Podcaster: Dr. Kyle Kneisl and Dr. Joseph Bohanon
Title: Introductory Astrophotography and the Advanced Observer Program at Kitt Peak
Link: Sky and Telescope — Astrophotography : http://www.skyandtelescope.com/howto/astrophotography
AstroTrac : http://www.astrotrac.com/
Dr. Bohanon’s Astrophotography Blog: http://www.joebohanon.com
Older Photos from Dr. Bohanon: http://joebohanon.com/astro/latest2.html
Advanced Observing Program: http://www.noao.edu/outreach/aop/
Description: Astrophotography always fascinate people. An interview with Dr. Joseph Bohanon will gives an introduction to astrophotography as well as advanced observer program at Kitt Peak.
Bio: Dr. Kneisl has given a few podcasts before for this astronomy series. A mathematician by profession, he maintains a lifelong interest in astronomy and science education, which he hopes to pass along to his two children. He lives in the Washington, DC, area.
Dr. Bohanon, also a mathematician from the Washington, DC, area, is a deeply involved amateur astronomer and astrophotographer.
Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by — no one. We still need sponsors for many days in 2013, so please consider sponsoring a day or two. Just click on the “Donate” button on the lower left side of this webpage, or contact us at signup@365daysofastronomy.org.
Transcript:
[KK: Dr. Kyle Kneisl, interviewer]
[JB: Dr. Joseph Bohanon, amateur astronomer and astrophotographer]
[Interview conducted remotely using free and open source Mumble VoIP software and the OPUS Codec on equipment operated by Dr. Kneisl]
KK: So, as mentioned in the introduction, we are talking to Dr. Joseph Bohanon who is not only a mathematician by day, but with his spare time, he is also an avid amateur astronomer, and he is also very interested in astrophotography, or, the photography of astronomical objects. He has recently returned from a week-long trip to Arizona where he went to Kitt Peak and took a number of marvelous photos which we are going to tell you about. Joe, when did you start getting interested in astronomy? I assume like most people like you and me who grow into adults that are very interested in astronomy that it was from an early time?
JB: Yeah, I think I was probably interested in astronomy about as long as I can remember…being a kid, and I grew up in kind of a sciency household…I had an interest in astronomy growing up but it wasn’t until about college years that I got more interested. So, there was another guy in my dorm that had one of these real cheap refractors that you can buy in like a science store, and so he would show me the Moon and Jupiter and Saturn and things. It wasn’t a particularly good telescope, but it got me interested enough that I really wanted to save up to buy a decent telescope, so…
KK: This day and age, when everybody has some kind of digital camera: what happens if you take the family’s digital camera that cost maybe $100 or $200, and you take it out in the yard, and you just, with that camera in your hands, attempt to take pictures of the Moon, or, even, brighter stars? Is there anything that can be done with that or is that doomed to failure?
JB: There are some things that can be done with that. You have to first consider these point and shoot cameras are designed for taking fairly wide-angle shots during the daytime, and even at nighttime, you know it tries to use the flash to illuminate things. So, when it’s night and you’re trying to take a picture of say the Moon; the Moon is bright enough that it might be able to–the auto features inside the camera might be to sort of figure out the exposure, but, you might be able to get some pictures of stars with this, so what you probably want to do is put it on a tripod because you’re going to have to take a longer exposure. So, within thirty seconds to one minute, you can actually see the stars moving just a little bit. So, if you don’t want any movement, you want to limit to maybe fifteen second shots or a little bit less. You can take pictures of constellations and things like that. You’re not going to get really good photos of, say, Jupiter just because Jupiter is very small so you need a decent amount of magnification to do it.
KK: OK, so, let’s say that someone wanted to do something very minimal. They were willing to buy a tripod, and they already had for some other reason they already had a very good SLR camera that somebody else in the house paid five or six or seven hundred dollars for. Now, even though there’s no telescope involved yet, is a setup like that going to be able to, you know, are there pictures you can take in the sky that will be impressive to the first-time astrophotographer? And what resources would somebody interested in doing that want to consult?
JB: Yeah there certainly are some you can take just with the camera not involving a telescope at all. So, for instance, if you just get a tripod and point it at the North Star and just let it expose for like fifteen minutes, the picture that you see, you will see the star trails moving around the poles. You get these nice concentric, you know, roughly circles. So, you’re going to see just a couple of degrees of movement in fifteen minutes. There have been some fantastic photos that people have taken where they do that for you know, three or four hours. Those are the types of photos that, assuming you get a really good shot, you can go somewhere scenic and try to get a tree in the background…or if you live near Washington DC you can get the Washington Monument in the foreground of your shot. There’s a decent amount of stuff that you can do just using the camera. On top of that, you sort of have to consider the fact the camera that you have, when you attach a lens, you’re essentially turning it into a type of telescope. So, it’s kind of like a refractor when you’re doing that. You know you can treat your camera like a telescope, and if you put it on a mount, so there’s something which I think we can provide a link to in the show notes, it’s called an AstroTrac, and basically it’s just a very light weight mount tha tyou can set up anywhere; you just have to polar align it and then get going, you just stick your camera right on top of that and you can actually take tracked photos anywhere in the sky.
