Cheap "lucky Imaging" Rivals Adaptive Optics, UK stargazers enjoy 'Lucky' break Options

[tacitus]

I found this article a few days ago on the BBC News website:

UK astronomers are finding new stars in the sky using a remarkable low-cost camera technique. Known as Lucky Imaging, it has helped the Cambridge team overcome the problem of turbulence in the atmosphere which makes stars twinkle and hard to see.

The group's camera takes millions of images very quickly in the hope that just a few are not blurred. The scientists say the clearest pictures are as sharp as those captured by the Hubble Space Telescope.

Lucky Imaging is an approach previously only used by amateurs, who cannot afford the imaging methods now used on the world's most sophisticated telescopes. Governments around the world have spent hundreds of millions of pounds on Active and Adaptive Optics, which use a complicated system of mirrors and computers to get detailed pictures.

But the Institute of Astronomy project has so far cost just £20,000.

Click this link for the rest of the article and some video.

There is a lot more information at the Lucky Imaging website. Check it out.

Now, to my purely amateur mind, this strikes me as revolutionary. They are claiming that Lucky Imaging can equal or even better Adaptive Optics in many cases, and at a tiny fraction of the cost of installing and operating the equipment.

Now of course, if you have to "throw away" 90% or more of your images, then your going to need longer exposures to see the faintest objects, but for many situations, lucky imaging would appear to be a no-brainer considering the cost.

Is this merely hype or are we soon going to be able to get cut-price Hubble-like clarity from telescopes that install their own LI instruments?

[tacitus]

Oops - just realized this is "Spaced Based Observing" forum. Sorry about that - feel free to move or delete this topic if deemed inappropriate for this section. (Good story though!)

[Guest_Richard Trigaux_*]

Interesting idea, but it seems to me that what we see in a telescope when we look with our eyes is a moving image rather than a blurred image. So with lucky imaging, we may capture it at a still moment, and thus equal the theoretical resolution of the telescope and have great images. But there are two ways in which we cannot equal adaptative optics:

-the lucky images are clear, not blurred, but they are distorted, so that we cannot use them for astrometry or planet search.

-as many of the images are thrown away, even if we composite the remaining good images, the composite will be blurred and the total useful exposure is much less than with the adaptative optic.

So lucky imaging may become important for many onservations, but I think adaptative optic is irreplacable for faint objects or accurate measurements. It is not a waste of money to install it on the most powerfull instruments.

[deglr6328]

I think lucky imaging is a neat hack but I do not think it is the UNBELIEVABLE BREAKTHROUGH(!!!) that it is being touted as in the media this week. It has its niche certainly (binary star observations) but it seems useless for all but the brightest objects. The shorter your exposures are the less photons you capture and this technique demands extremely short exposure times due to the rapid temporal fluctuations of the atmosphere, so it looks like you are fundamentally limited to very bright and small (sub-arcsec?) objects for observation. That is, unless you can compensate by having an unbelievably huge telescope.

[Guest_Richard Trigaux_*]

I think lucky imaging is a neat hack but I do not think it is the UNBELIEVABLE BREAKTHROUGH(!!!) that it is being touted as in the media this week. It has its niche certainly (binary star observations) but it seems useless for all but the brightest objects. The shorter your exposures are the less photons you capture and this technique demands extremely short exposure times due to the rapid temporal fluctuations of the atmosphere, so it looks like you are fundamentally limited to very bright and small (sub-arcsec?) objects for observation. That is, unless you can compensate by having an unbelievably huge telescope.

We can do a composite of the best images, but each of the image will be distorted in a different way, resulting in a blurred composite.

A better deal was speckle interferometry, but now with adaptative optics we do not hear too much about speckle interferometry.