49 votes
Accepted

What causes these white, squiggly lines in my photos?

This image shows a rather long exposure. The image in general is very dark, but a few spots are light. Probably some reflection on shiny surfaces like the door knob, the sink and the tap. If you ...
Gerhardh's user avatar
  • 622
47 votes
Accepted

Taken a picture of my monitor while spinning in circles - why is it distorted?

The reflection on the screen tells me you used a flash. The flash only lasts a very short time (at most 1/200 of a second), while the shutter was probably open for a much longer time (maybe 1/30 of a ...
Jules's user avatar
  • 1,050
35 votes
Accepted

What causes these inconsistent dark bands in some of my photos from an indoor event?

The variability you are seeing in your photos is due to the way many types of lighting convert alternating current into light. Although they look constant and steady state to our eyes, in reality they ...
Michael C's user avatar
  • 174k
29 votes
Accepted

What could be the reason for these block-like artefacts in the blue sky?

I would suggest that it might actually be a sensor fault (or firmware bug). My reason for suspecting this rather than JPEG artefacts or banding is that the surrounding sky has exactly the same ...
thomasrutter's user avatar
  • 13.6k
21 votes

What could be the reason for these block-like artefacts in the blue sky?

These look like JPEG compression artifacts, possibly caused by picking a lower-quality setting in the camera settings. On many cameras there's e.g. a Fine JPEG mode and a SuperFine mode, or something ...
twalberg's user avatar
  • 5,093
19 votes
Accepted

Solve unwanted white "waves" and "Pacman squares" in low-light picture - post using Google Photos

This is known as "banding". Dark parts in the picture have a small range of values (in a JPG, you only have 256 values per color), when you lighten them, you increase the gap between consecutive ...
xenoid's user avatar
  • 20.3k
17 votes

How can I avoid circular banding artifacts in clear skies when de-noising?

I actually wouldn't describe what you're seeing as a halo artifact. It seems to me to be posterization — there just aren't enough tones to smoothly represent the gradient of the sky. It just happens ...
mattdm's user avatar
  • 143k
17 votes
Accepted

How do I take a photo so the moon doesn't have bright "rays"?

The "ray" effect is known as sunstar. There are 2 conditions to achieve sunstars : use a narrow aperture (like f/16). point camera to small and bright light source. You achieved that effect very ...
jihems's user avatar
  • 710
15 votes
Accepted

What causes these streaked rays from light sources?

In my opinion that "flare" is caused by a dirty lens. I'm guessing you attempted to clean it, by using a wipe, but failed to properly clean it, which is why the flare has directionality. Try using a ...
Rafael's user avatar
  • 23.2k
11 votes

What could cause this visible artifact which seems to a be a glowing inverse of something outside of the frame overlayed on this photograph?

What you are seeing in the photo is a specific type of lens flare known as ghosting. It is an inverted and reversed reflection of the brightest highlights of the scene. If you were to draw an x and y ...
Michael C's user avatar
  • 174k
11 votes
Accepted

What is this shadow in my photo?

It is either subject motion or camera motion. 1/80 second is pretty slow for human subjects not making a specific effort to be still. It is also pretty slow to use hand held if you are going to pixel ...
Michael C's user avatar
  • 174k
11 votes

What caused some of the bright, diffuse areas of sky in some of the Apollo images from the moon?

It looks like lens flare. It is an internal reflection inside the lens. It is caused by off axis light allowed to fall on the front surface if the lens from outside the field of view. For an example ...
Michael C's user avatar
  • 174k
11 votes
Accepted

How to edit photograph to remove flashes of light / glow / glare?

When an image contains pure white (#fff or values RGB 255/255/255) - we refer to this as "blown" or "blown out". There is nothing you can do to alter these pixels to gain lost detail. For example, I'...
OnBreak.'s user avatar
  • 20.5k
11 votes

What is causing the "bright spot" artifact in my picture?

This artifact falls under the heading of flare / ghost image. It is caused by internal reflections. The camera lens is a complex array of multiple polished glass lens elements. Some elements are ...
Alan Marcus's user avatar
  • 38.5k
10 votes
Accepted

What is "veiling glare"? How does it affect my photos, and how can I avoid it?

