I know that zoom lenses are usually worse quality-wise than prime lenses, but I would specifically like to know what I lose when choosing a Nikkor 24-85mm f/2.8-4D IF set at 24 mm, instead of a prime 24mm f/2.8 D, apart from weight.

-- Guan Yang (guan@unicast.org), April 03, 2001

Answers

Much worse geometric distortion.
All wide-to-tele zooms go from noticeable barrel distortion at the short end, to pincushion at the long end. The 24mm f/2.8 fixed lens has almost no distortion.
As far as sharpness goes, I don't think there's much to choose.

-- Pete Andrews (p.l.andrews@bham.ac.uk), April 04, 2001.

On thing that is lost is the annotations for depth of field zones. Time was everyone knew how to use depth of field marks on their lenses, especially wide angle lenses. Now with zooms, they are often not available.

If you are doing landscapes, and need the boulder a few feet from the camera and the mountain at infinity sharp, depth of field markings make this effortless. If you are doing a group photo and need a zone from 9-15 feet sharp, it would take 3 seconds to arrive at the correct aperture and focus point with depth of field marks, no guessing, absolute certainty... autofocus gives no benefit in these situations.

The big work around when using an unmarked zoom is to stop your lens down all of the way, but most lenses have reduced performance at the minimal apertures due to diffraction. I'd rather use my lens at f/8 or f/11 than f/22, and using the depth of field marks on prime lenses allow me to know when this is possible. Many zooms sit unused on my shelf after I realized how much I used those little marks. Prime lenses will always live on my camera.

-- Al Smith (smith58@msn.com), April 04, 2001.

The 24-85 set at 24mm will be bigger, heavier, and have more distortion than a 24mm prime. I own the 24-85/2.8-4 and also a 24/2 AI (and used to own the 24/2.8D and 24-120/3.5-5.6). The 24-85 will be somewhat harder to focus manually, because of the short focusing ring throw (better than the 24-120 in manual focusing feel, but a very short throw). This is important on the wide end, because I find that the AF usually picks the wrong thing to focus on, so I work faster in MF mode.

If you use a built-in flash for fill, the 24-85 will block a bit at the bottom all the way up to around 55mm.

The prime also focuses about 7" closer than the zoom at 24mm.

Of course, what you gain with the zoom are all the focal lengths betwen 25mm and 85mm, plus the ability to go 1:2 at 85mm, but that's not what you were asking.

-- John Kuraoka (john@kuraoka.com), April 05, 2001.

Jim Tardio has an interesting review of this lens. http://www.jimtardio.com/24-85.html Also try, http://www.photographyreview.com/

-- Anth Plummer (anthplummer@bigpond.com), June 19, 2001.