meteor

THE SCIENCE AND ART OF PHOTOGRAPHING METEORS Marsha Kirschbaum and Rick Whitacre

bbbbbbbbbbbbbbbbbb.jpg

INTRODUCTION

Of all the night sky phenomena to watch and photograph, a meteor shower is among the most exciting. The anticipation and surprise of those tiny bits of cosmic dust streaking

across the sky is thrilling. To capture them in camera is even more amazing. This article gives the photographer, whether beginner or advanced, the tools necessary to take amazing meteor shower images. We will also provide ideas on how to incorporate meteors into compelling compositions.

WHAT IS A METEOR SHOWER?

When earth’s orbit takes it through streams of cosmic debris from a disintegrating comet or asteroid (in case of Geminids or Quadrantids), we have a meteor shower.

These showers occur the same time each year as our earth revolves around the sun. When the earth passes through the greatest debris field of a given shower, it is called the Peak. Some showers are better seen in the Northern hemisphere; others in the Southern hemisphere; and some worldwide.

A following table lists the major meteor showers for 2019. Not all meteors come from the annual meteor showers. They can show up randomly at any time. For purposes of this article, we will focus on photographing the major, annual showers.

Meteors often appear to be coming from a single point in the sky, called the radiant point. Meteor showers are generally named after the constellation they appear to come from.

(Perseids from constellation Perseus; Geminids from constellation Gemini, etc.) Most meteors are smaller than a grain of sand, throwing off intense streaks of light as they burn

up in the earth’s atmosphere. Meteors enter the earth’s atmosphere at speeds ranging from 25,000 to 160,000 mph. That’s fast!

bbbbbbbbbbbbbbbbbbb.jpg

HOW DOES A CAMERA CAPTURE A METEOR

In order to capture those flying bits of cosmic dust, the settings in our cameras must be optimized to ensure success. This means the optimum sensitivity to light: Wide enough

aperture (small F-stop) to allow the most light onto the sensor as possible; Enough sensitivity (ISO) to record the meteor streak in its entirety, but not blow it out either; and

sufficient time (shutter/exposure) to capture the complete streak without clipping it.

These settings will be discussed in detail under Camera Settings.

Another factor for success in capturing meteors is to have the meteor pass within the camera’s field of view! That is why using a wide-angle lens is also recommended. It is unfortunately a very common refrain to hear, ’’Oh, if only my camera was pointed in the other direction.“

GEAR

Camera related equipment.

• DSLR or Mirrorless Camera that allows for interchangeable lenses. Since most meteors are fairly faint, ISO settings of 3200-6400 are common. For best results, you need a camera body that can shoot at those ISO values with manageable noise levels. Since you want to cover as much sky as possible to increase your chances of capturing meteors, you also want a wide field of view. Full-frame cameras are often best for both their ISO capabilities as well as their field of view with any given lens, but many fantastic images have been captured with crop-sensors.

• Sturdy tripod – The tripod should be sturdy enough to hold your camera and not shake in a breeze or light wind. If conditions are very windy, a heavy bag – like your camera bag – is useful to weigh it down.

• Wide, fast lens (2.8 or faster) – A 14 mm lens allows for a nice wide field of view, which increases the probability of more meteors in your frame. While one can go wider, know that the meteor streaks will be smaller relative to the

size of the frame. Faster (wider aperture) lenses allow for more light to reach the sensor. If shooting with a longer lens, say a 24mm, then the wider the aperture should be, to allow for more light and pinpoint stars. (see camera settings discussion)

• Intervalometer / Remote Timer – This device will allow for setting the exposure time and to continuously fire one exposure after another at intervals of 1 second (to allow the camera to write to the memory card). This ensures the probability that most meteors that fly in front camera will be captured.

• Large memory card - Meteor showers at Peak can last for more than a couple of hours. In fact, daylight often terminates the ability to see the meteors and that’s when to call it quits. Make sure to start with a cleanly formatted, empty

memory card that will hold several hour’s worth of exposures for your particular camera.

• Spare batteries or battery pack – The colder the temperature is, the quicker the batteries run down. This is particularly true for the Sony cameras. In colder temperatures, keeping batteries in a warm pocket next to your body will extend their life a little more. Even better is a battery pack, which will allow for longer uninterrupted exposures (more meteor capture potential). Speaking from experience, usually the biggest meteors fly past when one is changing the battery.

