|[Note Guidelines] Photographer's Note|
|The theory behind the hot air balloon|
A hot air balloon consists of a bag called the envelope that is capable of containing hot air. Suspended beneath is the gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule) which carries a source of heat capable of producing a sufficient temperature gradient between the air inside the envelope and the surrounding air mass to give enough lift to keep the balloon and its passengers aloft. Unlike gas balloons, the envelope does not have to be sealed at the bottom since the rising hot air only exerts pressure on the upper hemisphere of the balloon to provide lift. In today's sports balloons the envelope is generally made from nylon fabric and the mouth of the balloon (closest to the burner flame) is made from fire resistant material such as Nomex.
Raising the air temperature inside the envelope makes it lighter than the surrounding (ambient) air. This causes the balloon and its payload to rise. The amount of lift provided by a hot air balloon depends primarily upon the difference between the temperature of the air inside the envelope and the temperature of the air outside the envelope. For most envelopes made of nylon fabric, the maximum internal temperature is limited to approximately 120 °C (250 °F). It should be noted that the melting point of nylon is significantly higher than these maximum operating temperature — about 230 °C (450 °F). However the lower temperatures are generally used because the higher the temperature, the more quickly the strength of the nylon fabric degrades over time. With a maximum operating temperature of 120 °C (250 °F), balloon envelopes can generally be flown for between 400 and 500 hours before the fabric needs to be replaced. Many balloon pilots operate their envelopes at temperatures significantly below the maximum in order to extend the longevity of their envelope fabric.
Cloned the small balloon to a slightly higher position for a better compo
Cropped the picture
Resized & sharpened
Thanks for visiting, enjoy!
jonathanhart, ttreen, kurekpit, Mas, mjdundee has marked this note useful
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- [2007-08-29 4:57]
Belle présentation et excellentes explications.
fine colours, light & sharpness
good pic, good note
- [2007-08-29 9:25]
Very interesting notes.. Good idea to change the position of the little one! :)
Wonderful blue sky.. and amazing details on both balloons!
- [2007-08-29 10:53]
this picture is amazing. the composition you made here is great. and the exposure of this picture is perfect! well done!
Very nice picture,excellent saturation,sharpness and composition.
* Piotr *
- [2007-08-29 14:31]
Wow, krijgen we hier even les in physics ?
Mooie compositie, kleuren- en lijnenspel.
En een heel creatief frame !!
- [2007-09-04 16:34]
Perspective matters. This ballon event was huge and you have captured it. TFS. K2
I found this one in Hans's -greenbaron's - hot air balloon collection theme. Your framing and crop suits very well the balance between big ans small object.
Nice natural colours, good sharpness and great blue sky. TFS Thomas