How to choose a suitable telescope for your child?
1. Check magnification
Many people think that the higher the magnification of the telescope, the better the observation effect, but in fact, the magnification is inversely proportional to the field of view
The lower the magnification, the larger the viewing area, and the brighter and more stable image; the higher the magnification, the narrower the viewing area, and the lower brightness of the image.
Also, high-powered lenses require high stability, and if you don't hold the telescope steady (or use a tripod) for long periods of time, the image will shake violently, causing eyestrain or nausea.
Therefore, a portable telescope with a power of less than 10 times is the best choice for children.
2. Check the weight
Since the children are all observing by hand, the weight of the telescope should not be too heavy, otherwise it will be difficult to carry it, and the imaging effect will be unstable.
The weight of binoculars for children aged 5-10 should be kept below 500 grams.
3. Check the objective lens
Generally speaking, the larger the aperture of the objective lens, the larger the light-passing area, which helps the human eye to distinguish details, and the higher the resolution.
However, a large objective lens will increase the weight of the telescope, which is not conducive to children's use.
In recent years, with the development of telescope manufacturing technology, many small objective lenses around 20mm can also provide good imaging effects.
4. Check the optical coating
If the lens of the telescope is not coated, 50% of the light will be scattered when passing through the objective lens and cannot reach the human eye.
The best way is to apply multi-layer coating to the mirror surface, so that the light transmission rate can reach 90~95%.
5. Exit pupil diameter & pupil distance
The exit pupil of the telescope can intuitively indicate the amount of light entering the human eye. Only when the exit pupil matches the pupil of the human eye can a complete and bright image be seen.
The matching here includes size and position, that is, exit pupil diameter and exit pupil distance.
If the diameter of the exit pupil of the telescope is smaller than the pupil of the human eye, the image seen by the human eye will be blocked by the frame.
Generally speaking, the diameter of the pupil of a person in sunlight is about 2-3mm, and the pupil of children is larger than that of adults. The exit pupil diameter of children's telescopes should not be less than 2.5mm.
In addition, the position of the exit pupil is also critical.
If the exit pupil distance is too small, the human eye needs to be very close to the eyepiece to watch. It is bound to be uncomfortable to use, and it is not good if it is too far away. Generally speaking, this distance will be controlled at about 15mm, so as to obtain a comfortable viewing experience.
6. Check the price
The quality of optical products will definitely be limited by the price, so we do not recommend using telescopes that are too cheap.
But in the same way, we do not recommend high-priced telescopes that are thousands or tens of thousands of dollars in size. After all, children's needs for use have not reached the professional level, and it will be more distressing if they are broken.
What telescope would you choose for your child?
Contact Person: Miss. Allie Nie