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"Field Conditions": Match equipment to them?

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#1 jrbarnett

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Posted 26 November 2012 - 08:24 PM

Most of my observing, in terms of number of sessions per year, are conducted from my own suburban backyard. I have a sturdy storage shed, dedicated observing slab, decent horizons and typical suburban light pollution (maybe magnitude 5 at zenith after 11pm). In this environment, "field conditions" are relatively controlled. I have no qualms about setting up any gear, from fancy apochromatic refractors, through premium Dobs and large SCTs, and leaving them outside, covered, after the session.

However, even though the majority of my sessions annually happen at home, my best sessions typically happen further afield. In my case, either at CNer cuzimthedad's Sonoma farm, over the hill, or arid dark sky, higher elevation sites for extended multi-night stays. Each of these "away" sites present a more demanding environment for my scope. I'll discuss what I mean for each of these "away" sites, in turn.

The Farm is the home observing site for my local club, OFLI. It is located adjacent to a seasonal creek, and many times of the year moisture is a serious issue. I had my first Dob primary "dewing over" experience at the farm. Secondaries and objective/correctors need to be heated to blown dry to repel due more than half of the time. Moisture is the biggest challenge at the Farm site, and all that water on my fine optics and getting into the inner workings of my mounts gives me pause. I figure that the Farm puts considerably more wear and tear on my gear than does my home site. Hold that thought.

The other type of away site is generally high desert. Each year, and sometimes twice a year, OFLI heads out to the hinterlands for some serious star time in one of several high, dry and dark locales. One common problem for such sites is dust. Not the ordinary kind you feather duster off of the bookcases in your house, but the ultra fine talcum like rock dust one finds in the boonies. With this dust usually comes wind. The combination of fine dust and daytime wind means that whatever gear I field gets a serious dose of fine dust. After our last trip to the White Mountains, I spent two full days unpacking and cleaning optics and mount internals. The stuff was *everywhere*.

Now, I'm not a believer in "trailer queens". Telescopes and accessories are tools for a particular activity, and are going to get dirty and dusty and wet in ordinary usage. However, these two "away" sites are extremes; one for wetness and the other for dustiness. I'd be lying if I said that the thought of what the elements at such sites are doing to my fancy objectives and mirrors, and costly mounts and electronics.

This paranoia has me thinking along the following lines. Perhaps I should match the expense and rarity of the gear I choose to field to the severity of the conditions at the site? This would entail leaving the fancy apochromats and Dob at home and taking along a less expensive variant for wet and dirty field use. I've already played with that concept on the refractor front. I picked up a C8, C6 and AT111EDT, as potential alternatives to the TEC 140 for use at very harsh sites. Each of those is a tiny fraction of the investment I made in the TEC. Each has delivered worry free harsh condition use, too. On the Dob front, rather than my 16" f/5.1 Teeter/Lockwood I am noodling an Orion XX12i. Again, very modest in expense compared to the Teeter (the whole scope costs less than half the cost of the primary mirror alone in the Teeter). And most likely a scope that I wouldn't think twice about letting fend off dust devils and scorching heat by day in the middle of nowhere.

So what do you think? Does it make sense to have less-dear gear for more severe field conditions, or should I just use the fancy stuff to death no matter how wet, hot or dusty the site?

Regards,

Jim

#2 Ed Wiley

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Posted 26 November 2012 - 08:32 PM

As one of my friends once said: "What are you saving it for?"

Ed

#3 johntrob

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Posted 26 November 2012 - 08:52 PM

I buy some things cheaper, for harsh use, and keep the nicer objects for robust but not extreme conditions. This works in many aspects of our lives. Think of driving "expensive" cars to the river for fishing vs the old beater pick up?

#4 beatlejuice

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Posted 27 November 2012 - 12:24 AM

If I had these kinds of choices I would keep the TEC at home for lunar and planetary use. Take the Teeter to your dark sky sites and get the most out of it. If you have to clean the optics a little more often or give it a little more TLC when in the field it is probably worth the extra effort. You know you want the views this scope can give at a good site and you can't let that go to waste!

