March Night Sky

March is a transition month. Here in the Northern Hemisphere, the long dark nights of Winter are quickly giving way to longer days. Night sky photographers can look forward to the reappearance of the Milky Way core in March. But there are other potential events worthy of photographing, or just viewing, in the early Spring night sky. 

The Milky Way arching over the South San Juan Mountains (May, 2017). The pink glow on the left is from the town of Pagosa Springs, Co. Stitched panorama from 12 individual photos.

First though, the Milky Way. While our home galaxy is visible year round, beginning in March, the Galactic Center, the Milky Way “core” will be visible. This is perhaps the most dramatic and photogenic portion of our galaxy. The first prerequisite for good Milky Way viewing is a relatively dark sky, so we will need to wait until the recent Full Snow Moon wanes. Starting March 8, there will be periods in which the Galactic Center will be above the horizon with no moon interference in the early morning hours. Best viewing should be from March 9 through the 23rd, when the core will be visible in the hours before dawn. On the night of the new moon, March 13, the viewing time will be from about 2:39 until 4:54 AM (the beginning of astronomical dawn). After the switch to daylight savings time on the 14th, this window moves to 3:35 to 5:53 AM, which somehow seems a bit less onerous. The reward for early risers in Pagosa Springs will be a view of the Milky Way arching over the South San Juan Mountains. Spring is the best time of the year to see the full arc of the Milky Way, and in early spring it will be lower in the sky, allowing for better images of the landscape beneath the arc. 

There are other opportunities among the planets, and the stars. In the predawn hours of March 6 (and a few days before and after) is a good opportunity to see Mercury as it will reach its greatest western elongation from the sun. At about 5:25, Mercury will rise in the east and reach about 12° above the horizon before fading in the brightening sky. But it gets better, as Mercury will be within about a degree of the gas giant, Jupiter, and nicely aligned with Saturn as well. By March 9, Mercury will be much closer to the horizon (and more difficult to find), but Jupiter and Saturn will be joined by a young crescent moon. These will be close enough to the horizon to afford good nightscape opportunities. 

Jupiter and Saturn at their great conjunction on December 21, 2020. Also visible are Jupiter’s four Galilean moons. Exposure was at 1 second, f/2.8, 150 mm using an Olympus OMD EM1-Mk II (300 mm full frame field of view)

Meanwhile, Mars will be much higher in the sky, but will be quite close to the Pleiades open cluster in the evening sky. 

As winter turns to spring, so the winter constellations will gradually disappear. But in the late evenings of March, you can still find Orion and other familiar winter constellations. Look to the west a little before midnight, and Orion, and the bright star Sirius of Canis Major, will be low enough over the horizon to the west-southwest for nightscape photography. You might also look for the Winter Hexagon, featuring Sirius, Rigel , the Hyades, Capella, Pollux and Procyon in Canis Minor. 

Orion and the Winter Hexagon, as would be seen looking West-Southwest on March 15, around 11:40 PM, from Pagosa Springs. Screen capture from Sky Guide.

Finally, moonless evenings in early spring are the best time of the year to see zodiacal light in the Northern Hemisphere. Zodiacal light looks like a hazy triangle in the west, as darkness falls. Look for it along the path of the ecliptic. Find out more about zodiacal light at https://earthsky.org/tonight/zodiacal-light-is-glowing-pyramid-in-west-after-dark . By the way, I recommend EarthSky as a great website to keep up with heavenly happenings. To predict the locations of stars and planets, there are several great programs, including the free Stellarium, or apps such as Star Walk or Sky Guide for smart phones.  

Beyond the beginnings of “Milky Way season”, March skies have a lot to offer. Good viewing to you!

December Dark Sky Events

Saturn and Jupiter in the evening sky over Pagosa Springs, Dec 5, 2020 © Andy Butler

As we move towards the shortest day of the year, it’s a good time to think of night photography. There are a couple of significant events coming up that could be of interest to both photographers and stargazers. 

First, the Geminid meteor shower, one of the most reliable meteor showers of the year, will reach it’s peak on the night of Dec. 13-14. With the new moon on Dec 14, skies should be dark enough to see quite a few meteors. However, you should be able to see meteors any night beginning this weekend (Dec. 4).The Geminids appear to radiate from the constellation Gemini, which conveniently is above the horizon before midnight in December. The maximum activity should be after midnight in the early morning of December 14, with up to 75 meteors per hour visible. The Geminids are one of only a couple of major showers derived from an asteroid, 3200 Phaeton, rather than a comet. Look to the east for this shower. 

