Riccardi & Esprit 100

[AbsolutelyN]

I've been wanting a reducer for the Esprit 100 for some time and was wondering if anyone here has had success with the Riccardi 0.75 reducer? I've been in touch with TS-Optics who have kindly produced a list of all the adaptors required to make it work with the zwo 1600 with correct spacing. It works out under £700 and that converts it to f/4.1 and about 412mm focal length. I'd be really interested to hear if anyone has done this and if so how sensitive the spacing is and how good the results. The other option is to simply get an Esprit 80 which is not vastly more expensive than going the reducer route, especially if I can source one second hand. Any thoughts welcome.  

Edited May 27, 2019 by AbsolutelyN

[alexbb]

Maybe this is also worth checking: http://interferometrie.blogspot.com/2015/08/100550-esprit-optics-fitted-for.html

[AbsolutelyN]

I’ve searched and searched and never seen this, thanks!

[vlaiv]

29 minutes ago, alexbb said:

Maybe this is also worth checking: http://interferometrie.blogspot.com/2015/08/100550-esprit-optics-fitted-for.html

That is not for Riccardi reducer is it? I see TSFLAT2.5 mentioned in text and that is TS flattener without reduction factor. This one:

https://www.teleskop-express.de/shop/product_info.php/info/p2646_TS-Optics-REFRACTOR-1-0x-Flattener-for-full-sized-sensors---M68-connection.html

I would be very surprised if they found astigmatism in Riccardi reducer.

Back on original topic, I think this text will be more helpful as it discusses exact combination of scope / FF/FR:

http://photonenfangen.de/instruments/skywatcher-esprit-100-ed/

[alexbb]

37 minutes ago, vlaiv said:

That is not for Riccardi reducer is it? I see TSFLAT2.5 mentioned in text and that is TS flattener without reduction factor. This one:

https://www.teleskop-express.de/shop/product_info.php/info/p2646_TS-Optics-REFRACTOR-1-0x-Flattener-for-full-sized-sensors---M68-connection.html

I would be very surprised if they found astigmatism in Riccardi reducer.

Back on original topic, I think this text will be more helpful as it discusses exact combination of scope / FF/FR:

http://photonenfangen.de/instruments/skywatcher-esprit-100-ed/

Yes, you're right, the flattener was the TS one without reduction. Since I read the article I always erroneously assumed that it was the reducing one. I even considered the combo myself. Thanks for spotting!

[AbsolutelyN]

Thanks for the info here. I must admit as nice as f/4.1 would be I think I'm currently leaning towards an Esprit 80 at f/5 rather than risking a very expensive reducer that could be tricky to get right and potentially unknown image circle size. 

[Guest Vangelis]

I had a similar dilema looking for a decent reducer for my new Esprit 120.  I bought the Altair astro 0.8 reducer field flattener bringing me down to f 5.6  Cost me £99 and as long as your not totally anal regarding shapes of stars on the extremities of your field,  I'm really happy with it.  Try it or similar budget ones first before shelling out £700 which I think you should buy an Esprit 80 rather than the Riccardi. 

 

 

[Pompey Monkey]

On 28/05/2019 at 08:49, AbsolutelyN said:

Thanks for the info here. I must admit as nice as f/4.1 would be I think I'm currently leaning towards an Esprit 80 at f/5 rather than risking a very expensive reducer that could be tricky to get right and potentially unknown image circle size. 

You still might have "fun" getting the spacing correct with the 80...