Space Photos Taken From Shed Stun Astronomers 149
krou writes "Amateur astronomer Peter Shah has stunned astronomers around the world with amazing photos of the universe taken from his garden shed. Shah spent £20,000 on the equipment, hooking up a telescope in his shed to his home computer, and the results are being compared to images taken by the Hubble Space Telescope. 'Most men like to putter about in their garden shed,' said Shah, 'but mine is a bit more high tech than most. I have fitted it with a sliding roof so I can sit in comfort and look at the heavens. I have a very modest set up, but it just goes to show that a window to the universe is there for all of us – even with the smallest budgets. I had to be patient and take the images over a period of several months because the skies in Britain are often clouded over and you need clear conditions.' His images include the Monkey's head nebula, M33 Pinwheel Galaxy, Andromeda Galaxy and the Flaming Star Nebula, and are being put together for a book."
Fooooosh.... (Score:2, Funny)
Re:Fooooosh.... (Score:2)
Better check that the shed is still there...
Re:Fooooosh.... (Score:3, Insightful)
Re:Fooooosh.... (Score:2)
Is that a reference to a particular event?
Also maybe this:
http://www.sdnn.com/sandiego/2010-01-15/local-county-news/suspicious-object-prompts-school-evacuation [sdnn.com]
http://www.fark.com/cgi/comments.pl?IDLink=4942164 [fark.com]
To be fair, one of my friends got expelled for building a pipe bomb and bringing it to our magnet school (back in the pre-war-on-terrorism-panic days).
Is Eureka cancelled yet? :P
Beautiful pictures (Score:5, Interesting)
Amazing, I would like to see some more details of his setup, particularly which telescope and CCD he used.
I personally have a 6" Dobsonian, but without an equatorial mount it's nearly impossible to replicate his results.
Re:Beautiful pictures (Score:5, Informative)
Information found:
He used an ORION OPTICS UK AG8 Astrograph and a STARLIGHT XPRESS SXV-H16 CCD.
http://www.astropix.co.uk/equipment.html [astropix.co.uk]
Re:Beautiful pictures (Score:3, Funny)
STARLIGHT XPRESS SXV-H16 CCD.
So, the solution to quality astrophotography is basically a big gay Andrew Lloyd Webber musical on rollerskates?
Re:Beautiful pictures (Score:5, Informative)
There's info on the telescope and CCD here [astropix.co.uk]
Re:Beautiful pictures (Score:3, Funny)
Thats a great camera. I wonder if he does weddings?
Re:Beautiful pictures (Score:3)
Only if the ceremony is on the moon....
Re:Beautiful pictures (Score:2)
Computer ? (Score:2)
Doesn't say what he uses on his computer, though, or how much time he needs to process a picture.
Re:Computer ? (Score:4, Informative)
That part isn't hard. As a former astronomer:
:-)
1) Take a dark frame. Lens on, potentially the same duration of your planned exposure. This captures all the non-responsive/stuck pixels on your camera, and captures any heat noise caused by the rest of the instrument.
2) Take the image.
3) Subtract #1 from #2.
There might be additional post-processing, but that depends on the quality of your setup, and how into it you are. Most astronomers that I know of use custom written scripts in IDL or MATLAB to do such processing, although there is a bit of a trickle to move to things like R and Python, due to their being more full-fledged programming environments.
When I was doing astronomy, we'd set our exposure up, then go play video games for a half hour. Ten minutes of dark-frame, ten minutes of exposure, couple seconds of automated transfer over the nextwork, a button push, and a minute or so of processing. Then we'd have to pause our game, and move to the next target.
Re:Beautiful pictures (Score:2, Interesting)
What is impressive is how accurate and stable the tracking mount must be. Some exposures are 4 hour long yet in the resulting photo the brightest spots don't have any trail.
Re:Beautiful pictures (Score:2, Insightful)
I would assume he collects many hundreds of frames with a much shorter exposure time and then adjusts for the motion in the frame prior to "averageing" frames. A Bayesian statistical model that accounts for motion and various noise sources, any optical aberrations etc.. would be capable of extracting the level of information seen in these images.
