Long perng refractors

[hobbit]

Are these any good? I was looking at the 110mm doublet and quadruplet both at f6. They seem a bit on the cheap side to me. Has anyone used these?

[MortonH]

There have been similar questions posed here before. The general consensus seems to be that the optical quality can be lacking a bit. It's interesting that LP make at least some William Optics scopes, but their own branded models don't seem to be as good as the WO ones.

With quadruplets requiring four lenses to be aligned correctly I'd be wary of that model at least, unless the dealer agrees to refund your money if not satisfied.

The 110mm doublet might be ok for visual, but at f/6 and using FPL-51 glass I'd expect some false colour.

[cometcatcher]

My experience with the LP 90 doublet was terrible. The optics were extremely poor. Poor contrast and CA was worse then my SW120 achro. It's possible I got a faulty one but I'm not getting another to find out.

[hobbit]

guess that crosses them off the list. Any other suggestions for a 100ish apo? I did see the skywatcher but not sure about it being f9

[casstony]

If you want the scope for visual use f/7.5 or a little slower is better than the faster scopes in terms of field curvature; 900mm focal length is fairly comfortable to use (eyepiece not too close to the ground) and I personally wouldn't go longer than 1000mm, just for convenience and portability.

[LewisM]

Find an old Vixen FL102S - simply outstanding, and fluorite too :) One sold here recentl (Celestron badged)at a good price. Natively f/9 (GREAT for visual), and can be stopped down to f/6.3 with the proprietry (yet scarce) Vixen focal reducer (which I have, and which Claudio still may have a few of - exxy at $250 each, but worth it)

I have looked through many LP's - all terrible! Really, a waste of money.

I used an SW BD 100ED, and it was really good bang for the buck, as was the 80. I was never fond of the 120 - always seemed to show colour abberation. I have also used a couple WO mini-refractors, and again, decent for the price.

Long Perng and United Optics stuff is really average at best. An owner showed me through his over-priced UO 115 recently, and it was ghastly in comparison to the FL102S and the AX103 we had out. Just not good, despite the wild grandiose claims for UO (all hype and no substance)

[hobbit]

FYI this is 95% imaging very little visual use.

[Larryp]

I had a LP 90mm. Visually it was terrible-an enormous amount of chromatic aberration at both red and violet ends of the spectrum-took it back to the dealer and the replacement was just the same.
They would be a complete waste of time for imaging.

[casstony]

In that case you could put up a wanted ad for a Sharpstar 106 f/6.5 or equivalent scope with another brand - someone might be prepared to sell; these are top quality apo's at an affordable price.

[Stardrifter_WA]

I have the Williams Optic FLT110mm Apo and it is a magnificent scope. It cost me $2,500 landed (with tax), with a bonus Field Flattener.

This scope has become my favourite scope and I doubt I will ever part with it, unless I had the money for the FLT151mm. :D But then, the size of the 110 is easily manageable.

Cheers Pete

[MortonH]

What's your budget? Imaging is a bottomless money pit :lol:

[hobbit]

I'd like to try and stay below $2,000. preferably less than $1,500 if possible.

I don't understand why it needs to be a bottomless pit.
mount scope guider camera computer. does it really need much more than that?

[MortonH]

Sorry, what I meant is that there's no limit on what you can spend, depending on your requirements.

A decent imaging scope in the $1500-$2000 range shouldn't be too difficult. Next question: what sort of objects do you want to image? For wide field lots of people here use an ED80 (Skywatcher, Orion, etc) and they are very cheap.

I'm sure others will chime in. I don't actually do any imaging with my scopes but I've read enough to know the basics ;)

[hobbit]

Yeah ED80 was recommended in one of my earlier threads. This thread was originally just to see if the LP were any good as I wanted a bit more read than the 80.

[MortonH]

Sounds like you want a triplet or very good doublet around 100mm. For the budget best bet is something like a used William Optics, or the Sharpstar that was mentioned above. Maybe post an ad in the Trade/Wanted section and see what happens?

[MortonH]

Or if you don't mind an f/9 scope the Skywatcher Black Diamond 100ED is excellent value at around $1300 brand new.

[AG Hybrid]

Check out the Orion 110mm ED. Cheaper. With better quality control and pretty much everything else.

[Gem]

As I posted on another thread: my 80mm LP performs adequately for imaging. Of course you can get better scopes, but in terms of what you get for the price - I have no complaints. I do use it mainly for imaging not for observing.
It all comes down to budget and what you are wanting to do with a scope.

[kosh]

Sound good, but it only sounds that way :lol:
Adapters, filters, dew heaters & controllers, processing software, flatteners, reducers, focusers, masks... You won't get or need all of these things, but as you go, like most hobbies, there's always "something" you need. Trouble is AP's "something" is rarely ever cheap.
Goran.

[rmuhlack]

I have a LP 80mm f6 achromat, which I have experimented with for AP (Using a WO p-flat 88 field flattener and a WO VR1 violet reducing filter). See this thread http://www.iceinspace.com.au/forum/showthread.php?t=117205

[hobbit]

Thanks Richard but I'm going to cross LP off the list.

[brian nordstrom]

:sadeyes: I had one of these and I think I got the best of the 4-5 Andrews had but sadly as Laurie says the CA was NOT! APO standard , but saying that it was very well corrected in the blue end of the spectrum so would have been easy to filter the red out .

Probably ok for AP using filters as said but pretty bad visually , the red overpowered most bright objects .
( probably a good nebular shooter ? )
That's where these lenses were best , in the blue/green , not red .

Its a shame because the build quality was up there with the best , a nice scope to use and that's a real shame .

On a side note I sold mine as well and grabbed a Takahashi sky90 ( same specs 90mm f 5,5 , but a fluorite ) and now this is a scope , but at 4x the price of the LP it should be .

ps. their 60mm triplets and quads look interesting ? don't write them off to easily .

Brian.

[MortonH]

The new Orion EON 110mm ED f/6, and the smaller 62mm Starblast refractor, appear to be made by Long Perng. Interesting since Orion's other refractors were/are made by Synta.