A question of astrophotography...

[jkaufman]

Greetings,

 

I am interested in extending my nature photography into

astrophotography. This seems like a natural extension to me, as

such shots are really the ultimate landscape.

 

My question is whether to look toward a refractor or reflector (both

with motorized dual-axis drive). My primary goal would be

stargazing, with a close secondary goal of capturing galaxies,

nebulae, and star fields on film.

 

Thanks much to those who respond. I am a total novice in the area

of astrophotography, and would like to start planning now, a good 6

months before I purchase anything.

[richard_cochran]

I don't know the answer, I only know that both types have their

uses. You might want to try the Usenet group <a href="http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&group=sci.astro.amateur">sci.astro.amateur</a>. Be sure and search a bit, because I suspect the reflector vs.

refractor debate has been covered already.

[art_haykin]

A good mirror (or reflector) by all means. Most serious amateurs use them and virtually all pros. You get more magnification for the buck along with more light gathering power. You should have at least a 6 inch, and an 8 inch ideally with a tracking motor. Years ago, one of my industrial accounts was an old genius machine tool designer and maker and an avid astronomer. He hand ground his own 16 mirror, and built his scope, drive, and camera attachment from scratch. He did pay to have the mirror surface coated and he bought his eyepieces, but that was it!

[jerry thirsty]

Regardless of what type you go for, I would recommend favoring a fast f-ratio over a long focal length. Also, probably the best way to ease into astrophotography is piggybacking, so you might want to pay attention to how it would mount on a particular set-up (i.e. would the optical tube protrude into the camera field of view if you are using a wide-angle lens; is the piggyback mounting location reasonably close to being centered over the mount). Another thing to keep in mind is that if you get an 85 pound 10" Newtonian you may think of a lot more excuses not to go out at night than if you get a 35 pound refractor.

Personally, I have an 8" Schmidt-Cassegrain and I have been working on my piggybacking technique for over a year (whenever I have a clear weekend near the new moon). I have been finding that even piggybacking is not as easy as it sounds. All of my wide-angle lenses exhibit "seagulls" in the corners of the frame if used wide open or a stop down; my best lenses have turned out to be the 105 and 135mm. The only photos I've actually taken through the scope are lunar and planetary, and I have yet to cough up the $$$ for an off-axis guider and focal reducer. If I were starting over again and had the money, I think I would go for a fast refractor on the nicest mount I could afford.

[johnb]

Stick to a Refractor (not a reflector), a refractor works the same way your camera lenses work so it is usable night and day. ex. Good for bird photos. I use a Celestron Refractor (CR-150 HD 6) and it works almost as good as some of my lenses (almost). As far as f/stop I have found f/8 to be best overall usage for DOF (each telescope has only 1 f/stop). Oh yea make sure your telescope has a 2 inch diameter eye piece size to mount T adapter (adapter from camera to telescope), older telescopes used 1 1/4 inch which is much less light.

 

Good Luck<div></div>

[jonathan_bundick]

Jason,

 

I have comtemplated doing just what you are considering, but after several months of searching, reading, and agonizing over it, I have decided to try and get the most out of my home built Barn Door drive before spending the big bucks for a decent scope and heavy mount. I've played with it a few times, but never realy put the time in to try a precise polar alignment and long exposures at a dark site.

 

From all my searchning the best advice I have found is that most scopes are paired with a mount able to cary a scope one size smaller than what you are buying, and the mount is all important if you want to capture deep sky objects like you suggest. Buy a heavy mount, an EQ-3 or larger for a 6 inch scope.

 

Refractor/Reflector Two camps. Refractor guys will tell you that the Reflectors are almost useless for astro photography, and they have some draw backs, but for most of us, either will do the job, and you can get more light gathering ability for the buck with a reflector.

