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Sky-Watcher ESPRIT 120ED Super APO

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62 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.


#61 Barry A. Waters

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Posted 23 September 2020 - 08:20 PM

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

From what the manual says (I only have the online .PDF as there was no printed manual in the OTA box?!?) I appear to have everything assembled as it should be. From what I can see there really is no other way to assemble things due to the progressively smaller thread diameters of the components toward the DSLR end. The required 75mm distance between the Field Flattener's back face and the Focal Plane of the Nikon's Sensor (as marked on the D7100 Body) also measures out correctly.

 

Manual and equipment wise I have what the first attached image below shows (with the two-piece 3a-3b extender tube in my case). The second image shows the Nikon D7100 I have attached to the assembly. I'm thinking I still need a wee bit of an extension (1 1/2" to 2"?) in-between the focuser and the supplied Field Flattener.

 

I'm now at the point where I'm having questions that concern Auto-Guiding equipment selection, Dedicated Image Camera selection (Color vs Mono & CCD vs CMOS), Filter Wheel needs and Software requirements. For now I'm going to to spend a while (well into the Spring of 2021) with just using Mount Tracking (EQ6-R Pro) & the D7100 body for getting acquainted with things but want to get a start on the other stuff as soon as I can.

 

All of that (Auto-Guiding, Dedicated Imagers, Filter Wheels, Software etc.) sounds like they may be questions best asked in other areas of the site. Any direction of where I should ask them (Forum Title?) would be very much appreciated!

 

Barry             

Attached Thumbnails

  • SW_DSLR_Install.JPG
  • Sky-Watcher_120mm_Esprit_ED_APO 040_01.JPG

Edited by Barry A. Waters, 23 September 2020 - 08:33 PM.


#62 cyendrey

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Posted 24 September 2020 - 03:31 PM

I have a Esprit 120 on order and expecting delivery next month smile.gif A few questions...

 

1) The Losmandy plate that ships with it - are recent copies coming with the black or green plate? I have seen images on the web of both but not sure what the latest ones ship with (or if there's even a difference aside from colour?) I found the specs for the green one, but not the black one.

2) Is the stock plate that comes with it 'fit for purpose' or should it be replaced? 

3) I assume I would have no trouble mounting a Vixen-type bar to the top of the rings (onto which other accessories will be mounted, eg guide scope?) 

4) Can anyone confirm the appropriate size dew strap for this scope?

As a recent purchaser of an Esprit 100ED, I can tell you that the supplied (green) Losmandy D plate with the SW Esprit is for show only.  Amazon, ADM, HighPoint, Opt all can provide a longer D plate (I have an 11" on the bottom and a 14" on the top).  The reason you need the longer D plate is to allow movement to balance the rig in the DEC axis.  The supplied OEM D plate is barely long enough to fit the the saddle of the Skywatcher tripod and provide no range of motion for balance.  So, IMO< it has a cosmetic purpose, but functionally, it is almost useless.

I don't agree with the idea of loosening the rings and moving the scope in the rings for balance.  At least on the Esprit 100, the range of movement in the rings is very limited, only about 1/2" in either direction.  The DEC balance point with the FF, extensions, camera, focuser, Guide scope/guide camera will be well outside the limits imposed by the short OEM plate.  As I look at mine (now on an Ioptron GEM45), the center of the rear ring is just below the center of the saddle. which means that only the front ring would be in the clamp on the mount with the OEM D plate.  On the SW EQ6R, because of the way the clamp plate is shaped on the saddle, the rear portion would also be unsupported/clamped.  Thus the need for the longer D plate.  I don't have a field rotator or filter wheel, or OAG, all of which would tend to move the DEC cg further aft than it is currently.


Edited by cyendrey, 24 September 2020 - 03:42 PM.


#63 SilverLitz

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Posted 24 September 2020 - 05:56 PM

Esprit 100 5" dovetail works fine for me with my G11, BUT the G11 has a MUCH larger saddle (~8") than most mounts.  Smaller saddles could need longer dovetails.




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