Posts Made By: Thomas Dey

Well, THIS is interesting! All my life (?) I've been protecting my Dark Adaptation. You DS observers know the feeling - get to a nice Dark Site, equipment set up ready to go after the little fuzzies. You know all your gear by heart and can pretty much find things in the cases and the sky without turning on a light. And even at the eyepiece "averted vison" has become automatic. I recently got these (yep - TWO) Night Vision 1x monoculars. They are the GOOD ones and the 1X is Exactly 1x. Much to my surprise, I find that at 1X I can simply hold one to each eye and the images are naturally merged - TRUE binocular 1X Night Vision "Eyeglasses" is the feeling. Hard to explain, but It doesn't feel like looking thru an instrument at all - it feels more like looking thru a Window - A supercharged bionoc eyes window! My "limiting magintude" has jumped from around 6 to more like 8! It's like I'm on top of Mt. Everest! Just scanning around and M31 is of course brilliant and M33 has gone from fleetingly tough to a piece of cake. The Pleiades and Hyades look like true clusters now. It's Amazing, and I have to remind myself that Dark Adaptation doesn't even matter. Meteors and satellites all over the place. So that's great - But the truly amazing part was putting H-alpha 12nm "CCD" filters over the small (one-inch!) objectives. Look up and the sky is FULL of H-alpha stuff! The N American, Pelican and Gamma "Butterfly" are blazingly Obvions! California, Rosette, M42, The "boot", Orion Loop and even the region that contains the Horsehead all Obvious! (Horsehead itself a bit too small to see at 1X). And lots of other H-alpha blobs that I will have to visit the atlas to ID what they are. It's a Whole New World (Universe) looking through this window. Technical: I tried left only, right only the Both together. Surprising (although hoped for) is that indeed two eyes (With Two Completely Separate Optical Trains) is WAY better than one eye only. I still don't understand it - but Both together look much Brighter than one. They of course are Not - but it looks ... twice as bright! And the view is also much more "real" and better resolved and contrasty. I think part of it is because the "scintillation" L/R is of course uncorrelated, so the visual cortex is FAR more able to filter out anything that is not present in both eyes. If a little sparkle is only L or only R, the brain ignores it as Not being in the sky. Anyway, the extravagence has paid off in blow socks off experience looking up. Not done yet though - I have JMI RB16s and 1.25 adapters to use these as "eyepieces" I think I'm cheating? Tom

I consider the Horsehead to be right up there as one of the most challenging visual targets, and have only seen it a few times under the most ideal conditions. Decent sized scope and a specialized filter like the H-beta especially help - and even then I can only occasionally say, "Yep - OK - I definitely see it!" One of those objects that images superbly in H-alpha but not to the eye in that band because it is so blasted DIM and our Night Vision "scotopic - rods" are blind to the uber-red H-alpha. So far, so challenging. About a month ago I got TWO Gen 3 Night Vision monoculars, added 12nm H-alphas and looked at the sky. YIKES! All the H-alpha stuff just POPS because the device of course transforms the view to bright green phosphor that one can look straight at. I can see Barnard's Loop piece of cake and the nebulosity to the E and S of Orion's left belt star no problem at all. I had assumed the Horsehead Notch (B33) would be impossible at 1x. But tonight I looked again and - I SEE IT! Just as it should appear, a tiny dark notch hooking in from the left and upward. Again and again I ask myself if I'm actually seeing it at 1x and the answer keeps coming back - Yep...there it is. So now, after the fact - I check the literature and see it is about 4 arc-min in size (certainly resolvable by cone's centralis vision) and the NV 1:1 phosphor rates 64 line pairs/mm At a 1-inch focal length (both objective AND eyep), that translates to about 2 arc-min (for the pair) --- which would be just comfortable to resolve the object. I'm also convinced that using the TWO NVs feedng BOTH eyes immensely reduces the scintillation. So there you have it - I can see the Horsehead at unity mag using Gen 3 NV True Binos. And that's pretty amazing! Has anyone else tried this?! If you think I'm nuts, I understand. Comments/observations welcome! Tom

