Viewing difference between 7x50s and 10x50s

[Victoria1410]

Hi

I'm looking at getting a pair of bins for handheld use. I'm not ruling out ever getting a tripod but for now I'd like the ease of a grab-n-go type pair.

Practically speaking, does anyone know the viewing difference between 7x50s and 10x50s please? I know it's more magnification but what does this equate to? What more can you see? What can you still see in the 7s so don't necessarily need the 10s for?

Any help and opinions would be appreciated.

Thank you

[Dave In Vermont]

With the 10X, you won't have as wide a field-of-view - FOV - as you will with 7X. Usually. Exactly how much a difference this will be would best be found from the manufacturer of the binoculars.

Dave

[Victoria1410]

Thank you Dave.

I got some confusing advice about FOV last night and had just posted it in a new thread actually annoyingly I'm finding FOV confusing at the moment.

Would you recommend a bigger FOV over a certain magnification then?

I have found a pair of Opticron Imagic TGA WP 7x50 with 6.0 degrees advertised but jessops have a pair of Bushnell 10x50s with 6.6 degrees advertised. Would this make the 10s really worthwhile? Or it just that the 7s FOV is small for it's kind?

[Tinker1947]

If you're learning your way around the night sky then the 7's would be a much better buy, looking at the night sky with your eye shows only the brighter stars, looking through bins is a whole new sky up there, the wider the FOV the more you likely you are to match both views up......

[Victoria1410]

If you're learning your way around the night sky then the 7's would be a much better buy, looking at the night sky with your eye shows only the brighter stars, looking through bins is a whole new sky up there, the wider the FOV the more you likely you are to match both views up......

Thank you Tinker 

I'm looking forward to seeing more stars! 

What you say makes sense.  I think I'll go for smaller rather than 10s.  IYO please, would you choose 7x50s or 8x42s for a little more magnification?  Not sure if the drop in apperture is worth it or not.

[happy-kat]

As an example.

My 8x30 do not show me the 4 main moons on Jupiter.

My 8x42 do.

So is it the smaller apperature, but I do know that the size of the moons in the 8x42 is so pin dot that would they show in a 7x, I would not be confident and 8x42 is an easy size for multi use by size, weight and what I see.

Spend once buy wisely and you have a pair for life.

You know that there are some reviews very shortly to come out, may as well wait to read those to help you with your choice.

[Victoria1410]

As an example.

My 8x30 do not show me the 4 main moons on Jupiter.

My 8x42 do.

So is it the smaller apperature, but I do know that the size of the moons in the 8x42 is so pin dot that would they show in a 7x, I would not be confident and 8x42 is an easy size for multi use by size, weight and what I see.

Spend once buy wisely and you have a pair for life.

You know that there are some reviews very shortly to come out, may as well wait to read those to help you with your choice.

Thank you 

I know Binocular Sky is publishing his review of the Opticron's 8x42 soon  but I was at an astronomy meeting last night and was given some puzzling information about 42s being dim (and FOVs being different).  So I wanted to ask here about what people would recommend generally and about people's experiences.

I'm not sure how much magnification affects view so your post is helpful, thank you.

Sounds like 8x42s are better than 7x50s.  Do you have any 10x50s?  I'm worried about the weight and not sure about the FOV, especially after Tinker's helpful post, so definitely leaning towards the 8x42s but not sure if they will be too dim?

[Piero]

Personally I would go for a 10x50 over a 7x50. 

Apart from an increase in magnification, which will be noticeable between the two, you have a decrease in exit pupil (5mm for the 10x50, and ~7mm for the 7x50). The exit pupil is associated to the overall image brightness (therefore including background sky brightness) that you receive at the eyepiece. The smaller exit pupil the dimmer the overall image brightness will be.

For DSO, one generally does not want small exit pupils, but 5mm is already considered 'large' and 7mm will be much more suitable if you live under very dark skies. For a normal suburban or moderately light polluted sky, in my opinion, 5mm is the largest you really want to go for. 

If you look for large nebulae with a filter (e.g. UHC or OIII), 10x will help and 5mm is more then sufficient for observing the nebula. 

If you feel tired holding the bins, you may want to consider a light tripod (or possibly even better a monopod). This could make your observation more enjoyable. 

Hope this helps,

Piero

[happy-kat]

Have a read here

http://www.bestbinocularsreviews.com/blog/exit-pupil-06/

My own binoculars are very bright in use but they where not inexpensive.

[happy-kat]

My own binoculars are very bright in use but they where not inexpensive.

I have no experience with either of the other two sizes.

[Victoria1410]

Thank you happy-kat 

[Merlin]

Regarding the 8X40 spec Victoria. I once had a Japanese pair that were amazingly bright and also light to hold. Alas, I gave them to a friend some years ago and really missed them. It's a good size to have.

[Victoria1410]

Regarding the 8X40 spec Victoria. I once had a Japanese pair that were amazingly bright and also light to hold. Alas, I gave them to a friend some years ago and really missed them. It's a good size to have.

I'm sorry you no longer have them.  Thank you for your help though 

It's really interesting that you think they were bright (just like happy-kat).  May I ask, did you ever own a 7x50 pair of binos?

[BinocularSky]

(Review probably won't be published till next week:STEMming at a local school today and in Cardiff for the rugby tomorrow).

Binoculars are a very personal thing, but in general: There are few objects that look better in a 7x50 than a 10x50. Most of the time under UK skies you just can't get the benefits of a larger exit pupil of the 7x50, but they can be spectacular under very dark skies..

If you can hold them steadily (and, for many, that's a big "if"), the 10x50 is a "sweet spot" for hand-held binocular astronomy. The extra magnification compared to a 7x50 makes some of the slightly smaller stuff more recognisable, i.e. some double stars are easier to split, some small globulars & planetary nebulas look less like stars, the darker sky background with the higher magnification benefits almost all open clusters.

If, for steadiness issues, you need to reduce the magnification to 7x or 8x then, unless you have almost pristine skies, I think 40 or 42mm are a better option than 50mm: they will generally be lighter and the 5-ish mm exit pupil is sufficient for most people; in fact as you age, your eye pupils will vignette the exit pupil of the binocualr so that your eye will effectively stop down the extra aperture of the 7x50, so you might as well get a 42mm anyway id that's all your eyes are able to use of the 50mm.

In my opinion (and it is only that; other people have different opinions), the FoV thing is overstated for a number of reasons. Firstly, unless you get very good (i.e. expensive) binoculars, the edge of field of the wider FoV binocs tends to be mushy, so your sharp field is really no bigger. You mentioned 6* vs 6.6* - I bet you'd struggle to tell the difference in practice. I find that even the difference between 5* and 6.5* isn't really that great in practice for hand-held binoculars - you move the binoculars with your head if you want to see something away from the centre of the FoV. Also, in the binoculars we are discussing, the true FoV is related to eyepiece design & magnification, not aperture of the objective: if a 7x50 has a wider FoV than a 7x42, it's because of the eyepieces.

Far more important, in my opinion, is the quality of the glass: get the best you can.

[Stu]

In my mind it does now seem that 7x42 would be the optimum from both a weight and exit pupil perspective. Hand holding x7 binos is easier and that will make learning the sky much more relaxing and enjoyable.

Perhaps I was over optimistic with the 7mm exit pupil on my binos, but I did want to be able to get the maximum out of them at dark sites, so perhaps not too bad.

[Charic]

I prefer the wider views that my 8x40s provide ( +8°)  and supporting these gives an even  better visual view!

I use them to search the skies either with or without the telescope, but only my telescope will provide the details I require, the binoculars are just for browsing?

My  10x50s are good, but these were for more general use, rather than just astronomy, but the same applies, keep them rock steady, and the view is better.

I would accept the Opticron over the Bushnell binoculars that you have mentioned,  but you will only know by putting them to your eyes. You have the right to return goods if your not happy with them. 

[Victoria1410]

Thank you binocular sky, sumorian and charic!

Charic, would you still pick Opticron Imagic TGA WP 8x42s with 6.5' over Bushnell Legacy WP 8x42s with 8.3'?

Binocular Sky, I know I'm analysing a lot and probably over analysing (you're not the first to say this! ) but I just would like the perfect pair, or should I say the most perfect pair for me. Sorry if it seems like I keep mining you for information. I have to acquire some by a week on Friday so my novice questions hopefully won't last for long!

