Sharpest Images With "Lucky" Telescope

igny writes "Astronomers from the University of Cambridge and Caltech have developed a new camera that gives much more detailed pictures of stars and nebulae than even the Hubble Space Telescope, and does it from the ground. A new technique called 'Lucky imaging' has been used to diminish atmospheric noise in the visible range, creating the most detailed pictures of the sky in history."

Lucky Imaging

[dlawson]

First post, huh.
This technique is often used by amateur astrophotographers using newer CCD cameras and even webcams. Astronomy Picture Of the Day http://antwrp.gsfc.nasa.gov/apod/astropix.html [nasa.gov] is a great site to see this stuff. I haven't checked Googles pictures, but I am sure that there would be a number of them there, too.
The quality of some of these photos is amazing.
davel

Re:But surely...

[ScrewMaster]

I'm just blowing smoke here, but it seems to me that a technique designed to compensate for atmospheric distortion might not be all that useful when there's no atmospheric.

Exposure Time?

[MonorailCat]

TFA states that the camera takes 20 frames per second. Aren't most exposures of deep space objects on the order of seconds or minutes (or longer). Seems like 1/20th of a sec wouldn't cut it for all but the brightest objects.

Re:If they can do this from earth...

[Aesir1984]

The distortion they are trying to get rid of is caused by motion of the air in the atmosphere. It's similar to the waves and blurring you see looking across a parking lot on a hot day. They put space telescopes out of the atmosphere to get above these effects. The objects they're looking at don't have this problem because the thing being imaged is what is giving off the light, it's not something between the source and the viewer like the atmosphere is and so does not cause diffraction to the same extent. I would expect that this technique works rather well for bright objects, however I wouldn't expect it to work well for the very dim objects that the Hubble is normally tasked to look at. It order for them to use this technique they have to take many images per second. For very dim objects this would only mean a few photons per picture, not nearly enough to figure out if this image is any sharper than any other. So we won't be able to get rid of space telescopes or adaptive optics just yet.

Interesting but picture quality unjustified

[bit01]

The technique they're using, while interesting, needs more justification.

I'm wary when I see people doing any selection on random data because there's the problem of selection bias; throwing away the hundred results that don't match what they want and keeping the one that does. Just getting an image that seems plausible is not good enough.

Their quality measure [cam.ac.uk] isn't one I'd use. They should be comparing the technique-plus-low-resolution-optics against high-resolution-optics directly. That is, doing image differencing of images taken at the same time and seeing what differences there are. They may well have good reason for assuming it's all okay but until somebody does that test they cannot assume they've removed all the variability that the atmosphere provides; there could be all sorts of hidden biases due to various atmospheric, molecular and statistical effects.

---

"Intellectual Property" is unspeak. All inventions are the result of intellect. A better name is ECI - easy copy items.

They've got two things going on at once here

[Anonymous Coward]

You can't tell at all how much good the "lucky" camera is doing, although it is a tried and true
technique. Notice the before pictures in each case are wihtout adaptive optics and without the "lucky"
camera. The "after" images have both and EACH is likely to improve the image quality. I'd bet the adaptive
optics is doing most of it, but it's a pretty shoddy way to present the data.

Re:If they can do this from earth...

[vtcodger]

***Well sure. All you have to do is bounce your laser off of those gas clouds to find out how to compensate for them.***

That's adaptive optics. 'Lucky imaging' looks to be something different. Sounds like Lucky Imaging tries to catch and merge portions of the image that occasionally, by chance, make it through the ever changing atmosphere with minimal distortion.

But I think that the answer to the original question is probably still 'No" It doesn't sound like Lucky Imaging per se is an answer to the question "How can I see objects obscured by cosmic gas clouds?"

Reinvention

[maroberts]

http://www.ast.cam.ac.uk/~optics/Lucky_Web_Site/in dex.htm/ [cam.ac.uk] refers to a 1978 reference (Freid). It seems that some ideas keep popping up, only the technology actually available to do it has progressed from imaginary to real.