Currently have a 75-300 IS and not really fast enough focusing

[canonlover]

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

 

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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.

 

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

 

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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!

 

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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.

 

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

[isaac sibson]

More light.

 

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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.

 

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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.

[puppy_face2]

Of course, there are several great solutions, but they'll cost ya! The EF 100-400

IS USM comes to mind...

 

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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.

 

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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).

[Ken Katz]

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).

 

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

[NK Guy]

>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.

 

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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.

[paul_nicol]

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).

 

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Paul Nicol

[lee_shively]

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.