Which Apo?

[Damo636]

I have more or less decided that one of these will be my next scope.....

http://www.firstlightoptics.com/equinox/skywatcher-equinox-100-apo-pro-ota.html

but stumbled across this ...

http://www.teleskop-express.de/shop/product_info.php/info/p4964_TS-PHOTOLINE-ED-APO-102mm-f-7-with-3--Crayford-Focuser.html

and wondering has anyone any experience with this model.

I realise the longer fl of the Equinox would make it a better all rounder but would appreciate the frac guys thoughts.

[John]

I've not tried the TS one but I notice that it's an F/7 and does not disclose the ED element glass type, so I'd assume FPL-51 or similar. I reckon the colour correction of the Skywatcher (which uses FPL-53 glass) at F/9 is likely to be better.

[AndyH]

In theory..........

Even although they're ED doublets, The F9 should be better colour corrected, all things being equal. But if physical length is important the skywatcher will be roughly 8" longer.

You still have the potential for a very wide field of view with the F9.

Mmmm.

[Stephen]

Without being able to determine the glass in the TS on, I'd stick with the Equinox

One question, given that the Evostar and the Equinox have the same focal length / ratio at 100mm, and the same glass, why the Equinox?

[AndyH]

The equinox range has by far the nicest colour scheme of skywatchers offerings, if you're into that sort of thing

Andy.

[Stephen]

The equinox range has by far the nicest colour scheme of skywatchers offerings, if you're into that sort of thing

Andy.

True

[johninderby]

Yes the TS scope is most likely an FPL-51 and the Equinox should have less CA.

This one from TS should be better than the Equinox, but unfortruantely quite a bit more money as well. Looks interesting though.

http://www.teleskop-express.de/shop/product_info.php/info/p5143_TS-PHOTOLINE-Triplet-APO-102-700mm-Refractor---3--Crayford.html

John

[AndyH]

Yeah. The fact that it doesn't mention one of the glass types does make one think it's FPL51, which is a nice bit of glass, but probably needs to be of a longer focal length to achieve good colour correction.

We are of course speculating, but going by how manufacturers often omit glass types when FPL 51 is used, we could be on the right track?

[John]

In theory............

Yes, thats true. The quality of the mating element, accuracy of figuring and coating quality will make a big difference too. It's just that the Synta ED doublets have such a great reputation and, IMHO, are a "safe bet".

My little Vixen ED102SS is "only" an FPL-51 doublet at F/6.5 and does a great job of CA control so it shows it can be done. The Vixen listed at over £1K for the OTA when new though......

.

[Stephen]

The equinox range has by far the nicest colour scheme of skywatchers offerings, if you're into that sort of thing

Andy.

Then again I have a black sparkly OTA with a white dew shield, off black rings, a blue dovetail, a red focuser and a different red camera .....

My wife says I have no style, what does she know?

[AndyH]

.......................It's just that the Synta ED doublets have such a great reputation and, IMHO, are a "safe bet".

.

Yes indeedy, feedback from actual users is a VERY important point.

[Damo636]

Thanks guys. A couple of things stand the Equinox apart from the Evostar for me, the rotateable focuser and the overall fit and finish appears to be slightly better. The Evostar package is obviously better value with the included diagonal and finder but somehow I think I'd end up kicking myself for not going with the sexier Equinox

The TS scope is good value but if it has inferior optics I will scrub it from the shortlist.

[Damo636]

Yes the TS scope is most likely an FPL-51 and the Equinox should have less CA.

This one from TS should be better than the Equinox, but unfortruantely quite a bit more money as well. Looks interesting though.

http://www.teleskop-express.de/shop/product_info.php/info/p5143_TS-PHOTOLINE-Triplet-APO-102-700mm-Refractor---3--Crayford.html

John

It is indeed a nice scope John but unfortunately to expensive

[Caldwell 14]

Yes indeedy, feedback from actual users is a VERY important point.

Indeed!

You may have noticed this hobby is not cheap! I would always buy tried, tested, peer reviewed scopes, I always play safe, a mistake in this game is always an expensive one to make. As an example if I was going to get into imaging I would buy a SW ED80, they have a strong reputation built over years. TAL 100RS is widely held as the best 4 inch achro in its price tag, again a very safe bet, I would advise anyone who wanted to buy a new achro refractor to buy one, loads of people would. I went for my ED100 as it was a safe bet, everyone said so, there was no risk, they were right (cheap enough second hand too and availlable quite often on astro buy and sell sites.