For best viewing of the Geminids or other meteor showers, find a relatively dark site. If you want to photograph a meteor shower, there are a few things to keep in mind. First, the number of meteors “visible” includes the entire sky, while even a very wide-angle lens is not likely to cover more than 1/3 of the night sky. So you are unlikely to capture more than one shooting star even in a minute-long exposure. Second, if you want to keep the stars as points of light, rather than streaks, you will need to limit your exposure time. A rule of thumb is to limit exposure times to 500 divided by your lens focal length (in full-frame equivalent). So, if you have a 16 mm lens (full frame) then 500/16 is roughly 30 seconds. If you think you will be making large prints from your photos, you should be more conservative, maybe using 20 seconds in this example. A good starting point is to set your aperture to f/2.8, shutter speed 30 seconds, and ISO 6400; basically the same as you would use for Milky Way photos. To increase your chances of getting one or more photos that contain a shooting star, set up your camera to automatically take these 30 second exposures for several hours during the night. To do this, either use your camera’s built in intervalometer, or an external cable release with intervalometer. If you have chosen an interesting foreground subject in the landscape (you should!), it would be good to either take a longer exposure of it, or to take a separate photo of the landscape using light-painting or low level lighting. Back home, check all the photos to find the ones with meteors streaking through the sky. For a dramatic image, you can composite these with your landscape image using Photoshop or another editor. For a very thorough discussion of photographing and processing meteor showers, see: https://www.photopills.com/articles/meteor-shower-photography-guide 

Another event coming up will be a Great Conjunction of Jupiter and Saturn on Dec. 21. Jupiter and Saturn have been appearing closer and closer to one another this fall. Shortly after sunset, around 5:24 PM on the Dec. 21, these gas giants will be visible about 17° above the horizon in the Southwest. They will be within 0.1° of each other, or about 1/5 the apparent diameter of the moon. This is considered to be a “Great Conjunction”, as it happens only about once every 20 years. And in 2020 these planets will appear closer together than they have for about 800 years. The best viewing will be just at the end of civil twilight, so lighting should be good. You can observe these planets near one another on any clear night in December, as they appear closer and closer.  In fact, a few days before the conjunction, on December 16 or 17, you should also be able to see the new Moon very close to the two planets. For information, and some inspirational photos, see https://earthsky.org/todays-image/jupiter-saturn-photos-drawing-closer-conjunction-dec21-2020 .

Angle

by Joseph T. Sinclair

The classic photographic angle for shooting is 4.7 feet off the ground to 6 feet off the ground; that is, it depends on the height of the standing photographer. Clearly, this angle is not one-size-fits-all. Consequently, you should strive to take photographs from an angle that best suits the subject. The question is, how do you do that?

First, always be aware of what the possibilities are. For example, you can easily change the angle just by sitting down and shooting or even lying on your stomach. Such an angle is not appropriate for all photos, but it can add a lot of drama to some photos.

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Taken at lower than eyelevel on a trail along the Carquinez Strait

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Taken flat on the ground

Second, if you have an articulating LCD screen on your camera,  you can set it so that you can lower your camera at arm’s length or raise your camera at arm’s length to get an extra couple feet for a different angle in your shot. You need to set the articulation, of course, so that you can see the screen while you shoot.

Third. Can you climb on something nearby to get a higher angle shot without being arrested? I don’t advocate jumping on top of someone else’s car, but there may be something nearby that you can climb on safely and get that extra high shot. If you’re doing a well-prepared photo shoot, you can even bring along a stepladder to get a higher shot.

Fourth. Can you find a place where you can get a low shot? I don’t advocate removing manhole covers and climbing down into the sewer to get a street-level shot. But there are plenty of places where you might be able to get significantly downhill from the subject to take a good shot.

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Gerald R. Ford memorial nondominational chapel at Beaver Creek, Colorado

Fifth, along a horizontal plane, you can change your angle by moving right or left. It’s usually standing in front of the subject that might be the least interesting. But with a little energy, you might visit each side of the subject to see whether you can get a good side-angle shot that’s better than a front shot.

