Pages: [1]   Go Down

Author Topic: Help - testing Canon 24-105L vs Canon 17-85  (Read 3133 times)

kozure_ookami

  • Newbie
  • *
  • Offline Offline
  • Posts: 1
Help - testing Canon 24-105L vs Canon 17-85
« on: June 07, 2007, 11:46:05 am »

Hi,
I've recently purchased a 24-105L that I wanted to replace my 17-85EFs.
The EFs served me well, but I was never quite happy with it when zooming in at large apertures.
I took some tests shots, but the results are a bit puzzling to me:
- at 24mm the L is better than the EFs (the text on the BIC pen is clearer)
- at 70mm the EFs is better (the text on the L box is barely readable in the L shot)

Here are the tests (my server was pretty unstable this morning, so if the links do not work please copy/paste them in your browser). All shots were taken from tripod, time release, at f5.6. The camera is a Rebel XT. Center focus on the 'Canon' corner of the L box.

At 24mm:
<a href="http://brunovais.xhost.ro/Tests/24-105L_MG_2274-01.jpg">L at 24mm</a>
<a href="http://brunovais.xhost.ro/Tests/17-85_MG_2278-01.jpg">EFs at 24mm</a>

At 70mm:
<a href="http://brunovais.xhost.ro/Tests/24-105Lzoom_MG_2277-01.jpg">L at 70mm</a>
<a href="http://brunovais.xhost.ro/Tests/17-85zoom_MG_2281-01.jpg">EFs at 70mm</a>

Is this normal? I thought the L would win hands down. The colors are indeed better, but the focus is not what I expected.

thanks for your help
« Last Edit: June 07, 2007, 11:48:22 am by kozure_ookami »
Logged

joedevico

  • Full Member
  • ***
  • Offline Offline
  • Posts: 101
    • http://www.photographicdesigngroup.com
Help - testing Canon 24-105L vs Canon 17-85
« Reply #1 on: June 10, 2007, 10:01:44 pm »

In looking at your samples - it seems to my eye that the focus is different in each shot for the 70mm samples. That's why the text on the L box is blurry. It's beyond the focal plane.

I'd try the same shots with a ruler instead of the lens boxes to be sure exactly where the focus point is...

jdv
Logged
Joe DeVico
the PhotoGraphic Design Group

Ray

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 10365
Help - testing Canon 24-105L vs Canon 17-85
« Reply #2 on: June 11, 2007, 04:18:16 am »

Quote
In looking at your samples - it seems to my eye that the focus is different in each shot for the 70mm samples. That's why the text on the L box is blurry. It's beyond the focal plane.

I'd try the same shots with a ruler instead of the lens boxes to be sure exactly where the focus point is...

jdv
[a href=\"index.php?act=findpost&pid=122136\"][{POST_SNAPBACK}][/a]


That's absolutely right. The nearest corner of the EF 17-85mm box is sharper in the 24-105 shot at 70mm. The focussing is not the same for both shots.
Logged

alanrew

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 75
    • http://
Help - testing Canon 24-105L vs Canon 17-85
« Reply #3 on: June 18, 2007, 08:12:33 am »

Quote
Hi,
I've recently purchased a 24-105L that I wanted to replace my 17-85EFs.
The EFs served me well, but I was never quite happy with it when zooming in at large apertures.
I took some tests shots, but the results are a bit puzzling to me:
- at 24mm the L is better than the EFs (the text on the BIC pen is clearer)
- at 70mm the EFs is better (the text on the L box is barely readable in the L shot)

Here are the tests (my server was pretty unstable this morning, so if the links do not work please copy/paste them in your browser). All shots were taken from tripod, time release, at f5.6. The camera is a Rebel XT. Center focus on the 'Canon' corner of the L box.

At 24mm:
<a href="http://brunovais.xhost.ro/Tests/24-105L_MG_2274-01.jpg">L at 24mm</a>
<a href="http://brunovais.xhost.ro/Tests/17-85_MG_2278-01.jpg">EFs at 24mm</a>

At 70mm:
<a href="http://brunovais.xhost.ro/Tests/24-105Lzoom_MG_2277-01.jpg">L at 70mm</a>
<a href="http://brunovais.xhost.ro/Tests/17-85zoom_MG_2281-01.jpg">EFs at 70mm</a>

Is this normal? I thought the L would win hands down. The colors are indeed better, but the focus is not what I expected.

thanks for your help
[a href=\"index.php?act=findpost&pid=121627\"][{POST_SNAPBACK}][/a]

You say you're shooting on a tripod - in that case, did you switch OFF the image stabilisation on the 24-105 lens? I'm not sure which version of IS that lens has, but with some versions of IS you are advised by Canon to switch IS off when using a tripod, other wise you'll get _worse_ results.

HTH

Alan
Logged
Pages: [1]   Go Up