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FLO

Prototype Sky-Watcher Evolux ED Refractors

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The 82's focuser drawtube seems to be quite large relative to the main tube, probably to illuminate large sensors, which suggests the thing can be fitted with reducers/correctors. Very large focuser lock and dual finder/guidescope holder suggests imaging, too. If Sky-Watcher bothers with a new scope they probably have improved the doublet objective, with aspherical surfaces maybe and/or a better glass formula? The very long dewshield is a good thing, condensation and stray light are such stupid things to have to deal with.

I'm happy with my take-anywhere 80mm semi-apo and my stay-at-home 80mm triplet, so no personal interest in these, but the 62mm is smallish for my taste anyway. I was never satisfied with the brightness and resolution of scopes smaller than 70mm.

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On 08/10/2019 at 20:48, Davey-T said:

Where did the fashion for odd size objectives come from 61, 71, 62, 72, 73, 82 etc etc, does it really make any difference to the view ?

Dave

No its just variation dependent on how the objective lens is mounted by the manufacturer.  The lens within the cell is probably of identical size in a 70mm / 71mm etc, all that changes is how they stop the lens down to block lens spacers and similar from entering the light path. Some manufacturers (WO) tend to push it too far and it can result in incomplete star halos due to exposed lens clips. Apart from all that though some manufacturers produce lenses in inches but need to sell them in mm due to EU regulations and so that does not translate to whole numbers.  

My guess is that these will be triplets but not using FPL53 and having improved mechanics. I would be disappointed if its just a doublet with better mechanics. Not that I care I am most likely buying a Esprit 100 this week :)  

Measuring the length / diameter of the tube from the pictures it looks like an F6 design. I would say that is quite fast for a doublet design at 82mm aperture there is a good reason why most go with F7 or higher for a 80mm doublet.

Adam 

Edited by Adam J
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