Sixth, what about a shot from behind? Maybe shooting the subject head on is not your best photo. Maybe getting behind the subject and shooting will give you a better photo or at least an additional worthwhile photo.

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A horse of a different angle

Seventh, think of your subject as having a transparent geodesic dome over it and that you can take a photo from any place on the dome that you can reach safely (e.g., by walking, climbing, or drone).

Eighth, consider all the angles that might bring you some additional interest. For instance, if you consider all the angles, you might come with an angle it has a surprising foreground or background that you had not previously perceived. You might see additional subjects that you can include in your photograph that are otherwise not visible from your original shooting angle.

Ninth, when you find yourself at an unusual angle, take full advantage of it while you can. For instance, if you happen to be driving along the top of a hill, stop and take a look to see if there’s a good photograph to be taken of something below.

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Taken from a cruise ship in Alaska 70 feet above the water

Tenth, dive into the subject (the scene) to look for a photo. I once got to sit in the middle of the Denver Symphony Orchestra while in rehearsal, a great photo-op. For a more pedestrian example, most people go to the Grand Canyon, stand on the rim, and take photos. Sure, you can get some great shots. Never mind the haze in the air from West Coast pollution that’s been there for last 60 years. And when you’re done, you have the same photos that have been on 900 million postcards going back more than a century. But if you take the nearest trail down into the canyon, with each step down you’ll begin to see fantastic photo-ops that you’ve never seen before. It doesn’t matter which trail; you don’t have to go very far; and most of the tourist trails are not difficult. It’s the same world from a different angle. The different angle yields original new images.

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On a trail in the Grand Canyon below the rim

Finally, think ahead and go prepared. For instance, if you’re going to shoot flowers for several hours and be on your knees much of the time doing so, take along some knee pads. If you going to shoot insects laying on your stomach for a considerable time, take along a blanket to lay on. If you’re going to climb a hill to get a good angle, wear some sturdy shoes or hiking boots.

April Dark Skies

Spring in the northern hemisphere is the beginning of Milky Way season, when the Galactic Center is above the horizon at night. Although the Milky Way can be photographed anytime of the year when the sky is dark enough, the region around the Galactic Center contains the most detail and so is more photogenic. Spring is also the time when the Milky Way can be seen as a full arch, low enough in the horizon to photograph with some landscape visible. Fortunately, many of us in the Pagosa Springs area live where skies are dark enough that we can photograph the Milky Way without traveling, so it could be a good subject while we are “staying at home”.

In April 2020, opportunities to photograph the Milky Way from Pagosa Springs, without interference from the Moon, begin on the 14th and last into the first couple of days of May. The new moon will be April 22, so the best dark sky conditions and longest time for viewing the Milky Way would be a couple of days on either side of the 22nd. During this period, you could photograph the Milky Way from around 1 a.m. until shortly before dawn, about 4:45 a.m.. For details, see any of a number of apps, such as PhotoPills, Sun Surveyor, or The Photographer’s Ephemeris, desktop programs such as Stellarium. 

Night sky photography isn’t just about the Milky Way. A classic method of photographing the night sky is to make very long exposures which show the motion of the stars as star trails. As with any night scape photography, the best images will also have a strong foreground, perhaps illuminated by the waning moon, low level LED light panels, or by light painting with a flashlight. For tips and references on start trail photography, see this post. 

Also coming up next week is the Lyrid meteor shower, which should be active beginning April 19, and  peak in the predawn hours of April 22 this year. However, you should be able to see some activity of the Lyrid any dark night from April 10 through 23, with up to 10-15 meteors per hour. The Lyrid shower occurs every spring, and if the skies are dark and clear, it can be one of the best meteor showers of the year. Fortunately, with the new moon on the 22nd, there should be excellent viewing of the Lyrids this year. To photograph the Lyrids, all you need is a clear, dark sky, wide angle lens, camera and intervalometer (built in or external) and lots of patience. For an excellent introduction to techniques for photographing meteor showers, see this article by Glenn Randall.

