Eyepiece recommendations

Hello all. Its the "newbie" again. I have three eyepieces (that came with the scope) including a Meade 26mm, 9mm and an Orion 17 mm.

Can anyone give any recommendations for other eyepieces to own? What would the advantage be in using 2" eye pieces versus 1.25"? I think what I am getting at is the differences between for example a 20 mm that cost $40 and a 20 mm that cost $200 or more. Hope you all are doing great!

Mark Aguirre said:

Hello all. Its the "newbie" again. I have three eyepieces (that came with the scope) including a Meade 26mm, 9mm and an Orion 17 mm.

Can anyone give any recommendations for other eyepieces to own? What would the advantage be in using 2" eye pieces versus 1.25"? I think what I am getting at is the differences between for example a 20 mm that cost $40 and a 20 mm that cost $200 or more. Hope you all are doing great!

Mark: There is a lot to know about eyepieces... Here's a few bits to consider:

- Most eyepieces are sharp in the center of the field of view.

- The advantage of 2 inch eyepieces is that they offer the possibility of a wider field of view, important with longer focal length eyepieces. The field of view is determined by the diameter of the field stop of the eyepiece. The field stop is the ring you see at the edge of the view when looking through the eyepiece. Remove the eyepiece from the scope, turn over and look down the barrel and you will probably see a ring, this sets the size of the field you see.

Since the ring cannot be larger than the barrel diameter (the inner diameter of a 1.25 inch eyepiece is about 27.5mm) the way to get a larger field of view is to use a larger barrel, ie 2 inch.

- A reasonable 20mm Plossl will cost around $40, it will probably have reasonable coatings, it will provide a ~50 degree apparent field of view and in an F/6 telescope will provide quite nice views with minor astigmatism of the stars (no longer sharp) away from the center of the field of view.

As you pay more, you can buy yourself a variety of improvements, a wider field of view that is better corrected so that the edge stars are sharp even in an F/4.5 telescope. Or maybe better coatings that make for less internal reflected light and better transmission.

The eyepieces one can buy today for $40 are really quite good...

- Sugestions: A 2 inch widefield eyepiece with a focal length of 30mm-40mm. This will provide you with a nice finder eyepiece, ie a 1.5-2 degree True Field of View. At the low end, GSO Superviews are pretty decent and very affordable. At the high end, the 35mm Panoptic is quite nice and likely to be a lifetime's investment...

- A 2X barlow would help...

- Planetary eyepieces: Some of the BO/TMBs have nice eye relief, a nice 60 degree AFoV and quite nice optics. Used these are under $50. A 6 or 7mm would be a nice addition to your collection and later you might replace the Meade 9mm with the BO/TMB 9mm.

Eyepieces, you can never have too many...

Jon

It would be helpful to know the type and specifications of your telescope, but...

Being an eyepiece collector I can tell you there are many excellent ones to enjoy at all price levels. Personally I like Televue Plossls (especially the old smoothies), University Optics volcano top abbes,BO Planetaries, and GSO Superviews (especially the 30mm which is a 2" model) in the low priced arena. If you shop the Amart Classifieds all of these can be gotten for very good prices. The Televues are more money, but I think they are worth it. The barlow is also a good idea as you instantly double your focal length choices.

Best advice is to just pick the focal lengths you would like to have and go for it. Checking all this great equipment out for yourself is half the fun of this hobby. If you buy used then you can resell what does not suit you for little loss of funds.

Not sure if you are still monitoring the forum, but I'll throw in my 2 sense...

I have had an 8 inch F/6 dob for over 10 years. Initially, I tried several different eyepieces. For the last 9 years, I've been observing with 2 eyepieces and a quality barlow lens. In my experience, it has proven much better to have a few better quality eyepieces rather than a bunch of cheap ones. I have a Meade 24.5 SWA eyepiece for low and medium powers, and an older style 9 mm for medium and high powers. You can shop the classifieds and probably find both for a total cost of around $300. While these are by no means the best eyepieces available today, they are so much better than most eyepieces. I can't express how much more you will enjoy your telescope if you have quality eyepieces. Although what eyepieces you eventually settle on depend on your observing preferences, weather in your neck of the woods, etc... I've found that most things look good at powers between 50x and 150x. A higher power in the 200x range is nice to have. But because of the seeing I don't usually have the opportunity to use that kind of power. The best way to go about buying your eyepieces is to get eyepieces in the middle ranges first, then expand to the very low and very high power.