 

You can find much more indepth info at:

 

http://www.cloudynights.com/

 

Hours of reading with lots of knowledgable posts. Good luck and post some results when you can.<div></div>

[bert_krages1]

<p>

The different types of telescopes have their advantages and disadvantages for astrophotography. On the whole, the best choice for someone wanting to start telescope-based photography would be an eight-SCT with a wedge and computer guided mount such as the Meade LX200. Obtaining all the equipment you need to get started on a bare-bones basis will likely cost at least $3000. If you like the images you are getting with this kind of setup, you can add an autoguider and CCD for a few thousand dollars more.

<p>

All lot of people are tempted to try to get by with a less inexpensive setup but almost always end up being disappointed. Even on a calm night, keeping a guided telescope on a steady course for long exposures is nearly impossible with the mounts that come with the mid-range amateur telescopes. It can be fairly difficult with mounts designed for astrophotography since even slight disruptions can ruin an image.

<p>

The recommendation to start out with a barn door tracker is a good one. For an investment of $15 and some time, you can ascertain whether you really want to put up with the tedium and effort required to get deep sky images. I would add to that recommendation that you learn more about observational astronomy and get some experience using a fast 50mm lens and tripod. There are a lot of interesting objects and events that can be recorded with conventional equipment. The forthcoming Leonid meteor shower in November is a good example. A few years ago, a friend and I hiked up to a viewpoint opposite Mt. Hood in Oregon to photograph the <A HREF="http://www.krages.com/leonid.htm">showers</A>. I personally like making these kinds of images better than tracked photography but other people have different preferences. In any case, most astrophotographers strongly recommend getting into genre slowly and adding equipment after you become proficient at finding objects in the sky.

[alex_lofquist]

How portable do you wish to be?

[dave_mueller]

Read A LOT of information before you buy anything. There are pros and cons to both scope types for general viewing as well as astrophotography. The SCTs seem to have an edge for portability as well as being designed with photography as an option. A good refractor is the most expensive, but will have the smallest aperture for the money. Most Newtonian reflectors are designed for eyepieces, you might have problems reaching prime focus with the T adapter on the camera. I had this problem with mine, I had to move the mirror to push the focal point farther away from the tube. As a beginner, you probably won't seem any difference in any of the brand name scopes (Meade, Celestron, Orion, Discovery and a few other "big" names). For a reflector, probably a 6" f/6 to f/8 would be good, but you'll need a serious mount. The SCTs come with their own mount (usually), if you can, try to get the mount for the next size up scope. Check www.astropix.com, and Covington's book Astrophotography for the Amateur. I almost had my barn door finished when I got a nice bonus at work and came across a scope with a Losmandy G-11 mount. The scope weighs 20 pounds, the mount weighs about 80 (just like normal photography, the tripod and head make more of an impact on stability than the camera or lens).

[kirk_keyes]

Definitely save up our money as you will want to get better quality gear. I broke the bank for a Meade LX-200 8" SCT several years ago and I am thoroughly pleased with it. Quick to set up, easy to operate, and I can bolt a camera to the top of it or shoot through it.

 

But before you buy anything, check around your area and see where the nearest astronomy club is and addend some meetings and observing nights. Before I got my scope, I went to the Oregon Star Party and spent two nights with a bunch of hard-core astronomy people. They had lectures, and there were dealers there with equipment to look at, and best of all, there were about 100 telescopes there - and every owner was happy to let you look through their scope and answer questions about why they bought (or made) the equipment that they owned. It was very informative. You don't need to go to one of the bigger star parties to get this info - just find out where there is a club nearby and talk with them. There is nothing like a little hands-on (or eyes-on) experience when learning about telescopes.

[bruce_kapla]

Forget which type, Refractor or Reflector........put your money on a VERY stable mount, meaning high end with dual axis drive and PEC, such as those from Losmandy or Celestron. GEM preferrably(German equitorial). The best optics are useless without a good mount, especially for astrophotography.

[yeow_teng_kuah]

I second Bruce's view. You can have the best Refactor / Reflector / SCT or MCT ..... without a stable mount, you will have jitterly pictures. I suggest at least a GEM 5 mount for absolute stability up to 8 inch SCT.

