Sacked out

Male red kangaroo, LA Zoo.

Walter the squirrel

We have this squirrel that lives around our house. He's kind of a doofus. It's a good thing this is a predator-free environment, sometimes he makes enough racket in the trees that you'd think a couple of sasquatchi were getting it on. I call him Walter, in honor of Walter Sobchak. He's fat, noisy, but basically harmless, and if that isn't enough to earn the name, check this out:


He's also curious and if I'm out and about sometimes he'll just plunk down and watch me. Which affords me the opportunity to practice digiscoping if the birds aren't cooperating--which, lately, they ain't been.


Last Sunday afternoon, he was up on top of the telephone pole next to the driveway, chittering away at me in between breaks to groom his fur and--I am not making this up--scratch his pits. I hauled out my little scope and started snapping.


The lowest useful magnification my scope will do is 30x. To get this last shot, I had to open the gate to the back yard and go all the way to the end of the property just to get a wide enough field of view. That's a good problem to have.

Oklahoma tetrapods

This one's for Darren. The poor guy is working on at least two books, several technical papers, and keeping up two blogs, not to mention being a husband and father with an infant to take care of.

So here are some tetrapods for ya, Darren, from my recent vacation to Oklahoma. I think we've seen that my skillz at identifying non-sauropods are definitely sub-1337, but I will do my manful best. Everything is arranged in accordance with the Great Chain of Being, of course.

I reckon, given the brown coloration, the light spot on the eardrum, and the north-central Oklahoma locality, that this is a Plains Leopard Frog, Rana blairi. I can say for certain that it was too fast for me to catch.


Bullfrog, Rana catesbeiana. We saw this dude sunning himself every day.


The same, or at least a very similar, frog on a different day.


A juvenile watersnake in the genus Nerodia, but no tellin' what species. Note cow poop for scale.


Shed skin of an unidentified serpent.


My brother and I were walking along the creek near the house when we spotted this subadult raccoon, Procyon lotor, moving upstream.


It didn't seem unduly exercised by our presence, so we tailed it for thirty yards or so until it disappeared into some brush.


Nearby we found this skeletonized paw from a nine-banded armadillo, Dasypus novemcinctus.


Also this mostly skeletonized bobcat, Lynx rufus. I boiled and peroxided the skull and it is now sitting on my desk at work, distracting people who come by to give me more work. One of the ribs was broken and healed.

At last we come to the pinnacle of evolution, the saurischians.


A Common Grackle, Quiscalus quiscula. This one was in the top of a tree at my in-laws' place in Oklahoma City. Interesting bird to watch but irritating to listen to; it sounded as if it had eaten a squeaky wheel and dying cat and was trying to vomit them both out at the same time.


A red-winged blackbird, Agelaius phoeniceus. The wheat fields around my parents' place were full of these things.


Arf. I saved the best and worst for last. Best because this was the toughest photo of the bunch, and therefore the most satisfying. Worst, because I am probably going to choke on the ID. But here goes anyway. At first I was thinking that that the beak was too thick for it to be anything other than a finch. But further reflection (i.e., randomly thumbing through Sibley's) suggests another, more likely alternative: a Dickcissel, Spiza americana.

That's all I got. Coming soon: selected tetrapods from the LA Zoo.

Onward and upward

The cool thing about being on a learning curve is that you regularly do stuff that makes your previous efforts look pretty lame. Like this (click to embiggify):


For technical details and more like it, go here.

A big night in a big year

Everyone who is even remotely interested in the living world knows that 2009 is the bicentennial of Darwin's birth (1809) and the sesquicentennial of the first publication of On the Origin of Species (1859). And this year is the 400th anniversary of Galileo first turning a telescope to the heavens and the publication of Kepler's Astronomia Nova (1609), in honor of which the UN and the International Astronomical Union have declared 2009 the International Year of Astronomy.