Hoping someone there can point me toward a source and/or provide technical advice. Here's my Moral Dilemma, Dr. Laura: I have an f/4.5 DOB system and can't quite reach focus with my favorite eyepiece. (Yeah, it's the NV Micro IIE Image Intensifier eyepiece) I think I need 6-9mm of additional "in-travel" and have considered most of the usual suspects --- move PM forward, move focuser inward, machine the "eyepiece" so it slides farther in. All three of those has significant difficulties, so I am considering a 4th alternative that I have successfully used before. To add a MILD Barlow upstream from the eyepiece. There is a perfect location for it at the bottom of the focuser tube. If you're into Optics, I come up with a two-inch diam lens (1.75 actually used) that transforms an f/4.5 feed to f/5.2-ish. My rough computations show that a thin BK7 singlet negative meniscus with a power of -1.0 Diopter would work fine. Ideally, the meniscus would be "bent" to share the ray-bending twixt the two surfaces (to minimize spherical and chromatic).

I surfed lens houses and am perplexed that they have POSITIVE lenses in that size and focal length (1000mm of course) and even meniscus .. .but no NEGATIVE lenses except for small or short focal length ones. I know, my application is somewhat unusual, so no surprise. So far I have looked at Edmund Optics, Andromeda, B&H, Sunny Precision Optics, Lens Factory, Thor Labs, Westech Optical, Anchor Optics (= Edmunds old random surplus offerings), HIS Engineering, Altechna --- and the places that supply ophthalmic Test Kit lenses. GOD, I miss the (pre-retirement) days when I was an optical engineer at B&L, Kodak, ITT etc. Walk into the production areas and lenses being made far as the eye can see… Always doing developmental work so these wizards could fab ANY lens and Corp ENCOURAGED work-like hobby projects!

OK, Ok, ok … so I either need to Find a source, Commission custom ($$$?!) or [dread] actually get my hands dirty and make it (two, actually) Myself!

RECOMMENDATIONS WELCOME! --- Tom Dey

This was indeed "After Dark" last night: I have become obsessed with the Crab Pulsar and wanting to actually see it. Never had even tried before because assumed it's impossible. But I have this 29-inch Dob and the Pulsar is (ostensibly) mag (Mv) ~16; which would be just on the cusp of a scope that size. Well, Yes - I can see it, sort of: First I tried Nagler 31 107x no; then Ethos 17 196x no; then Ethos 13 256x ... maybe. By that I mean I could see something stellarish in the right place, but only fleeting with averted vision and that sort of subliminal where all I know is I could see Something there but not further describe it. And (knowing) there are actually Two stars there (the Pulsar and it's "companion"), I don't want to claim I saw the Pulsar itself as a discrete object. Next I tried the Night Vision (Micro IIE) ITT Gen3 "eyepiece." COOL! I can see the two stars! The "companion" is really pretty easy but the Pulsar is medium tough. They are quite close together, with the pulsar "leading" as they cruise across the field. I tried my visibility test for medium tough targets: Ask myself once a second for a full minute "Do I see it?" Yes, yes, yes ... , yes." So I can hold it for an entire minute without losing it = SEEN! A few technical notes: This is in agreement with my observation that Night Vision picks up 1-2 magnitudes on stars. There are other advantages (and disadvantages), but it is certailny something to consider adding to your eyepieces. I know some pureists would point out that I didn't actually SEE it, because I was cheating using the Night Vision. But, taken to its logical limit ... you'd better remove your eyeglasses before you claim you can see 10 stars in the Pleiades? Come to think of it - Galeleo cheated! Nother note: used my "Sky Quality Meter" for the 1st time. Pointing toward the "winter" constellations it reads 20.9 mag/sec^2; pointing toward the (dimmer) spring sky it reads 21.2. So regular star light actually does affect the reading! I am also pleased that my back yard sky is good - not Great ... but Good!

