Hi, I used to have a 400mm A f/5.6 lens. I paid about that price for it just about 4 years ago, in mint condition. I used it quite a lot - I was rather surprised by how much. In particular, I used it to photograph wildlife in South Africa, frequently with a T6-2X extender and later with an A2X-L extender. These extenders are very well matched to the lens. I tried it with a cheaper extender and the results were poor and it was very difficult to use because of the darkening of the viewfinder. I was using it with LXs and found that the sports/action finder was of enormous benefit when using the lens with extenders.
The lens letters you quote mean this: K - manual focus without a switch for automatic aperture setting A - manual focus with a switch for automatic aperture setting, so you can use a camera with shutter priority or full program AE mode. F - autofocus (includes the A capability as above) FA - same as F. Later version. I don't know the differences (not an AF man). There is also the M series which comes between the K and A series. They are essentially compact versions of the K lenses. --- Bob Friday, December 21, 2001, 11:38:53 AM, you wrote: > What are the differences between these various lenses ? > I'm looking at a used Pentax 400mm A F/5.6 for 549usd. Is this a good > buy ? I already have : > 50mm F/2 > 35-80mm F/4-5.6 > 70-210mm F/3.9 > 28-105mm F/2.8 - 3.8 > I'm looking at the 400mm for nature shots. I dont have an AF body. I'm > thinking of getting the 1.4 teleconverter also sometime in the near > future. I do have a Vivitar x2 btw. > Thanks > Chris - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .