Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Skywatcher Esprit 120 questions

This topic has been archived. This means that you cannot reply to this topic.
22 replies to this topic

#1 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 21 November 2013 - 04:34 PM

Hello. I am planning to buy 120mm premium APO and the esprit 120 fpl-53 triplet looks very attractive. I could not find any feedback in the forum from owners of it so if anybody have this scope i will be very happy to see some first hand info.

Two particular questions are worrying me - does it come with dedicated field flattener like the esprit 150 and if so what is the distance to sensor which should be maintained to achieve best correction?

Thanks in advance.

#2 skyward_eyes

skyward_eyes

    Vendor - Sky-Watcher USA

  • *****
  • Vendors
  • Posts: 5033
  • Joined: 12 Dec 2006

Posted 21 November 2013 - 05:01 PM

In the United States (Sky-Watcher USA) all of our Esprit triplet apos ship with their dedicated field as well as the proper spacing and adapters for Canon DSLRs.

For the Esprit 120ED the back focus of the flattener is 69.8mm and has an image circle of 43mm.

#3 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 21 November 2013 - 05:18 PM

Thank you very much for the quick reply. I hope that here in europe situation will be the same. So just to clarify - the flattener attaches through thread to the focuser and on the back i have M48 thread. From that M48 thread i should have 70mm to the camera sensor. Is that correct? One more question - what is the weight of esprit 120 with the rings, dovetail, finder and flattener attached?

#4 skyward_eyes

skyward_eyes

    Vendor - Sky-Watcher USA

  • *****
  • Vendors
  • Posts: 5033
  • Joined: 12 Dec 2006

Posted 22 November 2013 - 11:15 AM

Each Esprit comes with a set of adapters.

1) Focuser to Flatter ring
2) Field flattener
3) Spacer
4) Canon 48mm T-Ring

The 2" visual back ring threads off the focuser. This is replaced by the Focuser to Flattener ring which allows the rest of the accessories for imaging to thread on.

Yes, from the final element to the sensor it need to be 69.8mm (70 is fine too).

The final weight for the Esprit 120ED is 22lbs.

#5 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 22 November 2013 - 04:24 PM

Thanks for the info. Definitely this scope looks like what i need.

#6 jerry10137

jerry10137

    Viking 1

  • *****
  • Vendors
  • Posts: 779
  • Joined: 26 Jan 2013

Posted 24 November 2013 - 05:07 PM

The whole Esprit product line is truly amazing!

#7 skyward_eyes

skyward_eyes

    Vendor - Sky-Watcher USA

  • *****
  • Vendors
  • Posts: 5033
  • Joined: 12 Dec 2006

Posted 24 November 2013 - 05:26 PM

We are very excited to offer these scopes. I'm hoping to see more of th
In the hands of users in the next few years.

#8 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 25 November 2013 - 05:54 AM

I have one more question. I see that Esprit 120 comes with losmandy style dovetail. My mount have Vixen saddle. What is the length of the losmandy dovetail? Will i be able to easily replace it with vixen dovetail like this one:

http://www.teleskop-...arway-Doveta...

#9 jerry10137

jerry10137

    Viking 1

  • *****
  • Vendors
  • Posts: 779
  • Joined: 26 Jan 2013

Posted 25 November 2013 - 10:56 AM

The Esprit 120 is really too much scope IMO for a vixen style dovetail. My recommendation is to change the saddle plate your mount uses to one like this.

http://www.optcorp.c...-dual-eqg-sa...

#10 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 25 November 2013 - 11:10 AM

Thanks for the advice Jerry but why you think that vixen dovetail can't handle this scope? I had 8" newtonian before which weight with all accessories was around 12kg and i never had problems with the vixen dovetail. What kind of problems should i expect with the esprit and vixen dovetail?

Most probably in near future after purchasing the esprit i will also need to buy better mount because i am not sure that my heq5 pro will handle it properly. The new mount (most probably skywatcher azeq6)will be with with dual style saddle. That's why i prefer not to invest in dual saddle for my heq5 and just put vixen dovetail on the esprit for the beginning.

#11 jerry10137

jerry10137

    Viking 1

  • *****
  • Vendors
  • Posts: 779
  • Joined: 26 Jan 2013

Posted 25 November 2013 - 11:52 AM

You very well can run the vixen. I just wouldn't recommend it that's all. The losmandy d-plate design makes things solid and more rigid overall. When taking pictures, you want to limit as much flexure in your setup as possible. A vixen dovetail will work, and you should be able to get by with the 7 inch dovetail. The 120 with its full payload is getting very close to the weight limits of a lot of mounts. Can you get by? sure but be extra cautious. I was merely making a recommendation based on my opinion alone, nothing more.

