Binoculars review

Delta Optical Titanium 10x42

Delta Optical Titanium 10x42
15 January 2010
The Polish Delta Optical company in March 2007 enlarged its flag series of binoculars, called Titanium, by other models. Next to the 8x56, 8.5x45 and 10.5x45 instruments, already present on the marked, roof prism Titanium binoculars with 8x42 and 10x42 parameters hit the shelves.

The newest DO products are made in Japan and the company decided to take up a really difficult challenge. The binoculars are to be small (dimensions of 145x125x50 mm), physically light (about 670 grams) and solid at the same time (aluminum body padded with good quality rubber), nitrogen-filled, waterproof and, what’s unique in this class, they are to have a wide field of view – 7.15 degrees in the case of the 8x magnification model, 6.5 degrees, in the case of the 10x magnification model.

The optics is also to be of the highest quality. All air-to-glass surfaces are covered by four-layer anti-reflection coatings of the newest generation. On the roof prisms in the Schmidt-Pechan system we find phase correction coatings and on the reflective surface – a special 64-layer coating. They ensure that the light reflection will reach 99.9% and because of that the light losses on the prisms are to be limited to minimum and the overall transmission level is to be high.

  • Lornetka Delta Optical Titanium 10x42
  • Lornetka Delta Optical Titanium 10x42
  • Lornetka Delta Optical Titanium 10x42
  • Lornetka Delta Optical Titanium 10x42
Manufacturer data


Delta Optical
web site

Distribution / Sales:

Delta Optical
web site

Magnification Lens diameter Angular field of view Prisms Eye relief Weight Price
10 42 114/1000(6.5o) BaK-4/roof 14.5 mm 676 g 1990 PLN
Results of the review
Real front lens diameter Left:   41.96+/- 0.05 mm
Right:  42.01+/- 0.05 mm
8 / 8.0 pkt
Real magnification 10+/- 0.15x 3/3.0
Transmission 84+/- 3% 11.5/25.0
Chromatic aberration Slight in the centre, high at the edge. 5.2/10.0
Astigmatism Slight. 7.5/10.0
Distortion The distance of the first curved line from the field centre compared to the field of vision radius: 30% +\- 6% 2.5/10.0
Coma Slight. 7/10.0
Blurring at the edge of the FOV The blur occurs in the distance of 69% +\- 3% from the field of view centre. 3/10.0
Darkening at the edge the FOV Noticeable. 3.5/5.0
Whiteness of the image Very light pink. 4/5.0
Collimation Exemplary. 5/5.0
Internal reflections
Left: Right:
Delta Optical Titanium 10x42 - Internal reflections - Left Delta Optical Titanium 10x42 - Internal reflections - Right
Housing Very small, light and handy. Good rubber, slightly ribbed, it sticks out a bit near the objective lens. Twist-up eyecups with three detented stops seem to be very delicate. 7/8.0
Focusing Comfortable central screw (750 degrees) moves smoothly and is well-damped. Very comfortable ring on the right eyepiece works correctly but moves the lens. 4.6/5.0
Tripod There is a comfortable exit. 3/3.0
Interpupilary distance from 58.5 to 76.6mm 5/6.0
Closest focusing distance 1.60 m. 2/2.0
Eyepieces FOV Apparent field of view of 64.8 deg (according to simple formula) and 59.0 deg (according to tangent formula). 13.5/20.0
Field of view Measured by us amounted to 6.48 +\- 0.03 degrees and was in accordance with the specifications. A large field of view for this equipment class. 7.5/8.0
Quality of the interior of the barrels Black inner tubes, slightly shiny. Nice black bottom. A few specks of dust. 4/5.0
Left: Right:
Delta Optical Titanium 10x42 - Vignetting - Left Delta Optical Titanium 10x42 - Vignetting - Right
OL: 1.5%, OR: 3.2%.
Prisms quality High quality BaK-4. 8/8.0
Antireflection coatings Green-blue on the objectives and the prisms. Green-blue-yellow on the eyepieces. Low intensity. 5/5.0
Warranty [years] 8 4/6.0
Final result
30th place in global rank of our test of 10x42 binoculars.
131.9 / 190 pkt
Econo result 37th place in the Econo rank of our test of 10x42 binoculars. -1.7pkt.


  • small, handy and solid housing at the same time,
  • wide field of view,
  • wide IPD,
  • sharp image already from 1.6 metres,
  • slight coma and astigmatism,
  • good whiteness rendition,
  • good quality of prisms and coatings,
  • quite good blackening inside the binoculars.

  • high distortion,
  • average sharpness at the edge of the field of view,
  • distinct chromatic aberration at the field’s borders,
  • truncated exit pupils.

The Delta Optical company has almost always offered binoculars with a good or very good price/quality ratio so it has had a lot of less well-off customers who appreciated good quality nevertheless.

The Titanium series was supposed to be a step towards a higher price segment with keeping the excellent price/quality ratio at the same time. In the case of the 8x56 model it turned out well, in the case of the 10x42 instrument – not so well. We must pay about 700 USD for the binoculars and we get small weight, a wide field of view and good, but nor very good final score in the test instead. If we are able to accept a bit narrower field of view we will find several instruments cheaper and significantly better than the Titanium – it’s enough to mention such roof prism instruments as a Swift Ultralite, a Vortex Viper or an Olympus EXWP-I

If we care about a wide field of view we have three other possibilities and, unfortunately for the Delta Optical company, each of them is better than the purchase of the Titanium. We can add about 300 USD and buy an excellent Bynolyt Albatross. For only about 150 USD more we can buy a Bushnell Discoverer, which is slightly better than the Titanium. Finally we can give up a roof-prismatic instrument, save over 300 USD and buy an Opticron Countryman 10x42 MC T which is only slightly worse than the Titanium. If, however, the weight and handiness are crucial to you we must honestly admit that the DO Titanium is the best from the all the six devices, listed here.