Barlowing the binewt

[PhilW]

The latest eyepiece experiment that might interest this forum: yesterday I took delivery of a second Ultima barlow (thanks Wayne). This allowed me to try barlowing the 11mm Type 6s that are my 25cm bino's standard eyepiece set, giving 227x.

The upside is that they worked perfectly. Images stayed sharp, and the extra magnification came in handy when viewing the moon this morning. The Ultima barlows are perfect for this application because they are light and compact, & don't cause any balance problems. :D

The downside is that merging two images at this magnification is a delicate business. It took the slightest tweaks, just touches really, to the adjustment to merge the images. It also needed readjusting a few times in the course of the observing session. So it's not something that would be feasible at a star party, for example. :sadeyes:

Phil

[Omaroo]

Great stuff Phil. Sounds like a handy setup.

I know that when we design these binocular systems we put a lot of effort into making sure that they are easily adjustable for OTHER people - such as those at star parties and general club or society viewing sessions. Should we make the design so easily adaptable?

Should we not just tailor-build them to our own individual specs and be done with it? It'd certainly be easier! I'm in the middle of figuring out how to employ a radio-controlled servo system on my set of 12" binos with mixed differential throw on each side (2 servos per side) such that a new user could come up to the bino and just twiddle two little (or maybe even just one) joysticks to merge their own image. I'd probably have mine built by now if it weren't for this little feature. :doh:

Oh well - if we can't share our equipment with others we may as well stay at home!

[gbeal]

Chris,
you have spoken to Dave Moorehouse about this radio thing? I know he uses an R/C unit to "adjust" his 16" bino.
Gary

[Omaroo]

G'Day Gary :)

No, I haven't spoken directly with Dave - but will do sometime soon. Both Mark Suchting and I had a pretty long phone conversation over the design last month. We are both going this way on our respective binocular systems and doing away with the hinged mirror cell design.

Each mirror will be able to be "swivelled" in two dimensions via two servo-controlled screws on each mirror. The left will have these screws oriented in a triangle (upright with the apex at the top) and the bottom two will be driven. The right will have these screws oriented in a triangle (side-on with the apex towards the centre of the two mirrors) and the vertical two on the RHS will be driven. This way we'll get both mirrors able to be moved in a similar fashion to the older hinged design, yet will not (hopefully) suffer the flex involved.

[PhilW]

Dave provided me with some valuable advice when I built my bino. My image merging mechanism is similar to the one on the smaller solid-tube bino he has documented on his site. It is pretty basic, & what Chris is doing is altogether more sophisticated. :thumbsup:

The tailor-build idea would make life much simpler. Aside from the sharing issue, I can see some interesting challenges arising if you should ever sell it (when you build a bigger one, naturally). I can imagine an IIS listing along the lines of "pristine bino with superb optics, only available to purchasers with eyes spaced 64.5mm apart". :lol:

Phil