Eric

#5 FirstSight

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Posted 27 November 2012 - 12:37 AM

I have a similar concern about bringing my best gear down from Raleigh to my other home on a barrier island by the sea, even though the house is a quarter-mile back from the ocean. Sea breezes often contain extremely fine salt-infused dust, and the moist air itself often has a slight concentration of salt suspended in it. A marine environment is a much more abrasive, corrosive environment to materials than most inland environments.

I've nearly quit bringing my 12" reflector from Raleigh to the coast because of that, and will only use my NP101 on my rooftop deck (and not bring it down on the boardwalk behind the dunes), and even so I won't leave either the NP101 nor the mount up on my rooftop deck longer than necessary for each individual observing session. To be fair, part of the decision to only rarely bring the 12" reflector down with me anymore has to do with the fact that I have to lug it up 3 stories worth of stairs in two separate trips to the observing deck to initially get it up there, although I only have to take it back down one (rather steep) flight to store it in my bedroom beween sessions. However, the more important factor was that bringing it down to the coast vastly increased the number of occasions I needed to rinse the optics.

If I get the notion to set up on one of the boardwalks in the strip of low coastal forest just behind the dunes, I'll bring my Megrez-90, which is a decent but not nearly so premium a scope as the NP101. At some point, I may also consider getting an 8" or 10" commercial dob (one I don't have quite so much invested in) to leave down there.

#6 DavidNealMinnick

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Posted 27 November 2012 - 01:58 AM

After a serious dusting of my better optics at RTMC the last two years in a row, I will next time take a Chinese dob up there from now on. I do frequent a desert site where I'm happy to use my largest (premium) mirror, as it is too dark not to. I am willing to take my fluorite doublet there as well, but, use my best refractor at my suburban home only.

#7 Jon Isaacs

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Posted 27 November 2012 - 04:42 AM

As one of my friends once said: "What are you saving it for?"

Ed


:waytogo:

My backyard is quite benign but our place in the mountains where I spend most weekends is generally very dry, dusty and almost always windy. Occasionally though, one is living inside a cloud, it's foggy and very wet.

It makes sense to prepare the equipment for the particular conditions and do what is possible to mitigate the conditions but as Ed said, "What are you saving it for?" Equipment is meant to be used not admired from a far.

Jon

#8 jrbarnett

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Posted 27 November 2012 - 11:20 AM

No one is arguing that equipment is meant to be used. As I said in the OP, telescopes are tools. However, the question was really asking for something a bit more specific and pragmatic than that. It already takes the precious commodity of "time" to haul to and use gear at an away site. The nature of the away sites I use is such that it increases the maintenance needs of the gear I take there (i.e., requires that I spend two days cleaning objectives, mirrors, correctors, mount innards and eyepieces after returning). This would not be the case if I used the better stuff that I feel compelled to maintain diligently at home only, and instead fielded easily replaceable stuff that I would not bother cleaning after such a trip.

I've already used SCTs in this capacity in lieu of my better refractors. A little spit and a bare finger, followed by a little Pursol and a swab with a lens tissue and pollen, bug feces and goop are gone from the corrector. Could I scratch it? You bet. Do I care? At $399 for a 6" and $799 for an 8", not in the least. Would I treat my TEC 140 or FS-78 or 1/30th wave Lockwood primary in the same manner? Not a chance.

So in answer to the question "what am I saving it (i.e., the fancy stuff) for?", I'd say to use indefinitely from home and enjoy the near perfect quality images produced by these fine instruments, since repair or replacement of these is more difficult and costly.

