SW Esprit 100 with Focal Reducer

[Fellside]

Hi

I have recently fitted a TS PHOTOLINE 3" 3-element 0.79x reducer to my SW Esprit 100. Only one adapter is required. A TS M68M86.

https://www.teleskop-express.de/shop/product_info.php/info/p6085_TS-Optics-REFRACTOR-0-79x-3--ED-Reducer-Corrector-for-big-sensors.html

https://www.teleskop-express.de/shop/product_info.php/info/p9017_Lacerta-Adapter-to-female-M68x1-thread-for-Skywatcher-ESPRIT-apos.html

Focus is reached just over one thired out on the focuser. When fitted with the SW Esprit Flattener focus was reached just over half of the focucers travel.

Plate Solved Focal Length with Astometry.NET

SW Esprit 100 Flattener      553.3mm

SW Esprit TS 0.79 Reducer 445.5mm  Reduction 0.80

Calculated focal length      437.1mm for a 550mm scope.

The Reducer spacing I have at the moment is 57.6mm.

I have read Gorann` s thread and looking at the diagrams shown I think I need to increase the distance. Has anyone got any idea from there experience is it in or out?

I had a half hour window a couple of nights ago to try things out. Image below is one frame with a auto stretch in Gimp. No Flats or Darks applied.

Many thanks

Graham

[Jkulin]

I had my Esprit with the SW Flattener working at about 57.5mm and my stars were not perfect, I have been waiting 2 months now for Jtech to make me new flanges to reduce down to 55mm the recommended distance, which I know the Esprit can perform superbly at, the reason for the change was that I have moved over to OAG's on all my scopes as I find my guiding is so much better.

Unlike yourself I didn't want to reduce down the FL as I have an 80mm and a 100mm Esprit.

HTH

[Fellside]

HTH

When fitted with the SW Flattener I had the spacing at 56.5mm. Stars have a good shape in the corners.

Graham

[ollypenrice]

Somewhere 'out there' is an image showing what happens when too close/too far. This image is certainly on SGL if you have a rummage.

Olly

[x6gas]

4 minutes ago, ollypenrice said:

Somewhere 'out there' is an image showing what happens when too close/too far. This image is certainly on SGL if you have a rummage.

Olly

And for ease here it is again...  Too close:

Too far:

[Adam J]

On 25/02/2020 at 21:21, Fellside said:

Really interested in how you get on with this reducer, any updates on spacing and high resolution images of the results would be fantastic.

[Fellside]

Adam

Last night again I got a few images before mist rolled in. I added 0.21 spacer and there was a definite improvement. Three corners were good, slight elongation in one corner. Tilt was shown as under 2%. I think it is close. I will keep increasing the spacing until the corner stars start to deform. Fitting the TS reducer is an easy fit once you have the Lacerta Adapter to female M68x1.

I will post more info when I have it,

Graham