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Author Topic: Canon 24-105mm f4 IS Shadow/Darkness  (Read 5200 times)

aamir

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Canon 24-105mm f4 IS Shadow/Darkness
« on: August 09, 2006, 04:07:05 am »

Hi,

I am new to this forum, but I have been following the website for last few years. Just needed a little help regarding my new lens 24-105 f4. I just got this lens a week ago, but in most of the images, esp taken wide open, there is darkness/shadows at the edges/corners. I think there is a way to correct it. If someone can help, it will be appriciated.

Thanx
Amir
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francois

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Canon 24-105mm f4 IS Shadow/Darkness
« Reply #1 on: August 09, 2006, 06:04:31 am »

Quote
Hi,

I am new to this forum, but I have been following the website for last few years. Just needed a little help regarding my new lens 24-105 f4. I just got this lens a week ago, but in most of the images, esp taken wide open, there is darkness/shadows at the edges/corners. I think there is a way to correct it. If someone can help, it will be appriciated.

Thanx
Amir
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Amir,
It's called vignetting. With your camera, you can minimize vignetting by using smaller apertures (ex: f/8 instead of f/4). It is easily correctly later, on your computer, with Photoshop (while in Caera RAW or later). Other applications can also correct this (Bibble, Lightroom, PTLens on PCs and Kekus/LensFix on Macs) etc...

PS: In Photoshop use Filter>Distort>Lens Corrections  and look for the Vignette sliders. In Camera RAW, look for the Lens tab and then Vignetting.
« Last Edit: August 09, 2006, 06:09:02 am by francois »
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Francois

aamir

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Canon 24-105mm f4 IS Shadow/Darkness
« Reply #2 on: August 10, 2006, 04:24:46 am »

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Amir,
It's called vignetting. With your camera, you can minimize vignetting by using smaller apertures (ex: f/8 instead of f/4). It is easily correctly later, on your computer, with Photoshop (while in Caera RAW or later). Other applications can also correct this (Bibble, Lightroom, PTLens on PCs and Kekus/LensFix on Macs) etc...

PS: In Photoshop use Filter>Distort>Lens Corrections  and look for the Vignette sliders. In Camera RAW, look for the Lens tab and then Vignetting.
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Francois, Hi

Thanx for the mail. I am going to try the way you told me. I was reading on net somewhere, that there is a way to correct it by changing some settings in the camera. Do you have any idea about it?  If so, please let me know.
Thanx again
Have a good day
Amir
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francois

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Canon 24-105mm f4 IS Shadow/Darkness
« Reply #3 on: August 10, 2006, 07:14:29 am »

Changing settings on the camera can't help as it's an optical issue... It was already present with film cameras. The only thing you can do to lessen viggnetting is to move away from large apertures (wide-open for example). Some cameras use a centre neutral graduated filter as a workaround. You can see a photo of these filters on Michael's X-Pan 30mm lens review here.

You can learn more on vignetting here.

Corrections made in Photoshop (or other graphic applications) give excellent results provided your vignetting issue is not mecanical (caused by a filter or an oversized hood)....
« Last Edit: August 10, 2006, 07:19:01 am by francois »
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Francois

aamir

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Canon 24-105mm f4 IS Shadow/Darkness
« Reply #4 on: August 10, 2006, 09:56:46 am »

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Changing settings on the camera can't help as it's an optical issue... It was already present with film cameras. The only thing you can do to lessen viggnetting is to move away from large apertures (wide-open for example). Some cameras use a centre neutral graduated filter as a workaround. You can see a photo of these filters on Michael's X-Pan 30mm lens review here.

You can learn more on vignetting here.

Corrections made in Photoshop (or other graphic applications) give excellent results provided your vignetting issue is not mecanical (caused by a filter or an oversized hood)....
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Hi,

Thanx again for this information. I have tried to correct it with Photoshop CS, I am using 5D with 24-105 f4. I could not locate Lens Correction and Vignette sliders in Filters-Distort. Is there any other way to correct it. I am using MacBook Pro and could not locate anything in added programs too. I am only using Photoshop CS.
Sorry for you time and thanx a lot for your help.
Takecare
Amir
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francois

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Canon 24-105mm f4 IS Shadow/Darkness
« Reply #5 on: August 10, 2006, 10:41:57 am »

Quote
Hi,

Thanx again for this information. I have tried to correct it with Photoshop CS, I am using 5D with 24-105 f4. I could not locate Lens Correction and Vignette sliders in Filters-Distort. Is there any other way to correct it. I am using MacBook Pro and could not locate anything in added programs too. I am only using Photoshop CS.
Sorry for you time and thanx a lot for your help.
Takecare
Amir
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Well, I guess that lens corrections in Photoshop were introduced in version CS2. But all is not lost as you can download [a href=\"http://labs.adobe.com/technologies/lightroom/]Lightroom[/url] from Adobe Labs for free (until it gets out of beta, later this year) and Lightroom has vignetting correction support (look for the Lens Correction tab in the Develop module).
As an additional bonus, Lightroom is a universal binary application and should run much faster than Photoshop on your MacBook Pro.
Hope this helps!

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Francois

oak

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Canon 24-105mm f4 IS Shadow/Darkness
« Reply #6 on: August 17, 2006, 05:07:08 pm »

Minor comment but I'm using a 5D/24-105 combination and don't have any vignetting, even at F4. Are you sure that it's not a problem with too fat a UV or Polarising filter and/or a non-standard lens hood?
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marcmccalmont

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Canon 24-105mm f4 IS Shadow/Darkness
« Reply #7 on: August 17, 2006, 06:04:32 pm »

Amir
I just did a quick test of my 5d and 24-105 (24mm f4.0), with and without the Hoya protective filter and without the hood I get the same amount of vignetting so its the lens not the filter or hood. I noticed this when I first got the camera/lens too as it is more dramatic than when I was shooting film. I really like processing my RAWs with DXO optics it will correct the lens distortions at the same time and does a really good job. They have a 30 trial, my images got a lot better with it. Hope this helps.
Marc
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Marc McCalmont

Mark D Segal

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Canon 24-105mm f4 IS Shadow/Darkness
« Reply #8 on: August 17, 2006, 08:05:44 pm »

I have that lens mounted a Canon 1Ds, use it with a UV filter and the Canon supplied sunshade for that lens and I get negligible vignetting at wide-angle, but otherwise none.
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Mark D Segal (formerly MarkDS)
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