There are a couple of other astro-themed anniversaries this year, too. This July 20th will be the 40th anniversary of the first moon landing (1969). Bringing things right up to the 21st century, January 4th and 25th were the 5th anniversaries of the landings of the rovers Spirit and Opportunity, respectively, on Mars (2004). That's right, folks--it seems Mars missions either fail spectacularly or succeed beyond anyone's wildest dreams. The primary missions of the twin Mars Exploration Rovers were only 90 days apiece, and here they are still going strong 1854 and 1833 days later (as of this morning), more than 20 times longer. Bring that up the next time some tool complains about NASA's budget.


Last night I celebrated two of Galileo's discoveries: craters and "seas" on the moon, which showed that celestial bodies were not perfect and unchanging spheres, and the phases of Venus, which confirmed the hypothesis that the planets orbit the sun rather than the Earth. Andy Farke (a.k.a. the Open Source Paleontologist, who published a paper on Triceratops combat just this week in--naturally--an open access journal) brought some of his excellent home-brewed beer to the traditional Wedel Friday Night Fish-Stick Picnic, and we spent a little time cruising the sky. We got lucky, too--the atmosphere, which is usually a roiling swamp of turbulence and smog, was as still and clear as I've ever seen it down here. Lately Venus has been so smeared out by bad seeing that it looks like a hyperactive star, but last night we could see it for the planet that it is, and in a crescent phase not to different from that of the moon.


Next month will be even better. As Venus continues on around the sun toward inferior conjunction, it will appear larger and even more crescentic. On the evening of February 27, just after sunset, the crescent Venus will be right next to the much larger crescent moon above the western horizon (as shown above in a screencap from the free planetarium program Stellarium). Get out and take a look. It will be even better in binoculars or a telescope, so start thinking about how you're going to make that happen. I promise it will be worth it.

Gettin' squirrelly

People come to things by circuitous routes. I have heard of more than one person who got into paleontology through art; they started out by drawing dinosaurs and graduated to studying dinosaurs (not everyone makes that transition...).

I sometimes wonder if I will eventually become a birder. This thought first came to me when I was ODing on natural history a couple years ago. I dig watching animals, pretty much without reservation. I have a big aquarium and keep fish, for most of my life I kept turtles, and every time I've bumped into an animal--okay, a vertebrate--outdoors I've observed it with great interest, regardless of exactly what kind it is. You can go fishing and you can go herping, but those require going where the fish and herps are, and even then there's no guarantee you'll see any. You can't usually just "go mammaling" because usually mammals are either absent or laying low. But you can walk out the door just about anytime and see birds. So it seems reasonable to me that someone with a broad interest in watching critters might end up as a birder because birds are there to watch.

Any committed birders out there are probably appalled at my lack of passion. In which case, hold on, you ain't seen nothin' yet.


Over the holidays I blew a hundred bucks worth of Christmas money on a spotting scope. Partly because I'd always wanted one, partly because I intended to use it as a travel telescope for those dark Oklahoma skies (a successful venture, I might add). Today I was just monkeying around with it and decided to try taking some pictures of birds in the back yard. I didn't get any birds, but I did get some good pix of the neighborhood squirrel. If I do ever become a birder, it will be at least partly because I enjoy--in the immortal words of Mike Taylor--badgering around with telescopes.

UPDATE: I'm not alone! "I took my very first bird photograph through my astronomical telescope in 1998."

Taken by afocal projection using a Celestron C70 spotting scope, Orion 32mm Plossl eyepiece, and Nikon Coolpix 4500 digital camera.

Craters all the way down

Believe it or not, there are a few features on the moon that are not direct products or epiphenomena of asteroid and comet impacts. There are some small, fairly obscure volcanoes, some lava-carved valleys and collapsed lava tubes, and a few scarps produced through faulting. But these are all dwarfed, physically, in number, and in importance, by craters and impact basins. To a first approximation, everything you see on the moon is a crater, part of a crater, a crater flooded with lava (the maria or lunar seas), part of the rim of a crater since buried under lava (the lone mountains from the previous post), ejecta blown out by a crater (the bright rays extending from "young" craters (i.e., those less than a billion years old), valleys gouged by impact ejecta (the valleys from two posts ago), or in some other way a consequence of an impact. This is especially obvious in the southern highlands, which were never flooded by mare lavas and are thus just piles of superimposed craters, like the oft-rebuilt Troy of Schliemann.

