Total Solar Eclipse, U.S.A., 21 August 2017

[Bill De Jager]

A total solar eclipse will travel across the United States on 21 August 2017.  This will be the first total solar eclipse in the contiguous 48 states (excluding Alaska and Hawaii) since 1980, and the first one in these states with decent viewing conditions since 1970.  More information here: http://www.eclipse2017.org/xavier_redirect.htm.

This eclipse offers a great chance for a NG meet, and for photographing in a group where everyone knows the basics and people can look out for each other (and their equipment) against the distractions of the curious, the clumsy, or worse.  Furthermore, having traveled all the way to the narrow band of a total eclipse, some may then want to spend additional time touring and photographing nearby areas after the frenzy is over.

At this time interest is just starting to build, and we have not yet seen the tsunami of publicity that's sure to happen in the U.S. at some point well before the eclipse. However, those in the know are already making preparations, and I recently read that all lodging has already been reserved in at least one small city.  I expect lodging, recreational vehicles, etc. to be totally booked well in advance.

Totality will cross the Pacific coastline in the state of Oregon at 1015 local time (Pacific Daylight Time  = UTC-7) at Newport, Oregon.  It then races across northern Oregon and southern Idaho, right across the middles of Wyoming and Nebraska, and onward across Missouri and several other states before entering the Atlantic Ocean in South Carolina at 1449 Eastern Time (UTC - 4).  The duration of totality will range from about 2 minutes to 2 minutes 40 seconds.

As far as a viewing location goes, both seasonal and daily weather patterns should be considered.  I skimped on the description of the eastern half of the path in the U.S. because of greater risk of rain and generally hazy conditions in August.  But even in the West, August can a good time for thunderstorms.  On the other hand, the climate west of the Cascade Range in Oregon averages much cloudier in August than points farther east.  In addition, early in the day is better for avoiding cloud buildup and thunderstorms under typical summer conditions in the western U.S., so farther west is good.

All these considerations point to central and eastern Oregon as being perhaps the best location.  The time will be earlier in the day, plus it's the farthest-west area that's east of the Cascade Range so the weather outlook is relatively favorable.  One might hope to photograph the eclipse in a beautiful setting, but it will be relatively high in the sky - 42 degrees in eastern Oregon and higher at points east - so this is less of a consideration.  Valley locations offer the advantage of less risk of clouds in thunderstorm weather.  One other concern is adaptability; there is always the possibility of a last-minute weather problem that could force a change in viewing location, perhaps by 200 km or more.

Central and eastern Oregon is mostly steppe with forested mountains rising here and there.  Populations are low but the area is subject to recreational invasions from the larger population of western Oregon.  For those who might want to stay in the area afterwards, there is the nature-oriented High Desert Museum in Bend, the nearby lakes, forests, and volcanoes in the Cascade Range, and Crater Lake National Park.  Flights would be through Portland, Oregon (NOT to be confused with Portland, Maine which is 4000 km to the east and nowhere near the eclipse).  Portland is a small but cosmopolitan city and quite pleasant, but will miss totality.

As for me, there are a couple of things to mention.  I 've been rather inactive in photography for a couple of years, but personal circumstances have changed in a favorable direction so this will change as well. A couple of years ago I put a lot of effort into planning out how to photograph the eclipse, including formulating grandiose plans I couldn't possibly have executed for photographing in three focal lengths times three frequency bands (UV/vis/IR).  I plan to move forward with much more modest plans and to put in some time practicing so I'm ready.  I also may wish to collaborate with an astronomical group when the time comes, depending on the feasibility of arrangements, equipment borrowing, etc.

At this time my plan is to to rent a recreational vehicle, drive north to the eclipse path (I'm in California), and camp at a predetermined location, preferably with like-minded others to collaborate with.  Depending on the level of interest, people may want something more formalized than that, and perhaps may have other ideas on where to observe the eclipse.  However, any reservations for lodging would need to be made very soon.

[Øivind Tøien]

The partial solar eclipse that I was lucky to catch this spring in interior Alaska was posted here:
http://nikongear.net/revival/index.php/topic,2980.msg41281.html#msg41281

[Jakov Minić]

Bill, your idea is great!
Surely to be discussed in the months to come.
Personally, I find it very difficult to book so much in advance...
Thanks, Jakov

[pluton]

Agree that the eclipse is an excellent opportunity for a Nikongear field trip.
I'm in Southern California(about 15 hours of leisurely driving away), and have planned to make central Oregon my eclipse destination, based mainly on the weather prospects.  I also prefer to see it a 'natural' setting.  Aside from the sun and sky, I also wish to be in a place where I can see the shadow travel across the landscape...it moves really fast, but with an expansive view it can be seen.
I'm hoping to make a location scouting trip at some point, perhaps in the spring of 2017.
I'm looking at the idea of visiting the path of totality on public land, probably U.S. National Forest, which carries minimal restrictions on use.

[Bjørn Rørslett]

I definitively would be interested to attend.

What about renting a mobile home? Seems these are pretty ubiquitous "over there".

