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Posts Made By: Mike Swaim

April 2, 2003 03:13 AM Forum: Equipment Talk

stock vehicle built for astronomy

Posted By Mike Swaim

This is a little off-the-wall, but it might be of interest.

I've been looking into getting a new Honda Element AWD. The Honda Element is the boxy, Hummer-wannabe looking little SUV rather oddly mis-aimed at the Gen Y crowd. Well, not only is the inside made to be mud and spill friendly, but the back seats can be either swung up to the sides or removed altogether for almost small pickup carrying capacity. Not only does this mean that bulky scopes and mounts would fit far easier than in most competing small SUVs and minivans, but the Element has an element that is of particular interest to astronomers.

The 4WD models come with a moonroof, (misnamed 'sunroof' ;-), that is in the rear, over the cargo compartment. It's generously sized and directly over an area that looks like it would easily fit a small camp stool and tripod. I haven't taken any measurements, but it looks like it should be quite feasible to drive the vehicle to a dark sky site, and then sit inside the vehicle, well out of the cold, with a moderate sized, rear eyepiece scope poking up right out of the moonroof.

How cool is that? Well, if it's not quite enough, the seats can be laid back, with headrests removed, to form a bed. From a camping, birding, fishing, astronomy, mtn. biking point of view, this looks to me to be THE vehicle. It also gets gas mileage comparable to most smaller trucks and is priced more reasonably than most SUVs.

Just thought I'd pass that along. I've never really been psyched up about a vehicle before, but this one is pretty interesting.

Mike Swaim

April 8, 2003 03:33 AM Forum: Astro Binoculars

Broadband coatings

Posted By Mike Swaim

Is it true that broadband coatings scratch significantly easier, and are much more delicate than other coatings?
This was suggested by one of the more prominent importers of binox with these coatings. I'd like feedback from users and other marketers/importers. If true, at what level does this become a consideration? Is broadband as soft as the worst of the early multicoatings, that could practically be wiped off with a cotton cloth?

Thanks,
Mike Swaim

June 26, 2003 12:19 AM Forum: Astro Binoculars

Trying to better the Fujinon FMT-SX 16x70

Posted By Mike Swaim

For a couple years now, I've been on a quest to replace my Fujinon FMT-SX 16x70s. It's not that there's anything terribly wrong with the Fujis. I think they have more false color on bright objects like Jupiter and the Moon than they should. And frankly, I think their usage is a bit limited. Overall, I've been very, very pleased with them for astronomy. But, what I'd really like is a larger set of good binoculars for a combination of astronomy and terrestrial use. Ideally, I'd like them center focus and definitely well under $1,000. This would seem a reasonable enough thing to want, and evidently a lot of other folks want essentially the same thing: a binocular that would substantially better the Fujinons at a price that isn't well into large DOB land.

Well, after trying a number of the so-called competition, including the Miyauchi Exceeds in 20x77 and 30x77, and the Celestron 20x80s, and the Oberwerk 15x70s, I'm beginning to wonder if such a binocular really exists. I've tried going smaller, in the form of the Pentax PCF 16x60. I liked the fact that they were center focus and light enough to carry long distances. They would've been OK, except the FOV was so small as to be ridiculous.

I notice that in Phil Harrington's big bino comparative article, that the only large bino that he felt really bettered the Fujinons were the Zeiss BGAT 15x60. They sound interesting, but are both much more expensive, and smaller than what I'd like ideally. I could go for a really high quality 15x60, centerfocus binocular in the sub-$600 category. Or I could go for a really high quality 20x80 or 25x100 in the $800 category as long as it weighed under 10lbs, (to fit on my Unimount), and as long as it *really and truly* was a substantial improvement on the Fujinon FMT-SXes. But here's the thing: I don't think any of the sub-$1K Chinese binoculars fit the bill. From what I understand, most of the common 20x80s and 20somethings x100's tend to lose contrast and edge performance compared to the Fujinon FMT-SXes.

Constructive suggestions welcome. Hopefully, I've just overlooked some aspect of the market, but I seriously doubt it.

