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Esprit 100 flattner connection to ZWO 294

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#1 rishigarrod

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Posted 19 September 2019 - 12:11 PM

Hi 

 

I have been using my Esprit 100 with an EOS camera which all works fine.

Now I have a ZWO 294 and I am have issues finding the correct adaptors to physically connect everything together.

The flattner screws straight into the telescope but at the other end of the flattner is a 66mm thread. Currently I have an EOS T connector which fits.

I have just been to my local astro shop and we could not find a single 66mm adaptor.

 

I have done a lot of searching but I can't find anyone with a similar issue.

 

Any tips would be welcome.

 

Cheers

 

Rishi

 



#2 Marcelofig

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Posted 19 September 2019 - 02:14 PM

See page 8 of the Esprit 100 manual, there is an adapter that comes attached to the flattener. This leaves the backfocus at 55mm, with this you can use the spacers that come with the camera to reach that distance.

 

 

https://cdn.shopify....sprit100EDT.pdf


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#3 rishigarrod

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Posted 19 September 2019 - 02:49 PM

Thanks. I had found the manual. The issue for me is simply one of the actual physical connection. My flattner came with a M66 / EOS connection on the camera side. Now I need to connect the image train to it via a M66 / M48 adaptor which as far as I can see does not exist. I am happy to get one made up but I can't believe I am the only person with this issue? I am going to visit the company that delivered the flattner (in Europe it does not come with the telescope) just in case something was not delivered with the flattner.


Edited by rishigarrod, 19 September 2019 - 02:50 PM.


#4 premk19

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Posted 19 September 2019 - 09:27 PM

There is no M66-EOS single piece adapter. There should be a M66-M48 piece in between, which attaches to a M48-EOS adapater. As shown as '3' in this picture from the manual:

 

q9k6Iur.png

 

Back focus from this adapter# 3 is 55mm, which you should be able to achieve with ZWO provided adapters.



#5 SilverLitz

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Posted 19 September 2019 - 09:28 PM

I expect your M66/M48 adapter is still threaded into the EOS t-ring.  The t-ring has M48 female thread.


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#6 Marcelofig

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Posted 19 September 2019 - 09:45 PM

You may have a missing M48 adapter. According to TS Optics in Germany this is included with the flattener.

 

https://www.teleskop...ED-triplet.html



#7 rishigarrod

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Posted 20 September 2019 - 12:18 AM

You may have a missing M48 adapter. According to TS Optics in Germany this is included with the flattener.

 

https://www.teleskop...ED-triplet.html

Thanks. I think this is my issue.

 

My flattner came with a M66 / EOS adaptor. The EOS adaptor part is fixed to the M66 part using a beveled connection with 3 tiny allen screws keeping it in place but allowing you to rotate it. I can remove the EOS T ring but then I am left with a M66 to M44 (female).



#8 rishigarrod

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Posted 09 November 2019 - 05:27 AM

I have finally got the correct adaptor made up.

 

Looking in the instructions for the telescope/flattner it states that the total backfocus should be 63mm.

 

The 294 has 6.5mm from the front surface to the sensor so this leaves me with 56.5mm.

Using various adaptors and shims I have managed to achieve the 56.5mm spacing between the mating surface of the flattner and the front surface of the camera.

 

Can anyone with a similar setup confirm that this is correct?

 

The reason I am checking is that on every advertisement and some articles I see for the Esprit 100 flattner they state that the backfocus distance is 69.8

Attached Thumbnails

  • Screenshot_2019-11-09_13_10_16.jpg

Edited by rishigarrod, 09 November 2019 - 05:40 AM.


#9 Brule

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Posted 10 November 2019 - 11:06 AM

I have the 294 and 80 Esprit, but should be the same setup since they vary the length of extender tube attached to the flattener (according to the manual anyway) to compensate. Everything I needed for reaching back focus came with the Esprit and 294.

 

According to the manuals on the site (page 8),

80 Esprit: https://cdn.shopify....Esprit80EDT.pdf

100 Esprit: https://cdn.shopify....sprit100EDT.pdf

 

The 80 says it requires 66mm back focus, and the 100 needs 63mm. (Top of page 8).

Next, it mentions the ring spacer for the 80 as 11mm, and for the 100 as 8mm (Middle of page 8).

 

For me, the flattener came pre-assembled with the spacer already attached, but it sounds like yours is missing, or maybe you got it now?

 

Assuming it's attached, we can then subtract how much back focus we have left to fill,

80 needs 66mm - 11mm = 55mm

100 needs 63mm - 8mm = 55mm

So rest of setup should be same if we have the same camera.

 

With the ASI294, it should come with a 16.5mm spacer, a 21mm spacer, an 11mm spacer already attached to the camera, and an additional 6.5mm of space is between camera edge and sensor. This is according to the ZWO website (graphic at bottom of page): https://astronomy-im...294mc-pro-color. That gives a total of 16.5 + 21 + 11 + 6.5 = 55mm. This then gives a grand total of 11 + 55 = 66mm for the 80 and 8 + 55 = 63mm for the 100.

 

Here's a picture of the setup on the 80,

49042967308_fff67c3cfe_h.jpg

 

  1. Draw-tube adapter, does not affect as it's in front of field flattener, comes with Esprit.
  2. Adapter I bought which allows me to put in a 2-inch filter without having to mess up my back focus, since it's on the telescope side of the flattener. You can find it here if you're curious, but this is not required.
  3. Field Flattener
  4. The extender tube (M48 adapter) which came with the Esprit, came pre-attached to field flattener; for the 80 gives 11mm, for the 100 it should be 8mm
  5. 16.5mm extender, comes with ASI294
  6. 21mm extender, comes with ASI294
  7. 11mm extender, comes attached to ASI294, plus 6.5mm to the actual sensor for a total of 17.5mm

I hope that helps, but if anyone sees any issues with the above, let me know!

 

Jon


Edited by Brule, 10 November 2019 - 02:04 PM.



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