Re:Beautiful pictures (Score:2)
He's mounted the scope in cement, which accounts for the stability. Apparently it's wrapped in foil to prevent heat dissipation. You can actually get much better imaging in the winter as the heat always creates distortions in the atmosphere. He had a problem with the cement mount heating up and then causing distortions in the evenings. Very clever. I would imagine he uses the same technique as most amateur astrophotographers. He either uses a long exposure camera, or a cam. With the camera, he would take various length exposures (possibly in separate color lengths, combining the rgb later), or if he's using a cam, he would collect segments of video, and then evaluate each frame from the video to cherry pick the best frames and then stack those good frames using any number of stacking programs (most of which are FOSS). The stacking allows you to increase the signal to noise ratio significantly. The only problem with cams are the fact that they aren't designed for night work, and they tend to generate a lot of noise on their own.
I have an 8" Celestron but I never use it these days. The on-board computer is a little glitchy, and I could never get it to track properly for long exposures. It was great for local sights like the outer gas giants, and it could image decent pictures of mars, including the ice caps.
Re:Beautiful pictures (Score:2)
Several short exposures don't capture more light than a single long exposure. In fact, they capture far less.
Right, but atmospheric motion blurs long exposures, and background noise accumulates as well. So you take several short exposures and add them together. sort of the amateur's version of adaptive optics. TFA mentions he uses about 30 frames to make an image.
Re:Beautiful pictures (Score:2)
The impression I get is now the guide scope either have their own camera and is monitored by a computer or the main camera is sample for guidance correction via software. His equatorial mount [losmandy.com] accepts auto-guider systems.
Re:Beautiful pictures (Score:4, Informative)
Dobs are useless for photography. You would have to use an equatorial mount.
It would me even more interesting to know his digital process. That's where the magic happens. Of course you have to start with a good set of the right kind of exposures, but it's the processing that brings out the sort of details you see in the photos. The images that come out of the hardware don't look anything like the photos.
In fact, with a fairly modest mount/tracking setup, a DSLR, and the right processing (also a healthy dose of patience), you can get surprisingly good astrophotos.
Re:Beautiful pictures (Score:3, Informative)
Why worry about smooth equatorial tracking? Rig your camera using the cheapest tracking solution you have or move it by hand if you have to. Who cares if it jitters. It just can't jitter during the exposure. Merge the photos into 1 frame by removing the jitter and combining exposures.
A 100 second exposure pic is equal to 100 one second exposure pics. The problem is in finding software to stitch the photos into 1 frame. The easiest to try is to just get PhotoShop. Stitch the photos into 1 with Photo Merge [adobe.com]. You can also experiment with PhotoShop HDR merge [slashdot.org]. You may have to tweak the contrast/brightness and light levels before or after.
2nd option is using video stabilization software to remove the jitter. There are tons of software options for that but you want one will accept very large resolution pics with large dimensions. You want apps that will work on frames as individual photos instead of enforcing video formats on import and export. Off the shell software might be tuned for pics with normal daylight exposure, so look for options to fine tune the algorithm to work on dimly exposed pics.
If the software won't work on dimly exposed pics, perhaps you can experiment with batch processing the files to increase contrast and brightness or tweak the lighting levels. (Lots of software options.) Feed the result into the stabilization software. Batch process again to reverse the contrast/brightness increase.
The post-process step is to stitch and merge the photos into one as before. Plain stitching used to create panorama shots won't work. It needs to sum the exposure data. Photo apps solve these types of problems so there's a good chance it would work with PhotoShop or Paint Shop Pro (with "HDR Photo Merge [amazon.com]). You could shoot a series of fast exposures for the raw data and 1 long blurry exposure to use as a reference point for the HDR merge. Example. [photoshopcafe.com]
Re:Beautiful pictures (Score:3, Informative)
Re:Beautiful pictures (Score:2)
Astronomy already has a standard way to take care of CCD noise. You always take a dark-frame before your exposure. Some people also do one after. That's the same exposure, but with the lens closed. You then subtract the dark frame from the image you took.
Not only does it remove stuck pixels, but it can pick up on heat bleeding into the CCD from the rest of the instrumentation.
Re:Beautiful pictures (Score:3, Insightful)
In step 11 of the HDR link you provided it seems to me that, except for a bluer sky, the HDR photo is actually somewhat worse for details than the original on the left.
