My honest review of the 52 degree series from Explore Scientific.

[John]

8 minutes ago, Louis D said:

... What about a 3" 100° to max-out the available field in that size like the 30mm 82° does for 2"? ...

They have one of those:

https://explorescientificusa.com/products/100-30mm

[Louis D]

2 hours ago, John said:

They have one of those:

https://explorescientificusa.com/products/100-30mm

I mentioned it (They even have the giant 3" 30mm 100°.), but it only has a 52.2mm field stop diameter, only 6.2mm bigger than the 41mm Panoptic or 55mm TV Plossl field stops at 46mm diameter.  It would need to have a 3*25.4mm-4.8mm=71.4mm field stop to max out the 3" format (assuming the same barrel thickness and thin field stop edge as a 2" eyepiece that maxes out at a 46mm field stop).

[John]

4 minutes ago, Louis D said:

I mentioned it (They even have the giant 3" 30mm 100°.), but it only has a 52.2mm field stop diameter, only 6.2mm bigger than the 41mm Panoptic or 55mm TV Plossl field stops at 46mm diameter.  It would need to have a 3*25.4mm-4.8mm=71.4mm field stop to max out the 3" format (assuming the same barrel thickness and thin field stop edge as a 2" eyepiece that maxes out at a 46mm field stop).

Oops ! - I must read your posts a little more carefully Louis

 

[michael.h.f.wilkinson]

I eagerly await their 85.3° range

I must say I am slightly intrigued by this range. I have a couple of Vixen SLVs, mainly for travel, and these are really exquisitely sharp and comfortable, holding their own against the mighty Pentax XW line-up I have for home use, in all areas except FOV. I was half expecting this range of ES to go head-to-head with the SLVs, but the eye relief at the short end is not really as long as I would like. They only get 15-16mm which is borderline suitable, and what with the recessed eye lens, taking I would guess a mm or so off, I would struggle. The SLV line has 20mm eye relief throughout, which makes them preferable in my view.