Binoculars advice

[groaninjock]

Celestron 7x50 binoculars are going to be one of the Amazon Black Friday deals later today - are these any use for astronomy, or would they be completely useless?

[scoobee]

I found this site to be very good for advise/information, I use 10x50 and 20x80 i think 7x mag will be to small maybe could be good for the milkyway

http://binocularsky.com/binoc_choosing.php

[kenmyers]

I have a fair few sets of bino's and can confirm that 7x50's are my most used. They are small and lightweight and I see Andromeda galaxy, perseus clusters, plaides, haides and the moon very clearly in these. Yes they are quite widefield but they show great colour and sharpness.

Also see a LOT more stars per FOV with these than any of my other bino's. Also seeing dimmer stars much more clear due to low magnification (but still amazingly zoomed in!)

[groaninjock]

I don't know how much they're going to be, but it looks as though they'll be between £10 and £15 in the deal, so I might take a punt on them at that price.

[kenmyers]

Might grab myself a pair at that price! thanks

[John]

10x50's are better suited to astronomy than 7x50's from my experience with various types. While the 7x magnification is a little easier to hold steadily in the hands the 10x ones produce an exit pupil (circle of light that emerges from the eyepiece) that better matches most folks dilated pupils so you make full use of the 50mm aperture.

[michael.h.f.wilkinson]

I have a pair of 7x50s for the kids, and they love scanning the skies with them. I prefer 10x50 and 15x70. The exit pupil (diameter of the light beam leaving the EP) of the latter is smaller, meaning darker sky backgrounds. A 7x50 has a 7.14mm exit pupil, which can mean that not all light enters you own pupil (at age 50, the average maximum dilated pupil size is 6.2mm, but large variations occur). A 10x50 has an exit pupil of 5mm, which fits comfortable with the maximum dilated pupil size of most older people.

[michael.h.f.wilkinson]

10x50's are better suited to astronomy than 7x50's from my experience with various types. While the 7x magnification is a little easier to hold steadily in the hands the 10x ones produce an exit pupil (circle of light that emerges from the eyepiece) that better matches most folks dilated pupils so you make full use of the 50mm aperture.

SNAP!!

[kenmyers]

Still, 7x50's show a lot more stars than my 15x70's (using the 15x70's dim fov for comparison)

There is common knowledge vs logic here. The 7mm exit pupil is just fine for me (in my 30's) and it is not like you will ever notice this loss of light since the magnitude of stars you'll see are beyond what a pair of 10x50's will show. Neither are better or worse (depends on your eyes/age/preferance) but at this price they are a great purchase.

Don't let anyone tell you otherwise untill you see for yourself. I have a set of bino's for every occasion but still the 7x50's come out most often for stability, lightweight, large fov, bright fov and easy focus.

Also great for slightly cloudy nights.

[groaninjock]

Thanks - I'm in my early 30s, so I might not notice the exit pupil problem so much. I think I will grab a pair of the 7x50s in the deal just to have lying around for times I can't be bothered setting up the full telescope and tripod kit.

[michael.h.f.wilkinson]

Thanks - I'm in my early 30s, so I might not notice the exit pupil problem so much. I think I will grab a pair of the 7x50s in the deal just to have lying around for times I can't be bothered setting up the full telescope and tripod kit.

Go for them, you cannot go wrong at that price.

[kenmyers]

Thanks - I'm in my early 30s, so I might not notice the exit pupil problem so much. I think I will grab a pair of the 7x50s in the deal just to have lying around for times I can't be bothered setting up the full telescope and tripod kit.

Exactly!

[groaninjock]

£13.99, so I ordered a pair. I'll report back on my findings!

[jon1000]

£13.99, so I ordered a pair. I'll report back on my findings!

mine arrived today, im not overly impressed with the quality of them, but i went outside and tried them, they are ok, 7x mag was never going to be amazing. looked at the moon in them and it looked fine (with jupiter sitting beside it). Also looked at orion nebula but couldn't make much out, (i do live in a town near to street lights).

For £13.99 They was a good buy, im looking forward to getting my 20x80s at xmas now.

[Indispensable Hobbes]

Damn, I'm sad I missed this, I've been looking at these

[groaninjock]

Mine arrived earlier this week, but I haven't had a chance to use them yet. And I'm getting my first scope today...