If you are sheltering in place, don’t live in a dark sky area, or just are not into going outside to photograph the Milky Way in the wee hours, here is an indoor activity.  The week of April 19 to 26 has been designated as International Dark Sky Week by the International Dark Sky Association, with the goal of reconnecting people around the world with our night sky. On their website, https://idsw.darksky.org , you can find a variety of virtual presentations that you can watch each day of that week. Topics include the relationship between humans and the night sky through history, basic astronomy, and art and conservation. Some of the presentations are stories about the night sky, appropriate for kids. You can also follow these and other presentations of the IDSA on their Youtube channel.

Happy star gazing!

Spring Photography

The beautiful spring came; and when Nature resumes her loveliness, the human soul is apt to revive also. –Harriet Ann Jacobs

I was surprised to note that the vernal equinox, the official start of spring in the northern hemisphere, comes on March 19 this year (In the USA). That’s early. Typically the first day of spring is the 20th or 21st of March. Indeed, according to The Old Farmer’s Almanac, this is the earliest spring equinox since 1896!  It turns out that this is due to quirks in our calendar system related to leap year (and leap century). And as a result of these quirks, spring will begin on March 19 every leap year this century. 

Given how early the vernal equinox is this year, perhaps I should not have been surprised (but was, at least a little) to have 7 inches of new snow on the first day of spring. That’s the heaviest single snow fall we’ve had, at our house, during this somewhat dry winter! It was just a little reminder that here in the Rocky Mountains,  spring doesn’t always pay strict attention to the calendar. Still, this is a good time for a post about spring photography. 

Although we have many great opportunities for landscape and nature photography in the winter here in the southern Rockies, there is no question that the new life associated with Spring makes it a joy to photograph this time of year. The grass is green, one of the most evocative colors for humans. Birds and mammals are migrating. Flowers are beginning to bloom. And, given our altered way of life in the era of COVID-19, it is fortunate that there is still a lot of photography that we can do locally, often in our own backyards, this time of year

In a recent video, Photo Tom explores 9 tips and ideas for spring landscape photography. It’s worth watching to revisit some ideas for the season. One that I think is big, is to look for the transition time between seasons. The snow this week may present opportunities for photographing the contrast of flowers, for example, in snow. Other ideas include taking advantage of the bright green of spring foliage, weather patterns, and foggy mornings. Check the forecasts for the day after storms move through. Cool mornings after a storm will likely produce fog in the valleys, especially around our hot springs. Fog creates opportunities for interesting, moody photos. If you are on a ridge above valley fog, you may have a dramatic sunrise. Later in spring, as the snow melts from the high country, waterfalls and streams will be flowing strongly, making for excellent photographic opportunities. For more ideas about spring subjects, as well as composition and lighting tips to take advantage of them, check out this post by Larry Price.

Of course, one of the highlights of spring are the blooming flowers.  Anne Belmont is a creative flower photographer, and shares a number of good ideas for unique, artistic flower photos in a two part series. These articles are full of ideas, including  seeing flowers uniquely, and suggestions for creative aperture and composition  When thinking about flowers, as well as other spring subjects such as butterflies, you’ll want to think Macro. Macro photography is easily done in your own back yard (or even inside) and can be very rewarding in terms of training your eye to see textures and patterns Lee Hoy has some good suggestions for getting started .  

There are plenty of subjects worthy of a photographer’s attention in the spring. So take advantage of the season to practice your photography, but be safe about it!

Print Sharpness

It’s difficult to discuss sharpness without making some assumptions. The photograph itself has to be sharp. That means a good camera and lens, correct focus, steady platform, etc. This discussion assumes that you start with a sharp photograph. And then you print.

As an example, let’s use the Sony A7 II, a 24MP (megapixel) camera, which has a frame of 6000 x 4000 pixels.

Commercial printing (e.g. magazines) is done at 240 dpi. Fine art printing is done at 300 dpi. (Most people can’t see much more than 300 dpi.) At 240 dpi the Sony 24MP camera generates a physical print 25 x 16.7 inches. At 300 dpi the print is 20 x 13.3 inches. (length in pixels ÷ dpi). When you consider viewing distance, however, the further you get away from a photograph, the less dpi you need to create the same illusion of sharpness.

The distance/sharpness is difficult to calculate due to so many variables. But the chart at this website gives you something to go by:

http://resources.printhandbook.com/pages/viewing-distance-dpi.php.

