BinocularSky

9 hours ago, LukeSkywatcher said:

No bins (no matter the aperture or mag), will ever come close to to giving you the same view of DSO as a telescope will.  I have a set of 20x80, and Andromeda still is a faint fuzzy.

Yet many DSOs such as the larger Melotte and Collinder clusters, the Pleiades, Kemble's Cascade, and the Andromeda galaxy, overflow many telescope fields of view unless you use low magnification like that of a binocular (even my 37x100 magnifies too much for these). And I don't think the telescopic view of pretty starfields, like the one at the back of Leo, comes close to that in binoculars in which you can take in the whole thing. Since I started the "Binocular Sky" website & newsletter, I have had several correspondents tell me that they have subsequently "down"graded to binoculars, and get much more observing done and enjoy it more.

But agreed, it's not everyone's cup of tea. Horses for courses, I guess, if I may mix my metaphors.

On 28/07/2018 at 00:40, LukeSkywatcher said:

You can still heat the bins.

Only by either stuffing them under my jacket - which initially makes the dewing worse - or by taking a heating/power source to my observing site. (I do sometimes take a battery pack and hairdryer when it's a public outreach event)

22 hours ago, LukeSkywatcher said:

Buy a dew heater strap. They work well. 

And require power. Which my binocular doesn't.

I make mine at least 3x, unless it would make them unwieldy. At 4.5x, they actually work properly! (see length of primary "dew shield" on a solid-tubed Newtonian ? )

On 19/07/2018 at 19:36, F15Rules said:

Steve Tonkin posted an excellent easy maintenance guide some while back, I'll see if I can find it - very useful.

http://binocularsky.com/manuals/TG-manual.pdf

Cheap yoga/exercise mat. Can get it thinner than camping mats. Stitch velcro onto it to hold it in place.

On 10/04/2018 at 19:26, Swithin StCleeve said:

When did the 'Binocular Tour' feature start in the Sky at Night magazine?

April 2013.

16 hours ago, Swithin StCleeve said:

Would you expect to find most of the objects that are in the Sky at Night maps, with 8x40s?

Short answer: Yes.

TL;DNR version: I am aware that a lot of what people think are 10x50s are, in fact, internally stopped to 10x42 or less (one was 10x39!), and the 15x70s are often stopped to 15x62. Also, experience and reasonably good skies aid my observations (and deteriorating eyesight hinders them).  For this reason, I check all the "10x50" objects with 42mm or less (nowadays usually 6.5x32) and the "15x70" objects with 50mm or less. However, I may use the appropriate magnification for e.g. splitting doubles.

13 hours ago, Swithin StCleeve said:

 Tonkins

Nope, not plural, only one of me (many will be relieved to know).

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but I think I may start getting Sky at Night regularly, because his binocular sky maps are pretty fantastic.

Glad you like them, but they are actually done by Pete Lawrence (+ Steve Marsh from the S@N art department). I provide a chart from Guide output, and Pete makes it look nice for the mag.

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. I've ordered a copy of his book on the strength of these charts. Does anyone have it? Does it have maps comparable to the ones in Sky at Night?

No, the maps are very different in the book. They are on a white background; there are two types: summary charts covering approx 60* x 60* of sky that highlights object for which there are individual entries, plus 196 individual finder charts for each object or close group of objects (with an aperture circle dependent upon the size of binocular recommended) and descriptions for each object, eg:
 

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Cassiopeia: Open Cluster: NGC 654 (70mm)

NGC 654 is just over halfway from δ to ε Cas; it is in the same field of view as NGC 663.
NGC 654 appears as the more northerly apex of a tight equilateral triangle that has a bright (magnitude 7) and faint (magnitude 9) stars as the other apexes; the brighter of these is over 200 times more luminous than the sun. NGC 654 appears as a small, but very distinct, misty glow. It is about 20 million years old and 7,00 light-years distant.

 

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What maps do you guys use when you're  binocular observing?

If I'm seeking unfamiliar stuff, or stuff I've forgotten how to find, I mostly use Sky Safari or Collins Gem Stars - a surprisingly good little star atlas, with charts by the superb Wil Tirion, that fits in a shirt pocket or a binocular case.

On 31/03/2018 at 19:22, 25585 said:

8.4mm eye relief.

That doesn't mean what most people think it does; I wrote about this in the Dec 2015 Binosky Newsletter:

The first thing to note is that this is not a prismatic binocular. It has Galilean optics, i.e. the same as an opera glass, but the similarity with common opera glasses stops there.The specified field of view and eye relief are essentially meaningless. With a Galilean optical system the exit pupil is virtual and resides between the objective and the eyepiece. In addition, the field of view increases as you bring your eyes closer to the eyepieces. This means that spectacle wearers will have a smaller field of view than those who do not wear them. I measured the true field of view to be 23° without spectacles and 17.4° with them, both larger than the specified 12.2°.

