vignette problem no longer seen with lens shade removed. :)

vignette problem no longer seen with lens shade removed. :)

I kept asking people reporting this problem whether they actually did this test, but the answer was yes they did and vignetting was still there.

vignette problem no longer seen with lens shade removed. :)

I don't understand how this could be an issue, since the reported problem was in mid-zoom. I guess you could have a unique problem.

well, I see the issue quite clearly with the lens shade on, but not so doing
same exact test with it removed. Maybe a few others may/could confirm this.
I hope it's as simple as this.

well, I see the issue quite clearly with the lens shade on, but not so doing
same exact test with it removed. Maybe a few others may/could confirm this.
I hope it's as simple as this.

I agree that this should be investigated; there may be some strange dynamic affecting the lens. I hope others will try it.

My camera vignettes equally with or without the lens hood installed.

man... thats weird. I tried it twice here too before I posted.
Glad you tried it, but I don't have an explaination for it.
I just know that I will be using a matte box or something other than
the shade whenever possible.

When I first tried my camera, that's the first thing I tried.
No good.
Also, as it was mentioned it happens between 10mm-25mm not at it's wide position (5.8mm).

well, I'm stumped. I'm shooting a decently flat lit white wall at about f11
Waveform shows nice flat line around 60IRE.
I just did test again both with and without.... AND NOTHING... looked fine.
I know I had the problem earlier and have a clip of it, AND I've seen it before.
So my current test proves nothing I guess.
Now I'm in TEST mode!

Open up from F11, please.

You need to be at the widest aperture 1.9
Also pleasee use see the test thread:
http://dvinfo.net/conf/showthread.php?t=109119

Chris, if you could, please remove this thread. There is no "quick fix" for the vignetting issue.

Chris, if you could, please remove this thread. There is no "quick fix" for the vignetting issue.

I'll try recording a sample both with and without shade per your example.
I don't think deleting this thread is appropiate ... as I "do" have an EX-1 and am having similar, but mixed results and trying to help comfirm a possible mass problem.

If it were a problem with the shade it would be at a wide open aperature (1.9 on the EX1) and with the zoom set to it's widest position (5.8mm).

Everyone else include Adam Wilt's pre-production EX1 shows the the issue in the 10-25mm range.

Please post samples with and without your shade on with your camera set to its widest zoom setting and your aperure set to 1.9 (open).

These are the settings that would show the lens hood if it were to cause vignetting.

I'm going to go out on a limb here, and suggest an explanation for how it could be the hood. Zoom lenses are complicated beasts with floating elements. I wouldn't be surprised if the nodal point shifts while zooming. Maybe at the widest angle, the nodal point is way out near the front element, and seeing "around" the edge of the hood. As you zoom in, maybe the nodal point shifts back and the hood comes into view.

Hey, its a theory. Probably could do a test with a piece of gaffers tape stretched across the hood, so it shows along the edge even when at f/8 or so.

My 2 cents worth, :)
Ken Hull

Ken, I understand you line of reasoning, as I had considered that theory myself. But empirically, the vignetting in my camera, which seems to be a "classic" case, is identical with or without the hood fitted.

Also, as I mentioned before elsewhere, when vignetting occurs in front of a lens, as caused by a hard matte or filter ring or whatever, it generally worsened at a tighter stop, at the offending opaque object becomes sharper. In this case, the vignetting becomes worse with a wider stop, implying a blockage closer to the iris.

Sorry for bumping this misleading thread to the top.

Ken,

Everyone who has the stated vignetting problem has removed the hood. The vignetting is still there. Brian is the only one here who mentioned his was the hood.
Again, while staring at my monitor (SD out full raster) clearly showing the problem, I removed the hood and the vignetting is still there.

Therefore, mine is NOT the hood.

Gentleman, Thanks for the help in pushing me to test further. After playing
back a clip that I knew had the problem I noticed I wasn't now seeing it which pointed to user error. My bad. I had moved to my laptop for viewing and did not have overscan view on! My "quick fix" post was indeed my error as I do see the issue now with ALL the samples < And I did alot of them > both with and without the shade. Not being able to see it on a clip that I KNEW had it was what made me look at the obvious..... Add another bad camera to the list.

closed to avoid any further confusion...