[black_bird_blue]

Do you mean a "static caravan" or a "camper van"? There may be some language ambiguity here...

[charlie]

I suspect the reference is to an RV/Motor Home.
Yes, there are plenty of places they can be rented from over here.

[pluton]

The local terminology is "motor home', or 'RV'...RV being the most common.  Abbreviation for Recreational Vehicle. 
Edit: Charlie beat me to it.

[pluton]

This link takes you to a strip map of the TSE's entire path across the United States.  The map is zoomable and downloadable, and has logistical commentary in boxes.
http://eclipse-maps.com/Eclipse-Maps/Welcome.html
 I'm still looking for an eclipse path map, Garmin GPS-compatible(GPX file, right?),  that can be loaded into a Garmin units for direct display.

[Bill De Jager]

Thanks for all the expressions of interest!

Here's my assessment of some of the logistical issues:

1.  All lodging will be taken well in advance, except perhaps the most overpriced AirBNB offers or the most godawful bedbug-ridden dumps.

2.  All camping locations capable of being reserved will be taken far in advance.

3.  All other designated camping locations will be taken some days in advance.  I had figured on getting to a campsite by the preceding Wednesday but that may not be good enough.

4.  Camping on unimproved sites on public lands in remote areas is usually allowed, but the exceptional interest likely to develop may result in temporary restrictions.  Good sites will be taken in advance by locals.

5.  Such remote areas will be next to dirt roads so dust on optics will be an issue unless it has just rained (unlikely).  My usual tactic of getting off the maintained roads onto jeep trails using my four-wheel-drive truck won't work if one has an RV with poor ground clearance.

6.  Individuals attempting to set up for or actually photograph the eclipse with reasonably capable equipment in a popular location may be subject to friendly but disruptive interrogation by interested bystanders. These folks may also touch equipment or knock it out of alignment (in the very worst cases knocking it over though clumsiness or stealing it).  Thus, safety in numbers.  A small crowd of photographers/astronomers can fend off the inquisitive politely or take turns providing short or longer answers as feasible.

7.  My wife suggested renting a cabin having a suitable yard, to allow setup and photography while being relatively unmolested.  Of course there is always the question of renting a place sight unseen when considerations of visibility are so critical.

8.  While I recommend selecting a general location based on average weather conditions, one much be prepared to move a long distance if weather condition deteriorate unexpectedly.  Central and eastern Oregon are relatively clear and dry in August, but from time to time the North American Monsoon will progress farther north than usual and cause thunderstorms.  This kind of weather will also create atmospheric turbulence with its harmful effects on highly magnified images. 

Finally, a minor language note.  Technically, a "mobile home" is a manufactured home which could potentially be moved to a new location eventually via lorry/truck, while a "motor home" is an RV.  However, many Americans who are native speakers of English nonetheless get confused over this terminology, so you can expect to often hear RVs referred to as "mobile homes' here.

[pluton]

Good notes, Bill.
I'll add my immediate thoughts in order.
1.  Agree.  Conventional lodgings will be heavily booked.  Portland will be the worst, Seattle probably not as bad.
2.  I'm not as confident as you that "all" camping locations capable of being reserved will be reserved, but there certainly will be crowds in most well-known locations.
3.  Wednesday might be overkill for a Monday event, depending on the scenic value of the location.  In many locations I'm sure your expectations are accurate.  Highly motivated commercial photographers and science folks will stake out their sites early.
4.  Agree, but the eclipse will only be of passing interest to most rural locals(who will not be photographing the event, except with cell phone cameras), many of whom will will be satisfied to watch the eclipse from the side of the highway and then go home.
5.   Yes...being away from the immediate vicinity of dust-generating dirt-road and dirt parking lot vehicle traffic is always a good thing.
6.  Agree.
7.  I had a similar thought.  Perhaps some ranch/property owner along the TSE path would be open to having a small, sane, controlled, intelligent, friendly group visit for a day or two.  But this requires advance arrangements which are difficult for those of us who live 900 miles away.  Perhaps something to consider for a scouting trip in the spring.
8.  Agree.  I fully accept the possibility that I may end up viewing totality at a nondescript turnout along the highway somewhere.
Due to the short approx. 2 minute totality, I personally place priority on viewing the totality directly/with binoculars, photographing it is secondary.  At best, I'd like to spend totality directly viewing while a [tracked if necessary] automated camera clicks away through a tele lens or telescope, while another intervalometer-controlled wide angle camera catches a landscape, eclipse, and sky. For fun, a mirrorless or video camera recording wide angle video with good sound would fill out the set.

[Bill De Jager]

Good points, pluton!

At best, I'd like to spend totality directly viewing while a [tracked if necessary] automated camera clicks away through a tele lens or telescope, while another intervalometer-controlled wide angle camera catches a landscape, eclipse, and sky. For fun, a mirrorless or video camera recording wide angle video with good sound would fill out the set.

I hope to have a 1600mm scope on an equatorial mount with a smaller scope riding piggyback, both with cameras. 

