When I take photos, I have the same kind of artifact like in this photo (but not as much) : artifact

What is the cause of this artifact and how can I prevent it ?

An example from my camera, note particularly the pamphlets on the bricks near the bottom:

An example from my camera

Thank you

  • 1
    \$\begingroup\$ Can you please make a gigant circle pointing at the tiny artifact you see? \$\endgroup\$
    – Rafael
    Nov 18, 2016 at 22:24
  • 1
    \$\begingroup\$ It's the red blur on the floor of the bus, and the green blur on the shadow \$\endgroup\$
    – Anonymous
    Nov 18, 2016 at 22:26
  • 1
    \$\begingroup\$ OOoooohhhhh. Dam! That is a serius problem! \$\endgroup\$
    – Rafael
    Nov 18, 2016 at 22:30
  • \$\begingroup\$ Is your camera new? Still has its warranty? Did you purchased a second hand camera? Have you ever tried to clean the sensor? \$\endgroup\$
    – Rafael
    Nov 18, 2016 at 22:32
  • 2
    \$\begingroup\$ Post a photo of your photos. On this posted example looks like a damaged sensor, probably because some residual chemical. But your camera can not be opened to clean the sensor. So post your example. \$\endgroup\$
    – Rafael
    Nov 19, 2016 at 0:52

1 Answer 1


Fortunately for you it is essentially certain that the bus image problem and what your camera is doing are different. Your camera's issue is standard lens chromatic aberration which is part of what you get at that price-performance level and it can often be minimised once you understand what causes it.
However, the bus image contains both chromatic aberration plus indications of a more severe problem.

In the bus image, and in other images from the same photographer, it can be seen that the images have a strong red "bleed" on the "low" side of light to dark horizontal transitions and green "bleed" on the "low" side of dark to light horizontal transitions. It is not obvious whertehr this is a camera problem or due to something in his processing system, but a camera sensor or processing issue seems most likely.

strong text


Your issue is "normal" CA (chromatic aberration) - not nice to have, but at least well enough understood.

Your sample

enter image description here

Your example image has conventional purple-green chromatic aberration occurring on high contrast edges.

Seen most clearly on horizontal lines here

enter image description here

And on verticals here:

enter image description here



DPREVIEW are one of the top internet camera review sites
(IM & many others HOs). So their comments are liable to carry more weight than most reviews. I've copied some of their comments re the Canon SX210IS below.

  • Arguably the most important things to consider about a compact camera's performance are the consistency and accuracy of its metering, white balance, and AF systems, and the Canon performs very well in all of these respects. A slight tendency to overexpose in bright contrasty conditions is mildly annoying from a critical image quality point of view, but it does at least ensure that prints made straight from the camera are bright and punchy.

  • Our main concerns with the SX210 IS are actually ergonomic. As a picture taking tool, it's a fine camera, although at close to $350 it isn't cheap, and it faces strong competition from feature-rich competitors like the Samsung HZ35W and Panasonic Lumix DMC-ZS7, both of which offer a 24mm equivalent wideangle.

We like: Large screen, decent image quality at low ISO settings, fast and responsive operation, reliable metering, AF and WB.

We don't like: Annoying pop-up flash, poor use of screen real estate in shooting/review modes, poor detail capture at high ISO settings, fiddly zoom control.


More on the bus image and other photos from the same photographer:

Here is the source of the original bus image - Wikipedia. Photographer P Poschadel.

And here is a completely different image by the same photographer.

It can be seen to have the same "bleed" effect on some only horizontal boundaries. He tends to get red or purple "bleed" on light to dark transitions and green "bleed" on dark to light transitions (as in the bus image) . Thus -

enter image description here

It also has strongish but conventional CA on some verticals.

enter image description here

  • \$\begingroup\$ I think the bus image combines vertical bleed with chromatic aberration. Both of the images from that photographer show numerous vertical artifacts which are neither green nor magenta, but the location of the green and magenta fits normal CA patterns. \$\endgroup\$ Nov 19, 2016 at 10:02
  • \$\begingroup\$ @PeterTaylor Yes, I agree. I did not really appreciate how pervasive both effects were in both images initially. After a wander around the building image it became very obvious. But I've already spent more time on this than I can afford and than general interest is liable to merit. Quite a few comments but no up (or down) votes and the only OP upvote is my one. "Rep" is of no great interest to me in its own right - bt it is some sort of indication of how much interest a question/anseer is to people other than the OP. \$\endgroup\$ Nov 19, 2016 at 13:41
  • \$\begingroup\$ Thank you very much for answered my question. I am not really good at photography, I'm only a beginner. The time you spent answering my question is really appreciated. Oh, and my camera is a 210 IS, but it's not that bad. \$\endgroup\$
    – Anonymous
    Nov 19, 2016 at 17:31
  • \$\begingroup\$ @Anonymous - Sorry - I got the wrong Canon camra, as you saw. Re the SX 210 IS DPRview say "The Canon Powershot SX210 IS is a solid, well-specified compact digital camera with a very versatile lens, and as such, like most of the cameras on this test, it makes an ideal companion when on vacation, or out and about with family or friends. The core features are well-implemented and the camera's key systems, like AF, WB and metering, are accurate and reliable. " They also talk about less good features, but it's an OK starting camera. \$\endgroup\$ Nov 20, 2016 at 5:55

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