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SP 10x50 WP

Pentax porro 10x50

Item details

Model SP 10x50 WP
Lens diameter [mm] 50
Magnification [x] 10
Angular field of view [deg] 5
Linear field of view [m/m] 87/1000
Exit pupil [mm] 5
Eye relief [mm] 20
Min. focusing dist. [m] 5.5
Twilight factor 22.36
Brightness 25
Prisms BaK-4/Porro
Dimensions [mm] 178x183x79
Weight [g] 1060
Waterproof Yes
Nitogen filling Yes
Tripod exit Yes
Focusing central
Warranty [years] 30
(UK Street Price Jan 2018: 149)

Latest reviews

  • Bright, good for the price, waterproof, fog proof, recommended for astronomy
This binocular exceeds my expectations for the best binocular. The images are very clear, bright and colorful, the lenses are great.
  • Bright. Sharp for most of the field. Waterproof Porro. 10x
  • Closest focus is about 30ft. AFOV 5degr. poor lens caps.
The lens caps, rainguard, and strap are basic and the bag is just a cover but the finish and everything else gives an impression of quality. The weight seems less because they are large and have a comfortable shape with thumb depressions. There is plenty to hold on to, which makes the 10x magnification relatively easy to keep still.

The focus action is smooth and accurate. Unusually the focussing bridge itself is hidden inside the body and, although movements of the wheel require fairly firm pressure, the ribs on the wheel are sharp and prominent enough to make focussing easy. Using the natural and comfortable grip the large wheel falls straight to the middle fingers. There is no 'stiction' and the action is lighter than other waterproof porros (e.g. cf. Celestron Landscout and Nikon EX).

Dioptre adjustment has a clicking mechanism assisted by tabs, and the focus wheel slides forward with a click to lock it with a light but positive action. For subjects which are mainly in the middle and far distance this can usefully be set for best focus at infinity. The attachment thread for a tripod is directly above the centre of gravity.

The view was immediately pleasant, with natural colours. With the attention on the centre, the whole field seemed sharp and bright. Using a test chart, centre definition was only a little behind mid range roof prism 10x examples of Pentax ZD and Opticron DBA VHD, which understandably also appeared to have more saturated colour and stronger contrast. Away from the centre there was a little CA but pincushion distortion was notably less than usual: with a square frame occupying the whole field, all four lines were straight.

The August 2017 Albinos review https://www.allbinos.com/index.html?test=lornetki&test_l=324 says: "Blurring at the edge of the FOV: Blur occurs in a distance of 69% 4% from the field of view centre." In practice such blurring was not noticeable, although I suppose it contributed to Albinos' conclusion: "I would recommend the Pentax to those who care more about the usefulness of the instrument than its optical performance...."

Wearing glasses for distance, they worked for me with unextended click-up eyepiece covers. Close focus was as much as 30ft, with binocular overlap in evidence, and anyway the IPD would have needed adjustment for a closer view. The supplied individual objective caps were replaced with handier Vortex tethered rubber flip down covers.

I thought the sharpness, brightness, and colour were good for the purchase price of 155, and for me they were easy to use. Unless closer views are required I believe they offer an interesting large alternative.

Item information

Large Binoculars
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4.50 star(s) 2 ratings

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