Binoculars review

Results of the review

Real front lens diameter	Left:   41.97+/- 0.05mm Right:  41.99+/- 0.05mm	8/8.0
Real magnification	9.72+/- 0.05x	3/3.0
Transmission	75+/- 1.5%	8/15.0
Chromatic aberration	Medium in the centre, high on the edge.	3/10.0
Astigmatism	Average.	5.8/10.0
Distortion	The distance of the first curved line from the field centre compared to the field of view radius: 39% +\- 3%	4/10.0
Coma	Appears in the distance of about 65% from the center of FoV and is higher than average at the edge.	5.5/10.0
Blurring at the edge of the FOV	The blur occurs in the distance of 70% +\- 4% from the centre of field of view.	3/10.0
Darkening at the edge the FOV	Noticeable.	2.8/5.0
Whiteness of the image	Slanted transmission curve with a hollow for green light.	2.3/5.0
Collimation	Perfect.	5/5.0
Internal reflections	Left: Right: Noticeable „teardrop” next to the proper exit pupil.	3.5/5.0
Housing	Small, shapely, handy and stylish. Good, rough rubber padding so the binoculars are comfortable to handle and to look through. Rubberized eyecups with three click stops but can be set in between them too. The rubber doesn’t stick out near objectives. A surprisingly solid device for a pair of binoculars produced in China and sold at this price point.	8/8.0
Focusing	Comfortable and ribbed central wheel which full range amounts to 250 degrees. It moves smoothly and is well-damped. A handy individual focus ring on the right eyepiece. It works properly and it moves the outer lens.	4.5/5.0
Tripod	There is a comfortable tripod exit.	3/3.0
Interpupilary distance	from 56.2 to 75.4mm	5/6.0
Closest focusing distance	2.65 m	1.5/2.0
Eyepieces FOV	Apparent field of view of 57.3 degrees.	6/10.0
Field of view	Measured by us amounted to 5.90 +\- 0.05 degrees and it was just a tad smaller than stated in specifications. Typical field for this class of equipment.	5/8.0
Quality of the interior of the barrels	Dark and mostly matt inside the inner tubes. Bottom quite dark but not black. Some fine specks of dust , mainly in the right inner tube.	4/5.0
Vignetting	Left: Right: OL: 3.67%, OR: 6.19%. Significantly truncated exit pupils.	1.5/8.0
Prisms quality	Good quality BaK-4.	8/8.0
Antireflection coatings	Greenish everywhere, medium intensity.	4.5/5.0
Warranty [years]	Life time warranty	6/6.0
Final result		110.9/170 65.2%
Econo result		0pkt.

Summary

• small, compact and stylish casing,
• good blackening inside the inner tubes,
• good quality prisms, made of BaK-4 glass,
• sensible appearance of the area near the exit pupils,
• decently corrected coma,
• not very bothersome astigmatism,
• life time warranty period.

• noticeably truncated exit pupils,
• too high chromatic aberration,
• too weak transmission,
• resolution of the image on the edge of the field should have been better.

The Vanguard Spirit ED 10x42 is a small, handy and shapely pair of binoculars. When it comes to its build quality it is really beyond reproach. The attention to details, workmanship, design, cleanliness and blackening can put to shame many more expensive instruments. If you add to these a life time warranty you can expect many years of problem-free usage. The ED glass, which the Vanguard boasts of, suggested that, despite small dimensions, you can count on good optics either. Unfortunately the way the exit pupils looked brought us back down to earth very quickly. They are significantly truncated - apparently keeping the dimensions of these binoculars small was performed at the cost of the prisms. It causes low image quality on the very edge of the field. What’s more, the ED glass was not helpful at all when it comes to the proper correction of the chromatic aberration which level is simply too high.

The antireflection coatings also doesn’t meet contemporary standards. A graph posted below, can prove their low level performance.

As the value of less than 90%, reached for red light, is good, for shorter wavelengths the binoculars fares worryingly worse. The transmission level a bit over 70% is really not a result you can expect in a contemporary set of binoculars. What’s more the differences between particular wavelengths on the level of 20% make proper colour rendering virtually impossible.

To sum up we get here many medium results, too few very good results and one or two slip-ups too many for this piece of binoculars to be near the top in our 10x42 binoculars ranking.