Light Fall-Off ! - DPChallenge Forums

Canon EF 17-40mm f/4.0L USM

07/21/2006 11:00:48 AM · #1

The first test shots with my new lens shows quite a bit of light fall-off.
Is this effect more or less normal? Or should I ship the lens back for an exchange while I still can?

glad2badad

Apple iPhone 16 Pro

Lensbaby Sweet 35 Optic

07/21/2006 11:05:17 AM · #2

Heads up on the image links. The hosting site uses pop-unders.

What exactly is light fall-off? How can you tell that you are seeing it by looking at the images you've posted?

KiwiChris

Canon EOS-5D Mark II

07/21/2006 04:22:40 PM · #3

Are those at the wide end on the kit lens? You didn't mention which lens/focal length they were at. Also the apeture you're shooting at can make a difference, wide open (smallest apeture number) you'll get more falloff than you do at smaller apetures.

Some falloff / Vignetting is pretty common on consumer/kit lenses at the wider end of their range, and sometimes still present at the long end.

The falloff dosn't look too bad in the shceme of thinks in those two you posted, you'd only notice it if you always take photos of weatherboard or brick walls. In real-world photos I'd say that amount of fall off would be difficult to notice without enhancing it using PS etc.

Cheers, Me.

fotomann_forever

07/21/2006 04:26:55 PM · #4

I'm not seeing significant fall-off to warrant any concern in real-world situations.

Canon EF 24-105mm f/4.0L IS

07/21/2006 11:26:01 PM · #5

Those shots were taken with Nikon 70-200 AFS VR at medium focal lengths and f/2.8 aperture; the effect reduces significantly as I increase the stops. I'm only concerned because I actually rented this lens a few weeks ago, and that one NEVER produced falloff.

robs

Canon EOS R6 Mk II

07/21/2006 11:30:45 PM · #6

It seems ok to me and can be fixed pretty easily in post. Besides, How often do you take pics of flat white walls in the wild? :-)

KiwiChris

Canon EOS-5D Mark II

Canon EF 17-40mm f/4.0L USM

07/22/2006 02:23:20 AM · #7

Originally posted by peterish:

Is that a full frame lens? I'm surprised one of the high end lenses (particularly in that focal length) would produce any fall-off.

Given you've spent a bit of money on it, it's up to you on the return issue... Did you buy it online, or a bricks'n'mortar shop?

Azrifel

Fujifilm X100VI

07/22/2006 04:38:01 AM · #8

Edited.

Tried the first one now, I see what you mean. Return it if you are not satisfied. No flash or other artificial light source involved?

For others: Here is an extreme contrast/saturation/gamma edit to show what is meant.

I wonder how big the role of the sun as a point source of light and the scattering of that light on the wall could be. You can also see this indoors with a single lightbulb or spot, the power intensity of the light drops off quite dramatically. I suggest you try this test again on an overcast day or on a shadow wall to rule this out.

Message edited by author 2006-07-22 04:52:11.

Canon RF 24-70mm f/2.8 L IS

07/22/2006 10:10:23 AM · #9

My tests shots were taken on an overcast day so the sun's angle played no role. The falloff effect can be detected even when shooting a complex subject, not just a white wall.

It was purchased from the very reputable buydig.com, so exchange shouldn't be too much of a hassel. Has anyone had experience with this particular issue dealing with buydig?

DjFenzl

07/22/2006 10:14:51 AM · #10

Do you have any filters on the lens? Do you have the lens hood on? Have you tried taking everything off the from of the lens and shooting?

kirbic

Canon EOS R5

07/22/2006 10:57:18 AM · #11

"Filter?" was my first question as well. There should be no detectable fall-off on a tele-zoom, especially one with as great a reputation as the Nikon 70-200/2.8

Edit: $*@^&@*!! pop-ups...

Message edited by author 2006-07-22 10:58:09.