I have recently bought into EOS system, and just made some R3 prints out of Velvia. One of my arsenal 24-85 was put on Manfrott 190 and ballhead, F8 and mirror prefire etc, anyway it turned out that 11x14 enlargement was only on par with same size enlargement from my Olympus Miu II. I know it is short of quality out of L or prime which I also have, and the enlargements from 50/2.5 macro and 70-200/4L did pronounce a lot better which are in the same lot back from a local pro lab(I made 11 enlargements all together), however, my questions are:

1) Is it a physical limit that this lens is not up to 8x10 critical sharpness on the best film? (I made the shot at the 24mm end)

2) I evaluated slides by a 8x loupe and thought the slides with 24-85 were as sharp as those I shot with other lens stated above. Can you help me if there is any rule of thumb to tell which slide is up for what size of enlargement by using 10x,16x or...... magnification loupe?

Many thanks for your time

2)

-- George Zhang (george.zhang@china.zeneca.com), June 21, 2000

Answers

i don't have the 24-85, but i do have the 28-105, which is almost identical in optical performance. i've always noticed that the wide end is kind of soft. but i've gotten pretty good results up to 8x10 with velvia and provia etc f8 or slower.

and also, when you enlarge a 35mm slide to 11x14, you will see alot of softness that you couldn't seen with a 8x loupe, because 35mm to 11x14 is more than 8x...

-- howard shen (hshen@lsm.org), June 21, 2000.

You'll find that 8x10 is you safest bet, image quality-wise in 35mm. If you really want a larger print you need a prime lens and a medium format camera. That is the basic fact of size and image quality.

Having stated to obvious, you can try a set of prints yourself and see what you get. If you are thinking you will buy this lens and get huge print performance, you need to brush up on the capabilities of 35mm lens quality in general.

-- Chris Gillis (chris@photogenica.net), June 21, 2000.

George consumer zooms are notorious for bad performance at extreme ends of the zoom. If you're looking for large prints and don't want to replace everything you've invested in as some people may suggest, Canon makes some affordable 24-28mm primes as does Sigma that should be fine at 11x14.

-- Steven Fisher (srf@srf.com), June 22, 2000.

Might be your printer. I've had type R prints done at one printer, which came out pathetic, and got great results through another lab. Don't buy all the consumer-lens bashing you hear. Trust your eyes. If you're unhappy with the print quality, send it back. A good lab will try until you're satisfied...

-- Scott (bliorg@yahoo.com), June 27, 2000.

I have had a 24-85 Canon for a couple of years, and have used it professionally. I don't much care for it. I am not a rigorous lens testing sort, but I have high standards in lenses, gained partly through long experience with Leica M's. This lens doesn't satisfy me often enough.

It seems "mushy" at or near wide open, and at near 85mm unless stopped down well. I rented a EF 28-70 f 2.8 for a recent wedding job, and am much happier. I need to use lenses at max aperture often because I work in weak light and don't like to use flash all the time. The 28-70 will stand up to comparison to the Canon primes. It may not test as well but it's good enough. The 24-85 will probably either get sold or languish as a spare.

Too had. I love the range, and would be very happy with a L quality constant f2.8. But it would be even more of a tank than the 28-70, which is big enough.

If I didn't need the zoom for pro use, I'd stick to the 24mm 2.8 and the 85mm 1.8, and get excellent results even when used to their limits.

-- Jonathan Barber (jbarber@squonk.net), June 27, 2000.