On the other hand, Orion and GSO make fine Dobs. I've had several Orions and the GSOs owned by club mates have been very nice too. A 12" f/5 GSO Dob runs about $700. If a dust devil picks it up and hurls it into the arroyo, destroying its mirror and denting its tube, I would be disappointed, and might even cuss, but I'd get over it pretty quickly. If the scope survived the trip filthy but otherwise intact, I'd put it in the shed waiting for the next trip. If it needs a recoat, no biggy. A 12" mirror is a one-hander, and is shipped easily. :grin:

Regards,

Jim

#9 Midnight Dan

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Posted 27 November 2012 - 11:31 AM

... bug feces and goop are gone from the corrector


Ah, I think I see the problem! When driving out to a dark site, don't use the scope. Wait till you get there, and THEN set it up and use it. Using a scope at 60 mph is sure to get bug goop on the corrector. ;)

-Dan

#10 hottr6

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Posted 27 November 2012 - 12:22 PM

Does it make sense to have less-dear gear for more severe field conditions, or should I just use the fancy stuff to death no matter how wet, hot or dusty the site?

Having worked as a seismologist all my life, I get to play with some very expensive equipment in some of the worst environments on the planet. As a scientist, one is interested in data, and the tools used in the acquisition of that data are viewed as expendable, though modern research budgets dictate that we make every effort to extend the life of our tools. So a seismometer, telescope, camera, particle accelerator, etc, are just tools, nothing more. Put 'em out, use them, collect data. If tools break, repair or chuck it.

So, Jim, the question we amateurs need to answer is then what value do we place on our observations?

I live/work/play in NM, arguably the source of all dust on the planet ( ;)). If I was concerned about dust/dew, I'd never go outside.

#11 Mike B

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Posted 27 November 2012 - 12:58 PM

... bug feces and goop are gone from the corrector


Ah, I think I see the problem! When driving out to a dark site, don't use the scope. Wait till you get there, and THEN set it up and use it. Using a scope at 60 mph is sure to get bug goop on the corrector. ;)


:foreheadslap: :foreheadslap: :foreheadslap: So THAT's what i've been doin' wrong! The officer tried to tell me this, but i was too caught up in polar alignment to heed the advice. A 60mph wind can play havoc with that part of set-up, yaknow... :foreheadslap: :foreheadslap: :foreheadslap:

#12 cliffy54

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Posted 27 November 2012 - 01:07 PM

Sounds to me like you keep answering your own questions. :p

#13 Jon Isaacs

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Posted 27 November 2012 - 01:16 PM

So in answer to the question "what am I saving it (i.e., the fancy stuff) for?", I'd say to use indefinitely from home and enjoy the near perfect quality images produced by these fine instruments, since repair or replacement of these is more difficult and costly.



Jim:

I have observed throughout much of the southwest and spend a lot of time in the desert mountains east of San Diego. I do keep my equipment covered and in the garage when possible. The eyepieces are only out of the case when they are in the focuser. On the road, I keep the scopes and mounts covered or in the vehicle. I find they remain relatively clean.

Of course I am using Dobsonians and refractors on alt-az mounts but I have these scopes for just such occasions... at home I am much more likely to be using my 10 year old 10 inch GSO Dob or an garage sale refractor...

Just think... if you had left that 80mm F/6 Lomo triplet at home last year, you never would have split Sirius and you would have one less great story to tell.

It is true, a 12 inch Light Bridge is a pretty fine scope and if you took some time to iron out the bugs and customize it to fit your particular needs, it might be the right scope. Still, at some point you might find yourself thinking, "Gosh, I sure wish I had my Teeter with me."

If you want a cheapo deep sky refractor to borrow, I have a 100mm F/6 Orion Sky View with a reworked focuser that handles the 31mm Nagler as well as the $50 ES 35mm 70 degree... It does a pretty good imitation of an NP-101...

Jon

#14 Mike B

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Posted 27 November 2012 - 01:19 PM

... but as Ed said, "What are you saving it for?" Equipment is meant to be used not admired from a far.


What seems heartbreaking to me is the potential in both figure & aperture of that wonderful Teeter-16 being strapped-to-the-mast of a suburban yard & its LP. Just when it could be unfetter'd & loosed on a deep, dark sky... you'd wanna throw a second-stringer in to play?... a 12-incher, no less? :foreheadslap:

Our observing group has a slogan for this scenario:
"Whut was i theeeeenking!?"

