Sensor cleaned, but dust spots still show at f/22 — does it need another cleaning?
Asked 4/26/2025
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2 answers
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After a sensor cleaning, I still see several circular dark spots in a test shot of a plain wall at f/22. Before the cleaning, I made things worse by blowing on the sensor, wiping it with a glasses cloth, fogging it with breath, and even leaving a fingerprint. A phone photo of the sensor doesn’t show obvious scratches.
Could this still just be dust or residue that needs another proper cleaning, or does this suggest permanent damage? Also, are spots seen only in an f/22 wall test something to worry about in normal shooting?
Originally by KevinL337. Source · Licensed CC BY-SA 4.0
KevinL337
1y ago
2 Answers
3
There are several things to consider:
- i am not sure what subject you used for test photo. Would be best if you used a backlit sheet of paper placed close to front element at long focal length
- With F22 and that small sensor (and probably short focal length on top of that) you have good chance of getting the lens dirt projected on the sensor, it will look similar to what you posted
- unless you have specific use cases like long exposure in bright conditions you will never use F22 on M43 sensor anyway and you will never see the spots you posted at lower F-numbers.
Originally by Euri Pinhollow. Source · Licensed CC BY-SA 4.0
Euri Pinhollow
1y ago
0
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You’re probably not screwed. From the answers, this looks more like remaining dust or residue than obvious permanent damage.
A few key points:
- f/22 test shots against a plain wall strongly exaggerate dust spots.
- On smaller sensors and with shorter focal lengths, even lens dust can appear in this kind of test.
- If you don’t normally shoot at very narrow apertures, you may never notice these spots in real photos.
- Some of the spots, especially near a corner, could simply be dust left behind or pushed there during cleaning, which a better follow-up cleaning can remove.
So: maybe it needs another cleaning, but only if the spots appear in your actual images, not just in extreme test conditions. If you do regularly shoot stopped down, ask for another proper sensor cleaning and point out where the spots remain.
For testing, a more controlled method is to shoot an evenly lit, defocused bright surface rather than judging from random scenes. But if normal photos look fine, it’s probably not worth stressing over.
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UniqueBot
AI1y ago
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