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8SE OTA conversion to Equatorial?

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#1 bubbles3660

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Posted 30 April 2013 - 01:01 PM

Hello All,

Is it possible to convert an 8SE OTA to fit an equatorial mount? I'm looking at a Celestron Advanced VX or a CG5. Does it require a different rail?

#2 ben2112

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Posted 30 April 2013 - 01:32 PM

From my understanding, the 8SE comes with the Vixen rail which is compatible with the VX or CG5 mounts. I am planning on upgrading my 8SE to a VX mount down the road.

So yes, you should be able to upgrade.

#3 Midnight Dan

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Posted 30 April 2013 - 01:42 PM

The 8SE uses a standard Vixen sized rail. I'm pretty sure the CG-5 accepts a vixen rail, not sure about the VX but I would guess so.

-Dan

#4 bubbles3660

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Posted 30 April 2013 - 02:36 PM

Thanks, Gents.

--bubbles

#5 hopskipson

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Posted 30 April 2013 - 03:23 PM

If you were going with the cgem you would need the Losmandy (D) dovetail.

#6 mclewis1

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Posted 30 April 2013 - 03:41 PM

Yes the CG-5 and AVX both use the standard Vixen/CG-5 size dovetail so the ota off of one of the SE scopes will just "drop in". If someone wanted to use the CGEM mount then you have a couple of choices ... 1) get the ADM replacement "dual" saddle for the CGEM or 2) replace the dovetail bar on the 8SE with a Losmandy D compatible one ... either a Losmandy D type plate and suitable radius blocks or the Celestron CGE style bar for the C8.

#7 Terrance

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Posted 04 May 2013 - 08:57 PM

An 8SE OTA should fit no problem on any GEM mount with a vixen size dovetail mount saddle.

However, Note that the dovetail bar on the SE scope will mount onto a GEM with the bar on the scope's bottom, not on its side as with the SE mount. The finder mount position will therefore be shifted 90 degrees from where it was on the SE mount.

#8 cpl43uk

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Posted 09 May 2013 - 05:44 PM

I have recently purchased the VX for my 8SE OTA. As others note it is a straightforward swap. However the limited positions for finderscope attachment points and with the 90 degree twist of the scope I find it can be a bit inconvenient, especially since the star diagonal also needs to be rotated as the eqt mount locates its objects. I find I need occasionally to remove at least the red dot finder (i have a big baader sky surfer) but its no big deal. The real benefit for me are much improved gotos when combined with a heavy back end (binoviewers) and rock solid tracking so can finally use my focuser without the jitters. However one day I will probably loose an eyepiece because I will forget to lock it in the diagonal and the scope will rotate to a point it will fall out!

#9 RTLR 12

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Posted 09 May 2013 - 06:45 PM

The positions of the finder scope are the same no matter what OTA you have. Using the dovetail as the 6 o'clock position, the finder positions are at 10 o'clock and 2 o'clock no mater if it's an 8SE or a C8.

Stan

#10 toothdoc

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Posted 17 July 2013 - 05:59 PM

I too will be using my 8SE on a VX mount. I can trade in my 8SE tripod and mount or is there an advantage to keeping them?

#11 mskillen

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Posted 17 July 2013 - 07:15 PM

I have the 6SE and I bought the AVX mount, no problem at all with the rail on the scope, finder moved from 2 o'clock to 10.
Works great nice mount, still looking for a bigger OTA for it at the minute, but it gave me all the practice I needed to get used to the mount.

Mark

#12 Midnight Dan

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Posted 17 July 2013 - 08:35 PM

Hi toothdoc:

I have a GEM mount (the iEQ45) that I use with the 8" SCT from my 8SE. It's great for astrophotography, but I find that for visual use it's cumbersome. It's heavy, takes a long time to set up, and put the OTA in some awkward positions for viewing. While the SE is more shaky and not as accurate on gotos, it is lightweight, simple to set up, and a breeze to use. For visual use I always find myself reaching for the SE.

So to answer your question, the advantage of keeping the SE is that you have the best of both worlds. A solid, accurate mount for astrophography, and a lightweight, easy to use mount for visual. The SE mount can also be used with a short refractor or other small scope if you like.

-Dan

#13 rockstarbill

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Posted 18 July 2013 - 12:16 AM

Totally agree with keeping the mount. I ordered the AVX today, and I plan on swapping between them, depending on what my main use for be for a given session (AP vs. Visual). I think its a great way to experience both worlds of mounts! Plus, if you want to get a completely separate scope solely for viewing, then you already have a mount ready for it!

#14 Widespread

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Posted 18 July 2013 - 01:32 PM

Definitely keep the 8SE mount!

The 8SE may be unique in offering 8" of aperture in a fully assembled rig that can be easily carried, and that's a big selling point for lazy folks like me.

If the vibrations with the stock tripod are a bit too much for you, the 8SE mount also fits the beefier tripod from the Celestron CPC series, and I have read that switching tripods significantly improves stability. I reckon it would still be light compared to the AVX, and let you use the user-friendly altaz configuration.

Best,
David

P.S.
Also, I have heard (and it makes sense) that the 8SE mount can be used without the tripod (e.g. on a solid table) with smaller SCTs such as 4/5SE (I think the C8 is too big, and would tip the mount over).

