Circles in photos - what are they?

<p>Hi,</p>

<p>I recently bought a Lumia 1020 to get as good as possible photo experience on a smartphone. I'm no expert in photography (as will be apparent) but generally I'm quite happy with the Lumia 1020. </p>

<p>On some photo I've noticed some odd circles. I've linked one picture as an example.</p>

<p>https://www.dropbox.com/s/37bhpo6kvz5m9tq/picture_with_circles.png?dl=0</p>

<p>I've blacked out the child's face for privacy. If you look near the child's head, there is a large circle. There's two more smaller circles on the opposite wall (not as obvious). These circles are not reflections from the balloons, as the same thing happened in other pictures (that did not have balloons). I did have the flash on, for what it is worth. Not all pictures exhibited this problem, but many did (and the flash was on for all these photos). I didn't see the spots on the same place on all my pictures.</p>

<p>Any ideas?</p>

<p>Thank you,<br>

Notre<br>

PS I asked the same question on a different forum, but as this site is more dedicated to photos, I wanted to get people's opinion here as well. http://forums.windowscentral.com/nokia-lumia-icon/323240-discolored-circle-photos.html</p>

<p>I've got a Lumia 920, and never had this kind of problem - since it's running the same software, I think it can be excluded probably.<br>

It is a problem I've seen with my compact camera though (which is worse than the Lumia btw) - and well, cleaning the lens often helps quite a bit; dust particles. It happens more with flash on that camera too, maybe because of reflections? I've never succeeded in finding a proper explanation (so curious to learn!) but in my case, it happens more frequently with a lens that has some dirt on it.</p>

<p>Looks like airborne dust particles illuminated by flash. Very common with many cameras where the flash is in close proximity to the lens, and the aperture is stopped down very small relative to the recording media size (film or digital). There's no EXIF data attached to PNGs, so I'm just guessing the camera automagically stopped down to f/5.6 or smaller for the flash photo.</p>

<p>This was so common with Sony's earliest Mavica digital cameras that used 3.5" floppy disks, that particular camera was favored by ghost hunters during the 1990s. They were convinced the dust motes they recorded with flash photos at night in cemeteries were <a href="https://www.google.com/search?q=%22orb+spirits%22&safe=off&rlz=1C1LENN_enUS490US490&es_sm=122&source=lnms&tbm=isch&sa=X&ei=J-mYVK2DCsXegwSzmYSQCg&ved=0CAgQ_AUoAQ#imgdii=_"><span>"orb spirits"</span></a>.</p>

<p>Dust particles are more likely to appear this way with direct flash and tiny sensor digicams, which includes phone cameras. The sensors are tiny compared with 35mm film. An aperture of f/4 or smaller is enough to bring the dust motes near the lens into reasonably sharp focus. With 35mm film or full frame digital, and larger recording media, the problem is seen less often because of shallower DOF - dust motes hovering in front of the lens will be so out of focus they're not noticeable.</p>

<p>If your phone camera has manual controls try a larger aperture, at or near the f/2.2 maximum aperture.</p>

<p>Orb spirits-- Love it.<br>

I am a big fan of "flying rods" myself.<br>

Sentient clouds called sylphs ( http://educate-yourself.org/zsl/sylphstransmutechemtrails06jun04.shtml ) are another great topic.</p>

<p>The dust reflection sounds about right to me. Here it is much multiplied by using a on-camera flash in a light snow.</p><div></div>

<p>JDM, you may have to zoom in a little...to see the 'rods'. :>)</p>

<p>Les</p>

<p>Thanks to all for the help! I've read that the 1020 (or any other camera phone) doesn't have any way to change the aperture. Apparently it is fixed at f2.2. (http://forums.windowscentral.com/nokia-lumia-1020/236989-aperture-priority-1020-a.html). I can adjust white balance, ISO, EV, and whether the flash is on.</p>

<p>A little more info on the picture. It was taken with the flash on, auto white balance, ISO 160, O EV, f2.2, a shutter speed of 1/125.</p>

<p>I'm guessing that Wouter's 920 didn't get this problem because either he doesn't use the flash much or the 920's flash being less powerful than the xenon flash on the 1020 doesn't pick up the dirt as much?</p>

<p>Any other suggestions for avoiding the dust reflections, besides perhaps not using the flash (or vacuuming more :) )? It does sound like it's not a defect of my particular Lumia 1020, but a general problem with the phone's camera.</p>

<p>Thank you again!</p>

<p>The 2/3" (or 1/1.5") sensor is unusually large for a camera phone, or even a compact digicam. And if the f/2.2 aperture is fixed, it would take an unusual combination of circumstances to produce visible dust motes. Unfortunately the close proximity of the lens and flash will cause this to happen once in awhile with direct flash photos.</p>

<p>If possible, you might try a homebrewed bounce/diffuser doodad. Something as simple as a white sheet of paper or index card, held at an angle between the lens and flash, could redirect the flash to bounce off nearby walls/ceiling for softer flash with less risk of dust specks appearing as orbs.</p>

<p>Being a shutterbug's enthusiast camera phone, it's likely some company is making simple stick-on flash bounce/diffusers for that model.</p>

<p>Indeed I do not use the flash all that often, because it lacks power in too many occassions. The lens on my lumia is very very prone to dirt, but more streaks of light (which can be rather effective at times). I just mentioned it to rule out the software, as with phonecameras software tends to play a significant role.<br>

For what it's worth, indeed I do not think it's specifically a problem with your phone, as my Panasonic P&S does the very same thing :-)</p>

<p>Thanks to both of you, Lex and Wouter. Lex, given that you think it's unusual that a fixed aperture of f/2.2 would produce visible dust motes, do you think the theory posted in the other link (see original post for URL) is likely? From that post:</p>

<blockquote>

<p>In your case the ghosting is coming from the flash. The flash is right next to the lens and the light is reflected straight back at the camera. Although the focusing elements are Carl Zeiss, the outer glass is NOT part of focusing, it is just protective in nature. Therefore, since the outer glass is protective in nature, the quality of glass is not the same as the lens elements themselves and doesn't have the same coatings as the lens elements. The light from the flash reflects straight back onto the sensor then back on to the outer glass which then reflects back onto the sensor, thus causing ghosting.</p>

</blockquote>

<p>I like the idea of a bounce/diffuser. I googled around and was a little surprised to not find one, but I'll probably try creating my own. Whether the cause of the circles is dust or reflection, I think the diffuser would probably help in both cases...</p>

Ghosting glare caused by the flash seems

unlikely. The flash would need to be in the

frame, in front of the foremost lens element.

Judging from photos of that phone the lens

appears to be shielded sufficiently from the

flash - otherwise it would be a design flaw and

would show in every flash photo taken by every

user. Ghosting flare also tends to have better

defined edges, some color, and some elongation or

piston shaped artifacts toward the edges of the

frame.

I'm still leaning toward the dust theory. It's

easy to test. Blow a tiny bit of flour or other

fine particulates in the air and wait for most of

it to dissipate, within a foot of the camera. Or stomp around on dusty ground, floor or carpet that hasn't been vacuumed recently.

Take a flash photo of something around six to ten

feet away. The orbs will probably look like those

in your photo, and in dozens of photos taken by

paranormal buffs and ghost hunters.