STOCK PICTURE ATTACHED - from my Observing Log, shows marked what I saw. Tom Dey

Hot of the presses 0801amedt here. I am surprised how big it is because Astronomy said it would be a dot. Also, Sol is still pretty active! Tom Dey

Hi Andy, I got big binos and learned how to collimate them. That takes the pressure off worrying about alignment anymore. I can only look thru straight-view ones reclining. Imaged the moon last few days and now waiting for it to get outa the way. Tom

I finally got all the parts to build my final biggest telescope: A 36-inch f/3.75 Dob (to replace my ~too-small~ 29-inch). The 36 will just fit my geodesic dome up this dark rural hill from the house. Found a buyer for the 29 and threw in a brand new enclosed deluxe 12x5x5 trailer almost free! Good for him and good for me. Thanx, Kevin! So I am committed to the 36, excited and a bit trepid. I got the excellent journal Amateur Astronomy back issues on DVD and have been reading back from the present to educate myself on the history of Dobs. Tom Clark composed an excellent article 10 years ago (issue 51) wherein he describes the +/- of scopes small to gigantic. He concludes that [scopes around half gigantic (such as half of 36) are generally most staisfying for a variety of reasons that we DS folks are familiar with.] And I gota admit my most satisfying By Far was the trusty 17.5 that I built using a (good!) Coulter mirror and oil drums. It resided in a 12-foot dome behind the house and was pure pleasure exploring the cosmos. Also cheap, easy, reliable = +++. My 29 was expensive and required more TLC to perform. The exceptional nights were indeed wonderful. Now comes the 36! Tom's consul regarding his 36a, 36b and 42 is: [exceptional on rare exceptional nights --- but smaller scopes far more often perform to capability.] And my experience with the 29 bears that out. When it's good, it's GREAT ... but the seeing cooperates far less often. So now I will build the 36, install it in the dome --- and hope for the best. I'm targeting 1st light by Aug 1st - might take longer. All excited and wondering what I have gotten mysely into. I'm actually very happy that I decided to do it. Worst that can happen is I won't like it all that much --- and that would be OK. Tom Dey

I need visual observing advice. I am trying to see Barnard's Star and went to the field shown in Burnham and elsewhere, expecting that it would be obvious and sorta bright (16-inch binos!) Convinced I found that wedge-shaped asterism etc. OK and then two stars downstream that should point at Barnards. Expecting/hoping to see a bright, warm colored star there. But nothing! I figure either it is WAY dimmer than I expect or it is one of the "other" stars and I'm just not interpreting the location properly. If it IS really dim (relative to identifying it among other dim ones), my backup plan is to use the Night Vision, which would enhance a "red" (3200K) star by a lot. Thanks for any hints/experiences you may have. Tom

My technique is indirect but easy: I open my image in the ubiquitous MS Paint. I "resize" it so it just fits on my typical laptop monitor display, which will therefore look good on anyone else's. I save that (as .jpg which is efficiently compressed a lot). I check that the size is less than the 500K. Do that to each attached image. Bonus is that this allows you to reframe and annotate images so they better match your ad. Additional bonus is that it uses less bandwidth x time to disseminate. Nearly all cameras oversample by a lot, so you are rarely degrading the displayed image when you do this. PS: The .jpg algorithm compresses bland images a lot more than busy ones. Other software may do this with one or 2 clicks. Oh yeah; there is some slight overhead in porting the image over to Astromart; it needs to be somewhat smaller than 500K.

There's a Nova just above the spout. I just googled it and am going out to look there with binos now. Mag may be 6 according to a friend. Article says 8. Anyway, certainly an easy bino object. Link to Sky & Tel nice article on identifying it. Has good finder charts. Tom
http://www.skyandtelescope.com/astronomy-news/observing-news/new-bright-nova-in-sagittarius/