The biggest crater visible above is Clavius. It's 140 miles across, 2 miles deep, and about four billion years old. It is also the site of Clavius Base in 2001. Speaking of, last year was the 40th anniversary of 2001, this July will be the 40th anniversary of the first moon landing, and this December will be the 37th anniversary of humans not going beyond Earth orbit anymore. The most optimistic projections for NASA and the Chinese space agency do not put people back on the moon before the 50th anniversary of the first landing, and it may be much later.

I wonder what future generations will think of our half century of going nowhere. Recall that the original point of the space station--the only reason anyone wanted one to begin with--was to be a launchpad for the moon and Mars.

Mega sigh.

Taken by afocal projection with an Orion XT6 Dobsonian telescope and Nikon Coolpix 4500 digital camera, through an Orion Sirius 25mm Plossl eyepiece and Orion Shorty 2x Barlow lens.

Sunset on the Sea of Rains

All of these pictures were taken by afocal projection with an Orion XT6 Dobsonian telescope and Nikon Coolpix 4500 digital camera. The first two shots were made through an Orion Sirius 25mm Plossl eyepiece and Orion Shorty 2x Barlow lens. The bottom shot was made through an Orion Sirius 32mm Plossl.

Sea of Crises

a.k.a. Mare Crisium. A basalt-filled impact basin 376 miles in diameter and more than 3.8 billion years old. It's got some killer mountains around it, and it's a good place to go exploring right after a full moon, when the rest of the moon is still washed out in direct sunlight.

Conditions were suboptimal tonight. It was windy so the atmosphere was just roiling through the eyepiece, which makes for less than crisp photos. But it's supposed to rain all week so I gave it a whirl anyway.



Southeast of Mare Crisium are four big craters in an arc: Langrenus, Vendelinus, Petavius, and Furnerius, in order from closest to Crisium to furthest away. There are also a couple of cool valleys, Valis Palitzsch and Vallis Snellius. There are no true water-carved valleys on the moon. Some lunar valleys formed by faulting, some were carved by flowing lava (strange but true), and some are collapsed lava tubes.

Valles Palitzsch and Snellius formed another way: they were gouged out by immense chunks of crust blasted away from the impacts that formed the maria. Vallis Palitzsch is 82 miles long and 25 miles wide at the fat end. For reference, Mount Everest is less than 6 miles tall and Mauna Kea is just over 6 miles tall if you measure from the ocean floor. Neither would amount to much compared to the block of crust that dug out Vallis Palitzsch when it landed.

Vallis Snellius is another secondary impact feature, created by a chunk of debris from the impact that formed Mare Nectaris. It is narrower but longer, 367 miles long in all. Imagine a piece of rock several miles wide rolling from LA to San Francisco (actually some puritans would probably like to see that happen).

I wonder about the mountains, craters, and so on that were in the way of those juggernauts. I would like to have been around to watch them get flattened.

Some fun, huh?

Howl, baby

Taken by me, from my driveway, about two hours ago.

You can't take the sky from me

People who dismiss the plains states as "flyover country" don't realize that out here, the sky is the scenery. These are views west from the house I grew up in, over our neighbor's wheat field, out in the country in north-central Oklahoma. I took them yesterday, on the evening of my birthday. The one above is just a few minutes before it started raining here--you can see a curtain of rain falling on the horizon. If you cover up the wheat and the bright sky under the clouds, it could be one of those artists' impressions of the atmosphere of Jupiter.


I took this about half an hour later, after the rain had passed. Some groovy mammatus clouds there on the bottom of the thunderhead.

Pretty good birthday present. Thanks, universe.

Shoot the moon II: Getting the most out of your binoculars

Part the First: Mount Up

The biggest pain in the butt about binoculars is that they shake. Or rather we do, no matter how we may try not to. If you can get rid of the shakes, using binoculars is awesome. But it ain't easy. Up until now I have done one of two things: steadied my binoculars against a nearby fence or wall, or steadied them against a monopod but without having them actually attached, just using the monopod as a sort of primitive mobile fencepost. But recently I came up with a better solution: I built a budget binocular bracket.

