How good are your binoculars - test?

[AlexG]

Can we have a quick test to see how good people's binoculars are?

I have been looking at Jupiter on one of these cold, clear nights through my 20x80s and am a little disappointed. I can see four moons fair enough but the planet itself seems to flare slightly differently through each eyepiece of the binoculars. So Jupiter is more fried egg than boiled egg shaped. Not flat as a plate but a bit

What about the rest of you?

AG

[yeti monster]

My binos are fine, for a freebee pair (the ubiquitous Bootes Ascot), 10x50s, good collimation and very clear image.

I'm toying with the idea of a pair of 25 x 125s that I saw last time I was in china, I'll have to have a good look at them next time I'm there, and then decide whether or not to throw 60-70 quid at them, but I do have a 10" scope to find the cash for as well. Decisions decisions.........

[yeti monster]

Oh, the test.... Jupiter looks round, as I'd expect, and small, due to the teenyness of the binos......

[fmeireso]

Jupiter is a difficult target.Actally no bino target at all.

Also abberations in the own eye like astigmastime shows up wel in big binos, especially on Jupiter.Be aware of that.

I never get i as i should be but i don't think the bino is the culprit.

Still i use 2 Kunming BA8 series bino's.(15x70 and 22x85) Quite some specimen both of them. I am very pleased with them.They give astounding views.

[FLO]

Jupiter is a difficult target.

Indeed it is. Jupiter is low on the horizon so you often see prismatic distortion (red-one-side, blue-the-other) as light travels through water vapour in the atmosphere. Also, it has the fastest speed of rotation of all the planets, this speed makes it wider at its equator than its poles.

HTH

[kniclander]

in my big APM's i can easily see the bands at x40 but the image is horrible to look at. in my russian 20x60's I can maybe see a hint of baning but only if the bins are on a tripod. Jupiter is a horrible bino target becasue it is too bright and at the moment too low. Use bins for what they are good for (particularly IMHO open clusters and the moon)

[fmeireso]

Some Nice bino objects :

Bright comets (if one pops up) and lunar eclipses are staggering in any binocular. Or the movements of jupites moons, but not the planet itself....

Big open clusters like M44,M45 etc like those in even small binos

[Saturnalia]

kniclander - what are your Russian binos and where did you get them...?

I'm interested in Russian optics

OK - no more OT

[kniclander]

kniclander - what are your Russian binos and where did you get them...?

I'm interested in Russian optics

OK - no more OT

I bought them 2nd hand from an SGl member. they are made by "Tento". they are horrid in daylight because everything is yellow but they are lovely for astro especially the moon - in fact, on the moon they rival my APM 20x100s which retail for about 10 times the price...HTH

[Starfleet]

I have a really old pair of 8x30s i had bought them back in 1983. I also have a newer pair of 8x40s which I have puchased a few years ago. I like to test them on close double stars.

First pair I tried was Nu Draconis. Passed the test easily. Then I tried Albireo and only managed a part of the split... even after i mounted the binocular on a window side.

The one I think will be the hardest test for me will be the star Theta Serpentis. This is only of 22" separation and the resolving limit for an 8x30 pair of binos is no greater than 30".

Has anyone tried close doubles with your binos?

[argonaut]

I tried Albireo in my 8x42's but couldn't manage the split,however in my 10x50's (mounted) I did manage it.

[Capricorn]

Tried Alberio on 8x42's and it was just about seperable. Had a hint of 2 different colours, but not specific enough.

Used the lesser good 8x42's I have and never tried the better set.

Interesting that 10x50's can separate.

[argonaut]

If my math is correct the Dawes limit for FULL APERTURE 10x50's is 23.2 arc seconds. Albireo is 34 arc seconds. I can't split it hand-held,only mounted.

There are other considerations that are part of the equation.

Glen.

[GazOC]

I had a pair of 20x60 Tentos, pretty good binos. Better than the 15x70 Alders I had.

[argonaut]

I've not looked through the Tento's. I did have a pair of Pentax 20x60's. Like an idiot I sold them. FOV a little narrow at 2.2° but the FOV they did show was good out to 95%. Pin sharp and a nice dark background with the 20x mag.

I believe these are still at a reasonable price from FLO.

Glen.

[themos]

Easily found M81 M82 M65 M66 galaxies tonight with the Revelation 15x70. M67 open cluster in Cancer was not resolved but showed up as extended nebulosity. The best part though was the open clusters in Auriga, there's a lot more than the Messiers in there that are such a beautiful sight.

[argonaut]

I have difficulty with M51 and M101 in all my binoculars. It's the light pollution in my backyard. Your right about M36,M37 and M38 in Auriga. I never get fed up with looking at these beauties.

Have a look at NGC457 in Cassiopeia,it's another of my favourites.

Clear Skies.

Glen.

[Starfleet]

I have tried looking for M51 for a number of years in my garden, but never seen it as the light pollution where I am is so attrocious.

Last night I tried out my Canon 300D for only the second time after buying it. I captured three bino doubles in one shot:

(removed picture - see below)

[acey]

Best way to test binos is in daytime: thin, straight objects (e.g. distant streetlamp posts) will show up chromatic aberration, field curvature etc.

Haven't tried looking at doubles but have seen plenty of DSOs with binos. Most memorable was M104 with 10x50s. All the Messiers are theoretically visible with 50mm aperture and a dark sky. I prefer 15x70 though.

[Starfleet]

Ooops... sorry I realise I had mis-labelled that photo!

It was actually four binocular doubles: Nu Draconis, Zeta Lyrae, Albireo and Omicron 1 Cygni:

[LukeSkywatcher]

About a year ago when i last observed Jupiter in my 20X90 bins the planet disc was perfectly round and flat. I saw NO detail (as you would not expect to), and all 4 main Jovian moons were clearly visible.

I'm toying with the idea of a pair of 25 x 125s that I saw last time I was in china, I'll have to have a good look at them next time I'm there, and then decide whether or not to throw 60-70 quid at them

Oh come on..................that is a no brainer. A pair of 25X125 bins for THAT price surely is worth investing in just to check them out.

Hell buy 2 pair and send one pair to me and i'll cover the cost+shipping from UK to Ireland. I bought a pair of 10X50 bins in the Canaries for 90 euro and they are pure rubbish..............and my 10X50 bins i bought in LIDL for 18 euro are perhaps the best bins i own.

[acey]

I've seen a Jovian cloud belt with a 40mm refractor and fixed magnification of x30, so I'd say that magnification rather than aperture is the key to seeing detail on Jupiter (assuming good optics of course). The scope was the one I had as a kid - in those days I never saw detail on Jupiter with it, only a bright disc and attendant moons. But when I dug it out a few years ago and pointed it through a double-glazed window I saw the equatorial belt quite easily. So along with magnification I'd maybe put experience. My eyes are certainly no better now than when I was twelve - they're a heck of a lot worse.

My dad claimed he saw at least one the moons with the naked eye (they're theoretically visible if you block the planet from view and the air is clear enough - Ganymede is about mag 5).