The battery pack becomes even more important if one is planning to compile images into a timelapse, where gaps are problematic.

• Headlamp / red light – A headlamp is a good way of keeping hands free for camera settings, foreground focus or safely wandering off to the bushes for some private time. A red light is recommended so that night vision is kept intact. However, please, please be courteous with your light so as not to destroy fellow photographers’ night vision or image capture. Try to ask if light is ok before turning it on.

• Planisphere or Apps (TPE, Photopills, Stellarium) These tools are very helpful to guide and familiarize the photographer with the night sky. The Planisphere is a round wheel with the map of the stars in the night sky. It can be adjusted

by month, date and time to show the stars at that time. The beauty of the Planisphere is that it is accurate and does not need batteries. I keep one in my car at all times. That said, there are many apps for desktop and mobile devices that assist in planning for meteor captures or any astro landscape

photography for that matter. These are particularly helpful if one cannot scout the location before hand. The more you learn to recognize the stars and constellations the easier it becomes to make last minute on-site adjustments. This recognition comes the more one looks at the stars.

PLANNING

• Calendar – The most important item on the planning checklist is the Meteor Calendar. When do the major meteor showers occur and when is the peak (when the earth passes through the heaviest part of the debris field). This is when most of the meteors are likely to occur and is measured in meteors/hour. Most meteor showers are best seen after midnight, when the radiant point of the shower is high in the sky. When planning the best night to go out, be aware that some sites give the date as the “night of” the peak, and others show the actual date of the peak, which is typically after midnight: ie. the next morning.

A list of the major meteor events is listed below (showing the night of the peak):

bbbbbbbbbbbbbbbbbbbb.jpg

• Moon phase – No matter how dark the skies, if the moon is up, the skies will be too bright to see all but the brightest of the meteors. The light from the moon can be mitigated somewhat by photographing at a site where there is a large hill or mountain between you and the moon.

• Dark skies – The darker the skies are, the better chance your camera has of capturing a meteor. There are mobile device apps and websites that will let you know about light pollution and how dark the skies are at or near the area you wish to photograph (see Handy Links at the end of this article) . Clear Dark Sky (www.cleardarksky.com) is a desktop web page I use all the time for forecasts regarding weather and seeing.

They have maps showing many astronomy sites. I bring up their maps and click on the site closest to where I

want to photograph to obtain information about seeing (how clear the sky is based on moisture, light pollution, etc.) Another mobile app, I just started using is called Astrospheric (www.astrospheric.com), which combines the Clear Dark Sky info with satellite maps showing cloud cover and forecasted

movement of those clouds. Dark Site Finder (www.darksitefinder.com) has good maps showing light pollution.

bbbbbbbbbbbbbbbbbbbbb.jpg

• Weather – Of all the variables not under our control, the weather can quickly put a stop to all meteor photography. Even after you have chosen your meteor shower, found a dark enough sky site, the weather has to be constantly

monitored right up until you walk out the door to photograph. Anything that obscures the sky (clouds, fog, smoke) makes photographing meteors very difficult.

PRE-VISUALIZATION EXAMPLE

The easiest way to address these subjects is to walk through a real-life scenario in which we collaborated to photograph the 2018 Geminid Meteor Shower. Checking the meteor calendar for the year, the peak of the Geminid Shower was

predicted for the 12/14/2018. Both of us live in the San Francisco Bay Area, which is pretty light polluted. To find darker skies, we would have to travel. A weather system

was incoming and clouds were predicted along the coast during the Peak of the Geminid shower.

bbbbbbbbbbbbbbbbbbbbbb.jpg

This meant that we would have to turn our dark sky search eastward to try and get ahead of the weather system. According to Dark Sky Finder, Death Valley National

Park, a seven hour drive away seemed like a good spot. (See Figure 1) Checking weather, particularly for cloud cover, there was a window of a couple of hours for mostly clear skies during the time needed. The hourly weather report indicated that later in the morning the percentage of cloud cover would increase. This would have to be closely monitored for changes right up until we got ready to depart.

Next, we checked Stellarium for the radiant point or where the meteors would appear to come from. Both of us knew at the time of the peak, the radiant would be high (See Figure 2), nearly overhead. Since we both love astro landscape photography, we wanted a foreground in our images. This would be a challenge with the radiant point so high in the sky. We came up with the idea of using tree canopies as our foreground, similar to what Marsha had done previously with the Milky Way.