22 hours ago, Charic said:

@BinocularSky has forgotten his early report on the 10x50's where he measured 14mm with doubt? read it here http://www.strathspey.co.uk/10x50rev.html

 

Indeed he had forgotten this! Thanks. Must be 15 years old. Very odd that 19mm/14mm thing; the effect is certainly more like 19mm. Sometime (within the next 15 years? ) I must figure out what's going on.

20 hours ago, 25585 said:

Many thanks. 14mm is too short. I will look into the 10x50 waterproof cf model instead.

See above (& the review) re 14mm/19mm; as I said earlier, fine with specs on. The WP CF model is OK (nice and sharp, less internally stopped than the Marine), but it does have annoying focus lag -- essentially, this is the waterproofing O-rings in the eyepiece tubes doing their job.

1 hour ago, LukeSkywatcher said:

How do the little Vixen bins (on the bottom right of the 1st image) perform?. Been pondering buying a pair myself for some time. Probably as well as any Vixen product ive ever bought, im guessing.

Lovely, but unlike anything else. They add a bit more than a magnitude of depth and I don't notice the magnification. It's sort of like counteracting LP a bit. @DirkSteele has written a comprehensive review of them.

17 hours ago, 25585 said:

Interesting collection. Strathspey Marine bins are excellent if a bit heavy. I have a 7x50 pair. What is the eye relief for 10x50 please?

I've not measured it but, with the eye-cups folded down, it's easily adequate for use with spectacles.

Main Stable (i.e. stuff I use regularly):

From the back, L-R: Miyauchi Bj-100 (my most used astro instrument by a long way), Lunt Magnesium 16x70 (quick & easy grab-and-go on a monopod), Lunt Magnesium 10x50 (my brightest hand-held bino)

Strathspey Marine 10x50 (robust, abused, live in the car), Opticron BGA 10x42 (lovely quality, small & light enough to be a "holiday" binocular when space/weight is tight), Vixen SG 6.5x32 ED (stunning image, now my favourite hand-held bino), Vixen SG 2.1x42 (magnificent under a very dark sky).

Outreach bins (used for teaching, outreach, etc.):

From the back, L-R: Opticron Oregon 20x80 (recently acquired for outreach project; also used for teaching; OK on monopod or Skymount/Paragon parallelogram), Revelation Astro 15x70 (BA-1 variant, used for teaching, and as a "loan" instrument), Unbranded (well, would you want your name on something like this?) 12-60x70 zoom with the "latest ruby coatings"  (the result of a manufacturer stooping to the challenge: "Just how bad can a binocular be for £79?"; used for teaching/warning)

Opticron Adventurer T 8x42 WP (Used for outreach; the result of a manufacturer rising to the challenge: "Just how good can a binocular be for £79?"; I recently acquired a bunch of these for an outreach project), Vortex Raptor 6.5x32 (used for teaching & visiting grandchildren), No-name plastic-lensed Galilean type 4x20 (used for teaching, mostly to demonstrate that two of Jupiter's Galilean moons can be visible with cheap toy binoculars; ridiculously narrow FoV)

18 minutes ago, Alan White said:

I am looking for a second 10 x 50 so I can play nicely with my wife and children when they observe in the summer.
Any ideas for up to about £150 mark appreciated.

 

Some ideas here,and some reviews here - you will struggle to better the Pentax SP 50mm WP in your budget, or the Helios Stellar II if you want an IF model.

1 hour ago, happy-kat said:

I've an old 8*30 from 40 years ago nothing remarkable Charles Frank with Frank Nipole optics but they are used daily for the garden birds, I need to collimate them as slight double vision if I ever work out how to get in there

I have an old 10x50 Frank Nipole; collimation is done with eccentric rings on the objectives. Ideally requires peg spanners. Non-trivial!

On 04/02/2017 at 19:55, Damo636 said:

 The APM is just that bit brighter and more colour neutral.

Sort of expected if less light is being lost into the spectrum, especially off-axis. Have you yet been able to assess how much brighter it is on-axis?

@abhoriel The PWMs arrived very quickly (ordered 30 Dec, arrived 7th Jan), it was the illuminated switches that took so long.

@Daz69 https://www.amazon.co.uk/gp/product/B007Q82F98/

1 minute ago, doormij said:

My latest: EL 10x50 roof,

Envious! Nicest 10x50 I've looked through. Ever.

Those are not binoculars, but BSOs (*). As such, they might be useful as a "talking point" paperweight, but not much else.

* Binocular-Shaped Objects

...and even less charitably: most of the time they can actually see what another is using; most of the time, we can't.

But also, for most astronomers, binoculars are not the primary instrument and the main lucre goes into a scope, mount and decent camera and .....

Yesterday I showed you why you shouldn't use Eyepiece-fitting Solar Filters. This video shows you two simple and inexpensive ways to safely observe the Sun (including binoculars). 
https://youtu.be/eDZ_nDR1BYk

36 minutes ago, Joe12345 said:

Ouch!

I was wandering if projecting the sun with 10*50 bins would let me see mercury?

Yes, it will, but be careful if there are any plastic "internals"; the heat can melt them. (Guess how I know.)