Mike Swaim

June 26, 2003 09:11 PM Forum: Astro Binoculars

Vixen BT80M-A

Posted By Mike Swaim

This looks interesting:

http://www.buytelescopes.com/product.asp?t=&pid=5188&m=

There's a review on cloudynights.
http://www.cloudynights.com/breviews/bt80s4.htm

It's interesting that while they are theoretically interchangeable eyepiece design, that interchanability may be almost as limited as some interchangeable models that only take proprietary eyepieces. The Vixens aren't quite that bad, but limiting one to only select Vixen eyepieces is somewhat of a purchase consideration. Also, I'm concerned that I see no indication of FMC, or any other reference to coatings. Still, the price is about right.

Has anybody got any first hand experience with these?

Thanks,
Mike Swaim

July 21, 2003 04:28 PM Forum: Astro Binoculars

Miyauchi at Oberwerk

Posted By Mike Swaim

Has anybody yet noticed that Kevin B. at Oberwerk has added the line of Miyauchi astro bins at very good prices? I'll be interested to learn more about that new f8 22x71, and the prices on the 22x60s and 20x77s look practically affordable. (Well, comparitively.)

Mike Swaim

July 23, 2003 07:32 PM Forum: Astro Binoculars

What size max pupil?

Posted By Mike Swaim

I've written before about the perils of assuming that one's own pupil is magically transformed to 5mm max at age 50 (or 40, depending on which source is cited. This chart of 1263 measured individuals may shed some light on the extreme range of max human pupil dilation.

http://f1.grp.yahoofs.com/v1/MNseP0ifWCCMyrEiC0BGBigSJTe53aqDXCJ7c6qRTT4d4ubJz1lQrVFSaBNcXHrXSyVoW-uHX4tx4AlT/Pupil.jpg

You may have to copy and paste that rather long link back together. Note that not only are there individuals at 60 & even 75 with near 7mm max pupils, but also note the incredible range of the 15year olds, and the general spread. Sure, there is a very definite downward trend, with most grouped in the middle, but it looks like a lot of folks may tend more towards 6mm well into their 60s. I thought that chart was pretty interesting. Guess it just goes to show that there's no substitute for measuring one's own pupils.

Mike Swaim

July 26, 2003 04:59 PM Forum: Equipment Talk

How I avoided aperature fever

Posted By Mike Swaim

I've had a number of small scopes, both astronomical and terrestrial in the 60mm to 150mm category. Considering that I got introduced to this hobby by some folks with 16" Starmasters and Starsplitters, it's both funny and pathetic that to date my "big" scopes have been a 6" Mak and a 5" Mak newt, (Oh, and a 6" truss tube clockwork reflector that never even saw starlight, for a variety of reasons.)

Anyway, I've always fancied that I really wanted a nice premium grade truss tube DOB in the 12-16" range. But every time I looked at the increasing cost of those fine instruments, reality got in the way. So, I was pretty sure that I was the perfect target market for a nice 10"-13" sonotube tube.

I was prepared to order either one of the new Discovery 13" DOBs, or maybe even one of the lesser Asian 10" DOBs. I squandered who knows how many hours pouring over all the different specs, options, models and brands. It all sounded pretty good, and started to make lots of sense to me. The Discovery 13 struck me as a heck of a bargain, and the new crop of Taiwanese metal tube 10" DOBs struck me as bargain basement gold. Then I did a very simple experiment that completely changed my thinking.

I put 55lbs of freeweights in the bottom of a 6g. bucket. Then I duct-taped another 6g bucket on top of that, and duct-taped (2) more 5g. buckets on top of that. That all resulted in a 64" tall realistic replication of what either a 10" metal or 13" sonotube DOB might actually represent. Then I carried it up the stairs, through a couple doors, and out of the basement to "set it up" in the yard. That was it. It was that simple.

That easy experiment convinced me beyond any doubt that a 50-something pound, rather clumsy OTA was more than I'd actually be willing to observe with on a regular basis. Sure, I can do it, but I know myself well enough to know that I often wouldn't; particularly during those frequently unplanned observing sessions when I'm outside only because I'm awake. Obviously, not everybody has the same set of limitations and same personality. But, it was sure an eyeopener for me.

