Hello everyone. Today I have a review of a rather unusual thing, that all the boys in the old school days must have dreamed of. But the school has long been over, all are grown up, and childhood dreams have been long forgotten. And to make my "I" in the distant past happy, to make my childhood dream come true, this pair of binoculars was purchased. And not a fake one, but a real, although it is cheaper than a standard Barbie doll from the toy store.
I based on the following criteria when choosing binoculars:
• 1. They must look like a real binoculars, I mean, there must be a Porro system of prisms. For reference – there are 2 systems, Porro and Roof. When using the Roof system eyepiece and objective lens are on the same axis, so the binoculars are more compact, but the image quality is lower. For the classic Porro system, with separated optical axes of the lens and eyepiece, the image quality and the stereo image is higher.
There are a lot of articles in the Web about the technical specifications of binoculars.
• 2. Zoom. The binoculars should have a sufficiently large zoom, and hence the size. So small "theater" binoculars should be rejected immediately. At the same time, too big and heavy binoculars are also not suitable enough.
In the end, the choice fell on this model BIJIA 20 x 50 Portable.
Specifications declared by the manufacturer:
• Size 180 x 180 X 60 mm
• Objective lens diameter: 50 mm
• Eyepiece diameter: 20 mm
• Field of view angle: 150 m / 1000 m
• Magnification: 20X
• System of prisms: Porro BAK4
• Minimum focus distance: 10m
The binoculars was delievered in a cardboard box with printing of high quality. There was a thin package on top of the box, but surprisingly, the box came fully intact.
There was also the tubular package inside the box with inflated air in the walls that should protect the binoculars from bumps during shipping.
Included with the binoculars is a crossbody bag, for convenient carrying and storage. Bag is made of a standard waterproof material, with a rubber sheet inside, and with cloth on the back. Bag closes using Velcro fasteners, straps are adjustable.
There is already the binoculars inside the bag, as well as instructions and a couple of leaflets in the Chinese. No English instructions, all is written in Chinese. But instructions are purely nominal for such a simple device. Importantly, it stated that you must not look through the binoculars at the sun, otherwise you can lose vision.
The package has also 2 cloth for wiping the lens, and the strap for the binoculars.
To protect the lens during storage and transportation the manufacturer has provided protective caps. But they do not fix on the body of the binoculars and they have no grooves to fix them on the cord.
The body of the binoculars made of metal, top is completely covered with a layer of rubber with plastic inserts. The manufacturer promises protection from moisture. It refers protection from the rain. However, they can not be used under water.
In places where your fingers wrap binoculars, there are additional anti-slip rubber inserts embossed. Binoculars lie in hand conveniently and integrally.
The binoculars also feature a holographic sticker with a stretch code that confirms the authenticity of the product.
Also in the binoculars there is a standard threaded socket for mounting it on a tripod. The socket is closed with a plastic plug.
Eyecups made of soft rubber. On the right eyepiece there is a diopter adjustment. Left and right eyes of most people have different levels of visual acuity. Therefore, when setting the binoculars for the first time you should adjust sharpness of the left eye with a large central regulator on the binoculars, and then the right eye sharpness should be constrained using this adjustment. This adjustment may be configured as "+" and "-". In fact, you only need once to adjust the binoculars under your vision in order to both eyes could see a clear picture at the same time.
The size of the binoculars is 18 cm x 18 cm x 6 cm. Weight - 769g.
Now, the most interesting, the zoom. To learn zoom, I'll do 2 photos of the same object – just on the phone, and on the phone, but with the binoculars. Then I`ll measure the objects in the images and will calculate the zooming. For more accurate measures I`ll take photos of 2 different objects in this manner.
First, I fix the phone on the binoculars. There are special clamps for regular use, of the type of http://www.gearbest.com/binoculars-and-telescopes/pp_598021.html . For single use my version will be OK.
Now, I take 2 pictures, without the use of binoculars.
Next, I cut crop objects from photos, which I will compare. Crop is a part of a photo cut from full pictures without reducing size.
Then, I take pictures of the same places, but with the binoculars.
By the way, you can the quality of the binoculars in these photos – the picture is bright and crisp without artifacts. There is a slight darkening at the edges due to the fact that it is difficult to compare the camera of the phone clearly on the same line as the image in the eyepiece.
I take crop objects already from photos through binoculars
And then, I combine the pictures in photoshop, where I measure the size of objects and calculate proportions.
From images you can see that in the first case we received zoom in x43, in the second case in x46, which is very close to the first result. Therefore, I believe that the methodology and results can be trusted.
So, total measured zoom of Portable binoculars BIJIA 20 x 50, is x45.
But what is this "Multiplicity: 20X"? Googling, I learned that it is the ratio of the angular size of the object observed through binoculars to the size of the same object, visible to the naked eye. All my life I was sure that the multiplicity is the number of zooming of the binoculars. So it is, trust –but verify.
And for example – here's a crop from the camera, with a x12 zoom capability. But here both the matrix is more than in phone and technologies are a little more serious.
As a result, I like binoculars BIJIA, it is so good that I'll have to take it for a trip. Of course, it takes place, but the opportunity to see things, for example in the mountains or in the countryside, to enjoy the scenery and feel closer to hundreds of meters, is worth it.