If newness or *pretty* is the restraining issue here, then hows'bout buy a cheap, semi-disposable housing (ie. someone's cast-off 'Lightbridge' structure, new longer poles?) for hazardous darksky duty, and simply fit the Teeter optics therein? Then all yer lookin' at is a mirror bath upon returning home.

Bet that would cost less than a functional 12i, too.
;)

#15 csrlice12

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Posted 27 November 2012 - 01:31 PM

well, if the wind was strong enough to pick up a 12" Dob OTA and blow it into an arroyo; it's probably too windy for viewing anywho....

#16 Mike B

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Posted 27 November 2012 - 01:50 PM

Perhaps the arroyo would afford a shield from the wind? Leave it down there, & observe where it be flung! :grin:

#17 MDB

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Posted 27 November 2012 - 04:41 PM

Dark, remote and sometimes environmentally hostile places are the reason I have a best scope. Sure I use it at home mostly but dark sky places are what it was made for. Mine is only a 12.5 inch Obsession but I wouldn't dream of going to a best viewing site and not taking/using my best equipment. If that requires increased maintenance and more frequent mirror re-coating so be it. I hope I am lucky enough to wear it out!

Mike

#18 csrlice12

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Posted 27 November 2012 - 04:43 PM

Dark, remote and sometimes environmentally hostile places are the reason I have a best scope. Sure I use it at home mostly but dark sky places are what it was made for. Mine is only a 12.5 inch Obsession but I wouldn't dream of going to a best viewing site and not taking/using my best equipment. If that requires increased maintenance and more frequent mirror re-coating so be it. I hope I am lucky enough to wear it out!

Mike


Totally agree...You go viewing with the equipment you have, not the equipment you wish you had.......

#19 jrbarnett

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Posted 27 November 2012 - 08:43 PM

"Just think... if you had left that 80mm F/6 Lomo triplet at home last year, you never would have split Sirius and you would have one less great story to tell."

I don't have a LOMO 80/480 triplet. Never have. That was Jared's scope, not mine. My relatively cheap AT111EDT has no trouble with Sirius B. I'd much rather sacrifice it than my TEC to harsh conditions, frequent cleanings and the like. (The TEC was the other scope that managed Sirius B in the Mojave that trip). It's easy to replace a 4" APO with another reasonable quality 4" APO for less than $2k.

I'm now looking at an alternative to peppering the Lockwood primary of the Teeter with wind-borne abrasives. A $700 12" GSO Dob is looking like a fine sacrificial victim, with plenty of aperture, for that role. :shrug:

- Jim

#20 Jon Isaacs

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Posted 27 November 2012 - 11:50 PM

I'm now looking at an alternative to peppering the Lockwood primary of the Teeter with wind-borne abrasives. A $700 12" GSO Dob is looking like a fine sacrificial victim, with plenty of aperture, for that role.

- Jim



The 12 inch GSO is not a 16 inch but I often take my 12.5 inch when traveling. Honestly though, I am wondering how the conditions can be so bad. I spent a lot of time wandering around around the California deserts as well as Arizona and New Mexico and while I have had wind blow over telescopes, protecting them from the dust has not be a major issue.

Jon

#21 starrancher

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Posted 28 November 2012 - 12:39 AM

Not being a Dobsonian owner , who am I to say but high desert observing is about all I know and I would think that with a good ground cloth down (I use furniture pads aka movers blanket) and a shroud for a truss Dob should keep things fairly clean . If the wind is that bad I'm not calling it an observing night anyway .
Then again , who am I to say ?
:shrug:
With my tripod mounted scopes , I can go quite a while between any kind of wet cleaning . I do hit everything with a bulb blower at the end of every session before the covers go back on .

#22 Mike B

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Posted 28 November 2012 - 12:49 AM

Maybe the Beach Boys put it down straight:
"None of the guys go steady 'cause it wouldn't be right to leave your best girl home on a Saturday nite"
:lol:

The 12 inch GSO is not a 16 inch...


