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So you want to -- photograph a lunar eclipse
For this article, I use the eclipse on April 15th 2014 as an example and as a location I have picked San Francisco. The path of the moon & the timing is dependent on your own location and you will have to make adjustments for that.

Here are some examples and a bit of background of the various attempts : www.ipernity.com/doc/stargazer95050/album/389379

WHEN & WHERE is answered easily : every year, NASA summarizes all eclipses on one page. Here is the link for 2014 : eclipse.gsfc.nasa.gov/OH/OH2014.html. The detailed PDFs contain maps, showing where each eclipse will be visible. A total lunar eclipse is visible -- at least to some extend -- on approx 1/2...3/4 of the world. Therefore your chances of seing one without traveling are pretty good.
To improve the planning for a specific location, I recommend a "Holy Trinity" of free tools : stargazer95050/23964727.

April 15th 2014 :
On the US west coast (PDT = UTC - 7), the eclipse will start on APRIL 14TH !!
moonrise 19:28 April 14th PDT -- Az/Alt = 102°/0°
P1 is at : 21:53 April 14th PDT -- Az/Alt = 126°/24°
U1 is at : 22:58 April 14th PDT -- Az/Alt = 141°/33°
--------------------- midnight
U2 is at : 00:06 April 15th PDT -- Az/Alt = 160°/39°
greatest : 00:45 April 15th PDT -- Az/Alt = 172°/41°
max altitude 41.3° @ 01:16
U3 is at : 01:24 April 15th PDT -- Az/Alt = 184°/41°
U4 is at : 02:33 April 15th PDT -- Az/Alt = 205°/37°
P4 is at : 03:37 April 15th PDT -- Az/Alt = 222°/30°
moonset 06:45 April 15th PDT -- Az/Alt = 256°/0°


HOW TO OBSERVE : That also is easy. Bring a lawn chair, dress warm and add hot coco or a camp fire. If the moon is very high in the sky, stretch out on a recliner to look skywards without straining your neck. For added magnification any kind of optical scope or opera-glasses will do.

HOW TO PHOTOGRAPH : The first suggestion is to prepare for such a shoot in advance. PRACTICE shooting the moon -- full or otherwise. That experience will help. Chances are good, you already have done that :-)
You can follow one of several approaches -- based on your taste and the amount of time & effort you want to put into this


The "scenic route" shooting a wide-angle with landscape -- you first have to check, if that is a viable option. Especially in winter, the moon rises so high, it is impractical to compose such a shot. For example during the eclipse in 2010, the altitude of the moon reached as high as 75°. That's nearly straight overhead.

For the eclipse this April (2014) here in San Francisco, the moon will reach it's peak altitude during the eclipse and will be 41.5° high in the sky. Add a few degrees to better frame the scene and you need VERTICAL FOV of 46° .... 53° (28mm...24mm focal length on FX, 18mm...15mm on DX) www.nikonians.org/reviews?alias=fov-tables
If you want to be able to capture the entire path of the moon from moonrise, the eclipse plus the moonset, you would have to cover 155° horizontally in a single shot. That means, you would need a rectilinear fisheye lens. Or use 2 cameras with 24mm FX each. Here my simulation using a perspective projection : /stargazer95050/29691555-- a lot of sky and a lot less moon & skyline. Other people's examples of a CONTINUOUS long exposure of a lunar eclipse : TLE2000Julmux-s & TLE2000Jan21trail1x

In my opinion, this approach is especially attractive, if the moon rises or sets during the eclipse and you can combine that with your favorite landmark or city skyline. Achieving the best balance will require some try & error, especially if the total eclipsed (and thus very dim) moon is close to the horizon.
Eclipses during twilight (regardless the angle of the moon) pose similar challenges as the changing brightness of the background will impact the exposure and in the worst case, will extinguish the faint light from the eclipsed moon

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How close do you want to or "need to" get

In most cases you already have a lens and the size of the eclipse will be the size of any other full moon -- just take a test shot and see if you are satisfied with that magnification. RENTING A LENS just for this occasion is a good idea. Just hurry before others have the same ...
Below, I have compiled images of the moon with various focal lengths. All are uncropped and the focal length indicates the FX full-frame equivalent :
A 700mm lens in front of a SLR with a DX sensor is a nice combination to capture moon plus surrounding landscape or stars Such a setup also is very easy to transport -- and much lighter and cheaper than a 600mm f/4D Nikkor.
At the other end of the scale is a still portable (over short distances) 10" reflector telescopes with over 2000mm focal length. That meets and even exceeds the requirements to fill a SLR sensor : For FX ~2300mm are needed and with a DX-camera, a 1600mm physical focal length is required to fill the sensor top to bottom with the (full) Moon.


