topic Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM in EF & RF Lenses

Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

XANDERIX — Tue, 23 Jan 2024 18:11:54 GMT

hi there, I have bought a - second hand - Canon lens EF 100-400mm f/4.5-5.6L IS USM from Japan from my EOS 70D. I use it for nature and airplane photography. I did not have any challenge with it and it worked well for 3 months or so. Then suddenly I discovered extreme vignetting when editing pictures. I did some comparison with differen focal lengths and aperture, see the image below. I am not using lens caps or anything.

Any suggestions on whether this can still be solved? The lens didn't drop or so, at least not with me, but I still need to discuss with the family...

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

rs-eos — Tue, 23 Jan 2024 18:15:11 GMT

Things are definitely darker along the right side. If you don't have any screw-on filters, or other attachements, then the lens may indeed have an issue. Though purchasing a lens used and not within the US, it may be very difficult to have Canon USA service it.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

kvbarkley — Tue, 23 Jan 2024 18:26:21 GMT

What are you using to edit?

Do you have lens corrections turned on?

Does your software recognise the correct lens?

Ken Rockwell showed the falloff he measured:

https://kenrockwell.com/canon/lenses/100-400mm.htm

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

XANDERIX — Tue, 23 Jan 2024 19:09:19 GMT

I am using the Canon software and already use the correction for the correct lens. As said, vignetting was hardly visible up to some two weeks ago. Can vignetting appear after the lens suffered a shock?

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

kvbarkley — Tue, 23 Jan 2024 19:15:48 GMT

I would think so. Can you see it through the viewfinder, or only when editing?

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

XANDERIX — Wed, 24 Jan 2024 07:30:52 GMT

no, not through the viewfinder, only when editing the pictures

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

MikeSowsun — Wed, 24 Jan 2024 14:50:21 GMT

@XANDERIX wrote:
no, not through the viewfinder, only when editing the pictures

I would say your lens is fine, but your editing software that has a problem.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

kvbarkley — Wed, 24 Jan 2024 15:49:10 GMT

Does it show up in JPEGS?

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

ebiggs1 — Wed, 24 Jan 2024 15:53:19 GMT

U/l an unedited raw file to a Dropbox or Google Drive and let some if us check out the original file. If it still shows the issue then you probably do have a faulty lens.

Post the link to the file here on the forum.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

XANDERIX — Wed, 31 Jan 2024 20:12:55 GMT

https://www.dropbox.com/scl/fi/oala1930dl5a92ty6yfrv/IMG_6026.JPG?rlkey=1hz0n15pfmsm2fmdzyvfvqk0s&dl=0

look, i just took this picture in heavy dust environment, it is RAW format and no cropping/editing:

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

rs-eos — Wed, 31 Jan 2024 22:11:39 GMT

What you uploaded to DropBox is not RAW. It's a scaled down JPEG. But I don't see any vignetting at all in it. It would thus be useful to have actual RAW images from the photos with the issues.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

ebiggs1 — Thu, 01 Feb 2024 15:26:12 GMT

Yes, it i not the raw file. Besides being underexposed what are your complaints with this photo? It isn't showing the vignetting of your OP.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

XANDERIX — Thu, 01 Feb 2024 16:08:59 GMT

so sorry, i shared the wrong file. Here I uploaded pictures in RAW format at 100 and 400 mm focal length:

https://www.dropbox.com/scl/fo/xlui3sb8bxsiz4dkkxam2/h?rlkey=09be9a607l3aqrfe97tpp1r4h&dl=0

I have added two picutres that show the vignetting. They are screenshots from the check for dust option at jetphotos.com where I share my plane pictures, but with this lens I can stop.

https://www.jetphotos.com/addphotos/ [check for dust option]

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

rs-eos — Thu, 01 Feb 2024 16:55:08 GMT

I have no idea why your software is leading to insanely poor results. If I open your RAW images in Adobe Lightroom (version 13.1 with Camera Raw 16.1), I get the following:

Note: Applied Profile was "Camera Standard". Zero adjustments made; everything at defaults.

First, with no lens corrections applied:

No Lens Corrections

Next, with lens corrections applied (very subtle reduction of the already limited vignetting):

With Lens Corrections

Here's a difference done in photoshop of the above images. Note that it's effectively all black (meaning very little differences in what the lens corrections did):

Difference

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

XANDERIX — Thu, 01 Feb 2024 18:57:52 GMT

Thanks a lot for your support. The vigentting is very visible on the 400mm zoomed image, with or without lens correction. On the 100 mm images, the lower part is dark and the uper corners are also dark.

What I explained is that I upoad my images to jetphotos and the 2 low res images in the dropbox folder are to detect any dust or vignetting. This is not what my software does; I use the Canon software Digital Photo Professional 4 since long without any issue. The vignetting that is so visible now, was not present when I acquired the lens.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

rs-eos — Thu, 01 Feb 2024 19:09:50 GMT

I'm not really following this. If you're opening up these RAW images in some software, and it's leading to that massive amount of vignetting, then it's something very wrong with the software.

Or, are you saying that when you upload these images to that web site, they're doing some kind of analysis? Note that this typically involves wild adjustments on a photo to over-exaggerate things. e.g. when editing in Photoshop say with Dodge & Burn techniques, I'll often create a "help layer" which turns the image to black and white, and wildly swings both brightness and contrast so as to overemphasize areas that need extra work.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

XANDERIX — Thu, 01 Feb 2024 19:18:17 GMT

There is nothing wrong with the software: I do some editing with it and the result looks as good as yours does with Lightroom. The image I shared is autmatically created by the Jetphotos website with the purpose to detect any dust spots or vignetting patterns. That's also the composite image I shared initially. Sorry if this wasn't clear from the beginning.

Previously I didn't have any issues with the lens, but now all photos show the vignetting. I believe it is the lens that has become faulty.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

rs-eos — Thu, 01 Feb 2024 20:01:05 GMT

But isn't that then an issue with the website in how they are processing things? These RAW files you shared have absolutely minimal amount of vignetting in them. So not sure what the issue is.

Re: Sudden vignetting visible - EF 100-400mm f/4.5-5.6L IS USM

ebiggs1 — Fri, 02 Feb 2024 15:12:14 GMT

I have to repeat.....

"These RAW files you shared have absolutely minimal amount of vignetting in them."

I don't know what else we can say but there is nothing wrong with your len(s).