Bengal white tigers having a moment
Still looking for that perfect HDR
I’ve been trying my hand at High Dynamic Range (HDR) images ever since I saw this slightly over the top one at Flickr. After many, many messed up attempts I’ve finally managed to get a few decent ones at Vellore last weekend:
If you aren’t familiar with HDR photography, you probably think these images were run through a hundred photoshop filters. Actually, HDRs are a result of combining three separate photographs of the same scene, but with different exposures. When the three images are combined, you get all the highlights and shadows in great detail. Click here to see the three original exposures of the Vellore fort, followed by the final HDR.
The trick with getting decent results is knowing how far to push the final output HDR. If you go too far, it would end up looking like this. I liked this shot on Flickr, think he/she got it just right. This night shot is nice as well. For some tutorials on taking HDRs, go here, here, here and here.
576 Megapixels?
No, it’s not a camera you use to make blowups that can be seen by passing aliens. According to this article on clarkvision.com, it’s the resolution of the human eye when compared to a digital camera.
The eye is not a single frame snapshot camera. It is more like a video stream. The eye moves rapidly in small angular amounts and continually updates the image in one’s brain to “paint” the detail. We also have two eyes, and our brains combine the signals to increase the resolution further. We also typically move our eyes around the scene to gather more information. Because of these factors, the eye plus brain assembles a higher resolution image than possible with the number of photoreceptors in the retina. So the megapixel equivalent numbers below refer to the spatial detail in an image that would be required to show what the human eye could see when you view a scene.
Based on the above data for the resolution of the human eye, let’s try a “small” example first. Consider a view in front of you that is 90 degrees by 90 degrees, like looking through an open window at a scene. The number of pixels would be
90 degrees * 60 arc-minutes/degree * 1/0.3 * 90 * 60 * 1/0.3 = 324,000,000 pixels (324 megapixels).
At any one moment, you actually do not perceive that many pixels, but your eye moves around the scene to see all the detail you want. But the human eye really sees a larger field of view, close to 180 degrees. Let’s be conservative and use 120 degrees for the field of view. Then we would see
120 * 120 * 60 * 60 / (0.3 * 0.3) = 576 megapixels.
The full angle of human vision would require even more megapixels. This kind of image detail requires A large format camera to record.
Hubble captures Galactic collision
Astronomers using the Hubble Space Telescope have snapped the most detailed image ever of a pair of colliding galaxies, known as the Antenna galaxy.
The galaxies are the nearest merging pair to Earth, and the youngest too: the collision began about 500m years ago. As the two galaxies smash into one another, they create ideal conditions for new stars to be born. And new stars are forming in their billions.
What’s in this picture? According to NASA:
“Nearly half of the faint objects in the Antennae are young clusters containing tens of thousands of stars. The orange blobs to the left and right of image centre are the two cores of the original galaxies and consist mainly of old stars criss-crossed by filaments of dark brown dust. The two galaxies are dotted with brilliant blue star-forming regions surrounded by pink hydrogen gas.”
Astronomers believe that the image captured by the Hubble telescope shows a probable scenario when the Milky Way galaxy collides with the Andromeda about six billion years from now.
Hmm. I can wait.
Shell Wildlife Photographer of the Year award
This award winning picture was nearly deleted from the camera!
Goran Ehlme’s shot of a walrus feeding on clams on the sea floor is a whirl of grey; the animal’s face is seen poking through a cloud of disturbed sediment.
He caught the magic moment on a digital camera and deleted many unwanted shots.
“My finger was poised to delete this one too, and then I noticed something special,” he told the BBC News website.
View the rest of award winners here.
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