7x50 binocular recommendation

I'm looking for a decent pair of 7x50 binoculars for
astronony/night use. I'm willing to spend up to $300.00.

Any recommendations?

-Eric

I'm looking for a decent pair of 7x50 binoculars for
astronony/night use. I'm willing to spend up to $300.00.

Any recommendations?

-Eric

1. Consider 10x50s Probably see more with 10x50s.

2. Try as many as you can. Lots of good ones but its pretty personal.

jon

(eric bazan) wrote in
om:

I'm looking for a decent pair of 7x50 binoculars for
astronony/night use. I'm willing to spend up to $300.00.

Any recommendations?

-Eric

7x50 binoculars are not recommended because the exit pupil is over 7mm, and
MOST people's eyes do not open to 7mm even in the darkest locations. If
you are near 40 you will be fortunate if your pupils open to 5mm, which
means you paid for 7x50s but got the equivalent of 7x35s (I'm guessing
here, because I'm too lazy to do the math-but you get the point).

P.S. If you're using them for daytime terrestrial observing your pupils
will be much, much smaller.

Any recommendations?

Everyone who has looked through our 7x50 Celestron Ultima binos has liked
them a lot, as do we. Check them out.

Dennis

7x50 binoculars are not recommended because the exit pupil is over 7mm,
and
MOST people's eyes do not open to 7mm even in the darkest locations. If
you are near 40 you will be fortunate if your pupils open to 5mm, which
means you paid for 7x50s but got the equivalent of 7x35s (I'm guessing
here, because I'm too lazy to do the math-but you get the point).

Paid for 50mm but only got 35mm? I didn't know that binos were sold by the
mm. Seriously, I think that this exit pupil/wasted aperture/wasted light
stuff is one of the biggest confusions regularly put forth on this
newsgroup.

Dennis

Paid for 50mm but only got 35mm? I didn't know that binos were sold by the
mm. Seriously, I think that this exit pupil/wasted aperture/wasted light
stuff is one of the biggest confusions regularly put forth on this
newsgroup.

Dennis


The interaction between the exit pupil and your own pupil dialation is really
quite simple but there are some subtle ramifications. If you eye will not open
sufficiently to admit the entire exit pupil then you are not utilizing the full
aperture of the instrument.

Not only is the brightness reduced, but the theoretical resolution is reduced
likewise. This effect can even reduce the false color in achromats under some
circumstance.

I think the awareness of the various issues surrounding the exit pupil/eye
dialation relationship along the awareness of the importance of magnification
has led to the increased popularity of 10x50s as the most useful general
purpose binoculars for astronomy, replacing the once popular 7x50's..

Jon Isaacs

Bu

Jon Isaacs wrote:

I think the awareness of the various issues surrounding the exit pupil/eye
dialation relationship along the awareness of the importance of magnification
has led to the increased popularity of 10x50s as the most useful general
purpose binoculars for astronomy, replacing the once popular 7x50's..


Not to quibble, but to balance this statement, it must be said that 10x
is somewhat harder to hand hold than 7x -- at least for me. And
generally you get a somewhat smaller FOV with 10x, as well.

Phil

Paul Lawler wrote in message .170.90...

7x50 binoculars are not recommended because the exit pupil is over 7mm, and
MOST people's eyes do not open to 7mm even in the darkest locations.

I wouldn't go *that* far! It's true that 7x50 binoculars have been
downrated since their glory days a couple of decades ago, when they
were considered the only binoculars worthy of serious consideration
for astronomy. And it's also true that if your pupils only open to
5mm, then 7x50 binoculars won't show any more than 7x35. However,
they also won't show any less than 7x35. The only disadvantages
of 7x50 as opposed to 7x35 are slightly greater weight and bulk
and (possibly) higher price. Set against that is the fact that
7x50 binoculars are more forgiving about interocular spacing and
where you place your eyes. If your eyes open to 5mm and your
binocular's exit pupils are 5mm, then you have to space the
eyepieces *exactly* the right distance and center your eyes
*exactly* behind them to take full advantage of the aperture.
That's why 7x50 is recommended for use on the deck of a ship.

As for 7x50 versus 10x50, the 10x50 will without a doubt show
fainter objects, and more detail in all objects. However, the
7x50 have a much wider true field of view (all other things
being equal) and are arguably easier to hand-hold.

All in all, most astronomers prefer 10x50, 8x40 or some such
specifications to 7x50, but 7x50 *certainly* fill an important
niche, and will always be the favorite size for some people.

- Tony Flanders

Not to quibble, but to balance this statement, it must be said that 10x
is somewhat harder to hand hold than 7x -- at least for me. And
generally you get a somewhat smaller FOV with 10x, as well.

Phil

I find 10x binos harder to hand hold, but I still see more in them. Birders
seem to prefer either 8x or 10x, I think again the same issue, see more in 10x
but a bit shaky. Personally I find Roof Prism binoculars easier to hand hold.
Roof Prism binoculars also have the advantage that they are most often water
proof and nitrogen purged so that they don't fog up internally.

FOV is something of an issue, though it is pretty rare to find 7x50s with
widefield eyepieces. I have often wondered if this had something to do with
prism sizing and the larger exit pupil.
----

For the orignal poster:

One model to consider is the Swift Audubon 8.5x44 porro prism binos. At 8.5X
these can be hand held without shaking and have some extra kick due to the
8.5X. They are water proof, have an 8.2 degree FOV, a 5mm exit pupil and only
weigh 25 oz.

jon

Jon Isaacs wrote:

Not to quibble, but to balance this statement, it must be said that 10x
is somewhat harder to hand hold than 7x -- at least for me. And
generally you get a somewhat smaller FOV with 10x, as well.

Phil


I find 10x binos harder to hand hold, but I still see more in them. Birders
seem to prefer either 8x or 10x, I think again the same issue, see more in 10x
but a bit shaky. Personally I find Roof Prism binoculars easier to hand hold.
Roof Prism binoculars also have the advantage that they are most often water
proof and nitrogen purged so that they don't fog up internally.


My day binos are smaller 8x28 or so with long eye relief and good water
resistance. Not so hot for astro, though.

FOV is something of an issue, though it is pretty rare to find 7x50s with
widefield eyepieces. I have often wondered if this had something to do with
prism sizing and the larger exit pupil.


I use 7x50 Alderblicks I've had for close to 15 years. I've not found
anything better for hand held astro use. When I get serious, I use my
15x70s on a UniMount. Even at 7x, a mount adds so much more to what I
can reliably see.

Phil