Generally speaking, the larger the aperture of the objective lens, the higher the brightness. The observation effect in low light environment will be better. Telescopes with a diameter of 40-60MM are brighter. However, the larger the caliber, the larger the volume and the higher the weight. It is definitely not easy to carry. Of course, under the same caliber, the higher the multiple, the lower the brightness. So don't blindly pursue high-powered telescopes.
But now the coating technology is relatively developed, and good coating can greatly improve the clarity and brightness of the telescope. Dr Bosch's trophy series, bird watching series or higher-end series are all patented technologies of phase coating. Therefore, even small-caliber telescopes can have high brightness, which is very suitable for low-light-level night vision.
This is just a brief introduction. If you want to observe without a light source at all, you need to use night vision equipment. Night vision equipment can only be used during the day and is not suitable for ordinary people. Unless there is a special need.
I suggest you go to the 38-degree telescope for more information. I hope it will help you! ! !