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Questions tagged [artifacts]

Elements of a photograph that are generally undesirable or have a negative impact. Examples include noise, flare, dead or hot pixels, sensor "spots", reflections inside the camera/lens system, etc.

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15 votes
1 answer
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is it normal to get significant lens flare with a 50mm f/1.8 prime lens?

I've purchased a Canon EF 50mm f/1.8 II. But I'm really disappointed in the results, especially when using it for night photography. :( In my night shots a lot of lens flare appears in my photos. I'...
Amro Ashraf's user avatar
32 votes
2 answers
5k views

What is noise in a digital photograph?

What kinds of effects are present in digital images that are referred to as "noise"? What are the different sources of noise? What causes each type of noise? What are the characteristics of the ...
Martin's user avatar
  • 642
61 votes
4 answers
78k views

What is moiré? How can we avoid it?

What is the image defect called "moiré"? What causes it, and how can we avoid or reduce it? Is it related to "false color"?
coneslayer's user avatar
  • 7,416
27 votes
6 answers
48k views

What are jpeg artifacts and what can be done about them?

I know JPEG is a "lossy" compression algorithm that discards information in order to save space. What is the visual impact of this? I've heard of "JPEG artifacts". What do these look like? Are there ...
mattdm's user avatar
  • 143k
18 votes
2 answers
6k views

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

Yesterday I took photos of an event at school. The lighting was poor so I increased the iso to 3200, shutter speed was between 80 and 250 and the aperture between 2.8 and 4.0. Canon EOS500 about 10%...
Nir's user avatar
  • 283
9 votes
2 answers
2k views

Dust-like speck visible every few pictures — is it dust, or worse?

I seem to have to dust-like speck on my Sony Cybershot S950's lens, but it appears randomly every few pictures. Could something be going bad internally?
Alan's user avatar
  • 193
7 votes
2 answers
3k views

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

An acquaintance recently posted an image to FB from his recent trip to the JFK Historic Site asking for an explanation of a visible artifact he states was not visible to the naked eye but was visible ...
Didgeridrew's user avatar
7 votes
2 answers
4k views

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

Someone mentioned that "veiling glare" or "veiling flare" was to blame for reduced contrast in a photo. What does this mean exactly? What causes veiling glare, and how can it be avoided? How does it ...
mattdm's user avatar
  • 143k
18 votes
4 answers
6k views

How can I avoid soft dull "spots" in my pictures?

Recently, I've been doing a lot more photography, particularly with my 100-400mm telephoto and 16-35mm wide. I am skilled enough that I can capture the shot mostly as I want with just the camera gear, ...
jrista's user avatar
  • 70.8k
4 votes
2 answers
9k views

What is causing the strange lighter circles in images taken with my Canon 15-85?

I took these pictures with my Canon EF-S 15-85mm f/3.5-5.6 IS USM lens this morning: Would somebody please tell me that what is that white part in the lower right corner of the picture? EXIF info: F/...
Kermia's user avatar
  • 195
12 votes
5 answers
61k views

What causes these streaked rays from light sources?

I recently bought an LG G4, whose camera can shoot in an auto and both manual mode (I can manually set the iso, aperture). I shoot 100% of the time in auto. It takes better than average photos at ...
Andrei Gavrila's user avatar
10 votes
5 answers
24k views

Why is my camera showing a lot of stuck red and white pixels?

After shooting for one hour with my Rebelt2i + Tamron 17-55 f2.8, I went back home and checked pictures on my computer. For every single picture, there are a lot of 'dead' pixels at the same location....
Eno's user avatar
  • 267
9 votes
3 answers
8k views

How can one correct intensity flicker due to AC line frequency?

Is there a good image processing method to get rid of the horizontal stripes in the images taken under fluorescent lighting? These stripes (flicker) occur when you take pictures indoors due to the 50 ...
chronosynclastic's user avatar
33 votes
7 answers
7k views

How can I stop my HDR shots looking so fake?

All my attempts at HDR come out looking remarkably fake, how can I reduce the halos effect?
Rowland Shaw's user avatar
  • 16.1k
8 votes
3 answers
4k views

What causes these green dots in my image?

I just received a 35mm f/1.8 DX lens for my Nikon D50 for Christmas, and took some shots where the lights on the tree were the main source of illumination. Almost all of them exhibit very prominent ...
Matt McHenry's user avatar
6 votes
2 answers
888 views

What causes a band-like pattern in photos of a CFL?

In an image of a compact fluorescent light bulb, I couldn't figure out the reason for the formation of light and dark bands sort of thing in the image. The same thing happens when I try taking a ...
WhizKid's user avatar
  • 61
5 votes
2 answers
1k views

Small, faint circle in corner of image. What is it?

I've started to notice a faint darkened circle in my photos. I tried to clean the lenses and I still see it. What's causing these circles? Link to imgur album since I don't have enough rep to post ...
smvulhop's user avatar
12 votes
4 answers
2k views

Where does this reflection come from in a long exposure shot?