KK: Let’s move on to the kinds of real astrophotography that people can start to do with not that much money that does involve a telescope, and does give you the kinds of shots that you are used to seeing in picturesque astronomy books. Is it the case that the type of starting telescopes—you know, three, four, five inch reflectors that people buy for $200 or less often times for their first scope, or a Dobsonian or something like that—in general, will all of these telescopes be the kinds of things that, without too much trouble, you can hook up to a camera? Now, before you answer that, I assume you have to have the kind of camera where the lenses are removable so that you can connect it to the telescope? I mean, a simple point and shoot with a fixed lens is not going to cut it, is that right?
JB: For the most part, at least for the better shots that you’re going to get. So, if you ever go to, like, a “star party” that a local astronomy club is hosting, people will come up all the time and they’ll look at the moon through your telescope and they’ll say “hey can I take a picture of this”, and they can sometimes get a pretty decent shot just putting their cell phone camera up to the eyepiece. But, the absolute best way is to be able to remove the lens, so if you have Canon or Nikon they make these things called T-ring adapters and you basically put that in where a lens would go and then on the other end you have a barrel that’s like an eyepiece that you just stick straight into the telescope and so that way you don’t have to worry about getting the edges of the eyepiece in your image so you can illuminate as much of the chip as possible and have the best chance of getting a decent image. So, I guess I’d mention, you know, the cheaper telescopes that you’re going to get, so, Dobsonians don’t come with any kind of mount that will track as you’re trying to take the picture, and that’s very important because the sky moves on the order of, you know, a star can move from one end to the other of a decent-sized eyepiece in maybe a minute. We’re talking exposures of lengths five minutes, ten minutes, and up, if you really want to get serious. So, that’s certainly something that you need to make sure that you have is a decent mount that will track the sky. I’d also mention that the optics are very important. A lot of the smaller telescopes that you can get decent wide field shots, you tend to see that with refractors instead of reflectors–typically that’s because refractors, you’re able to make the glass better quality than you can make the mirror on a small reflector. So the one tradeoff is you’re then paying more for the lenses, so my smallest telescope for instance is just an Astro-Tech refractor, and it’s what’s called apochromatic. It’s only 66mm across, but it gets me beautiful wide-range shots of the sky.
KK: Obviously there are a lot of things to think about as you get involved in this. But, if somebody were just getting into this, maybe a younger person, and they had a limited budget that they would be able to put forth on this venture of getting inolved in astrophotography. Let’s assume they already have a reasonable reflector or a reasonable refractor that they can use for this. With a motorized mount that is going to track the stars as you already said… which is, I think, many serious amateur astronomers of all ages would probably have a setup at least like that. What’s left then is the adapter to get the camera into the eyepiece; are there any other substantial hardware outlays, assuming they had that much besides what I think you called the T-adapter?
JB: So, yeah, there’s not any major extra things that you’d sort of have to purchase. There’s lots of little perks that you can get. This is just to sort of take the intermediate level shots, so not the ones that are going to featured by NASA or anything like that. But, just stuff to take of your own, so you’ll probably want to get a cable release for your camera, and assuming you have like a laptop that you can take out to the field, having the ability to connect your camera to your laptop is very useful–especially for doing, you know, longer bulb exposures.
KK: So let me ask you this, Joe, about what you will actually see when you start doing astrophotography. Everyone is aware when they look up at the stars that they’re looking at a wide variety of colors, for example, that the stars are supposed to possess. That being said, really, the gradations in color are very, sort of, subtle, when you’re standing there on the ground using your eyes to look at the stars. And you know the richness of, for example, the Orion Nebula that you see in the books and online–you don’t see anything like that with the kind of observations you do with your eyes…often times even with the telescope. When you start taking longer exposures with astrophotography, do you start seeing those stark contrasts and colors and some of those things that you’re used to seeing, or is that really a function of filtering what the camera sees or something like that?
JB: You definitely see an effect by taking longer exposures. So the issue is when you’re looking at it with your eye, that’s basically the equivalent of taking a fraction of a second image that’s being done with your eye in place of a camera. And, you know, it’s being transmitted to your brain and typically you’re not able to see anywhere near the color that you can get when you do a long exposure. So, you can see color in galaxies and things like that whereas optically, if I look at a galaxy, I’m lucky—you know everything is basically shades of gray. And the only things that really exhibit any color in the sky, you know, stars sometimes exhibit color, especially if they’re particularly bright, and, the planets certainly exhibit color, but you know in part that’s just because they’re a lot brighter and they are a lot closer than these big galaxies. So, the more the you expose, the better of a shot that you’re going to get within certain limits. You can’t just take a one hour exposure and, you know, expect for it to be spectacular without having to do a lot of extra work.