The problem with stacking astronomy photos over a long time without an equatorial mount is that the image field rotates from one photo to the next. Your software should take that into account, otherwise the result will be a lot of circles centered on the celestial pole.
Re:Beautiful pictures (Score:2)
Re:Beautiful pictures (Score:4, Informative)
"A 100 second exposure pic is equal to 100 one second exposure pics."
Not quite. Averaging multiple exposures lets you remove noise yes. Digital sensors are so sensitive that for reasonably bright objects what you say is true. But, if you want to image dimmer objects, you have to have a longer exposure simply to make sure you actually catch enough photons.
Re:Beautiful pictures (Score:2)
The number of photons over a fixed amount of time isn't going to change whether exposure time is sliced into a single exposure or multiple exposures. It's basic math.
Re:Beautiful pictures (Score:4, Informative)
Suppose my sensor registers 1 instead of zero, on average, when it is hit by ten photons. If my exposure is so short and the object I am imaging is so dim that I only collect five photons from it during each exposure, it will generally not register. I can average all the frames I want and I'm not going to get a good image of it.
Yes, it is simple math. Just not quite as simple as you're doing. You don't suppose you've discovered some novel concept that both amateur and professional astronomers have missed, do you? You better tell them - all the money they pour into larger apertures and better tracking is completely wasted!
Re:Beautiful pictures (Score:2)
You're assuming that photon collection events are discrete and the sensor is acting like an accumulator. This implies that it needs to accumulate a constant number of photons before it jumps into the triggered state (so it's a saturating accumulator). He sounds as if he is assuming that the sensor is acting probabilistically; each photon to sensor interaction has a 1/10 chance of flipping the sensor into the triggered state. In his case splitting the exposure into smaller windows would preserve the overall probability of a flip. In your case it is not quite as simple as you describe as you assuming that the distribution of photons has low enough variability that the saturating count has a low probability of being hit. So if the average was five but there was more noise you would get better performance.
I'm not sure who is correct, but it seems more like a question on the underlying physics in both models rather than the maths.
Re:Beautiful pictures (Score:2)
Yes. Actual image sensors are slightly more complicated than I've described, but as a first approximation they do behave that way. If you check the wikipedia page [wikipedia.org], you'll see that the light sensitive elements are basically photo-capacitors - definitely accumulators.
An additional complication is that image sensors never don't really register negative noise photons. Zero signal is as low as you can go. Averaging many exposures causes the noise to cancel, leaving signal, which is consistent from frame to frame. However, since very low amplitude noise does not cancel, there will always be a noise floor (and a noise floor that follows a skewed distribution at that) that very weak signals can get lost in, no matter how much averaging you do.
Film needs a lot of photons to cause a grain of silver to "flip." You needed long exposures to get any image at all on film, and long exposures are hard. The solution was to build bigger telescopes or to improve your tracking so you could do longer exposures.
Digital sensors are much more sensitive than film, and linear over a much greater portion of their dynamic range, but a lot of that sensitivity is lost in noise. You can recover it though, by averaging many frames. That works, but it's not a miracle - it has limits. So telescopes are much more powerful now, simply because the sensors are better. Once you hit those limits you're still back to building bigger telescopes or improving your tracking though.
If you think about it, you realize that the sensors used by astronomers MUST work this way. As I said, if the OP was correct that 100 one second exposures is the equivalent of 1 100 second exposure then astronomy would be very different. A large aperture telescope would be much less important and nobody would bother tracking. All astronomical exposures would be made at some exposure that is a fraction of a second to minimize movement. Astronomers, amateur or professional, simply do not take 1/1000 s exposures (unless they're looking at a bright target like the sun or a nearby planet).
I used to have a link to an amateur astrophotograher's page where he went deep into the physics and noise characteristics of CCD sensors. I can't find it, but you can probably find something similar. Amateur astrophotographers are generally very knowledgeable about their tools.
Re:Beautiful pictures (Score:2)
Thanks for the detailed and informative response. Very enlightening.
Re:Beautiful pictures (Score:4, Informative)
The number of photons over a fixed amount of time isn't going to change whether exposure time is sliced into a single exposure or multiple exposures. It's basic math.
Your assuming that the CCD is going to be equally sensitive to every photon many of the initial photons are going to be buried in the detector thermonic noise, this is why amateurs use peltier devices to cool their detectors and pros use cryogenic liquids. Additionally the electronics reading the charge on the CCD pixels will have a threshold level you have to get above. There are probably other factors that I am not aware of.
