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Sky-Watcher ESPRIT 120ED Super APO

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59 replies to this topic

#51 telfish

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Posted 10 September 2020 - 09:01 PM

I kept the one that came with the scope. It's fine. Try it and change it later if you feel it's not working for you. No need for a long plate as you can move the scope in the rings for balancing and a longer plate can allow more twist.



#52 mikela

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Posted 13 September 2020 - 01:16 PM

I currently have a CGX-L mount for my EdgeHD 14.  Would I be able to use this for the 120ED?



#53 thesubwaypusher

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Posted 14 September 2020 - 06:07 PM

I currently have a CGX-L mount for my EdgeHD 14.  Would I be able to use this for the 120ED?

It would be perfect, as mine is for the 150. waytogo.gif



#54 thesubwaypusher

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Posted 14 September 2020 - 06:23 PM

I have this problem with my Esprit 150.

 

I can't understand why there aren't three screws, if there were three then it would be possible to hold the extended dew shield in a straight position.

 

john 

Hi John:

 

I have the 150 and have never had a problem with the shield. But I can imagine that you guys are not pushing it up hard enough. Push it HARD to its fully extended position and HOLD IT and tighten the two screws. Don't allow it to start falling back down before tightening, or it will droop, causing the issue you have.

 

Good luck!


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#55 John Turley

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Posted 15 September 2020 - 09:45 AM

Hi John:

 

I have the 150 and have never had a problem with the shield. But I can imagine that you guys are not pushing it up hard enough. Push it HARD to its fully extended position and HOLD IT and tighten the two screws. Don't allow it to start falling back down before tightening, or it will droop, causing the issue you have.

 

Good luck!

Thanks for the tip, I tried it, but it didn't seem the make much difference with my scope, it tends to droop when you fit the lens cap.

 

John  


Edited by John Turley, 15 September 2020 - 09:47 AM.

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#56 Barry A. Waters

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Posted 17 September 2020 - 01:33 PM

Yet another question: I will most likely get a dedicated imager (CCD / CMOS) at some point in 2021 but for now a couple of APS-C Nikons (D5100/D7100) will have to do. I mounted them to the tube via the instructions in the manual and found that they both only achieved focus at the very end of the focuser's maximum extension. It looks like I need an extension between the  focuser tube and the flattener to give me some play on either side of focus. Does this sound right (normal)?

 

Barry



#57 telfish

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Posted 17 September 2020 - 01:41 PM

Yet another question: I will most likely get a dedicated imager (CCD / CMOS) at some point in 2021 but for now a couple of APS-C Nikons (D5100/D7100) will have to do. I mounted them to the tube via the instructions in the manual and found that they both only achieved focus at the very end of the focuser's maximum extension. It looks like I need an extension between the  focuser tube and the flattener to give me some play on either side of focus. Does this sound right (normal)?

 

Barry

With my ZWO cameras I am at around 7 on the scale on the drawtube.


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#58 Barry A. Waters

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Posted 19 September 2020 - 06:51 PM

With my ZWO cameras I am at around 7 on the scale on the drawtube.

I could work with that BUT I may not have as bad of a situation as I thought. I talked with the vendor (Woodland Hills C&T in my case), explained the issue and told them what I was focusing on. I haven't been able to get the scope outdoors so I'm looking out a window of my home. I'm in a pretty flat area so my best 'local' daytime targets are the tops of distant pine trees no more than 175+/- Yards away.

 

As their Tech explained to me, the Focus Point is the Focus Point BUT there can be quite a difference between focus at Infinity (as you would have with objects in the heavens) and things much, MUCH closer (my pine tree tops). I can say that in 'observation mode' (star diagonal & a 2" 40mm Plossl eyepiece) I was achieving focus on the pine tree tops at just past half travel on the focuser. The length added to the light path in that combination was a help apparently.

 

So I will wait until I can test 'outside & up' before I become further concerned. I CAN say that in 'observation mode' the Sky-Watcher 120mm Esprit makes for one HELL of a 'Distant Pine Tree Top Looker'... :-)

 

Barry



#59 Barry A. Waters

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Posted 19 September 2020 - 07:15 PM

Flattener only, e.g. ~1.0x.

 

I assume the ring holes are the normal 1/4"-20 (they are on my Esprit 100 rings).

Yes - The Sky-Watcher supplied piece is a Flattener ONLY (no FL change) and 1/4"-20 is correct for the ring's attachment bolt threads. Thanks! I just got 4 at the local ACE and they all threaded right in as smoothly as you could ask for. 

 

I got a response from Sky-Watcher on the other (smaller) drilled & tapped holes on the green anodized mounting plate and was told that those are M6 so I should be good now on adding a handle (1/4"-20 bolts) and some front/rear Anti-Launch blocks (M6). Thanks!

 

Barry  



#60 Bcteleskier

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Posted 20 September 2020 - 04:21 PM

Yet another question: I will most likely get a dedicated imager (CCD / CMOS) at some point in 2021 but for now a couple of APS-C Nikons (D5100/D7100) will have to do. I mounted them to the tube via the instructions in the manual and found that they both only achieved focus at the very end of the focuser's maximum extension. It looks like I need an extension between the  focuser tube and the flattener to give me some play on either side of focus. Does this sound right (normal)?

 

Barry

Barry,  check your back focus distance.   It should be 75mm from the camera facing face of the included flattener.   Google for the “Esprit 120 manual” and see the picture on page 8 of the pdf.  I believe the printed manual may have shown it incorrectly.   At 75mm back focus distance my focuser is at the 55mm mark.

 

Ralph


Edited by Bcteleskier, 20 September 2020 - 04:22 PM.



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