Using a long (10 second) exposure I found I was getting an odd "reflection" in the picture, where the brightest object leaves a residue in the opposite part of the frame. You can see it here:...
AlastairC's user avatar
  • 345
10 votes
1 answer
55k views

Why do I get dark horizontal lines (stripes or bands) in bad lighting with my Fuji X-T1?

Can anyone explain why I get these lines when taking photos in bad/weak lighting? Here are some photos.
Vova Sadovych's user avatar
9 votes
4 answers
2k views

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

I photograph in RAW, and convert using Darktable. Camera happens to be Nikon D40, 55-200mm lens. For a small number of photos, especially of clear blue skies, I cannot reduce noise without introducing ...
Jonathan Burley's user avatar
6 votes
4 answers
20k views

What is the blue circle in this moon image?

Using my Nikon D3200, I tried to capture an photo of the moon using the 18-55mm kit lens. I can see a faint blueish circle, even in my view finder, and also in the final picture. Is this lens flare ...
The King's user avatar
  • 163
5 votes
2 answers
291 views

Where do these "redshifts" and "blueshifts" come from?

I make many product photos for the company I work for. For this I use Canon 400D with two external flash devices Walimex CY-600K. I've noticed an interesting effect on many of the photos I take with ...
user avatar
1 vote
1 answer
304 views

What is this shadow in my photo?

I'm pretty sure the subject didn't move, the shutter speed was ok @1/80s. I was using Canon 70D + 18-55mm IS STM and a built-in flash and shot in RAW. What it could be? What may be causing this?
Giancarlo's user avatar
  • 459
28 votes
6 answers
19k views

Why do photos of digital screens turn out the way they do? [duplicate]

When I take pictures of a screen at school or at my house, they turn out really weirdly. When blown up to 100%, they look fine, but when they get sized down, they look really weird, here is a ...
Milo's user avatar
  • 383
12 votes
3 answers
1k views

Why are red lights in night / city scenes coming out as big red blobs?

I've noticed that in a lot of my night shots of cityscapes, red lights (e.g. neon signs on buildings, etc.) tend to come out as big red blobs: The above was taken with my Canon 500D. What can I do ...
Justin's user avatar
  • 630
6 votes
2 answers
7k views

Why does darkening skies in Photoshop cause banding, and how can I avoid it?

I am pretty new to Photoshop (I have Elements 10). When I darken highlights I find that the sky ends up in bands. I have read advice that says to reduce the effect of this by using either blur or ...
Jamie Kitson's user avatar
4 votes
2 answers
4k views

What causes longitudinal chromatic aberration on Nikon 50mm f/1.4D?

I have looked on my new 50mm lens photo (I have Nikon D90) and I see "purple fringing" around the unfocused objects (longitudinal chromatic aberration). What's is going on? Is it common for this lens (...
garik's user avatar
  • 1,469
4 votes
3 answers
2k views

Orange and other artifacts in photos from film camera

I've been thinking about getting into film photography for a while, so recently I grabbed the old Olympus OM-1 from work when they were cleaning out the media cupboard, I'm only mentioned in this so ...
Stew's user avatar
  • 43
4 votes
1 answer
2k views

What could cause this white speck in a blue sky?

I took a photo during blue hour, and notice that there are some strange white speck on the blue sky. What is this and why it happens? Initially I thought it was dust, but usually dust will leave black ...
rcs's user avatar
  • 1,095
3 votes
3 answers
2k views

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

Specifically, this photo. . This was taken with a Canon 1000D, with a 1985-ish Admiral/Panagor 55-225mm manual telephoto/macro that I picked up for cheap at a charity shop; it's a Minolta mount, so ...
David Given's user avatar
2 votes
2 answers
723 views

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

I took few long exposures of the night sky yesterday. I know about the hot pixels those appear brighter with longer exposures but this seems to be something different. Can anybody tell what it is? ...
Curious's user avatar
  • 21
1 vote
2 answers
3k views

What caused this pattern of lines (moire?) in this picture I scanned from a book?

I have scanned this photo from a book that's printed with color ink, but the picture is a black and white one. When I scanned it with Vuescan as a color photograph I get vertical lines like I think ...
PerseP's user avatar
  • 111
29 votes
2 answers
5k views

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

I just found a picture again I took years ago, and I'm wondering what's happened ever since then - I hope this is the right place to ask! I sat on my swivel chair and spun a few times, while taking ...
stuXnet's user avatar
  • 383
17 votes
1 answer
2k views

Why do I see this yellow color shift at high ISOs and fast shutter speeds? [duplicate]

I recently purchased a full-frame DSLR with a reported highest ISO of 204,800. I’m intrigued by the possibilities of the high ISO range and how far Lightroom and Aperture (I use each of them) can ...
user27181's user avatar
  • 171
16 votes
3 answers
4k views

What causes and how can I avoid this moiré pattern in a composite night sky photograph?