Re:Beautiful pictures (Score:2)
Re:Beautiful pictures (Score:3, Informative)
Try Astroart 4.0 [msb-astroart.com] seems like it'll do it all.
Re:Beautiful pictures (Score:2)
By definition a Dobsonian is a cheap alt-az mount that provides steady and smooth operation by hand, so yes they are useless for any kind of photography that requires long exposures.
It doesn't follow that you need an equatorial mount to do anything. I've seen some very nice photos made by stacking short exposures of bright objects that were hand tracked using an alt-az mount. And of course professional instruments these days use computer controlled alt-az mounts, but that's a different story. Possibly an amateur with a fixed observatory might be able to build a good enough alt-az setup to do long exposures, but there's no reason to. An equatorial mount is bound to be a better investment of time given the size instrument he's likely to have. The big advantage of the alt-az mount is that it is simple, stable, and lightweight for those observers who want to haul the scope out of the garage to do some visual observations.
Re:Beautiful pictures (Score:2)
In order to take the long exposures necessary an equatorial mount is necessary. As an object moves through the sky the field in an alt-az telescope rotates. Thus, you would have to take short enough exposures to ensure that the rotation doesn't smear the images and then rotate them as you stack them. Also, tracking is a bit more complicated since you have to drive on two axes.
The large alt-az telescopes like Magellan, Gemini, and Keck get around the field rotation problem by having the instruments on a rotator to take out the field rotation.
Re:Beautiful pictures (Score:2)
What I'm saying is that long exposures aren't necessary to make impressive pictures, if you're not taking pictures of nebulae. I've seen very nice pictures of asterisms, planets, and of course lunar pictures that were taken on alt-az mounts. I've even seem some fairly nice pictures taken where the astrophotographer hand guided an alt-az mount, although obviously that's only possible to do for a minute or so.
You can't argue with results.
Re:Beautiful pictures (Score:2)
Dobs are not "useless" for photography. People do manage to capture some pretty good images of the moon and planets with nice stable dobs that have tracking and a video camera. Check out Wes Higgin's images of Mars [higginsandsons.com], Jupiter [higginsandsons.com], and Saturn [higginsandsons.com] captured with an 14.5" Starmaster Dob. Judging by his page, he is fairly seriously into lunar imaging. Far from useless...
Re:Beautiful pictures (Score:5, Informative)
It takes quite a while to collect enough light from 100s of light years away in order to create a usable image.
For example, looking through my 6" telescope you can't see any nebula's like in pictures. Another thing they do is take multiple images and stack them together to amplify the signal and minimize the noise.
Re:Beautiful pictures (Score:2, Interesting)
There is more to it. What you can see at the visible light frequencies won't look that pretty. We just don't see enough. There is a lot of beauty in infra-red and UV/microwave that we can't see without aid.
It is usual to capture a number of black-and-white images at various specific frequencies (narrow-band) and use them to create a false color picture, e.g. give blue tint to the light at hidrogen frequency, etc.
Google for "astronomy picture of the day", search for deep-space object pictures like nebulae and galaxies, and read the descriptions.
Re:Beautiful pictures (Score:2)
Yeah, the image is all about the computer processing, and webcams in particular have done wonders for backyard astromony. A lot of work collecting those images in a 8" and putting everything together though. _Very_ nice.
Re:Beautiful pictures (Score:3, Interesting)
The image is definitely not all about the computer processing. In fact, that's a minor part.
It all comes down to the telescope and CCD you're using.
I've got a fair number of unprocessed images from my time doing astronomy which are FANTASTIC! Why? Good scope, clear night, long exposure, and a good CCD. I could make them a bit better with some processing, but I've never seen the need. Processing can never add data to a picture. The only thing that can do that is a longer exposure, better scope, or better CCD.
That being said, what this guy did is pretty nice work. I'm not overly surprised, as you can get a decent CCD for less and less as times goes on, and mainstream digital photography gets bigger. A decade or two ago, and you'd have spent a good fraction of his setup cost on a 1MP CCD!
Re:Beautiful pictures (Score:2)
It takes quite a while to collect enough light from 100s of light years away in order to create a usable image.