#12 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 25 November 2013 - 12:31 PM

Thanks Jerry. I understand that the losmandy system is more robust than vixen. If i see that my current mount can handle properly the esprit 120 i will most probably upgrade it to dual saddle. Unfortunately my past experience with the newtonian at similar weight makes me think that it will be needed to get another mount in near future so the vixen dovetail will be temporary solution in the beginning till i get enough money to also upgrade the mount. :)

#13 skyward_eyes

skyward_eyes

    Vendor - Sky-Watcher USA

  • *****
  • Vendors
  • Posts: 5033
  • Joined: 12 Dec 2006

Posted 25 November 2013 - 02:58 PM

The mounting plate on the Esprit is 295.275mm in length.

#14 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 25 November 2013 - 03:35 PM

Thank you for this info. In this case i better get the 30cm vixen dovetail instead of the 20cm one that i initially thought.

#15 cdh79

cdh79

    Explorer 1

  • -----
  • Posts: 76
  • Joined: 29 Oct 2013

Posted 25 November 2013 - 04:21 PM

hi neptun2

I was just looking at the homepage of a European store that sell them, and they also include the flattener:

http://www.robtics.n...roducts_id=2283 (i am in no way affiliated with this store)

#16 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 25 November 2013 - 04:34 PM

Thanks for the link. Interesting. I asked TS, FLO and optical vision and they told me that the flattener is unavailable. I continued the research and saw that APM have it for 260 euro:

http://www.apm-teles...=s9q86n679ln...

Obviously flattener can be bought in Europe albeit not so easy as in the USA. The price of robtics looks rather high though. The price of esprit 120 without flattener is around 2600 eur in europe and flattener in APM is another 260 so it should be around 2850 to 2900 eur not 3300. Good news is that the flattener can be found in europe.

#17 cdh79

cdh79

    Explorer 1

  • -----
  • Posts: 76
  • Joined: 29 Oct 2013

Posted 25 November 2013 - 05:13 PM

i just read on a UK astroimaging forum that they have reduced the price, because they don't include the flattener anymore due to availability problems..

at an Austrian store, they also advertise "reduced from 3200 to 2600 Euro", but don't include the flattener..

i think due to the unavailability of the flattener they needed to reduce the OTA much more than just the price of the flattener itself, because nobody can do any proper imaging without it (so no decent imaging at all for now for people that buy the scopes now)

either way, good luck and clear skies

#18 CosmicWreckingBall

CosmicWreckingBall

    Messenger

  • -----
  • Posts: 448
  • Joined: 25 Mar 2015

Posted 30 November 2013 - 04:37 AM

I just purchased a 100 Esprit here in the states and I'm in love with it. Would have loved the 120 but the funds just didn't support it.

It's been amazing optically. I'm imaging with it, riding a Hap Griffin modded 60d on a CGEM-DX mount. All of the astrophotographers I know are using imaging newtonian and CCD so I'm trying to give them a run for the money. So far it seems to be working.

So nice to not be chasing down all of the correctors, flatners, and rings with mixed results. I bought a used 80mm refractor initially without a field corrector or T mount, ordered what I thought would work, but no go... with the trouble I decided I'd use it for grab and go but I'm still trying to get the correct parts for it. :(

#19 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 01 December 2013 - 02:35 PM

Good to hear that you are happy with the esprit 100. Can you send me a single raw file from your 60D with the esprit?

#20 CosmicWreckingBall

CosmicWreckingBall

    Messenger

  • -----
  • Posts: 448
  • Joined: 25 Mar 2015

Posted 06 December 2013 - 06:55 PM

neptun2... Here is the link to the file:

http://www.dropbox.c...142/Example.tif

It's a bit on the soft focus as I was fine-tuning and hadn't focused with the Bahtinov yet. :( But I think it's what you are looking for- Orion for 90 seconds under a clear dark sky.

#21 neptun2

neptun2

    Apollo

  • -----
  • topic starter
  • Posts: 1153
  • Joined: 04 Mar 2007

Posted 09 December 2013 - 05:25 AM

Thank you for the link. :)

#22 Adacas

Adacas

    Explorer 1

  • -----
  • Posts: 73
  • Joined: 02 Jun 2011

Posted 12 December 2013 - 11:16 AM

Each Esprit comes with a set of adapters.

1) Focuser to Flatter ring
2) Field flattener
3) Spacer
4) Canon 48mm T-Ring

The 2" visual back ring threads off the focuser. This is replaced by the Focuser to Flattener ring which allows the rest of the accessories for imaging to thread on.

Yes, from the final element to the sensor it need to be 69.8mm (70 is fine too).

The final weight for the Esprit 120ED is 22lbs.


I am currently looking for a custom application to fit my Atik CCD to the FF and find that 70mm is conflicting with this article which notes "The field flattener has a back focus(distance from its rear element to the focal plane,where the sensor needs to sit) of 75mm"

http://ca.skywatcher...01329776355.pdf

I'm sure I am misunderstanding something, can this distance be clarified please?

#23 skyward_eyes

skyward_eyes

    Vendor - Sky-Watcher USA

  • *****
  • Vendors
  • Posts: 5033
  • Joined: 12 Dec 2006

Posted 12 December 2013 - 12:13 PM

This is 75mm from the last glass element of the flattener. The measurement we state is from the metal cell.

Prescision Parts can custom make any spacer you need.


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics