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7x50 vs. 10x50 Binoculars?

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#26 Obx


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Posted 23 June 2010 - 07:52 AM

IF is outstanding for long-range observation--astronomy, sailing and aircraft spotting--but not for much else.

#27 EdZ


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Posted 23 June 2010 - 07:53 AM

Hi EdZ,

I have a question. When you said that "10x will show more and closer objects," were you speaking of terrestrial landscape objects?

For astronomy, I can't see where 10x would show "closer" objects. Am I misreading this is some way?

Thank you in advance for your answer to my question.

Best Regards,

In my previous post, gave an example of what I meant by that.

Closer objects, means stars that are positioned closer to each other, not objects closer to you. Really the same holds true for terrestrial viewing. Leave no doubt that 10x will separate close objects much better than 7x.

More objects. A 10x50 binocular will see stars almost a half magnitude deeper than a 7x50. Therefore by more I mean rater thasn seeing 15 or 20 stars in a cluster, you might see 20 or 25 stars. Or rather than seeing an object with a Surface brightness of mag 12 you might be able to see mag 12.5.


#28 EdZ


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Posted 23 June 2010 - 07:56 AM

This writing is not made due to knowledge, but out of ignorance.

Does the user's knowledge of the sky make a difference (i.e. wide views to learn star patterns vs. pulling out the most stars in a smaller area?) in 7x or 10x?

Does expectations made a difference (to a newbie/ the experienced)? Like, does one expect to see ring separations of Saturn, the bands on Jupiter, DSO (seeing Hubble like views or even views like the time exposed pictures with CCD camera on a 12" RC)?

Also mentioned was Asro only, day and night, hand held only or both hand and tripod use? This would also cover IF or CF likes (dislikes) or has become familiar with one or the other (if one has only ever used CF will the IF be discouraging).

How about with or without the need of glasses?

Does standing or reclining viewing styles make a deference between 7x or 10x?

How about the amount of time spent under the stars per sessions (1/2 hour, couple hours or all night)?

How about plans for other telescopes (APO's, SCT, Newts and the likes)?

Just some thoughts.

You can answer almost all those questions by reading the Best Of threaads
First Binocular Choice and
What can be seen in Various Sizes Binoculars


#29 orbitaljump


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Posted 23 June 2010 - 05:11 PM


You are asking all the right questions. Now to find the answers from those in the know, researh, and gaining your own experience and understanding your personal preferences.

#30 marcelof


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Posted 24 June 2010 - 04:08 PM

If you want one unique par, 10x50.Test it you, and choice.
the binoculars are to look at, does not stop to make calculations. Each binocular one has its enchantment.
Good Luck

#31 BobinKy



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Posted 24 June 2010 - 04:36 PM

Each binocular . . . has its enchantment.


How true! Your sentence explains why thousands of posts have been written in this forum.

:bow: :bow: :bow: :bow: :bow:

#32 Erik D

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Posted 24 June 2010 - 08:06 PM

Yes. Quite correct. My favorite 10X50 is NOT..... I tend to use my compact Leupold 12X50 roof prisms for hand held observation most often. Especially when I am traveling. I am on a extend stay in Singapore this summer and that's what I brought. At ~28 oz with lens caps and neck strap attached it's a lot more compact than a full sized 50 mm porro prisms. I like the 12X50 roof Even though they have just 4.8 deg FOV.

I would prefer 10X50 over 7X50 too. But each pair IS different. Can't always pick them by configuration. My favorite 7X50 is NOT..... I prefer a pair of vintage Swift 7X35s with 11 deg FOV over my Celstron Nova 7X50 with 10 deg FOV.... Less edge distortion, better contrast.

Several years ago I purchased a pair of used EWA Minoalta 10X50s listed as having 7.8 deg FOV. They have the most Uninspiring views. I hardly ever use them. A pair of Vintage Sears 10X50s purchased for less than $50 ( 8 deg FOV) are better.

I never paid attention to the notion that one should not be able to hold binoculars above certain magnification either. From my suburban NJ home, higher power binoculars, within reason, always showed me more details. 10X is more than 7X, 12X more than 10X, etc. I can put a pair of premium priced 7X50s on a tripod, but a steady image is of no use to me if the object I wish to view is below the threshold of visibility in 7X. I can always find a way to brace high power binos. If not, I just get up and put my 20X80s back on the mount...

My Japanese Celestron Nova 7X50 has EWA 10 deg FOV. But extreme distortion in the outer 50%. Shows me gray, washout skies from suburban location. M45, fantastic view in giant binoculars on a dark night, is just not interesting at all in my 7X50s.