As luck would have it, Comet Wirtanen would be visible during the peak as well. Could we get the comet in the same field of view as the radiant point? Stellarium showed us

that we could. Figure 2 below shows the night sky and the field of view with a Rokinon 14 mm 2.8 lens. The Geminid Radiant and Comet Wirtanen, would easily fall within a 14

mm. frame (on a full frame camera). You can also see that the Radiant for the meteors would be nearly straight up at midnight!

bb.jpg

Since the Radiant and Wirtanen were both going to be nearly straight up, we needed to find tall trees to get under to shoot up from. Now, where do you find trees in a desert, like

Death Valley National Park, where we wanted to shoot? The Mesquites are too bushy to see through and the Joshua Trees were too far away to travel to from our base ofoperations in Furnace Creek. Palm Trees would have to do, and they presented a nice silhouette.

This is where Google Maps is a useful tool. We turned on the satellite view and zoomed in looking for likely Palm tree groves. (See Figure 3) These groves, of course, would have to be investigated when we were actually on site.

bbb.jpg

We now had the beginnings of a plan of action for the 2018 Geminid Meteor Shower. I say beginnings, because, once on site, many variables, like fences, No Trespassing signs, dead trees, etc., would make adjustments necessary. If at all possible, it is very important to scout in the day time. In this case, the palm trees at this location were bathed in landscape lights and not ideal. Since we gave ourselves time to scout, however, we did manage to find some trees nearby that worked very well!

bbbb.jpg

CAMERA SET UP RECOMMENDATIONS

A. Set camera to “RAW” for greatest flexibility in post processing.

B. Set ISO to 3200 or 6400 depending on how well your camera handles noise.

For cameras like the Sony A7S, you can even use ISO12,800.

C. Install a large, empty memory card. You need room for 120-180 images for

every hour of shooting.

D. Set the exposure mode to Bulb and connect your intervalometer (remote timer). If your caera has a built in intervalometer that will take back-to-back 20-30 second exposures for many hours, you can use that. Unfortunately, most cameras do not yet have built-in intervalometers capable of doing this. Test it before leaving home!

E. Use a wide angle lens to capture more of the sky. Focal lengths between 14-24mm (full frame equivalent) are recommended.

F. Set the Aperture to its widest setting; ideally f/1.4 - f/2.8 for capturing meteor streaks. You may want to stop down 1-2 stops for a sharper foreground image for blending in later, but shoot wide open for the meteors.

G. Intervalometer settings:

a. Delay: 2-5 seconds to give you time to secure the intervalometer. b. Exposure: 15-30 seconds to avoid clipping any meteors while not streaking the stars too much. We use the 400/Equiv Focal Length rule. Others use the 500/FL rule, which is a little looser: https:// shuttermuse.com/how-to-avoid-star-trails/ c. Interval: 1 second between shots. d. Number: Set to “- -“ which is below 1 and stands for infinity. The timer will continue until you stop it.

e. Beep: Off. Please don’t disturb others with the constant beeping.

H. Set the lens to Manual Focus and focus manually on the stars using Live View.

I. Set White Balance to something between 3500-4000K (or Incandescent) so the images will look natural when viewing on the LCD. When shooting RAW, it really doesn’t matter, but that is what we do.

J. Use the lens hood to reduce dew buildup on the front element and minimize impact from stray lights.

K. Make sure that LENR (Long Exposure Noise Reduction) is off.

L. Remove any lens filters to reduce stray light bouncing around.

M. Turn off Image Stabilization (IS, VR, OSS) since you are on a tripod.

N. If using a DSLR, turn off mirror lockup.

O. Install fresh battery or connect your extended battery pack for all-night shooting. If using batteries, have 1-2 spares warming up in your pocket.

COMPOSITION

As in most photography, composition is the most important aspect. Compose your scene with a strong, interesting foreground with as much sky as possible. While meteors can be

seen in all portions of the sky during a shower, most will originate from the radiant. If you want to create a composite image with several meteors aligned to the radiant (as in

the first image of the 2016 Perseid Meteor Shower), you will want to include the radiant in your composition. Since the radiant will appear to move during the night due to the

earth’s rotation, you will need to visualize where the radiant will arc through your chosen composition and make sure it stays in or near your field of view for most of the night.