Lots of astronomy equipment companies sell dedicated binocular brackets, for mounting binoculars to monopods or tripods. The current issue of Sky & Telescope has a review of a premium model that costs $70. That's more than double the cost of my best pair of binoculars! Even the budget model from Orion costs $30.

Well, bump that. You can build your own for about $5. Go to the hardware store and pick up a steel angle bracket like the one shown in the photo above, some 1/4-20 nuts, and a 1-inch-long 1/4-20 thumbscrew. One of the holes in the bracket will fit over the 1/4-20 bolt on your monopod or tripod. Put on a nut and tighten 'er down. I used needle-nose pliers to get in there and get that nut nice and tight--you don't want your binoculars swinging in the breeze, no matter how cheap they were. Put a couple of nuts on the thumbscrew before you put it through the bracket--these act as spacers and keep the flat end of the thumbscrew from bumping up against the bracket when you tighten the rig. Then stick the thumbscrew through the bracket and screw it into the socket on the front of your binoculars. If the thumbscrew reaches the end of the socket before it's tight, pull it out and slip on one more nut as another spacer--that's what I had to do, and in the photo above you can just see the edge of the nut peeking out between the bracket and the socket on the binoculars.

Bang, you're done. Point the binoculars at something interesting and enjoy a completely shake-free view. I like running them up on my camera tripod and observing the moon without having to touch anything at all. I'm telling you, it's a qualitatively different experience from any binocular observing you've ever done in the past. And not just of astronomical targets--it's good for birds, landscapes, sunsets, your perverted neighbors, whatever.

And it's damn near free. If you use binoculars at all and own a tripod, there's no reason not to build one of these. And my tripod is not fancy--it's the absolute cheapest full-size model that Wal-Mart has to offer. It shakes and wobbles like crazy with a telescope on top, but it's plenty sturdy for a pair of binoculars or a camera.

Part the Second: Absolute basics of image processing


This is, no lie, the un-fiddled-with raw photo of the moon that I took through my Celestron 10x50 UpClose binoculars tonight. Well, okay, not completely un-fiddled-with. I did rotate and crop the image to get the moon in the middle and get rid of most of the empty field. But I didn't mess with any color or sharpness settings, so the moon itself is exactly as it came out of the camera.

I don't like to brag, but I was freaking amazed that I could get a picture that sharp using just binoculars. The 10x50s are quite a bit better than the Tasco 7x35s I used for my last attempt, but still. The image quality of the mounted binoculars is not far behind that of a small telescope, either visually or photographically (proof--compare these pictures to this one). The one advantage of even a small scope is that you can crank up the magnification if you want to see, for example, the rings of Saturn. On the other hand, binoculars are cheaper, lighter, easier to set up, and grab a lot more sky--all the reasons amateur astronomers use them in the first place.

Anyway, this part isn't about the binoculars. It's about what to do once you get a picture.


First thing, seriously, always, is Unsharp Mask. It looks like a gimmick but it's not. It can be overdone, like almost anything, but you should be able to play around with the settings minimally and find something that works. And it's available in just about every serious image processing program out there, including Photoshop and GIMP (the latter is free, BTW). The only difference between the photo immediately above and the one at the top of this section is that I applied Unsharp Mask in GIMP, using the default settings.

You'll notice some distracting color in both of the above images. The north edge of the moon is outlined in blue haze, and the southern end is an unwholesome-looking yellowish brown. That's chromatic aberration, and it's an unavoidable consequence of refracting light through glass. For telescopes you can buy anti-fringing filters, or super- or hyper-expensive apochromatic telescopes that use special kinds of glass to minimize CA, but even the best only knock it down to below the threshold of perception. It's impossible to completely get rid of. Physics is like that sometimes.

Let me amend that. It's impossible to completely get rid of in optical trains with refracting elements. A major advantage of reflecting telescopes is that they collect light with mirrors rather than lenses, so their views are blessedly free of CA.

Interestingly, I've never seen any CA on the moon through binoculars, and I've looked for it. Possibly the weak signal of color falling on my cones is just blown out by the intensity of light falling on my rods. Whatever the explanation, in my experience it is a strictly photographic problem.


