File:Circles in Thin Ice, Lake Baikal, Russia.jpg

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Summary

Description	English: This image, a detailed astronaut photograph, shows a circle of thin ice (dark in colour, with a diameter of about 4.4 kilometers); this is the focal point for ice break up in the very southern end of the lake.
Date	20 April 2009
Source	NASA Earth Observatory
Author	Image provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Centre.

This image was taken with a Nikon 2DXs digital camera fitted with a 400mm lens.

Licensing

This file is in the public domain because it was solely created by NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (See Template:PD-USGov, NASA copyright policy page or JPL Image Use Policy.)

Warnings:

Use of NASA logos, insignia and emblems are restricted per US law 14 CFR 1221.
The NASA website hosts a large number of images from the Soviet/ Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
Materials based on Hubble Space Telescope data may be copyrighted if they are not explicitly produced by the STScI. See also {{ PD-Hubble}} and {{ Cc-Hubble}}.
The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use.
Images featured on the Astronomy Picture of the Day (APOD) web site may be copyrighted.

File usage

The following pages on Schools Wikipedia link to this image (list may be incomplete):

Lake Baikal

Metadata

This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. If the file has been modified from its original state, some details may not fully reflect the modified file.

Camera manufacturer	NIKON CORPORATION
Camera model	NIKON D3
Exposure time	1/1,600 sec (0.000625)
F-number	f/5.6
ISO speed rating	400
Date and time of data generation	23:51, 23 April 2009
Lens focal length	400 mm
Orientation	Normal
Horizontal resolution	240 dpi
Vertical resolution	240 dpi
Software used	Adobe Photoshop CS4 Macintosh
File change date and time	11:32, 22 May 2009
Exposure Program	Aperture priority
Exif version	2.21
Date and time of digitizing	23:51, 23 April 2009
Shutter speed	10.643856
APEX aperture	4.970854
Maximum land aperture	3 APEX (f/2.83)
Metering mode	Pattern
Light source	Unknown
Flash	Flash did not fire
DateTime subseconds	24
DateTimeOriginal subseconds	24
DateTimeDigitized subseconds	24
Colour space	sRGB
Sensing method	One-chip colour area sensor
Custom image processing	Normal process
Exposure mode	Auto exposure
White balance	Auto white balance
Digital zoom ratio	1
Focal length in 35 mm film	400 mm
Scene capture type	Standard
Contrast	Normal
Saturation	Normal
Sharpness	Normal
Subject distance range	Unknown

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