There are many desktop and smart phone apps that can help you with this. Additionally, to help with aligning the meteors around the radiant in post-processing, try to include the

North Star (Polaris) in your composition if possible. The North Star will not move significantly during the night in the Northern Hemisphere. Your foreground, movement of

the radiant, and location of the North Star are important considerations when selecting the camera orientation if planning to do a radiant composite(See Time Shift Comparison). If

you plan to collect random meteors, the position of the radiant and the North Star is less important. Both vertical and horizontal orientations can be used.

Since the camera settings for meteors are very similar to those used to capture the Milky Way, you can combine the Milky Way with meteors very effectively. The Perseids, for

example, originate in the northern arm of the summer Milky Way. With a little luck, you might be able to capture a meteor with the Galactic Center of the Milky Way.

TECHNIQUE

Once a composition has been determined, take a test shot at high ISO to confirm. Make sure your camera is level and the tripod stable. Focus on the brightest stars using 10X

LiveView, or set the focus manually on the lens at the pre-determined infinity or hyperfocal locations. Confirm sharp star focus on a test image. Zoom in and use a Hoodman or or magnifier if available.

With composition and focus set, we recommend you take a low-ISO, long exposure shot to have for possible future compositing in Photoshop. The stars will streak, of course, but

this will give you a low-noise, well lit foreground image to composite into your meteor shots in post-processing. This is especially effective if the moon is just setting or just

before twilight begins and the sky is still providing light on the foreground.

Confirm your camera settings for meteor capture (Bulb, high ISO, wide open aperture) and set your intervalometer to take an infinite (or very large) number of shots of 15-30 second duration (400 / FL rule) with 1 second between exposures. Put a fresh, full battery in the camera or hook up an external battery pack for all-night power. Insure that you have a large, empty memory card in your camera.

Start the intervalometer and insure that camera is functioning and taking successive images. Check the lens periodically for dew buildup and gently wipe it off if it appears. Periodically check your battery level and swap in fresh batteries as required. Lay back and enjoy the show!

After your sequence is done, it is always a good idea to take another low-ISO, long exposure image to use for blending in post-processing. This is especially true if your camera may have been bumped or if the moon has risen and provided some light on the foreground.

POST PROCESSING

Post processing your meteor images breaks down into the following steps:

A. Import your images from the meteor shower into your favorite image processor (like Lightroom). Select one of the images from near the middle of the night and process it

like you would a Milky Way or star image (white balance, highlights, shadows, noise reduction, clarity, etc). Copy these settings to all of the other images in the series.

B. Review every image in the series and mark those that contain meteor streaks. You can use the Lightroom “star” system or any other system that allows you to separate the

images with meteors from all the others that do not contain meteors.

C. Export all the images with meteors into Photoshop as Layers. From Lightroom, this is done by selecting all the images that have meteors and going to Photo > Edit In >

Open as Layers in Photoshop...

D. Change the Blend Mode of all the layers to Lighten Mode. This will result in a very messy image, but one that shows all the meteors. This will start to give you an idea of

what your image might look like. The image is messy because the stars from each layer are showing through and since the stars moved from one exposure to the next, they appear over and over again in different spots. We will get rid of all but one of the star fields in the following steps.

bbbbb.jpg

E. Choose one of the layers to be the Base Layer. This can be the layer with the best meteor or a layer where the Radiant is in the best spot, etc. Try to pick a layer that

does not have any airplane trails for your Base Layer. It makes life easier. We recommend picking one from near the middle of the shoot if possible.

F. Change the Blend Mode of the Base Layer to Normal Mode and rename it to “Base Layer” so you don’t get confused. Move it to the bottom of the Layer stack.

G. Decide if you want to composite all the meteors as they occurred during the night or “time-shift” them so all of the meteors point back to the radiant of the Base Layer.

Time-shifting can create a more uniform image, but non time-shifted images will have more meteors (because some will get time-shifted out of the frame). Perform the timeshifting if desired (see section below for instructions).

H. Make all the Layers invisible (turn off the eye ball) except for the Base Layer and the first meteor layer you want to work on. Click the "Add Mask" icon or go to menu

Layer > Layer Mask > Reveal All. Get a small, medium edge brush, and using black "ink" paint over the meteor in this layer mask until it disappears. With the layer mask

still selected, do an Image > Adjustments > Invert (Shortcut Cntr/Cmd-I) to invert the layer mask to reveal only the meteor.