#15 ben2112

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Posted 18 July 2013 - 02:42 PM

My original plans were to get the VX mount but still keep the SE mount. But my super awesome wife suggested for me to get the C8 with the VX mount and keep the 8SE intact. So while I am grabbing pics, I can do some visual observing when I go to dark sites.

#16 rockstarbill

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Posted 18 July 2013 - 05:21 PM

I got some binocs for keeping me entertained while imaging. :)

#17 hopskipson

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Posted 18 July 2013 - 05:52 PM

My original plans were to get the VX mount but still keep the SE mount. But my super awesome wife suggested for me to get the C8 with the VX mount and keep the 8SE intact. So while I am grabbing pics, I can do some visual observing when I go to dark sites.


You truly have an awesome wife :bow:, but having 2 C8's seems redundant. I would opt for something bigger for imaging like the C11 or to cut your teeth a fast refractor to make AP easier to learn. Or go for the C6 to make your optical set up easier to travel. Just a suggestion of course.

#18 Geo.

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Posted 18 July 2013 - 09:36 PM

If you were going with the cgem you would need the Losmandy (D) dovetail.


Nah, spring for the ADM dual sized saddle. Accepts Vixen or Losmandy D format. I have the ADM D to V insert, but wish the dually had been available when I bought it. May as well get the CGEM. The market seems to be $1K used, only a couple hundred more then the VX.

The SE is drilled just like the ASGT C8. There are no issues using it on a CG-5, VX or a "properly equipped" CGEM. And you can always put it back on the SE mount in a minute for portability.

#19 ke4kso

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Posted 19 July 2013 - 07:53 AM

My 8se on an ASGT mount, much more stable than the se mount, One of my fears was having to stand while observing, but that that fear was unfounded, I can still do most observing sitting in a chair. Setup is more time consuming but you get used to it I guess. Mount and tripod is pretty light with the ota and counterweight removed. I think I will need an ra finder for alignment because of some of the positions I have to get in when the alignment stars are high up. It almost eliminated the focusing jitters. also this mount was much louder than the se mount, but the more I use it the quieter it gets.

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#20 Midnight Dan

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Posted 19 July 2013 - 08:09 AM

My original plans were to get the VX mount but still keep the SE mount. But my super awesome wife suggested for me to get the C8 with the VX mount and keep the 8SE intact. So while I am grabbing pics, I can do some visual observing when I go to dark sites.


Your wife's a keeper! :waytogo:

I agree with James though. When you have multiple mounts, you tend to think in terms of mix and match. If you have one C8, you can use it on either mount. No need for a second. I'd think about a different OTA for that second mount.

I wouldn't go any larger than a C8 on the VX for astrophotography, so I think a larger SCT is too much. For AP, you want to think of your scope like a lens for your camera. Just like you'd have different lenses (telephoto, wideangle) for your DSLR to get images of different size/distance subjects, you need different OTAs to take capture different sized astro targets.

The C8 is a great scope, but it has a very long focal length and will not fit larger targets onto the imaging chip. A smaller refractor would make a great companion to the C8 both visually and for astrophotography. It will let you capture (or see) some of the wonderful extended targets like the North American Nebula, Veil Nebula, Double Cluster, and many others.

You might consider something in the 80-120mm range depending on how portable you want it to be. An APO would be wonderful, but also wonderfully expensive. My personal take is that a good quality doublet/ED refractor is 90% as good as a true APO and about half the price.

Just my 2 cents! :grin:
-Dan

#21 ben2112

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Posted 19 July 2013 - 09:52 AM

Yep.. She is a keeper.. 15 years and counting.. :D :jump:

I would love to go to a 9.25 but I would have to get a CGEM mount and then I have to deal with weight. I have to keep things kind of light due to my back. I do like the idea of a nice refractor. Got any suggestions?

#22 Midnight Dan

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Posted 20 July 2013 - 11:29 AM

Hi Ben:

One thing to point out - if you want to use the refractor on the SE mount, it will have to be pretty small. Generally, a short 80mm is about the limit or it will hit the base when pointing to zenith. Here's a few possibilities:

Astro-Tech 72mm ED ($379):
https://www.astronom...scope-black_...

Explore Scientific 80mm ED ($799):
http://www.optcorp.c...lescope-with...

Stellarvue 110mm ED ($1295):
http://www.optcorp.c...sv110-25sv.html

-Dan

#23 RTLR 12

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Posted 20 July 2013 - 02:00 PM

Dan,

Do you actually put your SV110 on your SE mount? I would never consider putting my SV115 on mine. Much too long and heavy for me. I do use my R130sf Vixen on the SE mount though.

Stan

#24 ben2112

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Posted 20 July 2013 - 03:42 PM

Dan - That Astro-Tech is the one I was considering. It would fit within my budget.

#25 Midnight Dan

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Posted 20 July 2013 - 06:09 PM

Hi Stan:

No, definitely not. The SV110 is way too big. The only scopes I've really used on the 8SE mount are the Shortube 80, and the EON 72 (same scope as the AstroTech 72mm).

I was just recommending a larger scope like the SV110 as a good astrophoto alternative to the C8 on the GEM mount.

-Dan






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