KK: OK, so, Joe I want to move on to this very interesting trip that you’ve recently come back from to Kitt Peak. Before we do that, if somebody’s interest has already been piqued by what you’ve said, and they want to think about getting started in astrophotography, there’s got to be some kind of a web page resource out there that is a good starting point, a good jumping-off point for people to learn more about that at their own pace. Maybe you can tell us what some of the resources are for that?
JB: Yeah sure, so, a good site to go to, if you go to skyandtelescope.com, and sort of browse around on that site, there’s plenty of both articles and just I think they even have an entire astrophotography section. On top of that, you can sort of, just google “how to get started in astrophotography”. So, lots of people have sort of set up websites on how to do this. We haven’t even touched on things like you can even use a webcam to do astrophotography; there’s also more advanced techniques like using CCD cameras, and those produce some of the real eye-opener pictures. But, yes, there’s a very wide community online that deals with this, and just about anything that you might want to get interested in there’s also probably a Yahoo! group around it. So, that’s sort of the forum where you can ask questions and try to figure out, you know, what you’re doing wrong, or, what you need to be doing…
KK: So, at some point, you became more than just a beginning astrophotographer. You became interested enough in it that you’ve actually gone and done some of the more advanced things that can be done with astrophotography by amateurs. So, I guess you went for a whole week to Kitt Peak, Arizona, where you were able to use some of that equipment over there with, in conjunction with your photography equipment to take some really spectacular photos that we’re going to tell people where they can see some of those photos. But, how does that work? How many observatories offer a service like that? How much does it cost? What does it take to get involved in that, and what you are getting, what is the difference when you go and do something like that?
JB: I first found out about this program down at Kitt Peak through a friend of mine whose sort of my mentor when it comes to getting into astronomy, and, he takes spectacular images and he basically just wanted to go down there to learn to use his CCD camera. So, he found out about this program that Kitt Peak runs called the Advanced Observer Program. So, the basic premise is it’s just you, and a guide, and one of the telescopes at Kitt Peak just all night long. And you can do whatever you want with them. They have people that want to do visual observing, they have people like me who want to go down and take a bunch of photos with a digital SLR. There’s also people like my friend that just want to learn how to use a CCD camera, and they may spend the entire night there and only get maybe two shots, two actual images out, but, the images are the type of things that you want to set as the wallpaper on your computer they’re so fantastic. So, in this case, Kitt Peak is an observatory down near Tucson, Arizona, it’s maybe 50 miles to the west of it. It is some of the darkest skies in the entire country. So, we haven’t really touched on this yet but where I live near Washington, DC, we get an awful lot of light pollution just from the city of DC and Baltimore and lots of other little towns nearby, so that, you know even driving thirty minutes out of town, you’re still not even close to what you need to do really serious astrophotography–the things where you’re talking like ten minute exposure just because the background brightness of the sky is so much that it kind of blows out your image. So Kitt Peak is close to as dark as you’re going to get in the continental United States. So they offer this program–so the cost of the program itself is $550, on top of that there’s a $150 fee for–so you get to stay in a dorm the next night–so the $550 covers up to two people, so you can bring a friend, so I went with my brother once and with a friend just this last time. So, you go there, you sort of stay up all night with the telescope, and then you sleep for a couple of hours during the day in the dorm. The views are spectacular up there, you’re about 7000 ft above sea level there, so you can see Tucson from there, you can see into Mexico. It’s just lots of very pretty mountainous territory. On top of that, Kitt Peak is also a pretty decent location for doing regular astronomy, so they have dozens of telescopes, each of which is doing a very specific type of mission so they have things doing variable stars, and asteroids, and gamma ray bursts, and just about anything that you can think of up there. So, while you’re there, you would be able to tour a couple of the bigger telescopes, so they have a solar telescope, and then a telescope with a two meter mirror, and another one with a four meter mirror, it used to be one of the biggest in the world…so right now it’s somewhere around thirtieth largest [it’s actually 27th, and is called the Nicholas U. Mayall 4 meter. I looked it up. -KK] . As to what other places might offer something like this, I believe there’s something similar on Mt. Lemmon [Observatory], down near Tucson. So this was started by somebody that used to be at Kitt Peak. But aside from that, there are not very many other locations in very good dark sites at famous observatories, where you, where it’s just going to be you and a guide all night doing some sort of amateur astronomy. There’s certainly places like the Keck Telescope out in Hawaii, but typically to get to use that, you have to be a serious researcher with funding. So there, you’re talking like tens of thousands of dollars to observe on it as opposed to just a few hundred.
