I currently have an EOS 30, 28-105 USM II and 75-300 IS.

I really like the 75-300 IS, but find that I miss some shots as it is really unreliable for locking on to or tracking subjects above around 250mm. At focal lengths below 250mm it seems fine.

Is this a problem with my lens or is it typical of this model?

I can't justify throwing pots of money at an L lens, and would miss the extra 50-100mm of my 75-300 compared to a 70-200L. Adding a 1.4x TC to the L lens would cost even more!

I did try a Sigma lens and Canon 100-300mm on my EOS30, but didn't find them to be that much better above 250mm.

Is there a solution to my dilema, of finding a fast focusing, reliable long zoom?

-- canonlover (canoneosd60@aol.com), February 08, 2002

Answers

More light.

I think the problem you're having is due to the focus sensor not getting enough light. In brighter conditions, you should find that it's fine.

The only solution is to use a faster aperture lens, or a body which is more capable in low light, eg an EOS 3, 1V or 1D.

-- Isaac Sibson (isibson@hotmail.com), February 08, 2002.

Of course, there are several great solutions, but they'll cost ya! The EF 100-400 IS USM comes to mind...

I have the EF 75-300 IS USM but don't use it anymore (I guess I should sell it). But, yes, AF is so slow it hurts my teeth. The slow AF is due to more than a lack of light: it has a weak and crappy motor (mine burnout while under warranty) and lacks internal focusing. A Micro Ultrasonic Motor drives the heavy front lens group and, thus, AF is painfully slow compared to the ring-type USM and internal focus of the EF 100-300 4.5-5.6 USM or EF 70-200 4L USM. The front element turns and the barrel extends/contracts during focus making use of polarizer filters frustrating. Furthermore, the AF mechanism lacks a clutch--primitive for an expensive lens--and, hence, the manual focusing ring rotates during AF. Watch your fingers! It lacks FT-M so you must flip a switch before manually focusing. If you want to prefocus manually, forget it because there is no distance window.

I faced the same dilemma last Summer. I bought the EF 70-200 4L USM and have been extremely happy with its performance. It has almost everything I wish the 75-300 IS had: robust build, ultra fast AF, distance window, FT-M and internal focus and zoom (i.e., no front element turning or extension). I miss the 300mm end (and IS), but I have an old EF 300 4L USM to fill that nich (a wonderful lens).

-- Puppy Face (doggieface@aol.com), February 08, 2002.

Using both the 100-300USM and 70-200 F4L, on an Elan IIE, I found that both lenses focused quickly and reliably, even in dim light. My EOS 3 also works well (maybe better than the Elan, but not dramatically better).

At 300mm, try using just use the center focusing sensor.

-- kenneth katz (socks@bestweb.net), February 08, 2002.

>Using both the 100-300USM and 70-200 F4L, on an Elan IIE, I found that both lenses focused quickly and reliably, even in dim light.

Indeed. I found the 100-300 USM to be mechanically quite a nice lens indeed. Optically it was disappointing - only slightly better than the 75-300 II USM. But the latter is such a slow lens and does not support full-time manual.

-- NK Guy (tela@tela.bc.ca), February 08, 2002.

kenneth katz is on to a solution. I found with my ElanII that when I switched to center only focusing, the speed and accuracy of focusing doubled. (in low light).

Paul Nicol

-- Paul Nicol (nicol@roadrunner.nf.net), February 09, 2002.

As odd as it may seem, I've read and heard a lot recently from many professional photographers who ONLY use the center focus points on all their cameras. A lot of these guys are using EOS 3's and 1V's and they've got 44 focus points they have decided they don't need. And I thought I was weird because I only use the center focus points on my EOS cameras.

-- Lee (Leemarthakiri@sport.rr.com), February 10, 2002.