Comparitively an 8" DOB tube can weigh in at just 20lbs. and can come in much shorter lengths depending on focal ratio. With that in mind, I didn't hesitate any longer to order a cheap $300 8" reflector. It's not the scope of my dreams, but I'll get to see if it's the scope of my reality. If it lets me observe while sitting in a chair, and if it is easy enough to actually use on a regular basis, then who knows? It may actually allow me some actual observing time that I probably wouldn't indulge in with a "better" instrument. If it works out for me, then I may even consider a "premium" 8" DOB, but I'm fairly sure that unless my situation changes dramatically, I probably won't be in the larger market any time soon. We'll see. That's the current thinking, anyway.

Mike Swaim (reserving the right to change my mind at any and all times ;-)

July 29, 2003 09:03 PM Forum: Astro Binoculars

Affordable 20x120??

Posted By Mike Swaim

I was just researching the BW-Optik 2" 30mm 80* eyepieces and came across this thread:

http://www.astromart.com/messages.asp?message_id=92552&page=

The guy has mated a pair of f5 Synta 120mm refractors and outfitted them with 80*, 2" e.p.s. to make a 20x120 binoscope. Holy cow!!! What an idea. It probably gives pretty purple views, but it probably didn't cost the mortgage, either.

Later,
Mike Swaim

July 29, 2003 10:17 PM Forum: Astro Binoculars

ideas for DIY binoscopes

Posted By Mike Swaim

Most of us fantasize about owning one of the really big astro binoculars, but for most of us, they will remain an unrealized dream, rather than a reality. Every once in awhile, I think about making something in the 100-150mm class. A few years ago I wondered about the feasibility of making a binoscope out of paired Astro Rubinar 100mm Maks. The fact that those converted camera lenses are helical, barrel twist focus pretty much rendered the idea worthless before I even finished fully thinking it through.
Now that ETXes are so far down in price, I wonder if paired ETXes wouldn't be a much better idea. I'd guesstimate that one could come up with some pretty darn good 40x90s for under $500 total using the ETX as an OTA platform.

Another one that really intrigues me is the idea of pairing a couple of newts. I know there are several folks out there who've successfully done just that, and JMI is now even offering a reverse view commercial version. However, my idea is perhaps even more grandiose, (and perhaps whackier).

What I envision is a lazy-susan style bino-chair, with the newt OTAs suspended above the observer on an oversize yoke mount. To view through them, you could use a pair of periscope mirror assemblies. The whole idea would be that the observer could control where the chair, and thus the optics pointed by means of a simple joystick controller. If the tubes were mounted on a simple alt-az mount, and if the chair reclined, then horizon to zenith shouldn't be a problem.

Some thoughts on OTAs would include the Orion 6" Pro EQ, which is now available as just the OTA for $179/ea. Or, for a true planetary binoscope, the Intes MN56 should prove to be a simply amazing binoscope platform, particularly since they're appearing on Astromart in the $350-$600 range. The problem with those ideas, is that I don't know to what extent the periscope mirrors would interfere with the viewing enjoyment.

So, anyway, what are your ideas for a cool, affordable binoscope? Let me know if anybody actually gets around to building any of this stuff. ;-)

Mike Swaim

July 30, 2003 12:50 AM Forum: Equipment Talk

ASM truss DOBs & ceramic mirrors

Posted By Mike Swaim

I just came across a couple pages that I printed out over a year ago about ASM mirror and telescope company in Canada. What ever happened to them? A quick web search shows that there is still a really poorly designed web page for the company, http://pages.infinit.net/asmprod/index.html and even a US distributor in OH that I've never heard of. http://homepages.accnorwalk.com/tddi/tech2000/asm/
It's a different one from last year. Last year it was APM-US, (now defunct). The prices have gone up since last year, but still look very reasonable compared to other quality truss tube DOBs.

So what's the scoop on this company and their truss tube Dobs? A year or two ago, there was a minimal amount of speculation about these new lightweight vitrified ceramic mirrors being the wave of the future, but I've not read a peep about this company or this concept since then.

Bob Hart: did your friend ever get one of the scopes? How'd it do?

Anybody else? Any info at all on ceramic mirrors, ASM or this whole concept? Or did this go the way of ceramic airplane and auto engines? (ie. nowhere)

Thanks,
Mike Swaim