The FOV also depends on the kind of photographic approach you want to use -- the numbers above are for "moon closeups". If you want to include landscape, that view will determine the lens you choose. My suggestion is to shoot the scene from a distance with a long tele. The moon's visual diameter is 0.5° and if you lens has a horizontal 5° FOV (300mm, DX), the moon occupies a respectable 10% of that. OTOH, if pick a 100mm lens on a DX body, the moon will the 1/40 the width of your scene.

For my location on the US west coast and during this eclipse (2014/04/15), if you want to go with the static "Piece of the Sky"-approach (without tracking) the necessary FOV will be huge -- I've simulate the path of the moon with STELLARIUM or TPE and entered time & date of the eclipse phases.
If you want to capture the eclipse from beginning to end : horizontal angle (Az) between P1...P4 is ~100°. Even if the imaging area is reduced to U1...U4, the horizontal FOV still is ~65°. The vertical movements are much smaller : the lowest position of the eclipse is at 24° above the horizon, the highest is 41.5°. Or just 33°...41.5° for the U1...U4
==> A FOV that is 65° wide horizontally means, the moon still will be tiny and in this case, that doesn't make any noticeable difference between a static LANDSCAPE-shot and the static SKYSCAPE shot. For this eclipse there is virtually no difference to a landscape shot with a 24....28mm lens.
NOTE : The further away you are from San Francisco, the more important it is to do your own math on the moon's path & timing.


If you want to go with the "Piece of the Sky"-approach and use either Alt/Az- or EQ- tracking, my quick simulations show a window the size of 2°x3° -- with proper guiding (or good tracking) can capture the entire eclipse and show the moon as it moves across the sky / through this frame. A sample setup would be a 102ED (700mm) with a FX sensor. Or a shorter focal length with a DX-sensor. Here is a look at what I have in mind : www.youtube.com/watch?v=y5tpLCkRyY4 & youtu.be/KBBFzHLvrvA



TIMELAPSE with (cityscape) foreground.
This is an interesting proposition and I have done that before when the eclipse occurred close to the horizon. This time I don't have that opportunity but you might.
For the April 2014 eclipse, it would requires a (very) wide-angle lens but before you try, keep the following in mind : your vertical FOV is much larger than the moon, depending on the max altitude. For this eclipse & my location, the moon is approx 100 times smaller than the vertical FOV -- 50° FOV and 0.5° diameter of the moon. You will be able to see the moon and even more so, you will be able to see the change in the sky & halo surrounding the moon. But seeing the details of the moon isn't possible with such a wide FOV.
An often overlooked factor to consider is the DOF, especially when you use a long focal length. If you choose a 70mm lens, you're not going to have any trouble (hyperfocal distance ~60m at f/4) but the image of the moon is small (~1/40th the width of the FOV). OTOH, the hyperfocal distance of a D7000 with a 400mm lens at f/10, is 794.1m and the moon covers 1/7th of the FOV. During the eclipse, f/10 may be too dark but when you open up to f/4, the hyperfocal distance increases to 2.000m -- and that is more than the distance from Treasure Island to Embarcadero and suddenly your foreground is not in focus anymore. With even longer (my favorite 900mm f/8) lens, the subject will have to be 6.000m away to have both the moon & foreground subject in focus at the same time : run the numbers for your setup : dofmaster.com/dofjs.html.
And of course, there are technical aspects like the duration, prevention of dew, consistency in the exposure. I'll discuss those later as they apply to the other techniques as well.

Thin clouds & fog moving the scene are less of a problem if you plan to turn your sequence into a movie. If they are not obstructing the view, these can add welcome movements to anotherwise mostly static scene.
OTOH, if you shoot a timelapse and plan to stack that sequence into one image to show the moon's path, you should be wary of clouds & fog. Simple stacking will create a mess and removing them in post will be a lot of work.
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Close-up shots of the moon during the eclipse
You are familiar with photography and know the moon is a moving target. To get a closer look, you need some extra focal length -- maybe plug a tele-converter onto your zoom, rent a super-tele or switch to an even (physically) bigger telescope.
For a single shot of a bright full moon, you might get away with a handheld (super)-tele setup. But as the weight of the longer tele increases, that isn't a feasible option for repeated shots or large lenses.
With the eclipse, naturally the moon's brightness decreases and therefore your ability to hold the lens steady during the increasingly long exposures will diminish. Better use a sturdy tripod.