This won't work for everything, but the moon is basically black and white in real life so it doesn't look weird if you convert the image to grayscale, as I've done here. And that's all I did--I didn't try to erase the dim halo around the northern regions, for example. It was always dim, and it only grabbed the eye because it was blue. Convert it to dark gray and it just disappears.


One last trick. I nudged up the contrast a little. It's really easy to overdo this, but if it's done right it certainly makes for a more interesting and pleasing image. The main problem with doing this on anything but a full moon is that the area near the terminator--the day/night line, where the lit part of the moon meets the unlit--drops off into blackness, and if you make the blacks blacker, the terminator appears to shift. Suddenly instead of describing a gentle curve or line from pole to pole, it zigs and zags as bright craters and dark maria pull it first one way and then the other. Which makes the photo look fake, because the real moon just doesn't look like that.

But there's an easy fix. Copy the image and paste it into a new layer. Bump up the contrast on that layer, and watch the terminator move. Once the contrast on everything else looks good, grab a big fuzzy eraser and erase the parts that got blackened out. The normally-lit terminator in the original image shows through. Flatten and save. You're done.

And so am I (UPDATE: no I'm not. Keep reading). Like I said, this is the bare bones of image processing. There's lots more here, and in many other places on the web. Have fun!

-------

Hoo boy, what a dumbass I am. The picture above is actually how not to do contrast. I screwed up bigtime, but I'm leaving it in as a teaching tool. There are two big problems with that image, and somehow my poor addled brain didn't catch them until this morning. The first is that I only grabbed part of the image when I copied and pasted, so there is a distinct black box from the contrasty layer visible against the skyglow from the original background. Lesson 1: copy the entire image into the layer you're going to mess with. The second problem is that I colored outside the lines with the eraser, so next to the terminator there is a weird light-colored strip like a fuzzy caterpillar (if you can't see this, try tilting your monitor so the image looks lighter. Lesson 2: if you're going to up the contrast and then erase some of the contrasty layer, you have to be careful not to get off of your foreground target or the brighter background will show through. Both problems are fixed in this version:


I'd like to be able to say that I planned this little goof/save in advance, but I didn't. Just shouldn't process images in a dark room or blog when I'm tired. Sheesh. Keeps me humble.

Now I'm going to take Mike's advice and get back to work. No sarcastic commentary needed.

Shoot the moon: digiscoping 101

In a comment on a recent post, TheBrummell said, "Any advice on getting a couple of seconds exposure through 1/2 a pair of binoculars with a Nikon coolpix 5200?" Which may sound like a crazy question. Most of us own a pair of binoculars and a camera, but I'll reckon the fraction that have used the two in conjunction is vanishingly small.

I, however, am a member of this elite group. And I realized that although I have blogged the results of my digiscoping adventures here*, I haven't actually explained anything about the process, or given any instructions for doing it yourself. So here goes.

* A lot; possibly too much for those of you who came here hoping in vain for something paleo-related, but now that I have to feed SV-POW! regularly I send most of my paleo ramblings there.

What Digiscoping Is

Afocal projection photography, also known as digiscoping amongst birders and as white trash astrophotography by me, is the simplest and cheapest way of taking pictures using any kind of optical device: you just hold the camera up to the eyepiece and snap away. You can do it with just about anything. TheBrummell reports taking zillions of pictures through dissecting microscopes, my anatomy students take pictures of prepared slides through the compound microscopes in the teaching lab, birders and other nature lovers use spotting scopes or, less frequently, binoculars, and amateur astronomers use telescopes. The results can be striking--do a Google image search for 'digiscoped bird' and you'll see what I mean. The picture at the top of the post is my best image from 8 months of experimentation. Click on it for the full-size version, and check out the detail.

Okay, that's the what. What about the how?

Holding the Camera Steady

I use a Nikon Coolpix 4500, and for almost all of my pictures I really have just held the camera up to the eyepiece of whatever I'm shooting through. For steadier results you could put the camera on a tripod, or buy a dedicated adapter for mounting the camera behind the eyepiece, like the Steadypix from Orion (image from Orion's website).


