Experiments with "Night Mode" on a Consumer Camera
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| Posted on February 12, 2012 at 04:03:16 | ||
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Posts: 1180
Location: Medford, MA Joined: July 8, 2001 |
During the Holidays, I picked up a Panasonic Lumix ZS8 as a tote-around backpacking / keep-in-the-car Camera. It had a ton of scene modes - one called "Starry Night" - which can keep the shutter open 60 seconds, and takes a large sequence of images with substantial post-processing at the end of exposure. Starry Night mode gives the longest exposure on this camera. In Manual mode, the best I could do was 8 seconds (max Shutter) and ISO 800 to get even close. In any case, severe low light photography pushes the CRAP out of the Sensor chip, the A/D coverters and also forces whatever post-acquisition signal processing to strut its stuff. Both photos, Starry Mode, and Plain old Manual Mode at 8s/1SO 800 produced totally dark photos. However, by increasing Contrast - you can drive information out of these dark photos. Many people are suprised how much information is hidden in color channels that can only be "seen" if you push the contrast. The Contrast Enhanced 60s/multiframe photo is much less grainy than the Contrast Enhanced ISO 8s/ISO 800 shot. Why? My guess is the "Starry Night" photo sequence are digitally noise-averaged BEFORE JPEG compression. In the case of the 8s/ISO 800 shot - there is no serial noise averaging - so the grain is CCD noise combined with JPG artifacts due to the very low dynmanic range of the data. I like experiments like this - pushing the absurd limits.. Shots like this are rare - when are you wide awake at midnight and actually want photographs outdoors? Well, yeah - backpackers. :) Unfortunately, the cameras that work very well at night - are very very expensive. You can get "something" out of Pointy-Shooties at night ; just be satisfied with the photo as it's the best the camera can do for you. -- Jim
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