It indicates that at a 24-inch viewing distance, you need 300 dpi to get the maximum sharpness. Yet at a 40-inch distance, you need only 180 dpi to get the maximum sharpness. Think of 24 inches as being about the distance you view a photography book or look at a computer monitor. Think of 40 inches as being about the typical distance you look at a photograph hanging on the wall in a museum, gallery, office, or home.

Using the 40-inch viewing distance, you can generate a 33.3 x 22.2 inch print of a 6000 x 4000 pixel photograph at 180 dpi, and it will look as sharp as can be. But if someone sticks their nose into it (gets closer than 40 inches), it will not look its maximum sharpness.

Another means of determining distance/sharpness is to calculate the maximum viewing distance according to the diagonal measurement of the printed photograph. Some experts say the viewing distance should be 2x, some 1.5x, and some 1x (of the diagonal).

Calculate the diagonal with the formula: c = √(a2 + b2) where a and b are the frame dimensions and c is the frame diagonal. Thus, for a 20 x 13.3 inch print, the diagonal is 24 inches. At the conservative 1x, the viewing distance is 24 inches for maximum sharpness (300 dpi). At 1.5x, the viewing distance is 36 inches. And at 2x the viewing distance is 48 inches. Thus, for these last two distances, you would need only a dpi well under 300 to provide maximum sharpness for viewers.

It’s all very subjective. But one thing is certain. The first consideration of sharpness is how the viewer will see the print. And distance matters.

The next consideration is whether you can improve the sharping because it’s a digital photograph and not a film photograph? For many digital photographs the answer is a modest yes. For some photographs the answer is an absolute yes. Sharping digital photographs is beyond the scope of this article and is also subjective. But you may be able to enlarge a photograph 10%, 20%, or 30% and still retain its inherent sharpness by applying sharping in postprocessing. (However, you can’t take an unsharp photograph and make it sharp with postprocessing.) In other words, just by sharping in postprocessing, you may be able to enlarge a photograph a little without the loss of sharpness.

Another consideration is general enlarging. How much can you enlarge a photograph without noticeably losing sharpness? One of the original guidelines was that you could enlarge about 30% by doing 10% at a time, without noticeably losing sharpness. Today the algorithms are better, but the experts’ opinions are subjective. Some say 50% enlargement. Some as high as 400%. But this is something that depends on the characteristics of the photograph, your enlarging experimentation, and the software you use. You might want to do your experimenting with a small portion of your photograph first before committing to printing the whole enlargement.

You will want to remember that enlarging 2x does not double the frame dimensions. It doubles the area of the photograph. If you double the frame dimensions, you enlarge the area 4x.

Finally, consider the medium. Metal prints can be printed at 300 dpi, although 240 dpi is a typical default for metal printing services. The dpi of inkjet printers is virtually impossible to calculate without a lot of specifications you probably can’t easily get. The dpi for inkjet and laser printers is based on advertising, not on the traditional printing dpi. In other words, a 1200-dpi inkjet printer may print only at 280 dpi according to traditional printing specifications. If you buy a printer, you may want to ascertain the actual traditional print specification first, if available. Likewise, if a photographic service provider uses an ink et printer, you will want to likewise ascertain the actual traditional print specifications.

A word of warning. You can order a 12000 x 8000 print of your 6000 x 4000 pixel photograph, and no one at a photographic service will give it a second thought. They will simply automatically enlarge it 4x as part of their processing. Although they usually have good enlarging software, it raises the question of whether you would rather enlarge it yourself knowing that your photograph will otherwise be automatically enlarged. In other words, just because you can order something, doesn’t mean that it will retain its sharpness to the degree you require for your viewers. You may want to have more control.

What’s my practice? I don’t enlarge anything and don’t worry about sharpness. With my 25 MP camera, this is a practical point of view. Nonetheless, there are always those situations where I need a large print, and enlargement is required. In such cases (rare for me because I print few photographs), I decide how to enlarge based on the factors outlined in this article; that is, I handle each photograph on a custom basis. But if you find yourself enlarging your photographs all the time, you may want to get a camera with more MPs thus enabling you to forgo enlarging so much of the time. The new Sony A7R IV has 61 MPs (35mm type camera) with a 9504 x 6336 pixel frame, and its brand competitors are comparable.

Finally, if you typically crop much of a digital photograph away, you may have a need to enlarge what you have left. In that case, a camera with plenty of MPs is doubly useful to your photography efforts.