13 replies to this topic

[MaasAstro]

There is a Meade LXD55 8 inch SCT for sale near to me here in the UK. Can you help me to put a value on this telescope please?

 

I find Meade's naming really complicated. It seems that the name of the mounts and telescopes were not always distinguished, and they sometimes used the same code for different scopes, such as the LXD55 that could be SCT or SNT. In addition, scopes with the same model name came in different apertures, so I will try to be totally clear which one I am talking about.

 

The telescope in question is the Schmidt-Cassegrain 8 inch version of the LXD55, not the Schmidt newtonian or 6 inch SCT version. I know that the LXD55 mounts had a bad reputation, but this sale is the OTA only. The OTA is in good condition but comes bare, no diagonal or eyepieces.

 

What is a fair price for this telescope?

[rob1986]

All post lx3 pre acf meade f10 scts are the same.

Price is the same, in the states between 400 for really lowball buyitnow to about 800 for excellent condition and theybuyer really wants one.

[Bill Barlow]

I once owned one of these older Meade LX55 8” SCT’s several years ago.  It was a very good performer, had sharp optics and the owner kept it in mint condition.  But prices of 8” SCT’s have gone up quite a bit from 10 years ago.  I would say if it is in good to excellent condition (cosmetically and optically) and doesn’t have a focuser with a lot of image shift, I would offer something around $600 US.  
 

Bill

[MaasAstro]

Thank you Rob and Bill, that's really helpful.

 

I like the look of this telescope: compact but large aperture. If we can agree on the price I'll buy it

[carolinaskies]

An LXD55 would be a classic SCT OTA in line with an LX10/LX50/LX90 non-ACF.   

Pre pandemic $300-400 and I still see them in this range in the US sold on CN classifieds and local marketplace.  Anything above $400 you're paying a premium price for an older OTA and it should come with other accessories for the higher price.   

I wouldn't fork out more than $450-500 for the LX200 version without accessories, non-ACF, there's just no reason to spend more.   Remember 8" is the most common and popular size and they come on the market very regular.   

 

[MaasAstro]

$400 is about £325 at the moment. The seller is asking £550 (about €680). I know we pay a bit more for second hand kit here in the UK, but this seems a bit too much. I guess everyone starts high knowing they'll be offered below asking price. I'll contact the seller to see what he can do on the price.

You mention ACF. I assume this is a coating? Does it make much difference?

[rob1986]

No its optical. Acf is mostly if you intend to use big sensors for ap.

[Bill Barlow]

The LXD55 was before the ACF (Advanced Coma Free) optics were introduced.  They help correct coma and astigmatism.  I also like these older LXD55/75 8” Meade’s with the white glossy paint finishes.  I also owned one of the LXD75 8” Meade ACF’s that had very nice optics.

 

Bill

[jgraham]

The LXD75 SC8 was my first Schmidt-Cassegrain and I still have it. As near as I can tell the only difference this and other pre-ACF SCTs is that they were white (as were the MTS SCTs) and they had a chrome handle on the back of the scope. The optics in my example are excellent and have produced some of the best planetary images that I have taken. The asking price seems a bit high, but in line with what I have been seeing over the last couple of years for an 8" SCT with good optics and in good condition. Value is in the eyes of the beholder.

 

My baby...

 

 

 

[carolinaskies]

ACF optics are "Advanced Coma Free" which revamped the optical train to make stars towards the outer edge of the focal plane remain points instead of showing curvature.   This effect is seen both visually and with a camera at wide-low power viewing.   

Early ACF models introduced by Meade will have something on the corrector plate retaining ring which show either an "R" or "Ritchey Chretien" before being marked ACF. If the OTA in question does not have these markings it is a classic SCT design (most likely in this case).  

In general, those who've used an ACF side by side with a classic SCT whether Meade or Celestron have been able to see the performance gain.  

 

[MaasAstro]

This is my first post on Cloudy nights. I'm amazed at how quickly I can access a pretty vast collective knowledge. Thanks for all the prompt, useful answers.

I don't see any extra letters to indicate ACF, but that's not an issue for me. It will be my first scope so it's likely I'll be happy with it.

I can see that it has a knob on the back for focusing. I assume this moves the primary mirror to focus. Is it possible to add a focuser between the back and the diagonal, like on a Newtonian? I realise that would be a totally different method and I'm not sure if it would work, or what you would then do with the original focus knob, but I think I've seen this on other telescopes (perhaps I'm confusing this with Maks).

It will only be used for visual observing, so if the knob focuser is adequate I can leave it as it is

[jgraham]

The ACF optics are very nice, but benefit imagers more than visual unless you are really sensitive to off-axis coma. You can improve the field of the pre-ACF scopes by adding an 0.63x focal reducer/field flattener. Yes, you can add an external focuser to the port on the back of the scope and this is a common addition. GSO makes a relatively inexpensive external focuser for SCTs. You can also use a Meade micro focuser if you can find a hand box to drive it.

 

Like most 8” SCTs the SC8 is a pretty versatile scope.

 

My SC8 on a Twilight II paired with a C80ED for star-hopping...

 

 

...and riding solo on a Twilight I...

 

 

Edited by jgraham, 26 January 2023 - 05:50 PM.

[carolinaskies]

Visually there isn't great need to add an external focuser though they can offer easy fine-tuning focus without moving the mirror. (they bolt in place of the visual back you normally screw on to the back of the telescope).  

The cost of adding either an external focuser or replacing the coarse focus knob with a dual speed focuser is very similar.  Easier is to add a larger dial over the focus knob to make a defacto fine focuser. 

[MaasAstro]

Okay, thanks for explaining that.

Unfortunately the seller replied to say the Meade LXD55 is already sold. On the plus side, I think I've discovered the ideal telescope in this process. The 8 inch SCTs seem like a lot of aperture for minimal weight, and a more versatile focal length than the maks.

I recently bought a Celestron CG5 mount second hand (at an irresistibly low price), in preparation for a medium aperture cat/cass scope. I was really shocked at how big and heavy this mount is, especially as it is considered a lightweight mount by many. Then I read people saying that a 7 inch Mak needs an even bigger mount! That would be totally impractical for me.

I'll be keeping my eye out for another 8 inch SCT in the classifieds from now on. Thanks again for your help.