Telescope Reviews: Brunton 'Lite-Tech' 10x42 mini -review

I brought these on my local E.Bay site. They are the entry level Brunton ‘Lite-Tech’ models. These are the 10x42 versions and are Chinese sourced. They cost me the equivalent of US$80 which appears to be the asking price in the USA. Brunton produce a range of outdoor products.

Specs:

They have a FOV of 5.5 and an Afov of 55 degrees. They are W.P. and nitrogen purged. The specs say they are F.M.C. which Brunton call ‘Emerald Fire’. The front and rear lens reflects a medium green / emerald hue. They weigh 850gms / 30 oz. The minimum focus distance is a close 10 Ft./ 3 mtrs. The eye relief is 13.6 mm. The oculars measured 20 mms. The exit pupil is 4.2mm. I measured the IDP at 56-74mm. The outer covering is black rubber armor over a polymer frame. They have Bak-4 prisms. They are tripod mountable. They are not phase coated.

Build:

The build quality appears good - surprising so at this price point. They feel solid and easy to hold. The hinge is firm and solid. Looking down the barrels they appear clear with no prism cut off. There were no obvious internal white reflections. I could see the faint outline of my reflected face. There were no baffles. The exit pupils were round. The focus wheel is very firm and precise with no play. Focus speed is medium
The individual hard twist eyecups are very firm to adjust but again provide no play. There are no click stops. The right diopter is very firm to rotate. It has a good range of accommodation.

Optics and viewing:

Optically they provide moderately bright day time images, with reasonable resolution and neutral color. Central images appeared generally sharp. Contrast and depth of field appears adequate. Good focus was easy to achieve. There were no blackouts.
Surprisingly again at this price point again there are no major aberrations and distortions. There is mild field curvature, barrel distortion and astigmatism but these are generally unobtrusive.
Noticeable edge distortions occur in the last 20% of view but this measurement is subjective.
Overall there is surprisingly minimal CA.
At night on axis stars are reasonably sharp. The field appears reasonably flat.
On dark skies the image quality is actually good. Due to the relatively flat field it tends to suit astronomical applications.

They appeared well collimated with no eyestrain noted following viewing for one hour.
They were comfortable to hold.
At 30 Oz. / 955 Grams. they are not ‘lite’ as such compared to similar size binoculars.
The 5.5 degree FOV and 55 degree Afov whilst certainly not wide does not have a constricted feeling. The relatively narrow FOV may account for it’s reasonably aberration free image.

The main negative however is noticeable internal reflections and light scatter on bright objects.
This is noted at day time and night time.
When objects are viewed in the vicinity of the Sun moderate and distracting internal reflections occur.
The same effect occurs when viewing near the vicinity of moon - internal reflections and secondary ghosting are noted. I believe this is in part due to the fact that the blackening paint used in the internal surfaces is not a matt black. There is a moderate reflective shine to it.
Also on the outside of the cell in front of the objective lens there is a threading for the cell ring – again this is not matt black there is a light shine to it and it enables reflected light to enter. [See also ‘F.M.C.’ comments below].

Also at times and on certain angles stray light enters the side of the eyes and creates secondary reflections on the ocular which again at times are distracting.
‘Cupping’ the eyepieces with one hand removed these reflections.
A simple solution would be the use of winged eye cups.
I am aware this would be logistically difficult due to the nature of the twist eyecups.

When looking at the full moon there is a mild halo effect noticed.
On bright sodium vapour lights there is moderate spiking and multiple secondary ghostings noted.
When the sun or the bright moon is at your back or the conditions are dull or dark these internal reflections are not noticeable.

Comparison:

One other issue I should briefly mention is that I actually resolved more faint stars in the open cluster M7 with my 8x40 Minolta Activa WP FMC / Bak-4 porro-prism binoculars.
Contrast was mildly superior also.
Obviously this was a very ‘unscientific’ test.
This may be due to ‘inferior’ and / or not true ‘F.M.C.’ lens coatings on the Bruntons and / or resolution differences between the porro and roof prism design. Obviously other factors have to be taken into account like eyepieces, magnifications, build and optical qualities.
The Minoltas also displayed minimal internal reflections on bright objects.
The Minolta Activas however cost me approx. twice the price.
The ‘inferior’ and / or not true F.M.C. lens may also explain the excessive internal reflections in the Bruntons.

Summary:

Overall they are reasonable binoculars. They do provide - at times - good quality images. They have good build qualities. They are waterproof.
At this price point they would be considered good value.
However the main negative being is - at times - excessive and multiple internal reflections and extraneous light scatter which occurs primarily in the vicinity of bright objects.

Due to this factor they are difficult to recommend.

This is a disappointment as otherwise they are an inexpensive robust ‘cross over’ waterproof roof prism binocular.

Chris

[I have no affiliation with Brunton or Minolta.]

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35 binos.
80mm Cat.
WO66ED
SV NH 80mm / EQ3
Meade 8in.LX90
Skywatcher Equinox ED120 / Goto HEQ5.