Veiling glare is light that's not intended to be part of the image, per se, but ends up on the recording medium (film or sensor) anyway. It's caused by reflections and scattering of light by optical ...
mattdm's user avatar
  • 143k
9 votes
Accepted

Strange pattern in picture

These are demosaicing artefacts introduced when converting the image from the bayer array that the sensor records into an image with complete colour information for each pixel. In an effort to ...
PeterT's user avatar
  • 621
9 votes
Accepted

What causes blue artifacts when viewing an image in Camera Raw or Lightroom?

The blue and red highlights in Adobe Camera Raw or Adobe Lightroom are called the Shadow/Highlight clipping warnings. They are indications of shadow or highlight areas that are lacking detail, meaning ...
Mike Dixon's user avatar
9 votes

What caused the strange "wave X" lines in the out of focus background area in this photo?

It strongly appears you were shooting through a chain-link fence, chicken wire, or something else with a diamond-shaped pattern. Here is where I think the fence or wire would be (apologies for my ...
scottbb's user avatar
  • 32.2k
8 votes

What is this bright squarish pattern that I'm getting in long exposure images?

It is a hot pixel. The reason it makes that little checkerboard shaped mark is because of the way digital cameras use single luminance values for each pixel to create color information by filtering ...
Michael C's user avatar
  • 174k
8 votes

Why is the bottom of this image over-exposed?

My bet is on the same thing you guess — light reflected from the diffuser bouncing around badly. This is especially likely if you've tipped the flash to point the diffuser dome forward, as I've seen ...
mattdm's user avatar
  • 143k
8 votes

How to edit photograph to remove flashes of light / glow / glare?

Another approach, since as Hueco mentions in his answer, this detail is blown out and unrecoverable - is we can try to reduce it's impact by attempting to darken some of the blurred "halo" effects ...
Tyzoid's user avatar
  • 201
8 votes

How do I take a photo so the moon doesn't have bright "rays"?

Opening your aperture fully, so the actual aperture opening is circular, will get rid of the sunstars - but can give just too much of a halo (even more with a fast prime lens than with a small zoom!). ...
rackandboneman's user avatar
8 votes

What is the difference between Diffraction Spikes and Lens Flare?

Diffraction spikes are caused by diffraction at the edge of the aperture. The number of spikes relates to the number of blades and the intensity of the effect relates to the exact shape of the blades ...
AshleyF's user avatar
  • 181
7 votes
Accepted

Why do white flowers always have a weird surrounding "glow"?

You applied surplus of sharpening. Sharpening means for a computer to find a lightness transition and make the dark part of it darker and the lighter part lighter. If you apply disastrous amount of ...
Euri Pinhollow's user avatar
7 votes

Pink/Purple lines on my photos while shooting long exposure?

TL;DR: You did not cover your viewfinder during your bulb exposure, which resulted in light bleed or light leak into your image. When the shutter is open, the mirror is rotated up out of the way of ...
scottbb's user avatar
  • 32.2k
7 votes
Accepted

What's causing this white smudge in the middle of the photo?

Some film era lenses could produce this effect on digital cameras, it's called a "hot spot". The reason is that unlike film emulsion, which is matte, digital sensor is glossy (as it's composed of ...
lightproof's user avatar
7 votes
Accepted

Is an artifact in form of a purple dot squat in the middle of the picture an effect of lens optics?

From reading the linked question and the answers to that question as well as the discussion in the comments there a picture of what created this artifact is fairly clear. It's not lens flare. The ...
Michael C's user avatar
  • 174k
7 votes

What is the cause of these hard transitions after HDR processing?

Those artifacts look like the result of JPEG compression. Such compression artifacts are particularly likely to be visible in large flat areas with slowly changing intensity, like your blue sky. If ...
Olin Lathrop's user avatar
  • 17.4k
7 votes

What is the cause of inclusions in my bokeh?

Probably the dots are dried water specs. Definitely the unsightly rings are from the glass polishing process. Zeiss Batis 2.8/135 See this Imaging-Resource article: "The end of onion-ring bokeh? ...
Rob's user avatar
  • 1,803
7 votes

Is it just me, or do smartphone cameras not have any chromatic aberations at all?

It is likely because chromatic aberrations are easy to fix on a fixed focal length, and fixed focus lens. And whatever remains is hidden by the heavy-handed post-processing that occurs.
xenoid's user avatar
  • 20.3k

Only top scored, non community-wiki answers of a minimum length are eligible