Location: home,
Equipment: Stelarvue 102ED on
Altair Astro Positive Lock 2” Prism test.
I have picked this prism last year but never put it through a thorough testing. Had to ship it from UK since it is not available in US. The prism is built like a tank. Fit and finishes look very similar to Baader Click Lock (with similar locking mechanism). Albeit Baader Click Lock is a dielectric mirror diagonal.
The rest of the session was devoted to Aquarius doubles. There were some though splits, and the diagonal performed admirably. What sold me was STF 2752 split (detailed below), where I have barlowed TV Delite 5mm with Baader Q 2.25x barlow for whooping 322x (0.3mm exit pupil) and yet got very sharp well defined airy disks for both components.
When splitting doubles I typically use entire
; just occasionally pulling TV Delite 3mm (238x) out of the Aquarius
STF 2706 AB – 8.7, 10.8, 11.2”, orange, blue – nice colors (65x).
HDS 2970 – 9.0, 10, 15.2”, yellow, orange (39x).
STF 2752 AB – 7.3, 10, 3.5”, yellow, white. Went through my
BU 473 AB – 8.9, 10, 1.9” – FAIL – I guess this is a bit too much for 4” frac.
STF 2770 – 7.6, 10.8, 7.5”, golden, blue – nice colors (65x).
STF 2768 – 7.8, 10.5, 7.9”, yellow, blue. (143x).
STF 2775 – 7.5, 10.4, 11.1, 11.5, 10.5, ac21.4”, ad170.2”, de74.5”, af184.7”, white, 4x silver (143x). I would not call it a beautiful system, but I like to look at stars
, and systems like this provide a good challenge identifying components by distance, PA and magnitude. Some of the components were also at the limit of detection for the sky conditions on that night, which added another difficulty level. On a good night 4” scope can push below mag 12. The system looks optical, but apparently AC and DE are physical pairs. STF 2776 – 8.3, 9.9, 10.9, ab83.5”, bc5.9”, yellow, white, white. AB were wide apart at 39x, BC split required 143x.
STF 2778 AB – 8.7, 10.9, 18.3”, white, gray. Secondary was detected with averted vision at 143x.
STF 2781 – 8.7, 8.9, 2.7”, white pair – clean tight split at 143x.
BU 161 – 8.2, 10.3, 11.6, ab100.7”, bc8.2”, yellow, 2x white. AB is a wide pair at low power. AC was a challenge to split. C was detected with averted vision at 238x.
BU 165 – 8.6, 10.6, 5.4”, yellow, gray. B detected with averted vision at 238x.
HJ 3039 – 8.8, 10.1, 11.7”, 2x white (65x).
At 22:30 the fog started moving up the hill which ended my session.
