this one is so off-topic so I decided to share it with you:
yesterday, I was playing with my camera around my desk, and took some pictures of the Official case for RasPi Zero, with the camera module running, connected to my Asus Zenpad tablet via AP-WiFi config on Zero W.
Lighting was dim and the image appeared too dark, so I opened the original .jpg in GIMP, adjusted the levels quite a bit, scaled the image down to 800x600px and downsampled to 72dpi, exported as .jpg, optimising the image down to 52% quality.
At this point, I didn't notice anything out of ordinary. After a while I took another look of the image and found some debris starting from where the Zero W antenna is, and ending to the tablet... Checked the lenses and camera sensor, all clean, no dust, hair or debris. The debris had turned visible at some point after my edits on the image!
I've found no explanation for this, other than the debris is the Wifi signal.
Today, I tried to replicate my adjustments with the original image, no luck, couldn't reveal the "signal" again. I should have saved a working copy in GIMP instead of just exporting it as .jpg. I'm going to investigate this further someday.
All this is totally confusing, and I'm asking, have any of you had similar experiences photographing WiFi devices?
I've seen some experiments visualising the signals by photography, but they look like pretty lightpainting to me.
Attached the image with the "signal" visible, original image (2.3Mb) is also available, just ask if you think I'm crazy and just doodled something on it.
- "Signal" visible
- official-zero-case-4.jpg (41.97 KiB) Viewed 3760 times
Last edited by esaofeccola
on Thu Mar 30, 2017 10:12 am, edited 1 time in total.