Originally posted by The Shrike
Originally posted by Phage
reply to post by The Shrike
The objects are not in focus. They are very much out of focus and exhibiting the phenomenon known as bokeh. Do you see those circles over the out of focus guy's shoulder? That is bokeh.
edit on 3/24/2012 by Phage because: (no reason given)
I should have edited out that part of the photo so that it wouldn't end in confusement as it did with you. What I was trying to illustrate is that if a camera is focused on a nearby object, let's say an ice crystal a short distance from the shuttle in inches or maybe a foot, then distance objects will be blurred. If you focus on a distant object, then the nearby object will be out of focus. Some special lenses will allow both near and far objects to be in focus but I don't think that the cameras on the shuttle have these lenses
Its NOT SPECIAL lenses its all to do with focal length and aperture and a thing called hyperfocal distance.
Other things can effect it if you use a digital camera sensor size for example.
Here is a link to explain it.
Every lens has a depth of filed chart which shows which area will be in focus at a certain aperture using data like this if you know a lens is focused at infinity you can work out if an object was to close to the camera to be in focus.
Here is some info re wide angle lenses
Normal to wide-angle lenses (50mm and shorter lenses on 35mm cameras) are good candidates for hyperfocal distance focusing. These lenses have a relatively short hyperfocal distance when set to larger f-numbers. For example, the hyperfocal distance for a 28mm lens set to f/16 on a 35mm camera is about 5.5 feet. Everything from 2.75 feet to infinity will be sharp in a photograph taken with this lens focused at the hyperfocal distance.
Telephoto lenses are rarely used for hyperfocal distance focusing. The hyperfocal distance is quite distant with these lenses. For example, the hyperfocal distance for a 200mm lens set to f/16 on a 35mm camera is about 275 feet. Everything from about 138 feet to infinity will be sharp in a photograph taken with this lens focused at the hyperfocal distance. You can see that a 200mm lens isn't useful for taking a landscape photograph in which you want near objects to be sharp.
This was all looked at in previous threads!