Zenithstar 80 Opinions

[frogdr1ver]

Thinking about getting a small APO to go with my larger scope. Whats the opinions on the zenithstar 80? Is it definately an APO as the web seems to say its both an APO and an Achromat? How does it perform for astrophotography as well as a small grab and go?

Cheers

[russ.will]

Duplicate post - Mods; Please remove.

Cheers,

Russell

[russ.will]

I'm only just getting into using mine for AP, so in that regard, others opinions will carry more weight. However, it's definitely a doublet APO, under the currently accepted definition. I was playing with it (and my new ST80 achro for use as a guide scope) and it displays none (or at least, negligible amounts) of the false color of an achro. The target was a wood pigeon on a TV aerial against a bright flat cloudy sky. Dunno why it sat still so long (hypothermia?) but it was handy none the less, as it was a dull subject, with just a hint of it's own colour.

One, of two, issues I have found with the ZS80 under a dark sky, is that the focuser needs tuning to work at it's best. Keep an eye on the allen head grub screws that tension the rotatable focuser. Too tight and it doesn't rotate and a fraction too loose and the whole damn thing droops. It's a fine line, but do-able.

The other issue is the draw tube lock screw that inevitably seems to shift focus when you screw it in. However, with a Bahtinov mask, it's easy to see which way locking the draw tube shifts focus and defocus to offset the action of locking.

The final piece of advice, I should attribute to the bloke who sold me the scope - Save some bunce and buy the Ian King IKHAROS 0.8x field flattener - Scroll down until you see it. It's spot on, with nice sharp stars to the edge of field. Budget an extra few pence, because for some reason, it doesn't come with end caps. Weird.

I've also been quite surprised by what I can see on good dark nights. Sure, it isn't the light bucket of the 200p, but I was quite pleased with how well it picked out M81 & 82, the relative orientations being clear to see. Less detail, sure, but I've used it on nights were the extra bulk of the 200p wouldn't have tempted me out to risk a polar alignment, followed by a three star alignment, for an hour of visual in between cloud banks. It's size makes it quicker to get out and it's ready, with minimal cool down, from the get go.

Having handled the ZS80 (and it's clones), plus the SW alternatives, the one thing you will find is that there is some lovely metal going on - There's a real pride of ownership in the quality of the way it feels and handles. It makes my 200p feel like a cheap tin can and the ST80 is embarrassing in comparison. It's definitely a keeper, even if terminal upgradeitis eventually relegates it to guide/travel scope status.

Everything else is down to my technique letting the side down!

Russell

[frogdr1ver]

Thanks for taking the time to reply, much appreciated! I notice in your signature you have the zsII, is that what you wrote about above or are you talking about the original one?

[russ.will]

Oh ****? There's two?

I have this one.

Russell

[russ.will]

Quick Google - The original is an achro, the Mk II is an apo.

Russell

[frogdr1ver]

Yeah thats the mark two, ive spotted the original one and its a bit conflicting if its an APO or not. Just found this

http://www.williamoptics.com/support/download/zenithstar80fd.pdf

which says its an APO but other reviews claim its an achromat. Your review and comments were still really helpful though, thank you

[russ.will]

That PDF is the one I downloaded as my instruction manual. If you're sure that's the one in question (there seem to be loads of colours), then I can't see the point in producing a fluorite NON-apo, if you follow?

I thought the original achro was from about seven years ago - See this.

I suspect the mechanical limitations are much the same though.

I forgot to mention, I prefer the R&P focuser of the ST80. I'm coming to the conclusion that I don't like Crayfords. They seem like a half arsed solution, regardless of how highly evolved they are...

Russell

[frogdr1ver]

yeah thats the review i had read but the manual states that its a fluorite APO, hence my confusion.

[russ.will]

Well, if nothing else, the MkII has a 10:1 dual speed focuser. That review sample definitely doesn't. That seems to clear up the Mk I or II issue, if nothing else.

<EDIT>My ZS80 clearly states APO on the lens cell. The review I linked to, does not.

Russell

[russ.will]

Have iPhone, will travel - Does this help?

[frogdr1ver]

yeah it does the one ive been looking at (used) doesnt say any of that!

[russ.will]

How much are they asking? Mine was £250, plus a bit of haggling that got the 2" WO star diagonal and scope rings into the bargain at £325.

Russell

[frogdr1ver]

£258.75 posted with a celestron star diagonal, and a couple of eyepieces. No rings

[Magnum]

I saw the scope you are talking about 2 days ago, but its definitely the original Achromatic version, same build quality but will show violet halos if used for imaging!

Lee

[frogdr1ver]

Thanks for confirming that, will leave it alone i think.

[russ.will]

I just saw this in another thread. Ding dong!

Okay, it's a bit more money, but as budget creep goes, it won't be the worst case you'll ever commit.

Russell

[frogdr1ver]

Thats a good price for that eh, not bad with the reducer as well! Will do a bit of research on that one i think. Well spotted and thanks again.