Take another , M57, the last time I tested 12X50 roofs vs. 18X50 IS and 20X80 LW. I can see the most detail in 20X80 LW, braced. Visible in 12X50 binos. It's totally invisible to my eyes in 7X binoculars from my mag 4 backyard. So having a "Rock Steady" image doesn't help me much.

25 years ago, 7X50s, 8X56, 9X63, 10X70s were often recommended for astronomy. 7 mm exit pupil = brightest Image, right? Now we know better.

To me observing is about enjoyment, not bragging rights. I don't need to bag a certain number of M objects or NGCs each session. 99.5% of the time I am observing alone. No need to impress anyone.

My Celestron Regal 10X42 roofs are very nice. But most nights I just don't care to go lower power. Each observer have his own comfort zone. User comments here should be used as a general guide only.....

I am reading a book about the experience of several Navy SEALS from the early days of unit formation this week . 1960s. One guy said he loved long distance running. Even after he made the TEAMS he used to run 15 to 17 miles a day with average speed of 5 min mile! I was pretty fit in my younger days. Used to max score 100/100 in 4 of 5 events of the Army physical fitness test without breathing hard. But running was my weak event. I recall I may have done a 6.5 min mile on a flat out sprint. I was pleased to do 2 miles in less than 15 min. Asking me to run two miles in 10 min would be like flying to the moon. Now I am happy to keep up a 10 min mile. We are all different. Don't limit yourself by what someone else say you should or should not be able to do.

ERik D

#33 Jeronimo Cruz

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Posted 25 June 2010 - 10:15 PM

Last year I noticed that I could not see M27, for example, throught my PCF 7x50 WP whereas I could through my PCF 10x50 WPII's in a particular location with a lot of light pollution. The darker backgroud of the 10x50's, due to the increased mag. and smaller exit puipl, is much more aesthetically pleasing, IMO. Also open clusters are much better resolved in the 10x50's.

#34 BobinKy



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Posted 26 June 2010 - 06:25 AM

On dark nights, before the Moon rises, I can see M27 through my Fujinon FMT-SX 7x50 binoculars. My skies are NELM 5.0.

#35 Swedpat



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Posted 26 June 2010 - 12:03 PM

This is an interesting discussion. The conclusion is that 10x50 is for the most people and under the most circumstances better than a 7x50.
But I wonder: is there any case (if the background is dark enough, and providing the person have full 7mm eye pupil) where 7x50 is stated to be better and show more faint objects than a 10x50 ?

Regards, Patric

#36 BobinKy



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Posted 26 June 2010 - 12:34 PM

Yes, let us continue this interesting discussion.

7x50s can generally see what 10x50s see, but the image through 7x50s are smaller. This is a given.

What can 7x50s do better than 10x50s? This needs to be discussed. Here is a short list to keep the discussion rolling.
Some advantages of 7x50s over 10x50s

(1) Most 7x50s have a wider FOV than 10x50s. This permits viewing through wider windows of observation. Seeing more is not just seeing deeper. It can also mean seeing wider. And wide views aid in locating various stars and DSOs, more so than deeper more narrow views.

(2) If your eye pupil dark adapts to 6.5mm or greater you may appreciate the increased brightness through 7x50s (under skies of 5.0 NELM or darker). If you eye does not dark adapt that much--this may not be a point of issue.

(3) 7x50s make great binoculars for terrestrial observing during dark overcast days, heavy shade, and twilight. This is particularly true when you are interested in environmental or aesthetic observing (object and it surroundings). However, if you are more interested in detail or technical observing of a single object or a small area, 10x50s generally do better in low light because the increased magnification provides more detail.

(4) For some of us, the proportions of the view through 7x50s closely resemble the proportions we see when observing with the naked eye, more so than the tunnel-vision view through 10x50s.

(5) Views through 7x50s generally avoid issues of hand shake (stars dancing about), while 10x50s are more prone to hand shake with some observers. This difference is due to the increased magnification of 10x50s.

(6) If you find yourself viewing from an unstable position, such as in a boat on water or riding in a moving vehicle on land, 7x50s provide a wider exit pupil for your own eye pupils to dance around inside. This is not the case with 10x50s, which reguire stable viewing positions. I love to observe the night sky through the sun roof of a car while someone else drives--there is something exhilarating about binocular observing with wind brushing against your face. I am sure there are more differences to consider with either size. Let us keep this discussion going.

#37 Jon Isaacs

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Posted 26 June 2010 - 05:55 PM

Hi and hello..

My first inclination was to recommend 10x50s or maybe 10x42s but then I remembered that these days I use my 7x42s more than either of the 10x binoculars. You see more at 10x but 7x is more comfortable. A big factor, I rarely use binoculars with out a telescope set up nearby that will get most of the eyepiece time.

I like roof prism binoculars because I also like to watch birds and roofs typically will focus as close as 6 to 9 feet.


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