Love the info about the Earth photo, all the info contained in the metadata…
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“Now let's get serious about the photo.
This is a tweet for those interested in photography, astrophotography, and anyone who wants to know. Why is this photo incredible? Some conspiracy theorist, acting all suspicious, asked why this photo taken by the Artemis II commander looked more washed out than the photo taken by the Apollo 17 crew in 1972.
Well. Here's the exciting part. This photograph would have been impossible to take with an analog camera; and not just any digital camera can capture it. The original file for this photo is available for download on NASA's website. In the file's properties, you can see what camera it was taken with and the exposure settings that were used. Even the camera's serial number.
This, first and foremost, guarantees that the photo we're seeing wasn't created digitally or with AI, but captured by a real camera by a human. I know that's not enough argument for the conspiracy theorists, but oh well. That's the Earth right there. Now for the really interesting part. Why does it look more washed out than the one from '72?
Because it turns out that on the side of the Earth we see in that photo, it's nighttime; if you zoom in, you can see the glow of nighttime lighting. But how, if it's nighttime, can it look like daytime?
Because the photo was taken with a super high ISO of 51200! ISO is the sensor's sensitivity to light. With most digital cameras, at ISOs over 6400, the noise is so much that the photo looks practically unreadable. But the camera that Commander Reid Wiseman has is a NIKON D5, which isn't a very new camera; it was released 10 years ago.
But its sensor is renowned for guaranteeing decent image quality at high ISOs. And that, for those who always ask how to take a good sky photo, is fundamental.
Why? Well, to be able to photograph the stars without having to lower the exposure speed too much. Because if you lower the exposure too much to let in more light, it captures the movement of the stars and the Earth's rotation, when you're on Earth.
So a high ISO like that made it possible for Wiseman to shoot at a speed of 1/4 of a second. Which is low, but not that low. It's, let's say, the limit for astrophotography. That's why this photo has noise, because it's still a super high ISO anyway.”