[gregbradley]

I have been researching lenses for my Nikon D800E lately and some of that may help with those wanting to use lens for astrophotography.

One big advantage of Nikon cameras is that they are all compatible with every lens Nikon has ever made. Nikon has made an enormous number of lenses.

Some of them that are quite old in design are still made today. Others are very cheap on the 2nd hand market despite beautiful metal bodies and super sharp performance.

Nikon AI and AIs lenses are often very cheap 2nd hand. Most of these are F2.8 or better.

For example the 105mm F2.5 AI is under $200 yet is rated as a 5 out of 5 at a lens review site and is considered a classic portrait lens that is ultra sharp wide open.

There are 20, 24, 28, 35mm F2.8 AI or AIS lenses 2nd hand that are under $400 each. A new Nikon latest model 24mm F1.4 is $2000+ so you get a lot of lens for the price.

180mm F2.8 ED is a well known classic Nikon lens that is good for astrophotography and is under $450 2nd hand.

Pentax 67 165mm F4 is very good and illuminates a large chipped ccd camera (16803).

Pentax 67 lenses have about 87mm of backfocus making them very handy for astro as you can put a focusing unit in between them and the camera and still achieve focus.

I thought I would pass the info on about the Nikon AI lenses.

You can use these on a Canon easily with a cheap under $20 adapter off Ebay. They'd be all manual focus but all lenses are anyway in astrophotography so that's no different.

What you want is a fast lens (F2.8 seems very workable) that is good wide open with good sharpness and minimal chromatic aberration.

SBIG and FLI and no doubt Apogee sell adapters for their cameras for Nikon lenses.

I have used Canon FD lenses for astro up to 200mm and they seemed good bang for your buck as well.

Greg.