Yes, indeed, folks. It's here: The Mark II Glowsurv Back Sight. Ready 24/7/365. For those Astro sights, or just for your second and third shifts to keep the income rolling at night.
Tribrach ready; runs on (3) triple A's for 10 hours+ of operations. No more field parties coming back to the office at 1700 hrs claiming "waning light"!
This is a G rated site .
OK. Here's the Mark III GLOWSURV Back Sight
> This is a G rated site .
Never thought of that. :-$
Now presenting the new Mark III; aka the "Stubby Buddy".
It features a new low profile; lower centering errors due to tribrach mis-leveling!
OK. Here's the Mark III GLOWSURV Back Sight
Have you tried them with the instrument in the dark, at the expected distances? I wonder are they perhaps too bright?
OK. Here's the Mark III GLOWSURV Back Sight
> Have you tried them with the instrument in the dark, at the expected distances? I wonder are they perhaps too bright?
Yes, that was my thought as well. Ideally, you'd want the brightness to be adjustable.
OK. Here's the Mark III GLOWSURV Back Sight
> > Have you tried them with the instrument in the dark, at the expected distances? I wonder are they perhaps too bright?
>
> Yes, that was my thought as well. Ideally, you'd want the brightness to be adjustable.
That will be in the next revision. This version uses a standard 6 led "mag light" type flashlight. At 150' in total darkness it is too bright. I still get some "bloom". For my next version, I'm going to bore the acrylic sight to insert an entire Mini Mag Light into it. That should be much less illumination, and also enhance the precision of the concentricity of the point relative to the tribrach mount.
Alternatively, I can insert just about any bulb and wire a control, but unless I can do it remotely (or I have my prism girl standing by), I doubt I'd make bunches of treks back and forth to dial it up or down.
One thing I've learned: In total darkness (or even dusk), at 30x, you really don't need much light. The thing works great! And totally interchangeable with my tribrachs.
Last revision will also be to sharpen the point and make it a much more acute angle...like 20 degrees.
OK. Here's the Mark III GLOWSURV Back Sight
You might want to look into LED flashlights like Fenix. My Fenix L2D (about 6 or 7 years old, so it's probably been discontinued and replaced with a new model by now) has multiple brightness levels, and several blinking/strobing modes. It uses 2 AA cells and is about the same size as a Minimag. They also had 1 AA or AAA cell models, as well as lithium CR123A models.
OK. Here's the Mark III GLOWSURV Back Sight
> You might want to look into LED flashlights like Fenix. My Fenix L2D (about 6 or 7 years old, so it's probably been discontinued and replaced with a new model by now) has multiple brightness levels, and several blinking/strobing modes. It uses 2 AA cells and is about the same size as a Minimag. They also had 1 AA or AAA cell models, as well as lithium CR123A models.
The one I'm looking for is even smaller. It's made by mag, but takes a single AAA. Very tiny. About .375" diam. Fenix makes a similar one (the E01). If I can't find the mag, I'll go with the Fenix. Thanks.
OK. Here's the Mark III GLOWSURV Back Sight
> One thing I've learned: In total darkness (or even dusk), at 30x, you really don't need much light. The thing works great! And totally interchangeable with my tribrachs.
>
> Last revision will also be to sharpen the point and make it a much more acute angle...like 20 degrees.
What about adding two rotatable polarizing filters between light source and target so that the light can be dimmed as the filters are rotated?
OK. Here's the Mark III GLOWSURV Back Sight
I wonder if a yellow or orange glowing part, rather than white, would reduce glare?
Lots of neat ideas here, but I still can't think of a circumstance in which I'd need such a thing.
(On the other hand, I just bought a nearly-new K&E Abney just because I've always wanted one. I'll keep it in the truck, but realistically don't think I'll ever need it.)
> Lots of neat ideas here, but I still can't think of a circumstance in which I'd need such a thing.
>
You never do astro shots any more? Guess it's not needed if you have GPS.
OK. Here's the Mark III GLOWSURV Back Sight
> I wonder if a yellow or orange glowing part, rather than white, would reduce glare?