Don't forget, you not only need a long exposure time, but you also need to account for the earth's rotation. This guy must have some sort of servo setup to automatically track the stars in ultra fine increments.
Re:Beautiful pictures (Score:2)
Re:Beautiful pictures (Score:2)
Google says... (Score:4, Informative)
Hubble? I don't think so (Score:5, Interesting)
They may resemble some of the aesthetics of Hubble, but not the resolution. Thus, the comparison is potentially misleading. The photos in the gallery are of relatively near or bright objects. It's more about careful timing, planning, and processing that brings out details of such objects. Major observatories often don't have the budget or motivation to spend the time to carefully process images of common astronomical objects.
One amateur reprocessed images from Soviet Venus landers and brought out some amazing detail, finding landscape features that weren't spotted before. It's simply the case that sometimes amateurs are simply motivated to spend the necessary time and attention to detail more so than "professionals", who normally have full in-boxes. Amateurs can decide to be as anal as they want. Call it open-source astronomy.
Re:Hubble? I don't think so (Score:4, Informative)
They may resemble some of the aesthetics of Hubble, but not the resolution. Thus, the comparison is potentially misleading.
I know. They look decent, but a ~200KB image does not compare to a ~200MB (~204800KB) Hubble photo.
Re:Hubble? I don't think so (Score:2)
Has it not occurred to you that he may have resized the full-res images for web posting? I'd be willing to bet that the originals aren't Hubble-quality, but they probably have more resolution than a 1996-era webcam.
Re:Hubble? I don't think so (Score:5, Informative)
Most amateur level astronomical CCDs (amateur is a relative term in this case) are pretty low resolution. The SBIG ST-7 I use for the observatory I run is only around 800x600. For this kind of equipment you're not looking for number of pixels nearly as much as low noise, good cooling, and pixels that are sized right for the optics you're running.
When the parent refers to resolution, he means the angular size of each pixel, not the sheer number of pixels. This is a function of aperture size and atmospheric clarity -- all the CCD can do is take maximum advantage of whats available by making each pixel about half of what can be resolved by the optics.
Re:Hubble? I don't think so (Score:2)
Let me introduce you to Apogee Instruments ccd.com [slashdot.org]. You can go much higher than 800x600. Of course, these aren't "cheap" but the article did state that the amateur astronomer spend more than £20,000.
Re:Hubble? I don't think so (Score:2)
It's also worth pointing out that the scientific value of an astronomical picture has nothing to do with how pretty it is. And it was science that justified the huge sums spent on Hubble, not pretty pictures. We're just used to seeing spectacular Hubble photos because NASA, ever mindful of PR, keeps pushing them out, often "enhancing" them to make the skies more photogenic.
Re:Hubble? I don't think so (Score:5, Informative)
And NASA isn't the only group putting out viewable Hubble images. The ESA publishes quite a few (which get published through the Hubble Heritage site). Check out www.spacetelescope.org. The lovely full view of Orion was done by them.
Re:Hubble? I don't think so (Score:4, Informative)
Nice web site. Very first image I pulled up was of Perseus A, and the text said "Detail and structure from optical, radio and X-ray wavelengths have been combined for an aesthetically pleasing image which shows the violent events in the galaxy's heart." And you seem to be saying that all images produced for mass consumption are like that. So these images are even more different from the ones that scientists care about than I thought they were.
The fact that the European counterpart to NASA also uses these photos for PR is kind of beside the point. And I'm not condemning either agency for doing this. Eye candy may not be as important as science, but it does help justify the budget that gets the science done. I'm just debunking the idea that eye candy is what Hubble is for.
Nor do I want to trivialize what Shah does. His work not only gives us cool-looking pictures, it raises interest in backyard astronomy — a "hobby" which does a lot of serious science [hobbyspace.com].
Re:Hubble? I don't think so (Score:2)
I just looked through a lot of those pictures in awe and amazement. :)
So much beauty in this universe
Re:Hubble? I don't think so (Score:3, Interesting)
Thanks! I looked it up, and if you are referring to Don Mitchell's story, it is indeed well worth reading. http://www.mentallandscape.com/C_CatalogVenus.htm [mentallandscape.com]
Even better, the re-processing pipeline for each of the Venera mission [mentallandscape.com] datasets is explained in great detail. For instance, about the Venera-9 mission images (from http://www.mentallandscape.com/V_DigitalImages.htm [mentallandscape.com]:
Re:Hubble? I don't think so (Score:2)
Here's a comparison:
Cool project and all... (Score:5, Insightful)
Re:Cool project and all... (Score:5, Funny)
quotes from actual, stunned astronomers.
