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Old 30-09-2011, 07:41 AM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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I guess the devil is in the detail.

OPT say the focuser has been redesigned. Very little info about the focuser details and the focuser would be critical as any flex would hammer you at F3 and a Proline 16803 which weighs 9lbs without filter wheel or MMOAG. It seems the focuser is quite short so that may help with flex.

It'd be nice to see more images and images with people using similar cameras and weight loadings. I suppose you could always just get rid of the focuser, use a solid screw on adapter and the FLI Atlas which is one option they sell. I would prefer that myself as drawtube focusers have to be super well made to handle these heavy imaging trains and even name brands are not meeting the task. That is a similar imaging train I used on a Tak BRC250 I had (what a wonderful scope that was) and I had no problems with tilt or flexure.

The main advantages of RH scope are; super compact, super fast for large aperture, no diffraction spikes on stars, tight stars, sealed corrector plate means less dirt on mirrors but harder to clean if it needs it, wide corrected flat field, I imagine collimation is less of an issue especially with the Officina model.
The disadvantages are: super fast = high potential for flexure and focuser issues, corrector plate dewing up like an SCT,the very fast F ratio means star shapes not as perfect as a slower APO per Roland Christen however looking at AP RHA images stars look fabulous., quite expensive for the aperture.

The closest competitor would be a Tak Epsilon 180ED but that had problems with the focuser. Tak beefed up the focuser but I don't know if it would be strong enough for such a heavy imaging train. Others would know and it'd be the first thing I'd check. I'd also check spot sizes as the Veloce appears to have unbeatably small spot sizes even 26mm offaxis, those numbers are really really low.

One point as well, the mounting dovetail. It mentions it is a Vixen style. That is silly, Vixen dovetails are tiny and could not possibly hold all that weight steady. Perhaps that aspect should be checked out as it sounds like a weak spot. If you use a MMOAG for guiding it would be less of an issue but if you used a guidescope expect flex.

Overall it looks superbly made and an exotic high performance instrument that could outperform many other scopes for imaging and F3 - wow, that sounds wonderful. Steve Crouch used a Tak Epsilon 180ED, it would be interesting to hear his view on imaging that fast.

Richard Crisp posted the same object imaged with both a Tak Epsilon 180ED F2.8 and an FSQ 106N F5. As I recall the Tak Epsilon got the same depth of image saturation in about 1/3rd the time. But images from the ED180 are not as sharp as FSQ106N. Always compromises.

Greg
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