[Charic]

.....take away the branding, probably the 8x42 with 8.3°, simply due to my liking for a  wider field of view.

Having had the same dilemma,  not knowing what to buy next,  or branding choice,  and  favouring wide angle, low power, there are still limits and variables for what is viewable in the night skies above MY head, this far North, as my skies are very much brighter during the Summer Months, and a pair of 10x50s may be a better option,  a little more magnification, gives a little more contrast to the  background in contrast to the target, all subtle differences, but only noticeable when the optics are in your hands, looking  through them.

I actually bought some Nikon EX 10x50s, and for me,  the worst pair of binoculars I have owned? ( but now have my doubts as too their authenticity?) but read the reports and Nikon Action Extremes are liked by many. I love Nikon's, all my camera gear is Nikon, so I expected highly of my 10x50s, yet that particular sample let me down?

42/8=5.25mm A decent sized exit pupil from 8x42 binoculars, and 5mm ( 10/50=5) from 10x50s) are you going to notice .25mm difference, or the contrast between the two against a dark sky? A side-by-side comparison will prove essential!

As your first binocular, a 10x50 could be a better choice over  the 8x40/42 mark ,  the little difference in contrast,  the higher magnification, little  less  field of view,  but both optics will still benefit from stability, all binoculars look better when stable, that does not mean having to buy image stabilised optics, although they are available at a price?

You need to grab hold of any brand of 10x50 and compare them to a 7x50, 8x40 or 8x42 and see, feel the difference for yourself, then buy that size in your favoured brand, as quite is the norm, the more you pay, supposedly the better the quality of the optics and build quality, the list goes on, yet my 8x40s were very cheap, in FLOs Summer sales, in fact I nearly bought the 10x50 equivalents, due to just being nice binoculars!

My 8x40s were purchased  to compare with my older Bressser Hunter 7x50s. The 8x40s are firmly my favourite optics at present. My 10x50s were £120 delivered, a few pence change, they too are good, although these were purchased as my multi-use, hard wearing  optics, that I could leave in the car maybe, Their still brand new, and although they have mil-spec (tough)  specifications, I still handle them with kid gloves, so to speak.

I could ramble on but the final choice can only be your decision, made from testing some optics. Even bought on-line, you can return goods if your not satisfied,  you don't always need a specialist shop nearby, but do choose a specialist supplier  whenever you do decide. Try First Light Optics. Give them a call, they will advise you for the right reasons, not just to make a sale. 

[BinocularSky]

 Sorry if it seems like I keep mining you for information.

No need to apologise: this is one of the things this forum is for. (And what the heck is the point of information if it's not shared? )

[Victoria1410]

Thank you so much for your detailed advice Charic!

Everyone on this forum is just amazing.

I'm going to try and hunt down some optic shops at the weekend to test to see the difference between 8x42s and 10x50s and between the different FOVs. 

(and see how heavy either pair are to hold above my head )

[RT65CB-SWL]

Hi Victoria,

I know it is a few months away, but Stephen Tonkin, aka BinocularSky, is giving a talk at Reading Astronomical Society on Saturday 19th March 2016.

[Victoria1410]

Awesome!  Thank you for letting me know 

[BinocularSky]

Hi Victoria,

I know it is a few months away, but Stephen Tonkin, aka BinocularSky, is giving a talk at Reading Astronomical Society on Saturday 19th March 2016.

And he is giving the same talk to Wiltshire AS next Tuesday (6th Oct)    :

http://www.wasnet.org.uk/meetings-2015-16/

I'd be delighted to meet people from these forums at any of the talks I give. There's a list of the ones I have been booked for here.

[BinocularSky]

I know Binocular Sky is publishing his review of the Opticron's 8x42 soon

Managed to get a couple of them completed today: in the "Information" tab on the website.

[BinocularSky]

On 01/10/2015 at 14:00, Philip R said:

Hi Victoria,

I know it is a few months away, but Stephen Tonkin, aka BinocularSky, is giving a talk at Reading Astronomical Society on Saturday 19th March 2016.

That's a week from today. I'd be delighted to meet any SGL members who attend. 

http://www.readingastro.org.uk/main-programme/