Equnioxs are very nice scope, an up-grade on the ED range from SW with the same optics

[johninderby]

One other thing to consider with the Equinox though is that the focuser is the weak point. New you should be OK though as the focuser can usually be adjusted to make it right if needed.

Used Equinoxs are a different story as I've seen no end of them with focusers that have been ruined by the "lets tighten every loose screw" brigade.

Of course there's always the Moonlite option later on.

John

[John]

.... I went for my ED100 as it was a safe bet, everyone said so, there was no risk, they were right (cheap enough second hand too and availlable quite often on astro buy and sell sites....

For those with long enough memories (like me ) the fact that you can today get a really well corrected 4" apo refractor for under £500 (well under often) on the used market is itself remarkable. In the 1980's and 1990's your choice was much more limited and you would need a budget of well over £1K to get into the 4" apo club.

The Chinese / Taiwanese manufacturers have done us a lot of favours

[Damo636]

One other thing to consider with the Equinox though is that the focuser is the weak point. New you should be OK though as the focuser can usually be adjusted to make it right if needed.

Used Equinoxs are a different story as I've seen no end of them with focusers that have been ruined by the "lets tighten every loose screw" brigade.

Of course there's always the Moonlite option later on.

John

I didn't know the focusers on these could be problematic John. Are they difficult to adjust if necessary? I might be better off saving a few quid and opting for the cheaper Evostar if I am going to end up changing the focused at a later date anyway

[johninderby]

I didn't know the focusers on these could be problematic John. Are they difficult to adjust if necessary? I might be better off saving a few quid and opting for the cheaper Evostar if I am going to end up changing the focused at a later date anyway

Unfortunately it seems that the Equinox quite often arrives with a focuser that is out of adjustment. Adjusting it though is usually straight forward. There is a good "how to" on adjusting a dual speed focuser in this manual for the Opticstar ED80.

http://www.opticstar.com/Download/Astro/Doc/Telescopes/Opticstar/Opticstar-ED80S.pdf

Also worth reading this thread.

http://stargazerslounge.com/showthread.php?t=173555

Pity Glen at Lyra Optics doesn't sell the Equinox, then the focuser would be perfectly adjusted before shipping.

John

[Damo636]

Post deleted.

[Damo636]

You read my mind John regarding Glen ,

[Damo636]

Hmmm, that second link is interesting reading. It would be sickening to spend that much money and then have to start pulling the thing to bits to make it useable!

[AndyH]

.......... There is a good "how to" on adjusting a dual speed focuser in this manual for the Opticstar ED80.

http://www.opticstar.com/Download/Astro/Doc/Telescopes/Opticstar/Opticstar-ED80S.pdf ........................

What an excellent manual

Well, apart from using a certain 8 letter word, when they shouldn't. It makes me roll my eyes and sigh

I blame W.O. for starting it.

Andy

[johninderby]

What an excellent manual

Well, apart from using a certain 8 letter word, when they shouldn't. It makes me roll my eyes and sigh

I blame W.O. for starting it.

Andy[/

That's how a scope manual should be written.

All credit to Opticsar.

John

PS

A copy of that manual should be sent to SkyWatcher, Celestron, Meade etc. with a note saying why can't you do manuals like this.

[Marki]

The TS that Damo636 orginally linked looks essentially the same as the Starwave 102ED to me. If so, I think its the fl51 glass as others have posted. I have the starwave and whilst I really like the big robust focusser it is not really an apo. The equinox should be better under almost all circumstances - I have an equinox 80 for grab and go, and notwithstanding the the short fl and limited aperture the views are gorgeous. Plus the scope looks well smart too! I'd go for the equinox if I had to make the choice for the 4" size again.

[tony4563]

Hi Damo

The Equinox 100ED is a stunning scope both optically and in build quality.

The focuser, I've found is FAR better and smoother than the cheaper DS Pro equivalent.

Only niggle I have is that although the build quality is top notch, I find the finish just a little bit too slippery.

The price has also just gone up quite a bit for a new one too, unfortunately