28" f2.7? Yes, really!

[erick]

http://www.astromart.com/articles/article.asp?article_id=829

[astroboy]

Hi Eric
Thanks for pointing me to that , some good information on just how good fast scopes can be.
I have a 24" F3.6 myself and have found that the Paracorr 2 has improved the performance with Ethos EPs a lot .
The Paracorr 2 is the game changer for fast scopes but of course we need very skilled mirror makers to make these fast mirrors as far as I know Steve Kennedy ( who made my 24" ) still only makes F3.6 .

Zane

[Satchmo]

Zane wrote : "Thanks for pointing me to that , some good information on just how good fast scopes can be."

Zane- I didn't get the same impression in the sense that the instruments weren't pushed anywhere near the useful upper limit of 25 X per inch ( and I consider a 1mm pupil the ideal for bench star testing as it is enough to reveal the true diffraction structure of the Airy Disc to the eye) .

I didn't see anything in the review that pointed to any rigorous practical test of optical excellence- just two large scopes being used at relatively lower power large exit pupils in comparison to each other : the 17mm eyepiece listed as the highest power used giving 5.3mm pupil or 4.7X per inch on the F2.75 - these are RFT `light bucket' type magnifications.. So from my perspective - wanting to know whether these particular examples of newer scopes on the market can equal the established general quality in the US market of their longer focal ration cousins, the report fell short.

I look forward to seeing some more rigorous reviews perhaps against a longer focus reference standard- and I say that coming from the perspective of having the opportunity of bench star testing two large fast ( F3.6 ) mirrors from USA in the last year.

[Rodstar]

Yeah, I'd be pretty sceptical about the quality of an f/2.7 too, with current technology anyhoo.

[jamespierce]

I like my telescopes fast and short, but there is something about scopes once they go sub F3 that just starts to look wrong... I reckon it's a violation of the greek golden mean or something :-). Have you gotten any further with your plans to cut the Mary Rose down to size Rod ?

[OICURMT]

:rofl:

Overall a great read, with some twisted humor thrown in... :D

[ballaratdragons]

5. You are pronouncing the names of all of the stars incorrectly. :rofl:

I want one :P

[gary]

Hi Eric,

First a disclaimer that Webster Telescopes are a customer and supply our telescope
computer as a value-added accessory.

Thanks for the link which I had not seen before and Dave Bonandrini's narrative
was fun to read. It sure sounded like hot and humid weather they experienced.

Dave's first hand account of a night with the 28" f/2.7 certainly left me wanting
to have a look through it. I had the opportunity to spend a couple of nights at
8500' observing with Steve Kennedy on his 32" f/3.66 Starstructure but the 28" f/2.7
is a different game altogether.
http://www.wildcard-innovations.com.au/images/kennedy1.jpg

Thanks again for the link. I am sure if some of us tried getting our tongues
around the Arabic pronunciation of the stars, we would probably just end up with
droplets of spit over the eyepiece.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place
Mount Kuring-Gai NSW 2080
Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au

[Rodstar]

Hey James, nice to hear from you!

No mate, I blew almost $10K on a trip to France this year, so making alterations to the Mary Rose will have to wait a bit longer.

My long-term plan will probably involve getting an f/4 mirror with a low rider style of mirror box, but that is probably at least two years away....