job

[Tinker1947]

How deeps your wallet, the wide angle will make finding DSO's a lot easier, when you find them, you have something to view them with...and what size is your Focus tube...??

[RikM]

A 32mm Plossl would be a good choice.

[LukeSkywatcher]

A 32mm Plossl would be a good choice.

I could not agree more. 32mm with a 50 degree FOV...........it really is great EP for scanning the skies.

£30-40 squids.

It is the work horse of many an observer.

I can personally say that this is the best i have ever used (30mm)

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

Great at picking up those "faint fuzzies".

[cs1cjc]

The Vixen 30mm plossl is a very nice and sharp eyepiece, however it is not very wide angle. I measure it at only about 46 degrees apparent field of view (the manufacurer quotes 50, which I guess is the same to one significant figure!). It has a field stop diameter of only about 24.6mm, which is about 10% less than the 27mm that some rival 1.25" eyepieces offer. It is the field stop that limits the true field of view, which you really want to maximise for a finder eyepiece.

[michael.h.f.wilkinson]

All good suggestions. A 24mm wide angle should also be considered. If you can afford it, a 24mm Hyperion gives the same FOV as a 32 mm Plossl, but at a smaller exit pupil, meaning a darker background. As the 130 is an F/5, 32 mm gives a 6.4mm exit pupil, which is not too big for many of us, but the 4.8mm exit pupil of a 24mm in your scope would be better in almost all cases. It is more expensive.

[Catweazel]

Yep! I have a GSO 32mm Plossl, which is great for finding DSO's, and a very nice, modestly priced, eyepiece

[rwilkey]

I use the 32mm PanaView for my DSO searches, not sure of the exit pupil but it works well for me on f/5

[Hobbes]

I tried a Revelation 30mm 2" Eyepiece at a group observing session recently and was really impressed. If you can fit a 2" eyepiece its worth looking at.

[scuffer]

Just looking into getting one of these myself , I have worked out for an exit pupil of 5mm the max size ep is 30mm , if I get a 32mm (because there aren't that many choices of 30mm) am I doing wrong by getting the extra 2mm ?

also cs1cjc when you say - It has a field stop diameter of only about 24.6mm, which is about 10% less than the 27mm that some rival 1.25" eyepieces offer . - can you name any of the rivals especially the ones that cost less than £50.

I think some times I look too deep into things and confuse myself more

[michael.h.f.wilkinson]

I use the 32mm PanaView for my DSO searches, not sure of the exit pupil but it works well for me on f/5

Exit pupil is just (focal length of ep) / (focal ratio of scope).

So in this example: exit pupil = 32mm / 5.0 = 6.4 mm

In my F/6 APO the 40mm Paragon gives 6.67 mm, which is largish, but still not a problem for many of us (if your pupil cannot dilate to 6.67 mm light is lost and you effectively are using a smaller scope). The background can become a bit washed out. With my 31mm I get an exit pupil of about 5.17, which gives a darker background and more contrast.

[cs1cjc]

also cs1cjc when you say - It has a field stop diameter of only about 24.6mm, which is about 10% less than the 27mm that some rival 1.25" eyepieces offer . - can you name any of the rivals especially the ones that cost less than £50.

Sadly few manufacturers publish field stop diameters widely, but they are sometimes buried away on web sites or mentioned in reviews. I can only measure or estimate the field stop diameter for eyepieces have had access to. Some values follow from a variety of sources, which I hope are at least approximately correct:

24mm Explore Scientific 68 27mm

24mm Tele Vue Panoptic 27mm

25mm BST Explorer (Astro Tech Paradigm, etc) 25.9mm

25mm "TMB Design" (Barsta ED, TS HR, etc) 26.4mm

25mm Celestron X-Cel LX (and Meade HD 60?) 25mm

30mm Vixen NPL 24.6mm

32mm Tele Vue Plossl 27mm

32mm GSO (Revelation) Plossl 26.8mm