 

Oh, and regarding the fast f/stop ratio and slow f/stop ratio, it all boils down to $$$ and what you want to take. For bright objects like Planets / Moon / Sun, a slow f/stop ratio will be better. You will get alot more contrast then a fast f/stop ratio scope. A Catadioptic Scope will be very much perfect for it.

 

For taking of Nebula, star trails, fast moving space objects (comet?), a fast ratio scope such as a Refractor will be better.

 

However, if you are not very particular about weight and being a newbie into astromoy, I suggest you start with a reflector instead. It gives you the very basics of all the telescopes in the future you may get. It has a high contrast and the f/ratio very much depends on your requirement (the longer the scope, the slower the f/ratio). It does not have C.A. like non APO refractor (btw, APO refractor cost a bomb, non APO refractor is good for dim object, but for bright object, you will see alot of false colour, something you will not see on a Catadioptic or Reflector).

 

But all in all, invest on a strong mount .... trust me .... for astrophotography, and even for general viewing .... you will need it .....

[b_b21]

IMHO there is nothing like hands on experience, on this page you are able to find your local astronomy club, and they will gladly show you how every type of telescope works. Pros and cons.

 

http://skyandtelescope.com/resources/organizations/default.asp

 

Remember that to have a nice nature fotograph you need a good tripod. In astronomy they are called mounts. Try and look at various types, and what you need. The farther the object you want to photograph, the dimmer it is going to be and the more stable and accurate your mount has to be.

 

Have a great time and be warm.

 

B. B.

[jkaufman]

Greetings All,

 

Thank you much for the many responses to my inquiry. In part the result of these responses, I have decided to first try my hand using fast films on a fixed tripod. If I get the hang of shooting the stars in this manner, then perhaps I will consider making the financial investment of true astrophotography. For the meantime, I shall play with the equipment I have.

[FilmPhotography-DuaneHorne]

In 2003 I printed an article by Art Whipple on Solar Photography. I also printed other articles by different writers on Astrophotography. I had purchased my first 35mm camera only 2 years before that. Prior to that I had no other interest in photography other that snap shots of family and vacations. I purchased a Canon Rebel and after that I got hooked.

 

I started purchasing additional lenses, nothing expensive or fancy, just a couple of consumer zooms. One day while window shopping at a used camera store, I found and old Bauch and Lomb 1200 mm mirror lens/ I thought it was the greatest discovery at that time and planned to use it to shoot wildlife. The salesman said it would be too slow with its f11 apeture (I did not know what "f11" meant and did not know what apeture was). Besides this salesman could not have known what he was talking about; as far as I was concerned it was the biggest lens I had ever seen and was delicious eye candy.

 

A trip to a wildlife refuge and a review of the resulting images proved his point. In any event I put the lens in the closet and left it there until I say a full moon one evening. I started reading on lunan photography and withing a few months, after taking countless images and finally investing in a sturdy tripod and learning to use the mirror lock up function on my new Elan 7e, I finally got a decent, detailed image of the moon.

 

When I ventured into solar photography, I made my own filter. The filter was dark red in color and made the sun appear orange. Later I purchased Baeder film, which renders images white. When the venus transit occured a few years ago, I took several images using slide film. I posted several of the on photo.net.

 

These images was recorded on film utilizing a home made solar filter (mylar material if the image is coloured or baedar "foil like film also refered to as a white filter" if the image is white). I used a 1200 mm f11 Bausch and Lomb Smcmidt-Cassergrin reflector, with or without a manual 2X TC, employing prime focus.

 

In a long winded way, I am endorsing reflectors. I bought mine very cheap, about 200 dollars. I have not done any deep space work or used any tracking equipment. Star Trails are next on my list and after that perhaps some deep space work. There is an observatory at a local university not too far from where I live. I have spoken to them and they have agreed to let me use their equipment.

[FilmPhotography-DuaneHorne]

Some examples<div></div>

[FilmPhotography-DuaneHorne]

another

[FilmPhotography-DuaneHorne]

another example<div></div>

[FilmPhotography-DuaneHorne]

last one<div></div>

[jkaufman]

Duane,

 

Thank you for the detailed response to my query from so far back. Kudos on the very nice photos.