I'm new to taking star trails, and fairly new to photography in general. After my first attempt at taking a star trail, I composited them in Photoshop and when I merged the layers I got this pattern ...
mekugi's user avatar
  • 161
16 votes
10 answers
13k views

Why does using flash sometimes create these white spots in the photo?

I have an Olympus FE-190. When I take a picture with flash in Digital Image Stabilizer (DIS) mode, I get white spots in pictures. This doesn't happen always. There is an option called Pixel Mapping, ...
theTuxRacer's user avatar
13 votes
4 answers
23k views

How to avoid jpeg compression artefacts when saving photos in web resolution?

When I save a web-resolution image (for example, 1920×1024px), flat areas tints often have damaged shades of color. I'm saving in Photoshop CS4 with quality 2 in standard mode, because I need the ...
Capsize's user avatar
  • 365
12 votes
2 answers
3k views

What causes faint circles in astrophotography images?

When processing an astro-images taken with a Canon 450D and prime focus, I often end up with a series of faint circles radiating outwards from an off centre point. What are they and how do I get rid ...
Ron Larter's user avatar
11 votes
3 answers
7k views

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

Any advice on how to remove moon "rays"? (Looking to learn how to take a photo without them, not remove them in post) Artistic opinion - is it too underexposed? The picture was shot at shutter speed ...
Erly Marie's user avatar
9 votes
4 answers
29k views

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

How can I remove the "glare" on the musicians in the photo below using Photoshop? I do not have the relevant vocabulary to express what this "glare" really should be called. I am not a photographer ...
Colin m Gilker's user avatar
9 votes
2 answers
1k views

Why do I get horizontal grey bar with flash at shutter speeds slower than max sync speed?

I'm a total newbie to flash photography, and I am just trying to do some test shooting with Canon Speedlite 580 EXII using my 7D. I saw on the user manual that the maximum sync speed is 1/250 sec. ...
albert's user avatar
  • 93
8 votes
5 answers
2k views

Are these blotches of wrong color caused by a corrupt SD card?

My old camera was taking images that had blotches of the wrong colors when zoomed in, and I take a lot of macro pictures. I bought a new camera and put my old sd card into it and now it's doing the ...
user avatar
7 votes
2 answers
967 views

What is the difference between Diffraction Spikes and Lens Flare?

When Googling for lens flare, one often finds images that also include stars (rays / diffraction spikes), like this: What is the difference between diffraction spikes and lens flare and are the two ...
OnBreak.'s user avatar
  • 20.5k
6 votes
1 answer
2k views

Is camera damage causing these severe diagonal lines from concentrated light sources?

Since a week or so, I have severe diagonal stripes around light-sources in my night-time photographs on my Canon Powershot A650. In the past, I had some (I guess due to Fraunhofer diffraction, see ...
gerrit's user avatar
  • 1,480
5 votes
1 answer
1k views

Why am I am seeing rings (banding) instead of smooth graduation in my sunrise pictures?

Below is a screen capture crop from Potoshop of an unaltered raw photo from my full frame Canon 6D taken with the new Canon 16-35 f4 L at 16mm, ISO 100, f22. I am seeing rings where I am expecting a ...
Jakub Sisak GeoGraphics's user avatar
5 votes
3 answers
1k views

What creates this strange flare and how to prevent it?

I shot at a concert for the first time. The pictures were pretty good for the capability of my equipment, but on some shots, the light has a very strange flare. It isn't the usual rays, but some soft, ...
rumtscho's user avatar
  • 2,002
5 votes
3 answers
11k views

How can I eliminate white glow/halos surrounding bright objects?

I recently took this picture and was frustrated by the white glow coming from the man's shirt. I realize it's a high contrast scene, but I don't understand the science behind why the shirt appears to ...
aardvarkk's user avatar
  • 153
4 votes
3 answers
3k views

Why is there a strange white spot on all of photos from my Zenit-B SLR?

I've taken some photos with my old Zenit-B camera. And I have some strange white spot on all of the photos in the upper right corner. Sometimes it is not too recognizable, but it is everywhere. It ...
levanovd's user avatar
  • 173
4 votes
4 answers
2k views

Where does the strange purple/blue glow around the headlight wearing subject's front come from?

I've found that a few of my recent trip photos have this odd artifact/ghosting resulting in a blue/purple glow around the helmet(see below pic): I've found this question which i think relates to ...
NULLZ's user avatar
  • 2,536
3 votes
0 answers
355 views

Why do I have a red dot in every photo? [duplicate]

Possible Duplicate: Why is my camera showing a lot of stuck red and white pixels? Every picture that I took today have a red dot on the same place in every photo. It looks like a monitor "pixel ...
gsharp's user avatar
  • 961