Ever been stunned before? Obviously the astronomers were just too stunned to say anything worth quoting.
Re:Cool project and all... (Score:3, Insightful)
Re:Cool project and all... (Score:5, Funny)
How many astronomers were stunned to make these pictures. Was it done humanely?
A random assault or did he planet? (Score:2)
No, you've misunderstood. The astronomers weren't stunned to make the pictures, they were stunned BY the pictures.
Evidently Mr. Shah silk-screened his photos onto the blade of a cricket bat and used said instrument to whack a cluster of astronomers upside their noggins, whereupon, they saw stars!
Re:Cool project and all... (Score:5, Insightful)
IAAPA (I am a professional astronomer), and I'm not stunned. Sorry. Nice work for a back-garden job, but any comparison with Hubble or any of our 4, 8, 10m class telescopes is utterly specious.
What's he and many other (admittedly very dedicated) amateurs are benefitting from is the enormous improvement in detectors (in this case, CCDs) over the past 20-odd years, plus the not-unrelated improvement in computer processing power to align, stack, and mosaic digital images. Obviously, professional astronomers have access to all that in spades, as well as much larger telescopes / telescopes above the atmosphere as well.
So yes, superficially similar and impressive coming from an amateur with limited resources, but to compare this with Hubble is completely lame-brained. Indeed, the cynic in me notes that TFA is puffing a book of his images: what a coincidence. A sidebar link takes you to a similar article in 2008 about another amateur who's "seeing the beginning of the Universe" from his shed: surprise, surprise, that article also puffs a book of his pictures. Of course, the article's in the Torygraph, which delights in celebrating a fifty years out of date vision of Britain populated by toffs, proles, and eccentric back garden amateur boffins, so hardly unexpected.
Going back to the point about better detectors, however, it's interesting to note that although we've built bigger and bigger telescopes over the past twenty years (as well as developing adaptive optics, space telescopes, broader wavelength coverage, etc.), the main gain we've experienced in terms of scientific performance has come from the vastly improved detectors. Problem is, we're now pretty close to detecting every photon that falls on the detectors and we can build detector arrays that almost fill the available focal plane.
To go further in ground-based astronomy then, we need much (much) larger telescopes, such as the E-ELT, TMT, and GMT. With their much larger collecting area and higher spatial resolution, you can expect truly fabulous things in the next ten years. From space, it's JWST, of course ...
Stunning? (Score:5, Insightful)
Re:Stunning? (Score:2)
The thing is, the advent of CCD imagers (cameras) has increased sensitivity so much and the use of PCs has allowed such better processing, that an amateur (even me!) today can easily get better pics than the professionals from 40 or 50 years ago: when everything had to be recorded on film, developed and with no hope of post-processing if you messed up.
What you won't be able to do, unless you live in the middle of nowhere, is get dark enough skies: without any light-pollution, to produce images of this quality. Oh yes, you'll also have to wait for the two or three days every month when it's not cloudy or raining.
If you want to know how it's done, visit http://ukastroimaging.co.uk/ [ukastroimaging.co.uk] of any of the other amateur astronomy sites.
Re:Stunning? (Score:3, Informative)
From the article: "....The superb photos, each made up of about 30 frames..."
Re:Stunning? (Score:2)
I would assume thats referring to mosaicing (setting the images side by side) rather than with stacking (adding the images on top of each other).
If you're trying to image something like andromeda through an 8" scope, you're going to have to scan across it. Really, for something that big, your best bet is to stick a DSLR piggyback on the telescope tube.
Conspiracy, I tell ya! (Score:2, Funny)
NGC1499 is also known as the "California Nebula". Most of the other nebulas are identified by their colloquial name, so why did they skip California? Bloody Brits still pissed about 1776! ;-)
Moderate parent up. (Score:2)
Nah (Score:2, Funny)
Re:Nah (Score:2)
Nah. Clearly photoshopped.