The tripod itself isn't sufficient -- you also need a tripod-head. You can use your existing setup and I don't want to start a shopping spree. But there are good reasons (other than lunar eclipses) to own a GIMBAL HEAD, especially if you own heavy tele-lenses and like sports, birding or stargazing. That combination allows you to balance the camera + lens setup, allowing for quick movements and you can move up/down without worrying about the (ballhead) accidentally slipping or tilting sideways (put a 10lbs setup on top of a ballhead and that sideways tilt happens easily). As you can see, at first I have used a ballhead & small telescope and later switched to a gimbal head & larger telescope. The gimbal head I use, has cost me ~$130USD -- not bad compared to $600 and more for similar items with the big, red logos on it. The "Sidekick" add-on (not a real gimbal) costs 75% more than a cheap but full-featured gimbal head.
Beside BALANCING, the gimbal heads also solve another problem many tripod heads have : VERY STEEP UPWARD ANGLES. The Manfrotto geared head capitulated at upward angles > 30° and wasn't able to handle 1/2 the weight the gimbal does. While this setup isn't something I recommend, it shows the possibilities and some remaining limitations : www.ipernity.com/doc/stargazer95050/19371119 -- that setup I use mostly for visual observation when portability & easy setup is paramount. With smaller scopes it also works satisfactory.

Sorry for the detour -- what I wanted to explain, that with a small investment you can boost your existing camera setup. And that investment is useful for more than just one task. And that small investment even can play with (future) big investments :-)


For many, getting a good close-up shot using their existing equipment is paramount. If you have a rental store, you may be surprised how cheap a 600mm f/4 can be had
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No Pain, No Gain -- it takes time/experience to master the increase in magnifications. And that is one reason, I suggest you to start practicing way in advance of the eclipse.
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The correct exposure to photograph the Dark Side of the Moon -- not really the dark side but the portions of the moon that are inside the Earth's shadow are much dimmer than the rest. Like Day & Night. And if you need a comparison in photography terms -- 16EV !! That's right the change is equivalent to 16 f-stops. And these changes are happening FAST : www.grelf.net/im/moon/EclipseGraph.gif ==> And now you see why even the most sophisticated cameras still have trouble with that kind of dynamic range. "Mr. Eclipse" has quantified the exposure suggestions -- but didn't quantify the rate at which the decrease occurs : mreclipse.com/LEphoto/image/LE-Exposure1w.GIF

That high dynamic range doesn't mean it is impossible -- it means YOU have to choose what is more important. OVEREXPOSE to see more details in the shadow or UNDEREXPOSE to see details in the highlights. OR DO BOTH. With software capable of controlling SLR/CCD cameras it is feasible to program sequences to capture images at various settings and insert "HDR-like" over- mid- & under-exposure combination into the flow.

This high dynamic range also means that when you start out with e.g. a 1/250 exposure @ ISO100, during totality, you need 2^16 = 65536 * 1/250 exposure. 260s isn't practical and naturally you will open the aperture (if you can) and increase ISO sensitivity (if you can), but even with a fast lens & high ISO, you still are looking at ~4sec exposure time (optimistic f/4, ISO1600).
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With exposure times that long, you cannot ignore that the moon is a moving object. And the longer your focal length, the narrower your FOV the "faster" is the moon's movement through your image.The "Rule of 600" is a simplification to avoid startrails but works here as well, but I tend to use a more conservative value of 500 instead. It is a a rule of thumb -- do your own match if you want to be certain.
500 / focal length [s] : The shortest exposure time obtained using this formula allows the moon to move 0.05% of the film diagonal.
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Memory storage is another item to plan ahead if you are planning a timelapse. Let's say, you want to capture the entire eclipse from beginning to end at a modest 30sec interval ==> 5.5hrs = 660 exposures. If you want to bracket exposures and shoot 3 HDR RAWs per 30s interval, you are looking at > 2000 images. A 32GB card may be just sufficient to capture that 3 x HDR scenario.
To simplify the shooting and also to avoid unwanted vibrations on the telescope, I shoot tethered and let a PC control the camera settings via USB cable. That way you also can transfer your files off the camera's card(s) before they are full.

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2 comments

CircadianReflections said:

Great write up! I'm not sure I'll be able to photograph it this year. I'll have to check the map to see if I will be able to view it from my back-yard. That may be my only shot at it this time.
10 years ago

Stargazer95050 said:

During the interesting part of the eclipse, the moon will be more than 30° above the horizon. Unless you have big old trees in your yard, it shouldn't be difficult to find a place on the lawn were you can see the moon without any obstructions blocking the view If you can see the (full) moon tonight, you shouldn't have any problems next month
10 years ago