Product Description
This is a very good quality medium power eyepiece for lunar observing, resolving globular clusters, picking up detail in emission and reflection nebulas, etc. It has a rubber grip ring for a comfortable grip in cold weather. It provides an almost 4.5mm exit pupil with an f/4.5 Dobsonian reflector for rich field scanning of the Milky Way star clouds in Sagittarius. It's an excellent choice to complement the 40mm eyepiece provided with some go-to Schmidt-Cassegrains. It will work well with any telescope type, at any focal ratio, under any seeing conditions. It has somewhat short eye relief that will limit the wide field for eyeglass wearers. Those who don't wear glasses should have no problem seeing the entire field in comfort. It is parfocal with other Series 4000 eyepieces except the 14mm UWA, 32mm and 40mm SWA, and 40mm and 56mm Plössls.
Tech Details
| Barrel Size | 1.25" |
|---|---|
| Eye Relief | 13mm |
| Field of view | 51 |
| Focal Length | 20mm |
| Number of optical elements | 4 |
| Weight | 5 oz |
| Warranty | 1 year |
Reviews
Review by: JohnC6
This is one of my favorite ‘pull out anytime’ and ‘pass around eyepiece’. It works in a nice range for most any focal length and most any telescope. No, it is not a $xxx.xx cost piece, but if you loose it, your not out much. P.S. buy the 32mm too. (Posted on 10/24/2019)
Review by: JohnC6
This is one of my favorite ‘pull out anytime’ and ‘pass around eyepiece’. It works in a nice range for most any focal length and most any telescope. No, it is not a $xxx.xx cost piece, but if you loose it, your not out much. P.S. buy the 32mm too. (Posted on 10/24/2019)
Review by: Skyhunter1
The 20mm series 4000 was one of my most used plossls for many years. I have owned nearly every series 4000 eyepiece and they are a great value for the money. If you're just starting out, they are a great value. I mostly used the 40, 26 and 20mm eyepieces but the higher powered ones from 15MM up perform very well. Used them mostly on a C9.25 and a meade 8" LX200. If you need multiple eyepieces, buy the series 4000 set and save some money. Used this eyepiece for many years before I upgraded to TeleVue and series 5000. the price /performance ratio is worth the cost. (Posted on 12/3/2018)