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Προβολή αναρτήσεων από Απρίλιος, 2012

Timelapse video flicker

In timelapse photography, when light changes fast and towards one direction (towards night-sunsets, or towards daylight-sunrises), if you use the aperture priority mode of your camera then there will be frames-photos lighter or darker than the nearby photos in the series. The drastic change in brightness will cause flickering in the timelapse video. This problem occurs because the light metering system isn't perfect.
The best way to deal with flickering caused by the light metering system of your camera is to avoid the aperture priority mode (or other auto modes) and change shutter speed (or aperture and ISO) manually (you could use spot-metering, but this is quite difficult to master..).
In order to do this you will need an extra device (another camera or a light meter) to meter the scene and your camera to take the photos. You take the meter indications, you average them and slowly increase or decrease exposure (by changing shutter speed, aperture or ISO). It is difficult to ch…

Dynamic range (data table)

Sunlit scene: around 17 stops
HDR file: from 16 to 20 stops
my Nikon D90: 12.5 stops

use the following link to view the data table:
https://docs.google.com/spreadsheet/pub?key=0AmeXsxxW0BJQdEd6ZW8yYzdfUzVkck1EWEhtb202RVE&single=true&gid=0&output=html

Visualize the field of view of your lens' focal length (DX sensor used)

Εικόνα
Below is a data table I created so that I could understand better the difference between my 18mm Nikkor lens (on my Nikon D90 - DX) and a 11mm wide angle lens..

Let's say that your eye is 10cm away from a plane vertical to the ground and parallel to you. Then by using basic trigonometry you can visualize the field of view of any lens' focal length.


You can use the following link as well:  https://docs.google.com/spreadsheet/pub?key=0AmeXsxxW0BJQdDRtRFhXXzBxTHF4YUJlZzBWc1Y4dlE&single=true&gid=1&output=html



For more data tables about photography use this link:
https://docs.google.com/spreadsheet/pub?key=0AmeXsxxW0BJQdDRtRFhXXzBxTHF4YUJlZzBWc1Y4dlE&output=html