I have also started experimenting with the camera on a monopod, which is what I used for the recent Earthshine photo. The monopod is nice because it's simple, lightweight, easily adjustable to any length, but sturdy enough to really damp out the little vibrations that you can't escape just because you're alive. (When I'm really trying to hold the camera still I can see my hands move ever so slightly in time with my pulse. Try it.) And mine was dirt cheap, something like $18.

An unexpected benefit of using a monopod is that it helps dampen out the shakes even when it's not on the ground, just by being long and heavy (relative to the camera). I discovered this when I was taking pictures in the OMNH last year and I wanted a tall-aspect photo, so I just picked up the camera plus monopod and flipped the whole rig on its side. The rig was easier to keep steady than the camera by itself, even when it wasn't propped against anything (you can sometimes prop a sideways monopod against a nearby wall, too).

Camera Settings

For settings I use macro mode, sometimes with a timer to eliminate the little bit of shake from manually pressing the shutter release. And I usually zoom in to eliminate vignetting, which is the "stopping down" of the image by the margins of the optical assembly (usually the field lens of the eyepiece). Here's what an unmodified vignetted image looks like:


Here's the same image rotated, cropped, and sharpened:


Vignetting is not a problem when I'm shooting at night, because the black margin does not show up against the dark sky. The settings I use to shoot the moon and planets don't usually show any stars anyway. If you want pictures of starfields, you'd be better off using a DSLR by itself--there are plenty of tutorials around that will explain how, and lots of camera-specific forums you can check out for advice and assistance.

Magnification

Zooming in can also boost the magnification significantly. Magnification of any optical device is equal to the focal length of the objective divided by the focal length of the eyepiece. So a 25mm eyepiece will yield 40x in a telescope with a 1 meter focal length, but only 20x in a telescope with a 500 mm focal length. It is hard to get up to high magnifications with small refractors or Newtonian reflectors just because of that fact. Catadioptric telescopes like Schmidt-Cassegrains and Maksutovs have the opposite problem--their folded light paths mean that very small telescopes have very long focal lengths, and even fairly long-focal-length eyepieces still yield fairly high magnifications. For example, I have an Orion Apex 90 Maksutov-Cassegrain, and the tube is four inches in diameter and less than a foot long--which makes it a good travel telescope, because it fits in a carry-on bag with room to spare--but the focal length is 1250 mm, longer than my "big" telescope, a 6-inch Dob (see below).

So, two points. First, contrary to what most people think, the main point of a telescope is light collection, not magnification. A lot of astronomical objects are big but dim, like galaxies and nebulae. Some magnification is helpful, for sure, but the main benefit of the telescope is that it's light-collecting area is vast compared to that of the naked human eye. I've blogged about this before and I won't beat it to death here.

On the other hand, a good digital camera can pull more detail out of the scene than can your eye, thanks to the zoom. I took the photo at the top of the post at a telescopic magnification of 37x and a camera magnification between 2-3x. Which means my eye saw the moon magnified 37 times, and the camera saw it magnified somewhere between 74x and 111x, and recorded that. I have a 16x20 inch print of that image ($9.99 at Costco, and 12x18s are only $2.99!), and the detail holds up even at that size, which is waaay beyond what I can see with the naked eye at 37x.

Almost all of my moon photos have been taken at low telescopic magnification. The only exceptions are closeups of just part of the moon, like the second pic down here. I am usually forced to use low magnification for the whole-moon shots, just to get the whole moon into the field of view at once.

Exposure Time

Although my Coolpix autofocuses just fine, it's not so hot on figuring out exposure times for small bright objects in a sea of inky blackness. So I go over to manual for most stuff now. Here's why this matters--these photos were taken about a minute apart, but the one of the left is a two-second exposure and the one on the right is a 1/15 second exposure.


The moon varies in brightness a lot. If it's full or nearly full, I may use exposure times as short as 1/250 second or even 1/500 second. And obviously exposure time and camera steadiness are related--the shorter the exposure time, the less you have to worry about the shakes.