Indeed. I can tell from some the of pixels and having shooped quite a few whoops in my time.
Cuts to UK astronomy (Score:3, Insightful)
Not THAT stunning. (Score:2, Informative)
Pretty pics, but not research grade (Score:5, Insightful)
However, none of them is worth a dam' for research use: where calibration is much more important that prettiness and resolution, low noise and even the spectrum of light used (not all light makes it through the atmosphere - esp. IR) are the sole reasons for spening all that money getting Hubble up there.
While I applaud the Telegraph for publicising this, it not what professional astronomers do - nor is it even close to what Hubble does to earn it's money.
Science! (Score:2, Interesting)
I'm wondering what sort of more scientific data one could get from a setup like this. Not for actual science purposes, but for my or his own fun. Do the CCDs used have enough intensity granularity that one could detect the red and blue shift differences in spinning galaxies, for instance, and do some dark matter calculations for oneself?
Re:Science! (Score:2)
If you want to things with redshift you need to have a spectrometer. You could probably build one without too much trouble, but it would take more than hooking up a camera to a telescope.
These are great pictures! (Score:2, Insightful)
Yes they can be compared to Hubble's pictures (Score:2)
They can indeed be compared to HST pictures, as in, they are not as good.
They are pretty, an impressive achievement for an amateur using a 8" telescope, an inspiration to many, but the pictures not as detailed or scientifically interesting.
Comparison (Score:3, Informative)
Sorry for duplicated post
Compare the referred author picture of NGC 6888 here [astropix.co.uk] to a professional job there [nasa.gov]. The former is still very impressive for an amateur, indeed this is the verbatim comment from the IAC site [www.iac.es] (where the professional picture was taken):
Small nit with summary (Score:2)
Amateur astronomer Peter Shah has stunned astronomers around the world with amazing photos of the universe taken from his garden shed.
As remarkable an accomplishment as these photos are, it would have been even more remarkable if he'd managed to take pictures of something other than the universe.
Not Impressive (Score:5, Informative)
I'm sorry, but his pics just aren't that great compared to other amateur imagers.
Compare Peter Shah's image [astropix.co.uk] of M42 with Rob Gendler's [robgendlerastropics.com]. Or how about this even more stunning one [astrophoto.com] captured by Tony and Daphne Hallas with a 6" refractor at the Winter Star Party.
IMHO, Peter Shah's self promotion is more impressive than his images.
stunning starbursts? (Score:2, Informative)
The starbursts are aesthetically pleasing (stunning) but I suspect they would be detrimental to any scientific use of the images. Their presence is most likely the result of post processing that favors artistic appearance over scientific accuracy. IANAA but I doubt that the images have any scientific relevance.
Impressive, but there are even better examples... (Score:2)
I can't even come close to replicating these photographs myself, but there are even more incredible examples of amateurs doing amazing space photography with relatively simple equipment. There are a couple of these geniuses in the SF Bay Area. One I'm familiar with is Rogelio Bernal Andreo. He is a fixture at astro sites around the Bay, and his photographs are simply jaw dropping. I believe most of his magic happens on the back end in the digital processing. His set up easily packs into his car.
Check some of these out: http://blog.deepskycolors.com/nebulas.html [deepskycolors.com]
You're joking, right? (Score:5, Insightful)
I am sorry to be negative, but this Slashdot post reads like it was written by someone with absolutely no experience in astronomy.
While the gentleman certainly takes high-quality pictures, he is solidly in the amateur category and no different from the thousands of other committed amateur astronomers that have a minimum of $20K in equipment to be able to observe and image the stars. There are amateurs who take much better pictures and have far more spectacular (and expensive) equipment out there.
Furthermore, it is absolutely ridiculous and insulting to compare his images to that of the Hubble Space Telescope. His telescope has a smaller aperature (8 inches versus 95 inches), his CCD resolution is much lower and has a much higher operating temperature. Furthermore, he has to contend with the effects of atmospheric distortion. Just because the object shapes and colors look similar to a layperson, his images achieve nowhere near the resolution and detail of the Hubble.
Love the story, thought it was a dupe/old but... (Score:2)
I read this and thought, haven't I seen this before? But no, apparently The Telegraph published a similar story in 2008 about another gentleman, living in england, who has also taken some amazing space photographs from his "garden shed." http://www.telegraph.co.uk/earth/3526362/Amateur-astronomer-captures-dawn-of-the-universe-from-back-garden-observatory.html [telegraph.co.uk] - interesting.