I tried red, because it doesn't mess with your night vision. Here's an early prototype made from one of those cheap road emergency "LED flare" thingys. I masked it with the same vinyl letters (upside down V) I used for my range testing. It works fine, but I thought that because the target is now on the front surface of the cylinder (or cone), one would have to take additional care to index it so that you don't get a centering error.
If I can combine red illumination with my acrylic, lathe turned, shot blast "needle", I think I'll have solved the glare problem.
It's unlikely that I'll need to adjust it once it's where I want it, because if it's good for total darkness, it will be fine under all other near dark conditions.
ps: this unit can flash too, lol! No hunting for that back sight anymore!
OK. Here's the Mark III GLOWSURV Back Sight
Another solution would be to machine the target with the illumination above it. An acrylic tube that the flashlight lens is glued to would work.
That is, it's a three-piece target:
- drilled and tapped base with machined cone and shoulder to fit acrylic tube to,
- acrylic tube, and
- flashlight up top.
OK. Here's the Mark III GLOWSURV Back Sight
How about a scrap of red theatrical lighting gel, or just some colored wrapping material, between the light and the acrylic cylinder? That should give it color, reduce the intensity, and still let you sight on axis.
If you have access to a lathe, putting a greater taper on the acrylic might help with sighting at both short and long distances.
OK. Here's the Mark III GLOWSURV Back Sight
Do you have a red one if I want to go to the Dark side?
OK. Here's the Mark III GLOWSURV Back Sight
> Another solution would be to machine the target with the illumination above it. An acrylic tube that the flashlight lens is glued to would work.
>
> That is, it's a three-piece target:
> - drilled and tapped base with machined cone and shoulder to fit acrylic tube to,
> - acrylic tube, and
> - flashlight up top.
Not following. What's the shape of the target? If it's just masking on the tubing, the light could be above. If it's a solid machined cone, externally lighting it will not work as well as internally lighting it. My original design (both the Mark II and Mark III) are solid acrylic that rely on the textured surface to diffuse the light.
Perhaps a sketch of the upside down version you envision might be in order.
OK. Here's the Mark III GLOWSURV Back Sight
> Perhaps a sketch of the upside down version you envision might be in order.
My scanner is momentarily on the fritz, but the idea may be understood thusly:
Take an ordinary flashlight and glue the plastic cover plate to a clear Lexan or acrylic tube (about 2" o.d., 3" long) so that the flashlight and tube are one assembled part.
Machine a cylindrical base with a 5/8" x 11 threaded hole on its bottom such that the o.d. of the cylinder is the same as the Lexan or acrylic tube and with a shoulder machined to fit the i.d. of the Lexan or acrylic tube.
Machine the upper end of the cylindrical base to form a cone with an apex in the range of 60 to 90 degrees.
Attach base to tribrach adapter and slip flashlight assembly over it to light the conical target. Figure out how to dim light shone on target by flashlight assembly.
OK. Here's the Mark III GLOWSURV Back Sight
> Machine a cylindrical base with a 5/8" x 11 threaded hole on its bottom such that the o.d. of the cylinder is the same as the Lexan or acrylic tube and with a shoulder machined to fit the i.d. of the Lexan or acrylic tube.
>
> Machine the upper end of the cylindrical base to form a cone with an apex in the range of 60 to 90 degrees.
>
Got it. Conical lit target, using reflective light...if the cone was painted flat white, this might work great. Really, it'd be the same as a flat target, externally lit, but with the advantage of compact form factor and no need to aim it. Slip it into the tribrach and turn it on.
My only reservation is that now the target is inside the tube that supports the light and that may add unwanted reflections. Easy enough to try though. I'll build one.
OK. Here's the Mark III GLOWSURV Back Sight
> My only reservation is that now the target is inside the tube that supports the light and that may add unwanted reflections. Easy enough to try though. I'll build one.
Since it takes so little light to illuminate the target and you want the target on the dimmer end of the illumination spectrum, it might make more sense not to use a full-size flashlight, but to use a longer Lexan or acrylic cylinder with the provision that a smaller penlight flashlight could be placed in it from above. That would also leave some room for the filters between flashlight and target to further adjust illumination.
I still like the two polarizing filters that can be rotated with respect to each other as a means of adjustment of lighting levels.
