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Binoviewing with Nikon HW12.5

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#1 DRodrigues

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Posted 27 December 2012 - 06:20 PM

I tested the HW 12.5 with my daylight bino combo http://www.pt-ducks....#CR-binoviewing and the field resulted the flatter I ever obtained with this bino combo. However the resulting magnifications are too high (deleted the Docter 12.5 from my wish to test list...), and the eye-relief too reduced to my daylight use. Just got curious if someone is using a pair of HWs for night use...

#2 pbsastro

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Posted 31 December 2012 - 08:02 AM

David was kind to let me try his HW 12.5 this weekend.
My goal was not to optical test the HW, I trusted CN reports that it is equal or better than Ethos. The goal was to check compatibility with my face for bino mode, comparing to Ethos.
My goal was really the 17s, but since they share the same eye-end optics, it should be the same for 12.5 and 17.

I knew in advance the HW diameter is compatible with my IPD (64mm).
But two additional factors come into play for bino mode: nose clearance and ER.
With Ethos I have no nose clearance issue, but I have ER issue. I don’t use glasses, but in order to see the full field I have to tilt my head a little in order to get closer. But in bino mode I cannot tilt the head or it will make the other eye farther from the other eyepiece. This is not a nose issue is the face that is not flat.
As the HW has a little more ER, I was hoping it would allow me to be a little farther from the eyepiece and so not required to tilt my head.
I knew in advance the HWs are a little wider at the top, which could create nose clearance issue, but I was hoping the additional ER could make up for that.

Unfortunately besides the ER difference not being significant, with the HW I have nose clearance problem, which means that I have to tilt my head more than I have to with the Ethos in order to see the full field.

So HWs are definitively a no for me. Do not work in bino for me, and for mono, the Ethos at half the price is good enough for me, besides being a little lighter.

Meanwhile, with training and some effort I am able to see the full field of the Ethos without tilting my head. It is not as comfortable as I wanted, it requires some concentration, but at least it works, and the 100 deg bino experience is worth the effort.
Also I can get comfortable viewing if I give up a little right field on the left eye and left field in the right eye. Combined I see the full field, only the left and right edges are not fully illuminated. But if I want that fully illuminated view for a while, I just need to concentrate more.

So Ethos will remain my 100 deg bino eyepieces. My HW budget is now moved to ES 30mm 100deg and 3” diagonal.

Pedro






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