Why Do Hubble Photos Have Black Squares?

[uknova]

Why do some photos have black squares cut out of them from hubble, like this:

http://nssdc.gsfc.nasa.gov/image/astro/hst_antennae_9734a1.jpg

 

[Hurkyl]

Maybe there's a bright foreground object there that would ruin the processing of the data?

 

[chroot]

The majority of the photos you see from the Hubble Space Telescope, like this one, were taken with the "Wide-Field Planetary Camera 2," which is composed of four independent CCD chips laid out in an array. One of the CCDs has a different optics package to increase its resolution, so, when used together to form a mosaic image, a "stairstep" pattern results. If you look closely at this image, you'll see the slightly different color balance from the "PC" CCD versus the other three, larger, "WFC" CCDs.

http://en.wikipedia.org/wiki/Wide_Field_and_Planetary_Camera_2

- Warren

 

[munky99999]

isnt it obvious...

alien saucer! and The MAN is covering it up!

just kidding.

Hurkyl explained one reason why this could be.

The other might be post-processing problems.

you should be aware that these pictures are slowly layered into colour.

personally with photoshop I've seen quite a few times problems when i tried this. I would layer the colours and the last steps the colours would over saturate and it would then make it very blurry. so to save the colour picture u need to remove the blur, and by that u need to remove the affecting light source.

 

[Hurkyl]

Hurkyl explained one reason why this could be.

I was speculating. chroot posted the answer already.

 

[Chronos]

Chroot is correct. The published photos are mosaic images. The missing pixels are merely gaps in the overlay.