jimoth001 Loc: Illinois

Hi, hoping someone can help me figure out why I sometimes see a faint curved line in some photographs. I thought it might have something to do with a lens hood, but I've seen it without that. In the example I'm posting, the curved line is to the left of the moon from top to bottom.

Thanks!

Example #2

sarge69 Loc: Ft Myers, FL

I see it but can't explain it. I had a D5100 also.

Sarge69
PS: I'm sure some of our more professional users will help out.

GoofyNewfie Loc: Kansas City

I see it too.
Does it show up in the same place every time you see it, regardless of what you're shooting?
If it does, my initial thought is a hair in front of your sensor.

Danilo Loc: Las Vegas

I would suggest two possibilities:
Look for a hair (human or pet) on the REAR glass element of your lens (not the front).
Look for the same thing on your sensor, inside the camera. You'll need to lock the mirror up to view this area.
Good luck!

Tea8 Loc: Where the wind comes sweeping down the plain.

I am not an expert or a professional, but it does look like a hair to me.

jimoth001 Loc: Illinois

I posted another picture with the same artifact.

Both were taken with the same lens, so maybe a hair on the lens (or under the nd filter) is the culprit. I'll check that and take some similar sky pictures with a different lens.

(Note that this is not in every photo)

Thanks for the feedback!

dspoon2 Loc: Rockwall TX

We could check with Fox Mulder but he's kinda hard to find these days....

GoofyNewfie Loc: Kansas City

If it is a hair and the photo is predominantly dark- you probably won't see it, but it will still be there.
Shoot a light blank wall in good light- throw the lens way out of focus and set the smallest aperture.
It's ok if you can't hold it steady. If it is still there, it's most likely on your sensor. Things on or in your lens rarely show up at all.

jimoth001 Loc: Illinois

Will do, thanks!

Jaime Loc: Los Angeles

Yep. Looks human and hair-like. Switch lenses (if you don't have another lens, go to your neighborhood camera store and do some acting) take some shots. If the hair disappears, it's probably on your rear element of your lens. If the hair is still there with the new lens... It's the sensor. Tell them in the camera store that you'll think about the new lens, but buy a bulb air cleaner and blast your problem away. Two other possibilities, damaged sensor from the factory, or damaged sensor during a wet cleaning. Good luck. Good luck.

RVDigitalBoy Loc: Clermont, Florida

It looks similar to what I have seen on a few of my D3100 images. Cleaning the sensor (menu option) should eliminate this.

I now clean the sensor before each day's shoot. I also clean it when I change the lens.

jimoth001 Loc: Illinois

Checked out the one lens, no issue with the lens itself, changed lenses and I think I see the artifact still (hard to see on the viewscreen, didn't have time to transfer to computer to see better).

Will try the sensor-cleaning function and hope that works before this newbie goes poking around inside.

rts2568

From rts2568

If the following doesn't result in removing the problem then let us know if you have a manual lens or an auto etc. Also fill us in by answering any questions we pose.

"GoofyNewfie" may have touched on the possibles.
The first image you've sent, I see two curved lines, one very much thinner that the one on the right, nearer the center. Let me get to possibles in two ways - body and the lens.

One hesitation in attempting to diagnose thiis phenomenon too, is the symetry; its too much so for my liking which might suggest a flaw in the lens itself. A way to check that possible out first is to take the lens off the camera, hold it up to a bright ligt source with the back of the lens facing the bright light and you looking through from the from the front of the lens. Move the lens across the light source to reassure yourself that their is no obvious flaw inside.

For the following, you will need a good magnifying device of some sort, a good penetrating light to reach into cavities and a pair of tweezers. When doing the checks as below, do use the tweezers very carefully. A blower too will be of use, but not one with a brush!@QQQQ!!!!!! If you find a hair, remove it with the tweezers, don't rely on a blower because you may very well just dislocate and relocate the hair instead of removing it.

One thing that might help you look very hard, while carrying out what I'm suggesting below. If you use a blower 'brush' to clean dust from either the back of the lens or inside the mirror box, then you can be pretty sure that a hair somewhere along the light path will be the problem.

Also, we may need to know how long you've been using this lens and when you first noticed the obstacle. For the moment, lets get you started on the investigative path.

First the body. There are as you know, many moving parts in the mirror box, a shutter openng in two actions actions for instance (opening/closing/resetting), so you need to take a very careful look just in front of the operating area of the shutter slides. In those slides, a hair could get caught, very rary, but possible. make sure the mirror box is well lit inside and you have a magnifying glass for close examination. You will need to open and close the shutter as you would to clean a sensor; when you have the blades in the open position, be very very careful. The line is so out of focus,I would suspect the hair, if that's what it is, is mostly likely just in front of the shutter curtains. However, you need to see those blades open because something like a hair just could be between the sensor and the blades where the blades' action allows a sort of spring action occurring and the hair popping out while the shutter blades are in the open position and disappear when the blades push or pull the hair back into the narrow space between the sensor and the shutter blades. that's one possible.

The other is to ensure you check under the mirror while it is locked. The rest of the mirror box will need to be examined carefully and in detail also. Note here that it isn't worth the bother of blowing out the mirror box and hoping that will do the trick. It's more likely a blow won't move a hair which has become embedded in crack of some sort, front or back of the shutter blades or around the mirror mechanisms or in the floor.

Next look at the rear of the lens, most lenses have a serious cavity at the rear and can suck in all sorts of rubbish. Now, there are at least two possibles for a stray hair to secure itself into a firm and fixed position.

a/ within the operating mechanism and this may not be easy to see unless you operate the aperture activating mechanism while the lens is off the camera and you have a well lit area, along with a magnifying lens. Don't operate the aperture mechanisms fast either, if you have one, just slowly and watch carefully.

b/ A hair can easily be caught in the grease too, often used to keep the various sliding surfaces smooth, especially in older lenses. this can have the effect of only appearing at a certain focusing point - I see that the two shots you've submitted are at or near to infinity as an example.

Keep in mind that if this aggravation is a hair, it may not be evident when no action from the mechanisms is happening, so activate them, safely and carefully as all mechanisms in a camera and lens are fragile, some very much so.

That should give you enough to go on with.

However there is one point I'd like to raise about the photos you submitted. I'd be rather concerned about what I see here as vignetting; perhaps from an ill fitting lens hood, filter or just rather poor optics. Think on this also, before you finish your close examination.

Let us hope that it turns out to be a hair because that is the easiest thing to solve.

Best of luck,

rts2568

:thumbdown: :thumbdown:

jimoth001 Loc: Illinois

Wow, rts, thanks for the extended suggestions!

In the first picture, there is ghosting from combining pictures, so that is probably why you see another line (I think I cleaned up only the moon ghosting a bit). Additionally, I believe the vignetting is from post-processing, everything was pretty uniform in the original RAWs.

As I said, I think I see the artifact with multiple lenses, I still need to confirm that, so inside the camera is probably the most likely scenario.

Thanks again and I'll report back what I find inside.

rts2568

from rts2568

From rts2568

Oh yes "jimoth001" I meant to include the possibility of failing aperture blades with regards the vignetting; slowing blades as a result of serious wear, grease creeping onto the aperture blades runners or because of a poor quality aperture assembly.

This asn ve tested for of course, but the best way to have this discovered for sure is to have a mechanic take the lens apart and take a closer look. Short of that, it might be possible for you to see grease thing by looking into the lens from the back in particular and check if the blades are looking completely dry, that is if you can activate the blades slowly - you may not be able to do that if the lens is of recent manufacture.

Again, all the best

rts2568