7x50, 10x50 or 20x50 binocular?

[Markx]

hello guys, i have just got really interested into astronomy and stargazing and want to buy a binocular. i know that first number means magnification, but i found out that Celestron Upclose G2 10x50 more expensive than Celestron Upclose G2 20x50, so why if 20x50 is better?

also can you tell which is the best binocular for stargazing out of this three:

https://www.amazon.com/Celestron-UpClose-10x50-Porro-Binocular/dp/B006ZN4TZS/ref=sr_1_8_sspa?ie=UTF8&qid=1535134081&sr=8-8-spons&keywords=celestron+cometron&psc=1

https://www.amazon.com/Celestron-UpClose-10x50-Porro-Binocular/dp/B006ZN53FS/ref=sr_1_8_sspa?ie=UTF8&qid=1535134081&sr=8-8-spons&keywords=celestron%2Bcometron&th=1

 

https://www.amazon.com/71198-Cometron-7X50-Each/dp/B07F2RDXHN/ref=sr_1_1?ie=UTF8&qid=1535134081&sr=8-1&keywords=celestron+cometron

[Peter Drew]

The 20x50 isn't better, the magnification will result in being virtually impossible to hold steady and will need a tripod, the field of view will be small as well. The best option and most popular is a 10x50 as a good all rounder.  ?

[Ricochet]

7s or 10s so that you have a chance of hand holding them. The 20s might be cheaper because Amazon reduce the price every day that no one buys a particular item. 

[mark81]

+1 for the 10x50

I've been using 10x50s for years. The mag is perfect for a nice crisp image and they are nice and lightweight for a steady image.  Check out the Olympus dpsi, great bins.

[Charic]

The 10x50 would be good, the 7x50 may look 'better', the 20x50 would be the last one for me?

I have, 8x40, 7x50, 10x50, 15x70. I favour the 8x40's just now,  their just as bright as my 10x50,s but the 8x40's are clearly my favourite as they posses the wider field of view. I can hold all these binoculars in the hand, but the higher the first number, the more noticeable and apparent the shake  becomes at the larger magnifications. For me though I mount all my binoculars for the perfect steady view, bar one binocular due to no mount fitting!

[johninderby]

Yes the 20x50 will be very unsuitable for hand holding. Both the 7x50 and 10x50 would be better choices. The best thing would be try a pair of 7x50 and 10x50 and choose the ones that feel more comfortable to use. Myself I prefer the 7x50 as I just find them easier and more comfortable to look through than the 10x50 but you might find that for you it’s the other way round. 

[Charic]

42 minutes ago, Markx said:

i know that first number means magnification

The second number is the size of the objective lens in mm.

If you divide the Objective by the Magnification so 50/10=5.    50/7=7.14.  50/20=2.5. 40/8=5

These resulting numbers refer to the exit pupil? Hold your binoculars at arms length towards a bright source ( NOT THE SUN  ) and that little circle of light you see that appears to be hovering in front of the eyepiece is the exit pupil. For low light operations, having an exit pupil that closely matches that of your eye will get the most benefit from the beam of light. The larger the exit pupil, the wider the exit and the brighter the image, the opposite is true, the smaller the number, the darker the image will appear and have a much smaller width to the beam of light.

You'll see from above that the 8x40 and 10x50 have the same exit pupil of 5mm, and for me, is appropriate for my eyes. The difference between the two binoculars will be the  field of view, normally wider for the lower powered, and the target will appear closer using the 10x over the 8x, but both optics will provide an image of equal brightness to my eyes.

Like tools in a chest, the 13mm spanner is good on 13mm  bolts and nuts. Folk may own several binoculars for similar reasons? the wide field low powered are great for scanning wider vistas if your looking over the Milky Way, whereas the 15x70's may offer better detail when looking at the Moon. Unfortunately, for the distant planets, don't expect to see any great detail using any of my binoculars!

[refractordude]