Double splitter.

[Theninjagecko]

what would you say is the best double star splitter per price category?

£2000 and up

£1000 to £2000

Under £1000

I had an old mak 127 years ago and was amazed how well it split doubles. 

[John]

Used or new prices ?

[mikeDnight]

Aperture determines resolution, while optical quality and design can determine how well the star image is represented. I've never considered a double star splitter in terms of price bracket before, but as generally the aperture and quality of a scope increases with price, I'd say potentially you'll get a better/cleaner split the more you pay, relative to aperture. But then again may be not. There are some wonderful scopes out there at relatively low prices.

Edited July 12, 2020 by mikeDnight

[jonathancd]

In my view refractors probably are best for splitting doubles.  In your top category, my current main scope is amazing with doubles and manages mediocre seeing very well allowing splits down to 1 arc second.  If you can afford one a TEC140 is hard to beat.

[Moonshane]

The best scope I have for doubles generally is my 120 Equinox but when conditions are right I think my 6"f11 OOUK newt beats it. The Equinox is 'easier' to use though. For £200 used the newt wins. For £1k used the Equinox is also great.

My 16" f4 newt when masked to 160mm beats both probably.

I think a tracking mount is in some respects most important as it allows you to concentrate on moments of good seeing which often reveals a tricky split. Big aperture sometimes also allows an easier albeit fuzzy split.

Newts are dirtier, fracs pretty and cleaner with distinct airy rings. Colours often better in fracs I find.

Swings and roundabouts.

 

[bomberbaz]

1 hour ago, jonathancd said:

In my view refractors probably are best for splitting doubles.  In your top category, my current main scope is amazing with doubles and manages mediocre seeing very well allowing splits down to 1 arc second.  If you can afford one a TEC140 is hard to beat.

wowser just been looking up the TEC140 and quickly came away from the website. I have spent enough this last 6 months. 

Personally I would say that is the type of scope that I would prefer to be  mounted on a pier 

[Whistlin Bob]

@Moonshane might have closed the thread by completely nailing it with his answer.

I use a 14” dob and with a mask it can split down to about 1 arc second, but the results aren't especially pretty. However, I quite like watching the stars float across the fov, separate as they approach the axis and then merge again when they've passed it.

I keep hearing about how good refractors are at this, and how nice the views are. Trying not to think about it as like @bomberbaz I'm trying to remove the direct access that astronomy seems to have to my bank account.

[Paz]

I think more outright aperture will give the best splitting resolution and the best performance on faint doubles (which is useful of you want to have a much bigger list of doubles to pick from when observing) so a big bucket would be good, but if you want clean and well presented doubles then a refractor would be best.

[bomberbaz]

I have a double atlas which I haven't actually had chance to use due mainly to the weather. However it is my intention to work through it constellation by constellation with my first weapon of choice being a 4" frac.  

Any that cannot be resolved will be hit with a light bucket, ie; large dob. 

[John]

The challenge with a newtonian is that the split is made but it is sometimes hard to see that it has been made due to diffraction from the secondary etc, etc.

 

[mikeDnight]

This is what you really want! As well as deep deep pockets of course!!

[F15Rules]

I think it's hard to beat a good long focus refractor for splitting doubles and presenting them beautifully.

F12 or slower achromats are really excellent, with F13-F15 being the sweet spot I feel. Why? Several reasons: Depth of focus ( no need for dual speed focuser as the long refractor focal ratio allows a good margin within which sharp focus can be achieved).

Also, long refractors present large airy disks which I feel can help to spot faint companions on or close to the first diffraction ring.

And long refractors seem also to be much less affected by atmospheric conditions, giving of their best more often.

Some of the older (1979s-80s) F15 refractors such as Towa Topic do come up for sale at reasonable prices from time to time say from £50-£100: mounted on a modern EQ5 class mount and modified with an adapter to take 1.25" eyepieces, they can give lovely views of close doubles down to c 2" or so of arc.

The challenge for the bigger scopes like these is mounting them properly, due to their long length and moment arm. But on a good equatorial they can be solid as a rock, as shown below on my old D&G USA 5" F15 achromat, now owned by a fellow SGLer and lovingly mounted on an EQ6 on a permanent pier. The views of doubles through this scope are just wonderful, best I have ever seen👍

Dave

Edited July 13, 2020 by F15Rules

[Paz]

2 hours ago, mikeDnight said:

 

 

39 minutes ago, F15Rules said:

 

Oooh - some nice eye candy there!

[John]

There is something about the view of double stars through a good quality refractor that is really satisfying. Even often observed ones such as Epsilon Lyrae merit frequent re-visiting when you have perfectly formed airy disks, a faint diffraction ring around each star and the subtle tint differences

Mak-cassegrains and mak-newtonians get very, very close to this as well though and are affordable in larger apertures too.