I have a Zeiss ZE 100mm f/2 macro lens that I use with a Canon 1Ds MkIII camera. Every photograph made with the lens shows a black curved line in roughly the shape of a fishing hook. I've attached a photograph with the shape circled in black. It's often sharper and blacker than it appears in this photograph. There are no scratches on the lens and I haven't dropped it or otherwise damaged it. When I look through the lens at a bright light I can see the usual minor dust but nothing that looks like this shape. I'd appreciate it if someone could tell me what this likely is and how I might get rid of it if that's possible, short of sending it off for repair?
campyone wrote:
I have a Zeiss ZE 100mm f/2 macro lens that I use with a Canon 1Ds MkIII camera. Every photograph made with the lens shows a black curved line in roughly the shape of a fishing hook. I've attached a photograph with the shape circled in black. It's often sharper and blacker than it appears in this photograph. There are no scratches on the lens and I haven't dropped it or otherwise damaged it. When I look through the lens at a bright light I can see the usual minor dust but nothing that looks like this shape. I'd appreciate it if someone could tell me what this likely is and how I might get rid of it if that's possible, short of sending it off for repair? ...Show more →
I think it's some kinds of string-like shape artifact that has got in the coating of one element. I have the same issue once when I bought a Zeiss polarization filter but I exchange it for a new one and it is fine
campyone wrote:
I have a Zeiss ZE 100mm f/2 macro lens that I use with a Canon 1Ds MkIII camera. Every photograph made with the lens shows a black curved line in roughly the shape of a fishing hook.
Did you check other lenses to rule out the familiar hair on the sensor?
It'll probably be sharper and darker at smaller apertures (Opanda IEXIF shows f/5.6 on your example photo), no matter where in the system it's located. Maybe you could send an email to ask Zeiss? Send example photos from the 100 ZE and 70-200 at 100, both at f/8 or so.
No, I bought it used from a dealer about six months ago. But I'm virtually certain it wasn't there when I first bought the lens, I just started noticing it about a month or two ago.
It seems unlikely that something of that size worked its way into the lens, so I suppose it was already in there and at some point already fell off. Asking Zeiss what it would cost to remove seems a logical next step. There is a faint possibility that it could be a mark on the lens, most likely on the rear element. These can be quite hard to spot.
I know the OP said it doesn't happen with other lenses but I'd suggest a test with another lens, pretty much any lens, at F22. This will show any dust on the sensor and at least eliminate sensor dust.
Since the mark is well defined it must be at a focal plane, eliminating the front or rear element. Anything on the sensor would not be so sharp. I think it must be internal.
I have used lenses full of dust and other crap previously and never seen anything in the photos, let alone such a well defined shape and so sharp. Imho, if it is in the lens, it must be very easy to see. If you can't see it while you look through the lens, it ain't there. To me, it looks to be on the sensor.
Yeah, if you can't see it in/on the lens(flashlight/torch near/through the rear the lens, while looking through the front end),
then it's the sensor, which is what I think it is.
If you have a rocket blower, use it on the camera sensor and back of the lens often, and it will stay cleaner longer.
A well defined shape like that can appear if the lens is focused all the way in to or near it's 1:2 MFD and stopped down some.
To check a lens for dust that wouldn't normally show up shine a bright LED flashlight through either end and let your eyes focus on each of the detectable element surfaces. If you don't see it that way then it's not there!
Note that this is different than looking at a bright light through the lens. Using the flashlight energizes the dust and fibre particles with light causing them to reflect copious amounts of light (very brightly), while looking thru to a bright room light or something will only show a (much harder to see) silhouette of the debris.
Also check the mount and adapters for hairs or fibers that may be attached and causing this.
As Bifurcator says, you must force your eyes to focus throughout the internals of the lens. Not an easy task with the liquid transparency of a Zeiss lens.
Thanks for all the responses. I haven't noticed this shape with any lens other than this one and I've used them all quite a bit since I first started noticing the shape with the Zeiss 100mm lens. However, I haven't done a real thorough test, which I'll do by photographing with each of my other lenses at minimum and maximum apertures, maximum and minimum focus distances, and in the case of zooms, at longest and shortest focal lengths. I'll also try looking through the lens with an LED flashlight. I've been looking through the lens using a table lamp and a ceiling light. Thanks again for all your help.
