First Impressions 

--The Svbony SA204 10 x 50 binocular.

The SA204 10 x 50 package took about two weeks to arrive from the Far East to my home. As usual with Svbony, I was extremely impressed with the attention to detail in how it was packaged during its long trip to the UK. The instrument arrived double boxed inside some bubble wrap to ensure that nothing moved out of place during transit.  All the accessories were also neatly packed away, including the ocular and objective covers, a carrying strap, lens cleaning cloth, a well-written instruction manual and a decent soft padded carry case. Inspecting the binocular, my first impressions were very favourable. The instrument is covered in a high-quality textured rubber substrate, ribbed at the sides for extra grip. The twist-up eyecups moved smoothly and were easy to adjust, keeping their individual positions firmly when clicked into place. Two intermediate positions are available between fully retracted and fully extended, so plenty of options for those who like to experiment.

--Belly side up.

The aluminium central hinge is nicely tensioned, allowing you to easily adjust it to your preferred IPD. Once there, it stays rigidly in place. The rubber-covered central focus wheel has deep ridges to afford extra grip. Turning is very smooth with no free play. It ‘s quite stiff though, a consequence I suppose of the instrument being properly sealed and nitrogen purged. The focuser moves the eyepiece assembly up and down with no annoying wobbles I’ve seen in other instruments in this price class. 0.8 turns anticlockwise takes you from closest focus to jut beyond infinity. Eye relief is very generous. I was easily able to engage with the entire field using my varifocals, although I don’t wear spectacles when glassing under normal circumstances.

The dioptre adjustment is made using a small lever under the right eyepiece that rotates either clockwise or counter-clockwise, and I was easily able to find my optimal position. Once set in place, it stays there. I would say it’s very nicely engineered.

--The large ocular lenses and twist-up eyepieces are easy to engage with.

The large ocular lenses have nice green multi-coatings and the objectives are decently recessed as all good binoculars ought to be. The objective coatings appear to be significantly more subdued to those applied to the ocular eyepieces and I detected a faint reflection off one of the interior lenses possibly indicative of one surface being singly coated. The rain guard and tethered ocular covers are quite basic but do an adequate job protecting the lenes from rain and dust.

--The 50mm objectives have good coatings although there appears to be one surface that may be singly coated based on its appearance in daylight.

The instrument feels really nice in the hand with plenty of wiggle room to engage with my medium-sized mitts, making it easy to hold the instrument firmly. I was pleasantly surprised by the weight of the instrument without the strap and lens covers. Although the specs claim 925g, my SA204 tipped the scales at just 875g or 50 g less than advertised!  All in all, I came away with the impression that this was indeed a nicely appointed binocular, significantly better built than other 10 x 50 Porros I’ve tested in the past, including the Opticron Adventuer T WP and the Nikon Aculon.

Optics

My optical testing began by measuring the effective aperture of the instrument by directing my iPhone 11 torch into one of the eyepieces and measuring the size of the resulting circular shaft of light emerging on the other side of the objectives. By tracing a circle of diameter 50mm, I was able to show that the circular light shaft fitted snugly into the circle indicating that the SA204 was operating at its full aperture.

--The SA204 10 x 50 operates at its full aperture.

And you can view the light test and resolution test of SA204 binoculars here

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