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Is the FLT 120 well matched to the EQ6-R mount?

William Optics Fluorostar 120 / FLT120 Sky-Watcher EQ6-R Pro Refractors Buying Advice
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Peter Robertson avatar
Peter Robertson avatar
Hi everyone 

I am thinking of purchasing the FLT 120 and wonder if owners who have used it with the EQ6-R mount, think it is a good match?

I know it’s under the limit of 20kg but does 120 mm scope pushes the limit of this mount? Or is it very well handled by the eq6-r? 

I am interested in the FLT 120 or similar, as the focal length is a good match for my full frame DSLR, either with the 0.8 reducer or with the flattener.

thanks for any comments or thoughts on the size of the FLT 120, and any other thoughts about buying this or other scopes.

Peter
Tom Boyd avatar
Tom Boyd avatar
I used an FLT132 on an EQ6R for a couple of years with no problems whatsoever. My total payload was about 33 lbs. Typical guiding was between .5" and .7".
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Peter Robertson avatar
Peter Robertson avatar
That certainly sounds promising, thank you Tom!
Ryan Benbow avatar
Ryan Benbow avatar
I've used a FLT120 on my eq6r as well and as Tom said, absolutely no issues regarding weight/guiding. However, one thing to be mindful of is if your imaging close to zenith, I found the scope/camera can come into contact with the legs of the tripod. Of course, with mount limits set this can be avoided.

It was for this reason I eventually swapped my FLT120 to an AM5 with an extension pier and put my SCT onto the eq6r.

But other than that it handled everything really well.
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Gustavo Fernandez Johnson avatar
Gustavo Fernandez Johnson avatar
I used 122mm APO telescope, 10kg all dressed up, no issues whatsoever on my EQ6 R Pro, guiding between .3-.5
Brian Diaz avatar
Brian Diaz avatar
hi

i used my FLT 120 with my ZWO AM5 

CS, Brian 

Rafael Amarins avatar
Rafael Amarins avatar
Get a pier and be happy
No issues whatsoever with the 120flt on a EQ6
I've used a lighter but still big 122mm sv122 triplet apo on a CEM25 and managed to get good images. You should have no trouble on the EQ6 with the 120flt sitting on it
Tom Boyd avatar
Tom Boyd avatar
Ryan Benbow:
I've used a FLT120 on my eq6r as well and as Tom said, absolutely no issues regarding weight/guiding. However, one thing to be mindful of is if your imaging close to zenith, I found the scope/camera can come into contact with the legs of the tripod. Of course, with mount limits set this can be avoided.

It was for this reason I eventually swapped my FLT120 to an AM5 with an extension pier and put my SCT onto the eq6r.

But other than that it handled everything really well.

Good point. I used a pier extension on my EQ6R to help mitigate this issue.

Funny you mentioned the AM5 - that is the exact swap I made too !-) I now run my FLT132 on an AM5...
Alex Nicholas avatar
Alex Nicholas avatar
I ran a FLT132 back in 2009 on a eq6r and had no dramas. I would SOLIDLY recommend getting the 8" pier adapter for the tripod, but otherwise, I really can't recommend the setup enough..

I eventually moved from the FLT132 to an FLT110, but that was because i got the 110 with TMB/LZOS optics…
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Peter Robertson avatar
Peter Robertson avatar
Thanks everyone for your advice, the pier extension looks like a great idea also, I hadn’t thought about the scope hitting the legs. Thanks again for the comments and photos, and  I’m glad the weight isn’t an issue. Looks the the fit 120 might be my best bet ! 

Peter
Patrick Graham avatar
Patrick Graham avatar
Brian Diaz:
hi

i used my FLT 120 with my ZWO AM5 

CS, Brian 


I have the exact same setup.....works great, no issues.
Pat
Peter Robertson avatar
Peter Robertson avatar
A follow up question… is the learning curve for a 120 scope very different from a 90-100 mm telescope such as the flt91 or Espirit 100.

For context my current experience is with telephoto lenses ( up to 400mm ) on a star tracker ( with guiding ) . The problem I have with a 100mm scope is that the typical field of view is not that different from a 400mm lens.

any opinion most welcome 

Thanks very much 
peter
John O'Mahony avatar
John O'Mahony avatar
I picked up an FLT120mm a few months ago and have been using it on my EQ6-R-Pro mount. To answer your question regarding the learning curve, the answer is probably yes. The scope needs to be well balanced. It does not handle any wind well without guiding issues. I have the FLT91 and I can run this unattended without any issues. With the 120mm I do need to keep an eye on the guiding and do lose the odd frame (gust of wind etc.) . I keep my subs to 3 minutes. Overall it works well 90% of the time. I use a pier extension to prevent any tripod collisions which makes it a bit more wobbly. It would probably work better without the pier but its very close to the tripod legs near the meridian. The mount is fine with the 120mm. I have my eye on an AM5 for next year.
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Peter Robertson avatar
Peter Robertson avatar
Good to know thanks. I guess the is a lot more surface area to cact the wind gusts!