Bad Lens?

DavidTO

So, I'm processing some of my shots from Bryce/Zion, and I'm noticing that my 70-200 f4L seems to have some funkiness going on. Ugh.

The problem is in the upper left corner in landscape orientation.

Here's a good example, click pic for EXIF:



Here's a 100% crop of the bad area on the left:




And a 100% crop of the good area on the right:




The link to the original.

David_S85

Tipoded?

DavidTO

David_S85 wrote:

Tipoded?

Not sure about tipoding, but I'm pretty sure it was on a tripod

Most of the image is sharp, so I'm thinking it's not camera shake....

DanielB

DavidTO wrote:

Not sure about tipoding, but I'm pretty sure it was on a tripod

Most of the image is sharp, so I'm thinking it's not camera shake....

could it have been heat sometimes if its real hot out you can see that similar effect from the heat rising off the ground... but i'm not sure what the temperature was like out there...

wxwax

Not just top left, but entire strip down the left side. very odd. On only one image w/this lens, or does it appear on others too?

DavidTO

wxwax wrote:

Not just top left, but entire strip down the left side. very odd. On only one image w/this lens, or does it appear on others too?

Looks like it's in this one, too:

Steve Cavigliano

Yep, it definitely looks off on the entire left side. I think it would be prudent to send it in to have it adjusted. Hopefully, it's still in warranty. I have seen similar results before from a dropped lens, so I think it's only an minor alignment issue.

Steve

DavidTO

Steve Cavigliano wrote:

Yep, it definitely looks off on the entire left side. I think it would be prudent to send it in to have it adjusted. Hopefully, it's still in warranty. I have seen similar results before from a dropped lens, so I think it's only an minor alignment issue.

Steve

Dang. Don't know if it's under warranty, I'll have to check with Lynnesite, whom I bought it from some time ago.

Bob Bell

I have looked at your shots David for some time trying to figure it out. I think I have 2 bad thoughts. The camera mount it slightly distorted on the left side. You can verify this with other lenses. The other one is that the lens isn't aligned correctly. Either do to the lens mount, optical alignment, or a misground glass.

If you isolate this to the lens. I would send it in, even outside of warrenty. I would expect Canon to fix it or replace it free of charge unless you dropped this down the side of bryce first to cause that kind of an issue

wxwax

Bummer, David. Do you see it with other lenses?

DavidTO

wxwax wrote:

Bummer, David. Do you see it with other lenses?

No. I also have shots with this lens that look good. May have happened at some point during the trip? I don't remember anything weird happening...or maybe the lens wasn't seated properly for those shots? I'm not convinced yet that it's busted...I'll have to do more research.

wxwax

Are the bad shots all at or near the same focal length, by any chance?

DavidTO

wxwax wrote:

Are the bad shots all at or near the same focal length, by any chance?

I'll have to look into it. Good thought, though. I'm furiously processing shots from the trip while I have time.

wxwax

DavidTO wrote:

I'll have to look into it. Good thought, though. I'm furiously processing shots from the trip while I have time.

I know the feeling.

jwear

if canon is anything like nikon -take camera and lens in and have them ck it .I just had them ck the d70 and a lens Hunter used they said it was not free but was when I came back to pick it up it was .Ask them to ck it before they repair then you are not just guessing --just a thought

DavidTO

It appears to be a combination of focal length somewhere over 150mm and an aperture of 4.0-5.6. Obviously, f4 at 200mm is the worst...which is what those shots were...

I guess I need to trust my camera more, the light was low, and I wanted to get a good exposure. Andy even warned us, "stay away from the extremes of your lens." Of course, I never listen to Andy...

It still looks like it's worse than it should be, so I'll probably take it in...

wxwax

DavidTO wrote:

It appears to be a combination of focal length somewhere over 150mm and an aperture of 4.0-5.6. Obviously, f4 at 200mm is the worst...which is what those shots were...

I guess I need to trust my camera more, the light was low, and I wanted to get a good exposure. Andy even warned us, "stay away from the extremes of your lens." Of course, I never listen to Andy...

It still looks like it's worse than it should be, so I'll probably take it in...

Yeah, that's way beyond what I'd expect from a lens being used at its limits. Something's defective.

gus

wxwax wrote:

Are the bad shots all at or near the same focal length, by any chance?

WOW !! Waxy you are always the thinker. Little escapes your critical eye.

What we have here is a typical signature reminent of a Quark proton drive unit. We had to stop using them after all the trouble in the 70's & 80's because during opening & closing of the entry portal ..we found a very rapid decay in your earths atmosphere in the immediate entry/exit area (high nitrogen our engineers report mentioned was a major player in the problem)

It caused all sorts of weird anomalies for you guys like you see in davids shot but.. had it been near a corn/wheat field...well you know the rest of that story.

R Johns

gus wrote:

What we have here is a typical signature reminent of a Quark proton drive unit. We had to stop using them after all the trouble in the 70's & 80's because during opening & closing of the entry portal ..we found a very rapid decay in your earths atmosphere in the immediate entry/exit area (high nitrogen our engineers report mentioned was a major player in the problem)

It caused all sorts of weird anomalies for you guys like you see in davids shot but.. had it been near a corn/wheat field...well you know the rest of that story.

I'm in all sorts of pain, from trying to wrap my mind around that statement...:twitch

gus

R Johns wrote:

I'm in all sorts of pain, from trying to wrap my mind around that statement...:twitch

Hey...dont fret. We have our best on the problem as i type.

For some time we have been experiencing great difficulty in locating a stolen Gorgonian freighter. Typical of the Gorgonians to leave it unattended with the penning trap still in the ignition !! One drunken Netarwon frat party & ...'whollah !' ...we have a several intoxicated medical students careering about the galaxy at will in a freighter with the braking capacity of a 1949 BSA Bantam in the wet.

Bigger problem though...the thing has enough fuel until your 2022 AD & it is carrying several thousand tons of your worst mexican tequila. We are at the least...very pleased that it isnt armed.

We did suspect that Zion would be a strong possibility for an attempt an entry.....for some odd reason...they like to port in & out in front of large camera crowds so we are studying all your IR shots for a large green spotty bum pressed up against a window.

Our only real hope is to get permission from the manufacturer of the freighter to access the crafts neuron dendritic tree & transmit a corrective homing beacon into it...thus we can nail the idiots. When (& if) this happens ..you will just see a supernova & maybe it will make page 3 of Popular Science.

patch29

I would find a large brick wall or another large flat surface with detail. Then I would run a series of tests. Square up to the wall, shoot at a few different distances and f-stops. Try to get back as far as possible, to resemble shooting at infinity, a large warehouse would be helpful. Then see if a pattern shows up with a certain focal length, shutter speed, f stop, focus distance and maybe use a different lens to for comparison?