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4" Achro's.. Tal100Rs, Lyra Optics or a new/old pretender in new cloths

Fozzie

By Fozzie
in Discussions - Scopes / Whole setups

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nightfisher

nightfisher

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Nice pics of a nice scope, i nearly got a used one a little while back, but i feel the f11 is just a tad to long for my AZ4, the Tal is very near the limit on this mount, also if i had bought it i would have had to sell my TAL, not doing that

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F15Rules

F15Rules

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Lovely scope John, brings back good memories of my Lyra F11 which went to a good home with Fondofchips (don't you just love that handle!! :grin:).

One of the things I like most about these Kunmings is the long dewshield. When I was a lad the received wisdom was that a dewshield should be between 50% and twice as long as the diameter of the objective - so a 4" lens should have a dewshield between 6" and 8" long. The Kunming is nearer the latter and it really makes a difference. I never had the Lyra lens dewing up with that dewshield on it.

The focuser also stood out as being first rate, a very smooth dual speed crayford. At high powers (over x200, and which these scopes will readily cope with) the ability to fine focus can be the difference between suspecting a double star split and knowing that you've split it.

Look forward to your first light report Fozzie!

On the general point of the scopes mentioned, I've owned the Tal RS, the Lyra and my son in law has the Omni 120F8. The Omni is not a bad scope, but it's nothing special and closer inspection reveals very thin paint and tube wall. The Tal is just plain rugged and, well, Russian - all the effort going into the optics, and the Lyra is up nearer William Optics/Equinox build, with matching very good optics. I'd personally have placed the Lyra at the top of my list optically, but I respect all the other views - I think the fact that we all see only marginal differences shows how good both the Tals and Kunmings are. You wouldn't be disappointed with either.

Regarding the Skywatcher ED100, I've never used one, but I did own 2 Celestron ED100 F9s, something of a classic budget apo scope. Couldn't fault it optically, it really is a good scope, and you can pick one up for around £250-£280. The tube build though is not the best, more Omni in quality than Equinox: but it's light in weight. If I had one today, I'd bin the stock focuser and invest in a TS single speed crayford for around £80 - a very good, simple and smooth focuser for not that much cash.

Aren't we spoilt for choice in the 4" refractor market! :p

Dave

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Merlin66

Merlin66

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I've owned a Genesis 4" for more than 25 years but needed a "good" 102mm for a PST mod/ solar observing and spectroscopy.

I bought the TS version of the Lyra/ Kunming achromat.

What can I say - it does what it says on the lid...great performer, just love it.

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Fozzie

Fozzie

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 I put it on the az 4 and it's a no go...

I wonder if an extension pier would work, think I recall seeing a photo, on here, of a longer FL frac on an AZ4 with an extension peir to give it the clearance from the extended legs...? 

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John

John

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I wonder if an extension pier would work, think I recall seeing a photo, on here, of a longer FL frac on an AZ4 with an extension peir to give it the clearance from the extended legs...? 

The height of the mount is one issue but the rigidity of the AZ-4 when used in conjunction with a long tube is the main issue. Long tubes produce a lot of moment arm force which translates to vibration at the eyepiece unless the mount can hold the tube very rigidly.

The AZ-4 is excellent with my F/6.5 4" Vixen refractor but is very borderline with the longer tubed ED120 and the 102mm F/11's are longer again than the ED120.

The Giro-type mount (like Shane is using) works better with the longer tubed refractors.

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A McEwan

A McEwan

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Hi all.

I currently own a Skywatcher ED100 Black Diamond and the Lyra 102mm f11 achro.

I've previously owned Celestron ED100, Skywatcher ED100 gold-tube and a Skywatcher 102mm f9.8 achro.

The Lyra 102mm is superior to the 102mm f9.8 Skywatcher achro I owned. Much less false colour and a totally different league when it comes to build quality.

The gold-tube ED100 gave colour-free performance with nicely made optics, in a bare-bones OTA, and for a 4-inch class scope it was very enjoyable and rewarding to use.

The new Black Diamond ED100 I have is just about perfect. Optics are bang-on and the OTA is very nice too. So nice I added a Moonlite dual-speed focuser.

Now, optically, the Lyra 102 is not far behind the ED100, and gives beautiful rendition to planetary detail and lunar landscapes, and splits double and multiple stars just sublimely. But hey - so does the ED100, and it does it without false colour. The thing is I got my ED100 with case, only months old, for a smidgen over £300. The used market is very unkind (or kind, depending on your viewpoint) to the ED100 scopes. That puts a used ED100 and a new Lyra virtually on the same pricepoint.

Now don't get me wrong - I really like the Lyra, and probably won't get rid of it simply because I have the ED100 as well; it does what it does slightly differently and scores as a nice example of a well-made achromat, and there is a subtle little extra bit of appreciation in me for the views it delivers because of that.

So I guess what I'm saying is, a Lyra 102 OR a good used ED100 are pretty similar for cost and performance, and given how little these scopes cost, there's no reason I can think of to now consider the old Skywatcher 102mm f9.8 or Celestron 102mm f9.8 achro's as contenders in the same ballpark.

Good hunting.

Ant

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fondofchips

fondofchips

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My Lyra 102 is not going anywhere, definitely a keeper, best value for money of any of my astro gear.  Fitting a Skywatcher type finder is not a problem with the single fixing hole on the focuser, I just drilled a hole through the centre of the finder shoe & put some double sided tape along the edges.

Started off as my only scope & is now used as my dark site scope.

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John

John

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I'll be interested to see how you get on with it. It's not the weight but the tube length thats the challenge but at low to medium power it might be OK.

A 150mm F/5 newtonian sits very well on the AZ-4 for DSO's under dark skies :smiley:

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nightfisher

nightfisher

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I used my Lyra effectively on an AZ4 with pier extension. It was fine. Now I use it on the SkyTee2, on which it is even finer! ;)

Ant

I still feel the Lyra is just a bit to long for an AZ4, my TAL is a bit shorter and lighter but struggles at higher power, but very good up to x80

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