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Can the BST Starguider series be decloaked to increase eye relief?

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I'm curious about using the BST Starguiders in binoviewers because I've found 60 degrees to be about the max usable field with BVs.  Beyond that, I have to swivel my eyeball around, and then I lose one or both views.

Since I need to wear eyeglasses at the eyepiece due to strong astigmatism, I need decent eye relief.  I've noticed that the BST Starguiders have an eyeguard that even when fully retracted isn't flush with the top of the housing like the Meade HD-60 series, wasting precious eye relief.  Is it possible to decloak (remove) the eyeguard?  Can that top part be peeled off, and then the rest removed as with the Pentax XL?  Is there a screw somewhere behind a label that can be removed as with the Meade 5000 SWA/UWA, Celestron Axiom/Luminos, Maxvision, etc. that allows the outer carapace to be removed?


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The rubber eyecup just pops off and then the rotating part in the lowered position is pretty much flush with the top of the internal unit. The two coloured rings and rubber grip must be glued in place. The black section beneath (with Starguider printed on) is part of the eyepiece body and can't be removed. Given that you're talking about decloaking you might be thinking they are bigger than they are. A size comparison between a 10.5mm XL and 8mm Starguider is included to give some idea of scale. The bottom of the Starguider eyecup is the same width as the top of an XW eyecup. 




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30 minutes ago, Ricochet said:

The rubber eyecup just pops off and then the rotating part in the lowered position is pretty much flush with the top of the internal unit.

Thanks, that's the information I was looking for.  Even with the lower part still in place, it should be narrow enough to use in binoviewers with my big nose. :laugh2:

Could you measure the diameter of the eye lens?  It looks to be about 21mm which would yield a maximum of 18mm of eye relief to the eye lens for a 60 degree field.

Looks like an XW style eye lens cap on that XL.  Mine came with a cap that fit around the outside of the top of the eyecup.

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17 hours ago, Ricochet said:

Actually, looking at it again you might lose 1mm eye relief to the twist up mechanism. The diameters of the eye lenses on the 5mm and 8mm are about 20.5mm.

Thanks.  I've gotten pretty good estimating eye lens diameter from photos based on the barrel diameter being 1.25".  Since it appears that the eye lens is recessed slightly due to the beveled top retaining ring, I'm guessing a maximum of 16mm of usable eye relief.  The closest eyepiece I have to that would be my 9mm Vixen LV with a 23mm eye lens.  It has a 50 degree AFOV and a measured 18mm of usable eye relief.  Given that the Starguiders have a 60 degree AFOV and a smaller eye lens, I probably wouldn't be able to use them comfortably with eyeglasses.

Thanks for all the help.

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