My birding friends sneer at these, or assume I use them only because I am ignorant about binoculars. Far from it.

These are Porro prism binoculars -- you can tell from the distinctive shape. Birders overwhelmingly prefer roof prism binoculars, the kind with the straight-through geometry. So, these are uncool. Still, I like them, for the following reasons:

First - bigger objective lens. That's the second number in, for instance, 10X50. Bigger objective lens means a better view in low light, and wider field of view. That means it's easier to find a small bird in a thicket. By comparison, roof plane binoculars usually have a 40 or 42 mm objective lens.

Second - stronger magnification. Most birders use 7 or 8 power (the first number in 10X50). Ten power is nicer if you're trying to see a small bird, a bit far away. The downside is that ten power tends to be a bit jiggly -- you can't hold them quite still enough. This is a bigger problem when the stuff you want to see is far away. It's worst with astronomy, and pretty bad at 100 yards or more. But there are ways to compensate. The best way is to prop one elbow or shoulder, or the binoculars themselves, against a tree or post. Next best, pull your elbows together and prop them on your own chest. Also, see next item.

Third, if you get a tripod adapter, optional, but inexpensive, you can mount them to a tripod for birding or astronomy. For birding alone, a monopod might be even better. Lightweight and very quick and simple to use. This completely eliminates the jiggling problem.

Fourth, they are very inexpensive compared to the usual binoculars that birders use. If they get damaged, you can afford to replace them.

Fifth, the optics seem pretty good. The focus is quite sharp.

A neutral item: The quick focus lever has been criticized a lot. In theory, it's a bad idea, but in practice, it seems to work okay.

They have some down sides. They are rather heavy and bang against your chest unpleasantly if you use a strap or harness and hike much. I prefer to carry them in one hand. They are not waterproof and probably not fog resistant. On cold, damp mornings, or in the rain, this could be a problem. On such days, I leave them at home and use something else. If they get damp inside, they may be ruined. But then, waterproof binoculars can cost hundreds of dollars. These are only fifty, give or take.

The other down side is that they don't focus as close as the roof prism binoculars favored by birders. These won't focus closer than about 40 feet. Every now and then, I have to take a couple of steps back to get a bird in focus. Given the foregoing advantages, I can live with that.

These are my personal preferences. Your mileage may vary.
My birding friends sneer at these, or assume I use them only because I am ignorant about binoculars. Far from it. These are Porro prism binoculars -- you can tell from the distinctive shape. Birders overwhelmingly prefer roof prism binoculars, the kind with the straight-through geometry. So, these are uncool. Still, I like them, for the following reasons:

First - bigger objective lens. That's the second number in, for instance, 10X50. Bigger objective lens means a better view in low light, and wider field of view. That means it's easier to find a small bird in a thicket. By comparison, roof plane binoculars usually have a 40 or 42 mm objective lens. Second - stronger magnification. Most birders use 7 or 8 power (the first number in 10X50). Ten power is nicer if you're trying to see a small bird, a bit far away. The downside is that ten power tends to be a bit jiggly -- you can't hold them quite still enough. This is a bigger problem when the stuff you want to see is far away. It's worst with astronomy, and pretty bad at 100 yards or more. But there are ways to compensate. The best way is to prop one elbow or shoulder, or the binoculars themselves, against a tree or post. Next best, pull your elbows together and prop them on your own chest. Also, see next item. Third, if you get a tripod adapter, optional, but inexpensive, you can mount them to a tripod for birding or astronomy. For birding alone, a monopod might be even better. Lightweight and very quick and simple to use. This completely eliminates the jiggling problem. Fourth, they are very inexpensive compared to the usual binoculars that birders use. If they get damaged, you can afford to replace them. Fifth, the optics seem pretty good. The focus is quite sharp. A neutral item: The quick focus lever has been criticized a lot. In theory, it's a bad idea, but in practice, it seems to work okay. They have some down sides. They are rather heavy and bang against your chest unpleasantly if you use a strap or harness and hike much. I prefer to carry them in one hand. They are not waterproof and probably not fog resistant. On cold, damp mornings, or in the rain, this could be a problem. On such days, I leave them at home and use something else. If they get damp inside, they may be ruined. But then, waterproof binoculars can cost hundreds of dollars. These are only fifty, give or take. The other down side is that they don't focus as close as the roof prism binoculars favored by birders. These won't focus closer than about 40 feet. Every now and then, I have to take a couple of steps back to get a bird in focus. Given the foregoing advantages, I can live with that. These are my personal preferences. Your mileage may vary.