I did eventually join an astronomy forum and quote “astrophotography is a slippery slope of escalating costs.” Some beautiful shots taken by one of the members with an L-Series Canon lens – but the camera was modified – removal of the factory IR filter – and the use of Hydrogen alpha and Oxygen III filters. I was hoping to avoid the costs, but that’s just not possible.

After weeks of research, and this may be of interest, there are several ways to artificially improve images taken in high contrast. A Minus Violet filter for camera lenses and the “Fringe Killer” filter for achromatic refractor telescopes, or just get a purpose built telescope.

I have since ordered an 80mm apochromatic refractor – f/6.3, FL 480mm, Hoya glass FPL-51 flourite triplet, with very good focus in the RGB wavelengths to eliminate fringe colour. The other option was to buy a Canon L-Series lens for around 750, but I went with the refractor – its sole purpose is to focus stars at infinity.

I also purchased a OIII filter for eliminating sodium and mercury wavelengths – street lighting – and increasing contrast when photographing nebula, and a field flattener to have nice circular stars throughout the FOV and a T-ring adapter and ….. you get the picture – so maybe the Leica lens was not such a bad idea after all!

The next purchase will be a good equatorial mount for precision tracking, the Leica lens is looking even better – this will be a huge improvement on my home made barn door tracker.

Many thanks for your advice.

Chromatic aberration is often a problem with high contrast subjects. (They don’t get much more contrasty than pure black to pure white in a pixel or two.) Chromatic aberration is even more of a problem if the lens is not precisely focussed. (You cannot just set the lens to “infinity” and expect it to be in focus for starry skies. Different lenses will behave differently; some can be set to BEYOND infinity, for example.)

You really need to find a good astrophotography forum and ask there. You would probably do best with a real telescope and an adapter to mount the camera. Astrophotography is much more complex than this site would even dream of.

From a pure optics standpoint, I expect that the best Canon lens for you might be the 85mm f/1.2L. Unfortunately, it’s also expensive and heavy–$1970 at B&H and 2.25 lb. You can read reviews of the lens by Ken Rockwell and Bryan Carnathan for more information. Do check on astrophotography forums, though.

The Canon 50mm f/1.2L is probably not as good for your use as the 85mm f/1.2L, though you should think about both.

You’ll also need a rock-solid tripod. Carbon fiber is better than aluminum at absorbing vibration and is lighter, but you should care more about stability than weight. I have a Feisol FT3372 that is quite stable but isn’t all that heavy (under 4 lbs) and “only” $500. (If you check out comparable Gitzo tripods, you’ll see why I said only. The Feisol is, IMO, better-made than Gitzo tripods and costs a lot less.) Mine has 3 leg sections, rather than 4, for more stability (and a bit less weight) and does NOT have a center column, again for better stability and less weight. (You can get a column, but the tripod goes to almost 5 ft. With a ballhead, it’s more than tall enough for me at 5’9″.) Check out other tripods, including aluminum and other metals.

You’ll also want to hang a weight (e.g., your camera bag) on the tripod’s hook.

Be sure to put a very good head on the tripod. A geared head like the Manfrotto 405 would probably be easiest to adjust precisely. Next down might be a 3-way head (each axis has a separate control and lock) like the Manfrotto 229. A very good ballhead would be more versatile, if you do other kinds of photography, but could be harder to line up precisely. You’d want a top-rated ballhead, not some cheap thing. The Really Right Stuff BH-55 or maybe their BH-40, Markins M-20 (or maybe M-10, the one I have), and similar heads could be worth checking out.

To quote from “http://www.dpreview.com/news/0809/08091505leica_50mm_f0_95.asp”, it is the world’s fastest aspherical lens. The wide maximum aperture gives extremely shallow depth of field and very low light capability. The wide maximum aperture gives extremely shallow depth of field and very low light capability. Hand assembled in Solms Germany, this lens is designed to retain its value and usability for decades.