What eyepieces to use?

[Guest]

I recently started to search for The Ring nebula with a 35mm eyepiece.I could not find it, so I put in a 15mm eyepiece and did find it.Finding objects by star hopping does require knowledge as to which focal length eyepiece would show the particular object (either The ring nebula type of object or a diffuse dim nebula).

I just wondered if there was a book that discussed this

[orion25]

What type of scope do you have? The Ring is kinda small and dim but I have no problem finding it with either my 127mm or 180mm scopes using a 20mm eyepiece. Your 35mm eyepiece probably gave you such a wide field that the Ring just got lost. To find nebulae, galaxies and globular clusters, I find that medium focal length eyepieces (around 15 to 20) are good with a scope of an aperture of at least 5 inches. Open clusters (like the Perseus double cluster and the Pleiades) will need more field so a longer focal length (25mm and up) would work better. Once you've found the object you can ramp up the magnification, if desired. I don't know of a book that discusses which eyepieces to use to find certain types of objects, but usually eyepieces in the 15-20 range are good for most DSOs with a scope 5 inches or more. Experiment and see what works best for you and your scope. Hope this helps!

Astronomical evenings,

Reggie 

[wookie1965]

Good advice from orion25 i use my 25mm for the ring and galaxies but my 32 for clusters and nebula`s then once found then i can ramp up the magnification.

[jetstream]

I find a zoom to be handy when looking for things once in the right area, some planetary nebulae can be hard (to me anyway) and need mag to distinguish them from other stuff. This is one reason I like widefields, a large TFOV/mag...easier to find things and has the mag to do it.

[Stu]

Have you tried Turn a Left at Orion? That gives some good descriptions of objects and how to observe them

Sent from my iPhone using Tapatalk

[acey]

Use a sufficiently detailed map so that you can get to the exact location of the target - I.e. a map that will show the stars that you see in the telescope FOV at low power. If the target is not immediately visible then raise the magnification until it comes into view. If you can't see it then the sky is too bright, you're looking in the wrong place, or the target is too faint. Sweeping around in search of a target will only work if the target is large and bright - many are both but most are neither.

[Moonshane]

Even the very basic but highly recommended (by me at least)  Sky & Telescope Pocket Sky Atlas provides a chart legend and this confirms the rough dimensions of the objects shown.

[Guest]

I am grateful for all you're advice.I will put it into action.I am using an Orion Optics UK 8 inch F6 Newtonian on an Altair Sabre mount.So star hopping will become my method of observing.

Martin.

[Moonshane]

A rdf and raci finder make star hopping easy. My adult nephew had never looked through a scope and after five minutes found Uranus in my 12" dob on his own.

[Guest]

That is a very good effort by your nephew Moonshane.I always walk into lamp posts because I am always looking up.It's second nature to understand what I 'm looking for when putting my eye to the eyepiece.It is interesting that a lot of people have no conception of what a telescope eyepiece can show them.

I do use a RDF ,but am going to use a green laser finder.

[allen g]

try with an O111 filter as it is a planetary nebula

[m.tweedy]

the downloadable guides do what you want 

http://www.faintfuzzies.com/DownloadableObservingGuides2.html

[michael.h.f.wilkinson]

An O-III filter is not really needed with the Ring. It should be resolved at 35x but more is better with the Ring, as it has good surface brightness but small size. I use a 22mm or 17mm EP on my C8 for the ring, most times (93x and 119x).