LX90 8" ACF on HEQ5??

[bill2stan]

I'm new to this forum, but would like some advice. After doing some research I've moved from the CPC 800 to the LX90 8" ACF, but I'm not sure which way to jump. I was about to buy the LX90 8"ACF when the supplier (teleskop-austria) suggested using the LX90 OTA with a HEQ5 GOTO mount.

Just wondered if any views on this (price for the HEQ5 €200 more) because "many users do not rate the LX90's stability as very high".

I had not noticed this in my research. I presume the HEQ5 would be better for astro photography.

[E621Keith]

HEQ5 is better for AP because you can use it with a fast light weight scope, such as a ED80, which is more tolerant on tracking errors. A F10 scope with 2 metre focal length is very demanding on the mount.

If you choose an ED80 as your imaging scope instead of the 8" ACF, you should have enough money left over for a Celestron C8 SCT for visual and planetary imaging.

Fork mounted SCT/ACF were designed for visual observation and AP in the film era. Most comments suggest they aren't good enough for digital sensor.

[Merlin66]

I de-forked both my Meade Lx200 8" and 10" OTA's...fitted the wider Losmandy dovetail, a dual saddle on the HEQ5pro mount and found the 8" worked very well.

The 10" needed IMHO the NEQ6pro mount.

I must ask...why the change from the CPC 800 to the Meade??

[bill2stan]

Hi guys,

Thanks for the replies.

I de-forked both my Meade Lx200 8" and 10" OTA's...fitted the wider Losmandy dovetail, a dual saddle on the HEQ5pro mount and found the 8" worked very well.

The 10" needed IMHO the NEQ6pro mount.

I must ask...why the change from the CPC 800 to the Meade??

It was an iterative process (?) which ended up with the Meade. The 8" ACF OTA seems to get very good reviews from users. I was also looking at a variety of different mounts. The Austrian supplier suggested the latest variant as a cpromise between that would alow me to dabble in AP if I want to - with limitations.

HEQ5 is better for AP because you can use it with a fast light weight scope, such as a ED80, which is more tolerant on tracking errors. A F10 scope with 2 metre focal length is very demanding on the mount.

If you choose an ED80 as your imaging scope instead of the 8" ACF, you should have enough money left over for a Celestron C8 SCT for visual and planetary imaging.

Are you suggesting dual mounting a C8 SCT and ED80? Hadn't thought of that. Limited options re suppliers here and price is higher than UK.

Decision time soon.

[alan potts]

I am not at all sure about this. The F/L of the LX 90 is 2000mm and it is not that light though it is fairly short in the body. I think for astro it will be difficult to guide for any length of time because of the focal length. I don't believe the HEQ5 pro is a problem up to 1000mm and maybe even just a little more but 2 meters. If it were only for visual I don't see a problem .

Alan

[E621Keith]

...

Are you suggesting dual mounting a C8 SCT and ED80? Hadn't thought of that. Limited options re suppliers here and price is higher than UK.

...

No, I was actually thinking you put on the ED80 for DSO imaging or removed it and replace with a SCT when you do visual observation. Unless you have permanently observatory, single scope set up will be easier to manage than dual scope.

[Merlin66]

I use both the HEQ5pro and the NEQ6pro for spectroscopy...

The guiding with PHD and Al's reticule is quite capable of keeping a target star on a 25micron slit indefinately...for convenience I usually run 10 min subs...

That's with a well balanced, PA set-up. An 8" SCT on the HEQ and C11 on the NEQ.

[bill2stan]

Looks like I'll be ok for visual and be able to dabble in AP and see how he HEQ5 copes wit the long focal length. I could always get a ED80 for AP.

Thanks for advice - invaluable.

I was also thinking of getting a Baader8-24mm Hyperion Zoom Mark-III FV=68 deg - ancomments?y

[bill2stan]

Decision time soon.

Went to teleskop-austria this morning and they had a special on the NEQ6 pro - only 155 Euros more than the HEQ5 pro - so I ordered it along with the Meade 8"ACF!! :grin: Should be ready in about one week - can't wait. Hopefully time for the gloomy weather here to improve. Had them both in the shop and I was able to test lift the NEQ6 - more of a hug than a lift - but fortunately it's not got to go very far.

All the best,

Bill

Again, thanks for advice and will report back when it arrives.