What causes a concentric circular blob in photos shot in sub-zero temperatures?
Asked 1/17/2015
62 views
2 answers
0
A few images taken in the Alps at about -14°C showed a large concentric circular pattern/"blob" in the frame. It did not appear in every shot. What can cause this kind of defect in very cold conditions?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
11y ago
2 Answers
3
I could be very well wrong, but those look a lot like Newton's rings, which can be caused by two layers of dissimilar materials that are normally in close contact expanding or contracting differently, making one of them buckle slightly. And by slightly, I mean that the spacing between them varies by fractions of a wavelength of light. (Another, similar possibility is differential stress polarization effects, again with a thermal basis. It's really hard to tell in B&W, though.) The "origin" of the pattern probably indicates a relative "hot spot". If the camera is shot cold, or allowed a little while to warm up completely, you probably wouldn't see a problem, but if it's been on just long enough to partially warm up, there might be enough difference in temperature across the sandwich that is the sensor, its lenses and filters, to cause a visible pattern.
Originally by user35658. Source · Licensed CC BY-SA 4.0
user35658
11y ago
0
Generated from our catalog & community — verify before relying on it.
The most likely cause is flare/ghosting from a bright light source—often the sun—just outside the frame. Even when the sun isn’t directly visible, reflections between lens elements can create circular or concentric artifacts in the image. This is why shading the lens or changing composition often helps.
A second possibility mentioned is a temperature-related optical effect such as Newton’s rings or stress-related interference inside a lens/filter/display layer, caused by uneven thermal expansion in very cold conditions. That could make the effect appear only when the camera or lens is partially warmed rather than fully cold-soaked.
Given the circular pattern and the shooting conditions, start by checking whether the sun or another bright source was just outside the image, and whether a hood or hand shading eliminates it. If it only happens during temperature transitions, let the gear fully acclimate and see if the issue disappears.
Recommended products
UniqueBot
AI11y ago
Your Answer
Related Questions
Why does a tripod ball head get stiff in cold weather, and can you prevent it?
What tripod features work best for shooting in sub-zero temperatures?
How should I protect my Canon DSLR gear when shooting in the Alps in winter?
Can I use a Canon 600D/Rebel DSLR in cold weather and snow?
How should I use a DSLR safely in cold weather, including around -9°C?