Starting with Astro shots on a budget ?

[J.A.F. Doorhof]

Hi,
I want to start out with astro photography but I have a few questions.
I live in the Netherlands in an area without sky polution and clear view most of the times.

I want to start out with astro photography but I don't want to break the bank YET.
What should I buy.

I allready own a 400mm lens and a 1.4x convertor when combining them I get arround 900mm (1.6x +1.4x) when looking at scopes they are arround 1000mm do I win very much or am I missing something ?

Hope some one can help me with a starters kit advice.

Greetings,
Frank

[kfong]

Hi,
I live in the Netherlands in an area without sky polution and clear view most of the times.

Oh you are soooo lucky...

I allready own a 400mm lens and a 1.4x convertor when combining them I get arround 900mm (1.6x +1.4x) when looking at scopes they are arround 1000mm do I win very much or am I missing something ?

Frank

Telescope's are around 1000mm to 2000mm because the eyepieces they use are built for this range.
Eyepiece focal lengths ranges from 2mm to 40mm, giving you a magnification range of 25X to 1000X. Realistically anytthing > 300X is un-useable due to atmospheric disturbance (pooring seeing). Your DSLR behaves as if it have a 50mm / 1.6 eyepiece, so that will give you a pretty wide field at the low end of the magnification range.
You didn't mention the aperature of your telephoto lens. This is very important in astrophotograhpy.
Other consideration is the types of objects you are interested in, listed in order of difficulties:

Star trail: you can use a 50mm and a sturdy tripod.

Consternation: a 50mm but with a tracking mount.

Moon: your 400mm will do just fine. Keep the exposure to below 1/100 s to mininize the effect of earth's rotation.

Bright nebula: A 400mm will do, but you'll probably need both a large aperature and a good tracking mount.

Planets: You'll need anywhere from 5000mm to 10000mm, so eyepiece projection through a telescope. Since the magnification is so high, a good tracking mount is also necessary.

Deep sky objects: This is like bright nebula, except that the light are much much weaker. Exposure of several hours are not uncommon. I haven't try this since I live in a suburban area .

The difficulties you'll encounter will be many, but with a telephoto lens the first 2 are
1. locating the object.
2. focusing.

Ken

[jaypie77]

Ken, any advice on where to buy good astrophotography equipment? I know that you can easily make a simple tracking mount, but I suck at building things.

[mattchase]

You will probably want to start out shooting with a normal lens, like a 50mm or so. It will be more forgiving to tracking errors, which when you are first starting out can be very frustrating and discouraging. With a long lens, in a matter of a couple of seconds things can start moving out of your view, so tracking accuracy is very important. The best place to start with astro work would be wide field shots of the stars and constelations (multiple minutes per shot, so you need to track them), and shots of the moon with a long lens at a fast shutter speed (no tracking). Once you get those down, move up to something like the Orion nebula, which is found around Orion's underarm, and could probably be shot with between a 500mm (a bit wide) to 1000mm lens at about 60 seconds depending on ISO and aperture.

Without breaking the bank, check out http://www.telescope.com . They have a few different tracking platforms / tripods that are pretty good. They aren't the most accurate, they suffer a bit for doing really long exposure work with a long lens where accuracy is very important, but they work well for wide field work and as a starter rig. They also won't break the bank. :)

I have two items from Orion, one is the mini eq mount and drive that is made specificaly for use with a camera http://www.telescope.com/shopping/product/detailmain.jsp?itemID=296&itemType=PRODUCT&iMainCat=6&iSubCat=24&iProductID=296 , which is a nice little head that is highly portable. The drawback is it can't handle much weight.

The other item I have is the SkyView Pro mount with dual axis drive, http://www.telescope.com/shopping/product/detailmain.jsp?itemID=376&itemType=PRODUCT&iMainCat=6&iSubCat=24&iProductID=376 . With this rig, I have done some wide field shots with a 50mm lens for about 6 or 8 or 10 minutes and gotten good results. See example here http://www.matthewchase.com/astrophotos/2_22_03/img_4561.htm .

If you want really high end, accurate tracking platforms, look into something like the Vixen line of mounts http://www.kendrick-ai.com/astro/mt_vixen.html or Losmandy http://www.kendrick-ai.com/astro/mt_losmandy.html . Brace yourself for a bit of sticker shock...

Did you survive the links? ;)

[kfong]

Ken, any advice on where to buy good astrophotography equipment? I know that you can easily make a simple tracking mount, but I suck at building things.

In addition to www.telescope.com, you may try www.scopetronix.com, www.digitalastronomy.com and www.jmimobile.com.

There is also a fairly good and not too long article in http://www.atscope.com.au/astrophoto.html on the equipments needed for different kinds of astrophotography.

As for building your own mount, the manual barn-door type is not too difficult, but it is only limited to no more than several minutes of tracking and low to medium magnification. Anything else would be better served by a German Equatorial Mount or a Alt-Az mount on a equatorial wedge. And unless you are a master machinist, I wouldn't recommend building your own. Commerical Off the shelf mounts ranges from a few hundred dollars to tens of thousand of dollars. In choosing which mount, you'll have to balance between cost, weight handling capacity, portability, stability and tracking accuracy.
I would recommend as a mininum a GEM with a motorized RA drive, but buy what you'll need in the next 5 year, NOT what you need NOW. The major cost of a mount is in its mechanical precision, so they don't go down in price and they cannot be upgraded easily.
Unlike terrestial photography, where a good picture is 90% photographer and 10% equipment, a good astrophoto is 90% mount, 9.9% optics and 0.1% luck(like capturing a meteor impact on the moon).

Ken

[Hatem Eldoronki]

Hi,
I allready own a 400mm lens and a 1.4x convertor when combining them I get arround 900mm (1.6x +1.4x)
Greetings,
Frank You don't have an equivalent of 900mm. You have 560mm. The 1.6 factor affects the field of view and not the magnification of the subject you're shooting.

Also, check this (http://web.canon.jp/Imaging/astro/index-e.html) for invaluable advice on astrophotography.

[Mark Kemp]

I am not sure about the Netherlands, but a lot of UK photo and optical stores have offers on telescopes at the moment as they are popular Christmas items. It might be worth a quick look around for any special offers.

[J.A.F. Doorhof]

Hi,
I'm looking in the second hand market and they can be bought for very little, will dive into this monday.

[Tom W]

Try http://www.astromart.com/forums/ for some good information as well. The link is the forum, but the site has a lot of other information.