What To Shoot

Digiscopers with an astronomical bent have a limited choice of targets. Basically, the moon, the bright planets, and any evening or nighttime scenes you want to see really close up. Starfields are better imaged without a telescope, or with a long-exposure photo on a tracking mount, which is a whole 'nother kettle of (much more expensive) fish. Nebulas, clusters, and galaxies are too dim. You can image those things with simple webcams, but I'm not going to blog about that because I don't have any experience doing it. Yet. (My birthday is coming.)

Still, the moon and planets are pretty great. It is easy to forget that moon is an entire world. Yeah, airless and dead, but still: a whole world. And it's right there. Even cheap binoculars will show you tons of details that you can't see with the naked eye.

So far, the only planets I've shot are Saturn and Jupiter. The results are not going to make APOD, but you can make out cloud belts, rings, and the Great Red Spot, which is pretty amazing considering the entire operation consisted of holding the camera up to the eyepiece and pushing the button.


What To Shoot Through

Whatever you have. Seriously. Experimentation costs nothing, it's fun, and any result you get will probably be better than what your naked eye could have served up. So go nuts.

But if you want some advice, bigger is better. In the case of a large, bright target like the entire moon, the advantage of big optics is neither light-gathering nor magnification but resolving power. Compare these photos from similar phases but taken through scopes of different apertures:


Note that the middle photo was actually taken at slightly lower magnification than the one on the left, but the resolution is far superior. Here's what those scopes look like in real life:


The travelscope is the skeletal thing perched on the tripod. It's currently in its third incarnation, or fourth if you count its ignoble birth as a National Geographic toy (you can read my thoughts on the utility of the original product and the ethics of its marketing here). Previous evolutionary stages are here and here. The red ball-type scope on the table is my Edmund Astroscan, object of my desire since I was about 12 and my primary scope for car trips. The black howitzer-looking thing is my Orion SkyQuest XT6, a Newtonian reflector like the others, but on a Dobsonian or "Dob" mount. It's actually a lot more imposing in person--the tube is four feet long and seven inches in diameter, and the whole thing weighs 35 lbs. It just looks small next to me, which is an occupational hazard for us sasquatchi. And it does look suspiciously like a weapon, which often gets me weird looks from the neighbors and passersby when I set it up out front. So I invite them over to have a look through it, which is a great way to make someone's day.

I have done most of my digiscoping through the XT6, at first because it was my only telescope. I went through a phase this spring of shooting through the Astroscan, because it is so small and portable. I can sling it over one shoulder, put the camera over the other, stuff a couple of eyepieces in my pockets and be outside observing in about a minute and a half. But the images served up by the Astroscan are just a little mushy compared to those from the XT6, probably because of the fast optics--f/4.4 is a steep light cone. For a while it was kind of an enjoyable challenge to see how well I could do with the Astroscan, but pretty soon I got tired of really working for so-so images when I could get better ones for less effort through the XT6.

And by "so-so", I mean only by comparison to the images I'd already been getting through the XT6. I'm actually quite proud of some of my Astroscan photos, and I don't mean to knock the little scope at all. But Aperture Rules. I'm sure if I had a 10-inch scope to play with, I'd stop digiscoping with the XT6.

Which brings up the question of why I have so many telescopes (the Apex 90 I mentioned earlier in the post is not in the above photo, nor is the Explorascope I mention below). Partly it's because I'm a telescope nut, but partly it's because different scopes serve different purposes. The XT6 is both my default scope and my big gun. If I'm home and I want to do some serious observing or digiscoping, that's what I use. The Astroscan is my grab-n-go or quick look scope, my car travel scope, and the scope I share with my little boy. The travelscope, Apex 90, and Explorascope are all contenders in my quest for the perfect airline portable scope. And anyway, according to Ed Ting one really needs six scopes, so I'm still under the legal limit.

But wait, you say, why am I blabbing on about telescopes when TheBrummell specifically asked about

Binoculars

Yes, you can take pictures through binoculars. It takes some forethought. The first problem is mounting them. Almost all binoculars have a mounting socket at the front of the center column, usually covered by a plastic cap. Lots of astronomy and camera stores sell dedicated tripod adapters, which are L-shaped rigs with a 1/4-20 bolt on the vertical side to screw into the binoculars, and a 1/4-20 socket in the base for the tripod bolt to screw into. You could also make your own out of 1/4-20 thumbscrews and scrap lumber for about two dollars. UPDATE: a five-dollar solution is shown in the next post.

