The swan nebula - first try with a new reducer on Esprit 150

[gorann]

I had a clear night last night, but full moon of course so it had to be Ha. It gave me the first chance to test a reducer I bought from TS just when the astro-season ended this spring. SW do not sell any reducers that will work on the Esprits (the 0.85 x reducer they have for their ED pro series will not work on the Esprits according to dealers I have talked to). So the options I have managed to find are the Riccardi 0.75 reducer from APM and TS 3" 0.79x reducer. They cost about the same but after som communication with APM and TS, I realized that I would have to spend 150 - 200 Euro on adapters for the Riccardi but only needed a single one (a Lacerta M68-M86 ring for 75 Euro - which also hurts) to fit the TS reducer to the scope and it has an ordinary M48 thread on the camera side.

So here is the result from last night. 18 x 15 min on IC1318 with the Esprit 150 working at FL 840 mm (f/5.6) with a ASI1600MMpro and a 3.5 um Baader Ha filter. Seeing was not the best so guiding was around 1"/pix which will have made the image a bit soft. However, the great news are the nice star shapes in the corners. I expect the reducer will work equally well on my Esprit 100 but I have not tested it there yet (the focuser is the same so it should at least fit). Of course the ASI1600 gave the expected microlensing effect around the bright gamma-cygnus.

Next clear night I will make a second panel to the left of the image to produce a "panorama" mosaic.

Only stretched - nothing else so far, not even any darks or flats.

Edited September 14, 2019 by gorann

[Astrobug]

It looks promising.  The 3" looks much better compared to the 2" version

[gorann]

1 hour ago, Astrobug said:

It looks promising.  The 3" looks much better compared to the 2" version

Thanks. The image circle (45mm on the 3") should at least be better, so no significant vignetting for most chips and possibly even usable for full size APS. Both recusers are 4 lens constructions so the optical deign and performance may be the same. I have had the 2" reducer for several years to use with my Explore Scientific refractors with 2" focusers, and it has done its job,  but it seemed like a waste of image circle to use it on the Esprits.

[Laurin Dave]

Very nice image and interesting idea Goran,  looks good into the corners..  do you plan on testing on larger format sensors?  The filter looks to have worked well too. 

Dave

[gorann]

17 minutes ago, Laurin Dave said:

Very nice image and interesting idea Goran,  looks good into the corners..  do you plan on testing on larger format sensors?  The filter looks to have worked well too. 

Dave

Thanks Dave. I will use it with my ASI071 OSC when the moon is gone. I am also waiting for a Sony A7S full frame APS to arrive and I should at least do some test shots with it to examine the limits for flat feeld and vignetting of this reducer.

Regarding the Baader 3.5 nm Ha filter, I have a feeling it gives sharper images than my old Baader 7 nm, but I have not compared them on the same night.

[dtastro]

Can anyone suggest a reducer for the Esprit 80ED?

[newbie alert]

8 hours ago, dtastro said:

Can anyone suggest a reducer for the Esprit 80ED?

You want it shorter than 400mm?

[Pompey Monkey]

On 03/10/2019 at 23:48, dtastro said:

Can anyone suggest a reducer for the Esprit 80ED?

I tried the tsred279 on my Esprit 80ed, which was "supposed" to work with the matching adaptor. However, by the time I had the backfocus getting to the right place, it wasn't  possible to wind the draw tube far enough in to get focus! 

Shame,  because the additional fov it was giving me made a heck of a difference! 

[dtastro]

On 04/10/2019 at 08:43, newbie alert said:

You want it shorter than 400mm?

Not any more...I've bought a Redcat 51 🙂