What are people’s views on Explore Scientific 52° eyepieces?

[Olli]

I am looking to buy the 20mm version and I was wondering if anyone’s used these before and how helpful are 52 degree eyepieces?

 

 

many thanks 

[vlaiv]

Why don't you just go with regular plossl in 20mm version?

Something like Vixen NPL will be cheaper and will offer almost the same specs - 15mm eye relief and 50 degree FOV.

Alternatively, if you want larger FOV - maybe 62 degree line? 68 degree line will almost certainly be better but is quite a bit more expensive.

[johninderby]

I did try one of the 52 degree ES eyepieces and it wasn’t bad but not memorable either. Just an ordinary eyepiece with nothing to make it stand out. Think the BST Starguiders would be a better choice and wider fov.

[Louis D]

The ES-52 line is really only advantageous at 15mm and below relative to a similar Plossl thanks to their more generous eye relief.  Those are all 6 elements in 3 groups eyepieces.  Presumably, they all have a negative/positive design similar to the Vixen SLV line at those focal lengths.

The 20mm, 25mm, 30mm, and 40mm are all 4 elements in 2 groups eyepieces.  Presumably, they are Plossl variants.  As such, I don't know what advantage the first three offer over a Plossl.

The 40mm is interesting in that it is a 2" eyepiece allowing for a 36mm field stop diameter instead of the usual 27mm FS limit imposed by a 40mm eyepiece in a 1.25" barrel.  Does anyone know of any other 40mm 2" Plossls?

[Ags]

In comparison to plossls they are heavy and long.