I think this looks very tempting:
(http://www.iankingimaging.com/images/products/dynamic/201w-0h/Veloce%20New%202.jpg)
The Officina Stellare Veloce RH 200 - Riccardi-Honders Astrograph
Very similar to the Tak Epsilon 180 ED "Bananascope" in terms of imaging performance but I see the following advantages:
1) The reflective surfaces are not exposed to the elements.
2) No need to remove mirrors for cleaning together with the associated painful re-collimation afterwards.
3) No diffraction spikes or "square" stars.
4) Temperature compensation means no re-focusing is required as the night-time temperature falls. This is a slight annoyance with the Tak.
5) It also has an optional built in motorised focuser.
6) It's fast, red and Italian - the nearest most of us will get to a Ferrari.
So what are the disadvantages
1) Central obstruction is 55% vs the Tak's 44%. It's also f/3 instead of f/2.8. Taken together this means imaging times are longer because 25% less light reaches the CCD.
Is there anything else I haven't considered?
QuoteIs there anything else I haven't considered?
Cost?
Amount of cloud cover required for the said purchase?
;)
Mac.
(http://farm9.staticflickr.com/8520/8466441934_64d259584c.jpg)
'And after 4 weeks poor old Frank was wondering, just how long this would last, as back down in the valley his new Officina Stellare Veloce RH 200 was sitting, waiting for first light' :roll:
Tony G
Err, Cost, Jealousy, internal reflections, cost (yes again), no more clear skies near Ashford (and the fallout area) for a considerable time,.... err, must be more...
You reckon internal reflections might be a problem? It's always a known risk with a glass corrector.
It is always a concern when you have refractive elements as there is never 100% transmission but in this case it seems that the designer has done a very good job.
Robert
Manly cloud and when it's not cloudy dew.
But you will get round stars.