KK: I see, that’s interesting. So, if anybody was going to make the step up to taking shots like that with real impressive telescopic equipment, Kitt Peak is really your main viable option?
JB: Yes, it’s definitely the premier place for taking astrophotography. I think you really want to get to a good dark site, and Kitt Peak is sort of set up for that. They have the telescopes, they have the cameras, you can bring your own camera if you like. I actually borrowed one of these Astro-Tracs from a friend, and outside I was just taking pictures of the night sky. So I took Milky Way shots, and wide field shots, using just my regular Canon [EOS Rebel] T2i, and then, so the telescope that I actually got to use, they have a twenty inch Ritchey–Chrétien telescope. I actually didn’t use that at all for taking pictures, but I used the finder scope on it, which is a Takahashi [Seisakusho] 106mm FSQ, which is one of the finest refractors ever made. So I got to take pictures through that with a Canon [EOS] 60Da, so this is a relatively new camera, that was specifically designed by Canon with astronomy in mind. So, it has increased sensitivity in infra-red and various other wavelengths. So, when you take pictures–some of the redder objects in the sky show up even redder than they would with a normal digital SLR, just thanks to this camera. So it was a fantastic experience!
KK: That’s interesting. And you’ve done it twice?
JB: Yes, the first time I went was in October of 2011, and then I decided to go again in April of this year–of 2013–and so by doing that, since each time I go I’m basically staying up the entire night, you end up seeing essentially the entire sky.
KK: I guess I was one of the first to see the results of your labors this last time. So let me tell people where they can see what you’ve done. Dr. Bohanon has a web site at joebohanon.com. So he has a web site there, and there is a number of resources there. Joe, like I said, is a mathematician, so there’s a little bit of math up there, but the bulk of the website is astronomy related, and quite a bit of astrophotography on there. At the top of the site you will see a button for Kitt Peak, and Joe had just recently put that up there for anyone listening to the podcast. If you click that button, you will be able to see several dozen–some of the pictures that Joe was able to take on this trip to Kitt Peak. And, if you poke around on the web site, you can see some of his other work, that he’s just taken, from various reasonable locations around here with the equipment that he has. So, that website’s got a lot of stuff on it. So, Joe, let’s say that there’s another amateur astrophotographer that wants to show you some of his work, or let’s say there’s somebody out there interested in getting involved, or a young person that wants to talk to you about this. They can send you an email I’m sure. That would be joe at joebohanon dot com yes?
JB: That is correct.
KK: You don’t mind receiving emails? You have no problem at all with that, right?
JB: No, I’m happy to help with somebody that’s interested in getting into astrophotography.
KK: OK great. Is there anything else that you want to add for people interested in this topic, Joe?
JB: So I mentioned if you just google “advanced observing program”, you should be able to find a link to the Kitt Peak web site, and, they have more information if you’d like to set up a night like this. Like I mentioned, if you want to just go and look through the telescope, you can do that the entire night. You don’t even have to bring an observing list. The guides there are very knowledgable, you can just say show me the best stuff there is to see, and they’ll be able to keep you occupied all night long. So that’s very helpful. I guess I’d also mention you do have some minor issues with the weather. So, the weather doesn’t always cooperate with astronomers. The people at Kitt Peak sort of understand that. The worst time to go is anytime in July or August because that’s when monsoon season hits in Arizona, so, it’s usually cloudy and rainy the entire time. Most of the rest of the year, you can expect fairly good weather, so you have a fairly decent chance of being able to go, so it turned out that the week that I was going to go, you sort of have to book these a couple months in advance, so they tell you expect to be down here for a week and find other things to do in the area just so you haven’t wasted a plane ticket if you come out. So I’d been looking at the weather the entire week leading up this. And, I was originally going to go on one night, and the weather looked a little bit better the previous night, so I actually called them a few days earlier, and said, hey, is there anyway we can move this back? And they were able to sort of work around their schedule and make this work for me. So it ended up being a fantastic night while I was down there, and then, the rest of the week I got to see the Grand Canyon and Meteor Crater, so we basically tooled all around the State of Arizona. So, you can see pictures of those on my blog as well, too.
KK: We’ve been talking for a long time about astrophotography and it’s all been very interesting. Hopefully, if anyone is interested in the topic, that this introduction has been enough for them to get started. By all means definitely check out Dr. Bohanon’s site; there’s just filled with very very nice photographs and other information about astronomy and certainly anybody listening to this podcast should find a lot to recommend on that site. And so thank you for your time Joe; it’s the kind of topic you don’t hear very much on this podcast. I’m glad you’ve been able to give a little bit of an introduction.
JB: Sure, thanks for having me!
End of podcast:
365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the New Media Working Group of the International Year of Astronomy 2009. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.
Trackbacks/Pingbacks