I. Correct for any halo that might show up around the meteor. Depending on what time of night, or what portion of sky the meteor came from, you may need to adjust it to get to blend into the Base Layer properly. The biggest problem is usually a bright halo around the meteor. To fix this, add a Curves Adjustment Layer as a Clipping Mask to the layer (go up to the Layer menu in the Menu Bar and choose New Adjustment Layer, select Curves, and check the box “use Previous Layer to Create Clipping Mask”). Then, adjust the black point on the curve until the halo disappears.

bbbbbb.jpg

J. Repeat Steps H and I for all the other meteor layers. When complete, you should have only one star field (from the Base Layer) with all the meteors showing up from the

other layers. Take a good look at your image and decide if any of the meteors are distracting (like they cross each other) or are too close to the edge, etc. Try turning their layer visibility on and off to see if your image is helped or hurt by having it.

Leave the eyeball off if you don’t like it.

K. Once you are completely happy with your meteor composite, Flatten the image and Save it. An image with 30-50-meteor layers is too large to save without flattening it.

L. Blend in one of your lower ISO, longer exposure, images for a cleaner, brighter foreground if desired.

M. Finish processing the image by dodging, burning, cloning, and adding clarity, contrast, noise reduction, etc as desired in either Photoshop or Lightroom.

TIME-SHIFTING METEORS

If your composition includes the North Star, locate it. This will be the reference for timeshifting all the other layers to match the Base Layer. If the North Star does not appear in your composition, estimate where it is and use that side or corner as a rough approximation. If you are comfortable with adding more canvas to your image, you can add enough canvas to include a "virtual" north star for reference and use that.

Turn off all of the layers except for the Base Layer and the first layer that you want to time-shift into place. With the first meteor layer highlighted in the Layer Palette, go to

menu Edit / Free Transform (shortcut Ctrl/Cmd-T). In the middle of the layer is a rotation mark. Move that mark to the North Star and drop it there. Now, when you rotate this layer, it will rotate around the North Star, similar to what happened during the meteor shower. Rotate the layer until the star pattern of this layer lines up with the star pattern of the Base Layer. It won't be exact due to lens distortion, but you should be able to get close. Double check by seeing that the meteor on the layer you are rotating points to the same area as the one on the Base Layer. When happy with the alignment, click the checkmark symbol near the top to complete the Transform. Now add a mask to that layer, use a black brush to paint over the meteor (make it disappear) and then invert that layer mask to make the meteor re-appear, but hide everything else from that layer. If there is a halo around the meteor, use a Curves Clipping Mask as detailed above.

Once satisfied with the first meteor, make the next meteor layer visible and repeat the Transform process to time-shift it into place. Mask out the meteor, invert the layer mask so that only the meteor shows, and use a Curves Clipping Mask to blend if necessary. Repeat for all the rest of the meteor layers.

It is not uncommon to have meteors that get time-shifted right off the edge or get placed on top of mountains and trees. Unfortunately, you will have to delete these layers and move on to the next one. If you find that you are throwing too many meteors away, you may want to start over and pick a new Base Layer to align all the other meteors to. This is the reason it usually works best to pick a middle image as your Base Layer if possible.

bbbbbbb.jpg
bbbbbbbb.jpg
bbbbbbbbb.jpg

ABOUT THE AUTHORS

Marsha Kirschbaum is a San Francisco Bay Area fine art landscape and astro landscape photographer. She says about her night photography “The mystery and magic of night

photography is especially powerful for me. I would like to awaken the viewer through my night photography to its visual possibilities, the excitement and wonder of a meteor

shower, the joy of the sparkling stars reflecting in a mountain lake or the quiet serenity the night’s dark silence can bring. The natural world and its connection to the universe at

large fills me with wonder and gratitude. We have been given the gift of this amazing planet and through my photography, I hope to share its beauty, inspire a hike, or entice a relaxing moment gazing skyward at the stars.”

Marsha’s photography can be found at:

https://www.marshakirschbaum.com and

https://www.flickr.com/photos/mkirschbaum/

Rick Whitacre is also based in the San Francisco Bay Area and focuses on landscape, night, and astro landscape photography. Rick was drawn to night photography both for

the technical challenges it presents and the ability to photograph scenes that have been shot over and over again in the daytime, but become completely different at night. In

addition to shooting meteors, Rick has been known to chase solar and lunar eclipses and other amazing astronomy events.

Rick’s photography can be found at:

https://www.whitacrephotography.com

https://www.flickr.com/photos/ricoshanchez/