Then a couple of shorter lens/camera setups (think a regular 105mm and a UV-Nikkor on DX) on regular tripods to catch the extended corona which can go 5 degrees on each side of the sun.  The latter two setups could be aligned a few minutes before totality starts and that would be good enough. 

The above cameras would all be mainly controlled by software on laptops/tablets; otherwise it would be too difficult to make it all work and one would miss actually seeing more than glimpses of totality. Plus, a super wide angle view of the scene and a circular fisheye view of the sky in time-lapse would be great.  These cameras could be on intervalometers set in advance so they would not need attention.

If I can make all this work on trial basis then it would be possible to spend most of totality actually looking at the eclipse instead of fussing with gear; otherwise, I'll need to scale back. With a group, tasks can be split up making it all easier.  We could make it a collective effort and share RAW files afterwards.

Eclipse stuff worth photographing falls into several categories, including:

-Partial eclipse phases (could do a time lapse)
-Special effects just before totality (beads, diamond ring)
-Chromosphere visible brief moments at the beginning and end of totality
-Totality itself; try HDR to catch the huge dynamic range of the corona
-Shots of the people watching the eclipse
-Landscape and sky shots
-Reverse order of all these as eclipse unwinds, to catch things missed the first time
-As you mentioned, video.  In particular, video of the moving interference bands just before totality.

On another note, I read recently of someone who many years ago was looking at a total eclipse through binoculars when it ended.  The momentary tiny sliver of sun his eyes caught knocked him to the ground with shock and caused permanent degradation of vision.  One critical task for the group will be to start a timer (or two!) at the onset of totality and then to sound the alarm perhaps 10 seconds before it ends so people can revert to unaided vision.

Another task will be lighting tripods, etc. with red LEDs so people don't trip over them during totality.  The closest I've gotten to totality was 94% occlusion of the sun during the 2012 annular eclipse in the U.S.  The 6% lighting was eerie but very usable for getting around, but it'll be on the darker side of dusk once totality arrives.  Eyes should be as dark-adapted as possible when totality arrives and stay that way, so dim red lights are the order of the day.

[dslater]

Not sure you really need an equatorial mount for the eclipse. Even at full totality, it's not that dark. Your exposures are still going to be fractions of a second, so the earth's rotation won't be an issue.

[Bill De Jager]

Not sure you really need an equatorial mount for the eclipse. Even at full totality, it's not that dark. Your exposures are still going to be fractions of a second, so the earth's rotation won't be an issue.

In amateur astrophotography, the longstanding rule of 600 (or a similar number) is traditionally used to determine the longest exposure that won't produce star trails.  Divide the focal length of the lens by 600 to get the shutter speed.  However, using this rule with high-resolution digital still can result in smearing across several pixels.
 
The extreme bracketing I had in mind means some surprisingly long exposures since the corona spans around 10 stops of exposure.  Check out the exposures listed here: http://www.mreclipse.com/SEphoto/SEphoto.html.  At ISO 800 (to keep noise nice and low) and f/8 (the larger scope of the two I intend to use) we're looking at 1/2 second to catch the faintest parts of the corona.   

The sky appears to rotate 21600 minutes of arc in 24 hours = 15 minutes of arc per minute of time or one minute of arc every 4 seconds.  I'll probably use a D7200 on the 1600mm scope and a D810 on the 600mm scope to get two very different views.  A 1600mm scope has a field of view on full frame of 1.5 degrees = 1 degree on DX.  A D7200 has 6000 pixels on the long dimension of the sensor which works out to 100 pixels per minute of arc.  That means 25 pixels per second of motion and significant loss of acuity even at 1/8 of a second.

I'm also concerned with keeping the scope pointed in the right direction automatically over a period of time.  When I shot the annular eclipse in 2012 with an angle of view equivalent to 1000mm on full frame, I had to periodically move the lens to follow the sun as the eclipse progressed.  Automating this process removes one more task and source of frustration.  It's true that equatorial mounts will drift a bit in a cyclical fashion due to mechanical imperfections inherent in a geared system, but this is a small factor compared to the apparent movement of the sky and is not an issue for a relatively short exposure.

[pluton]

On another note, I read recently of someone who many years ago was looking at a total eclipse through binoculars when it ended.  The momentary tiny sliver of sun his eyes caught knocked him to the ground with shock and caused permanent degradation of vision.  One critical task for the group will be to start a timer (or two!) at the onset of totality and then to sound the alarm perhaps 10 seconds before it ends so people can revert to unaided vision.

An excellent idea.  Everyone please be forewarned.
At best, I'll have acquired an apo refractor of modest power (approx. 800mm equivalent) and a tracking mount. The next lesser setup would be my 300/4 Nikkor, w/ or w/o an extender plus tracking. The next lower would be the 300 w/o tracking.  My biggest concern is vibration from the D800.  I may acquire Fujifilm XT-2 in the months ahead, which, If I'm not mistaken, would allow vibration-free intervalometer shooting with the electronic shutter.  I'll have to research that more.