Ya, no kidding! Nor is it likely to have premo optics, or mechanicals. :o

My 15-inch 'Starsplitter' came to me "used". Maybe not seein' pix of it bein' built, waiting aeons to have it finally arrive, nor paying a "new" price, helps to not have any particular "emotional" attachment to it?...

... but rather, to what it can do! :dob:

I hope I am lucky enough to wear it out!


Well stated, sir! Well stated! :waytogo: We should *ALL* be so fortunate to accomplish this.
:ubetcha:

#23 Eddgie

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Posted 28 November 2012 - 10:58 AM

This is speculation and only speculation because I have not tested or heard of tests being done to confirm this.

Normally, I would say that there is no great worry about using modern optics in dusty environments. The coatings on modern lenses and mirrors with SiO2 are very hard and durable.

Ah, but... In your case, if there is silica sand, silica is hard (After all, SiO2 is fused quarts which is basically silica). A Silica dust would be in fact somewhat like a very mild abrasive and wiping might be able to damage it.

Think about the MILSPEC use of Dielectric coatings. This requirement became essential after the first gulf war, and this is when modern dielectric diagonals came into the mainstream.

The value of the dielectric coatings was that they were harder than any kind of dust that would be encountered in any known combat environment. And the reason this was important was becasue in these environments, the optics need to be cleaned frequently and under feild conditions, and frequent cleaning could damage the older SiO2 coatings.

For most of us, dust is dust.

But if the dust has a high silica content, then I would think that some potential for damage is present.

Again, this is entirely speculation, but you won't find military optics without dielectric coatings anymore.

I am just doing the math on it, and it adds up to "Maybe you are right."

But only in cases where silica dust is present. For must of us, dust is dust and not a serious threat to modern coatings.

#24 killdabuddha

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Posted 28 November 2012 - 11:56 AM

Dark, remote and sometimes environmentally hostile places are the reason I have a best scope. Sure I use it at home mostly but dark sky places are what it was made for. Mine is only a 12.5 inch Obsession but I wouldn't dream of going to a best viewing site and not taking/using my best equipment. If that requires increased maintenance and more frequent mirror re-coating so be it. I hope I am lucky enough to wear it out!

Mike


Totally agree...You go viewing with the equipment you have, not the equipment you wish you had.......


And in yer consideration of a sacrificial GSO you'd only be compounding yer difficulties. Here's what I envision...you get to the optimum sky site for a week of bein blissed out once a year, but you can't get blissed cuz now you got a cheaper scope to abuse but the weather isn't cooperating, the night sky is mocking you, and yer Teeter wastes away, alone, on the biggest nights of the year for want of maybe a wind-screen that you might not even use. How DO you sleep? I doubt I'd even be able to gas the car without knowin the folly of my monkey-mind.

#25 csrlice12

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Posted 28 November 2012 - 12:36 PM

Dark, remote and sometimes environmentally hostile places are the reason I have a best scope. Sure I use it at home mostly but dark sky places are what it was made for. Mine is only a 12.5 inch Obsession but I wouldn't dream of going to a best viewing site and not taking/using my best equipment. If that requires increased maintenance and more frequent mirror re-coating so be it. I hope I am lucky enough to wear it out!

Mike


Totally agree...You go viewing with the equipment you have, not the equipment you wish you had.......


And in yer consideration of a sacrificial GSO you'd only be compounding yer difficulties. Here's what I envision...you get to the optimum sky site for a week of bein blissed out once a year, but you can't get blissed cuz now you got a cheaper scope to abuse but the weather isn't cooperating, the night sky is mocking you, and yer Teeter wastes away, alone, on the biggest nights of the year for want of maybe a wind-screen that you might not even use. How DO you sleep? I doubt I'd even be able to gas the car without knowin the folly of my monkey-mind.


What???? :question: Hey, it's my equipment. If I want to take and throw a handfull of dirt on the primary, that's my decision. I'd rather have that Teeter setting off to the side unused; rather then not have it and have the viewing weather be perfect...It's all individual preferences; it's a hobby and we can all do it however we want....






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