But that's not what I did. In my one adventure in binocular digiscoping, I used the Tasco 7x35s that I bought back in high school (or maybe even junior high). They have a mounting socket, but it's not a standard size, and I don't have a binocular adapter anyway. But I still got them mounted to the tripod. I used one of the struts from the travelscope, which has an inset 1/4-20 T-nut for tripod attachment, and simply lashed the binoculars to the strut with big rubber bands. It looked weird as hell:


How did it work out? Not too bad, actually. I had to squat down and put my head right next to the travelscope strut to sight the things in, but the focuser worked fine and I didn't have any problems taking pictures. I went a little nuts that night taking pictures of the same moon through several devices or none at all, in anticipation of writing this very post. Here's the comparison shot:


UPDATE: Gah! Better binocular photos now available, again in the next post.

The only real surprise in putting this together is how well the Coolpix did by itself, using maximum zoom and steadying the camera against one of the columns on the back porch.

To Shoot or Not To Shoot

I actually feel like kind of a weiner putting up the binocular shot here at the end, after having kicked off the post with a picture that is far better than you're ever going to get through binoculars. I'm not trying to discourage you--quite the contrary! The first time you get a nice, reasonably sharp photo of your own, it will feel pretty damn good. And it will hopefully make you want to do more.

I am always telling people that getting started in astronomy does not have to be prohibitively expensive. Even cheap binoculars will show you tons of stuff you can't see with the naked eye (especially if they're mounted on something), and not just on the moon. All of the Messier objects are visible in binoculars in dark skies, and most serious amateur astronomers spend at least part of their time observing with binoculars. Orion has several good beginner telescopes in the $100-250 range, a new Astroscan will run you $199 but used ones can be had for a little more than half that if you look around, and an XT6 is $269. But right now you can buy a workable telescope for about the same price as a modest pair of binoculars: Celestron's Explorascope, an 80 mm reflector, is on sale for under $40. Eighty mm is not much, and you won't get any XT6-worthy pictures through it, but the views will be closer to those through a six-inch scope than to those served up by binoculars (at least at higher magnifications; at low mag, maybe not). So if you've been reading and wondering if you'd get anything out of owning a telescope, now's a good time to find out without breaking the bank. I've got one in the mail, and I'll review it here once I get a chance to test it out.

Clear skies.

The moon by Earthlight

There's about a metric buttload of stuff I want to blog about, including the highlights of the Lick Observatory trip (now on my Flickr page) and some awesome predator/prey photos that one of my students took and the Western Pond Turtle that my wife caught crawling across our driveway last week, but it's the time of year when I've got finals to write and grade so all that stuff will have to wait.

In the meantime, this is what the moon looked like tonight. This fetching display is called "the old moon in the new moon's arms"; from the moon the Earth is nearly full and it bounces back enough light to dimly illuminate the shadowed regions of the moon. If you'd like to see it for yourself, you don't have to wait a month--the show should be almost as good for the next couple of nights.

For those who care, this was a two-second exposure with my Nikon Coolpix 4500, shooting through an Orion XT6 Dobsonian reflector with a 32mm Plossl eyepiece.

Saturn

This is what Saturn looks like at 120x from the polluted atmospheric swamp that is the central valley. On really clear nights, like right after a rain, it looks a lot better. This is my first Saturn photo ever. Not outstanding, but recognizable, which is pretty great considering that all I did was hold my camera up to the eyepiece of the telescope. And that if I had a tall enough ladder I could cut blocks of polluted air right out of the sky and sell them on the black market. As what, I don't know. Star-blockers, I guess. Constellation simplifiers. Troubled by that annoying Milky Way thing? Just look through one of these!

Actually it is just sad, because pictures are so flat compared to the experience. It is easy to look at a photo--especially this one--and think, "Meh." But every single time I find Saturn in the telescope my first thought is, "Holy shit, that's freakin' Saturn!" I will keep banging this drum as hard and loud as I can: the difference between seeing something in a picture and seeing it for yourself is as vast as the gulfs of space.