Good but not as good as the article indicates (Score:2)
I looked through his gallery, and although he certainly has done a good job, it's not really any better than the work of hundreds of other amateurs.
With modern SLRs, digital image stacking and a decent scope, a lot of people are doing this level of work. It takes some level of talent and a lot of patience, but it's nothing all that extraordinary.
It's CERTAINLY not up to the level of the current HST. None of those images show anything like the level of detail the Hubble has achieved.
Re:Stunning (Score:4, Insightful)
Totally... but comparable to photos from Hubble? Sure, I guess "not as good as" is a comparison. Living here in Britain I can confirm getting pictures of the sky like that is no easy feat, and are definitely impressive... but there's no way you could achieve anything like Hubble's output, what a silly thing for them to say! I expected better from news outlets than that... haha jk.
Re:Stunning (Score:4, Interesting)
I'll never forget taking a good friend of mine from England visiting Australia back to where I grew up. I was raised about 400 km west of Brisbane - essentially a whole lot of absolutely nothing. He just gawked at the night sky for about an hour. He'd never realised what was up there.
You can see so much that you see colours.
Re:Stunning (Score:2)
I actually know the feeling having lived at one of the few dark spots in Europe.
Re:Stunning (Score:5, Informative)
Indeed, as an astrophotographer I can say his images are high quality and I'm sure the comparison with Hubble is not his own. We know better than that... I use an even simpler setup (Losmandy GM-8, Canon 300mm f/2.8 Lens or 20cm Newtonian f/4.5 and modified Canon 20D camera) and even those images get compared to Hubble by people. That setup cost me less than 5k euros.
Hubble is about science, astrophotography as you get to see it is about "pretty pictures". We get as much sciene return as a casual wildlife photographer... By accident we may discover something (and we all dream of it...). Hubble press releases are "pretty pictures" as well; but usually distilled from valuable scientific data.
There are a lot of amateurs contributing to science, but you don't get too see much of them. Tom Boles for example has discovered over 120 supernova's (from Britain) and has been featured in the media (BBC). And he's picked a hot subject. Many others monitor asteroids, variable stars, faint comets and will never get noticed by a news channel...
His and astrophotographers' work is important though to popularize science. I myself got started by seeing images of the sky in books. Now I'm making them myself...
Astronomers stunned by space photos? (Score:2)
Re:Stunning; but compare (Score:5, Informative)
so really, from a strictly photographic perspective, yes, this guy's pictures are better, because they show what the thing *really* looks like.
Mine aren't Hubble-like, but then again... (Score:5, Interesting)
You can click on all sizes above any image to see larger versions:
My tracked astro photos [flickr.com]
My untracked astro photos [flickr.com]
Re:Mine aren't Hubble-like, but then again... (Score:2)
Those are some impressive pictures, Mr. Sobchak.
Re:Mine aren't Hubble-like, but then again... (Score:2)
Nice work! Mod this fella up....
Re:Mine aren't Hubble-like, but then again... (Score:2)
Wow, this is amazing. I didn't know it was even possible to capture such vivid pictures of the heavens without even using a telescope!
Modern hardware makes it relatively easy (Score:4, Informative)
Modern DSLR cameras have come a long way in the last three generations. Extremely high "pushed" ISOs, relatively low noise, combined with some really great lenses and just a little bit of software sophistication, and astro becomes very accessible.
If you add a tracking mount, which allows the camera to pivot on the tripod at the same rate the earth turns, keeping the camera pointed at the same subject for several minutes, you can use even lower-noise ISO ranges of the cameras and sharper f-stop ranges of the lenses. You can build yourself a "barn-door" mount for the cost of lumber, and a few bucks for screws and a clock drive (or a gear and a handle to turn it.) Or you can buy a premade tracking device like the Astrotrac I selected (because I'm too lazy to build a mount -- about a grand); or you can go nuts and buy a telescope mount that tracks (can cost ((up to many)) thousands.) Tracking really helps.
But, you don't have to go there. Just go outside, pop the camera on a tripod, use a lens you can set for f/2.8 or faster, crank the ISO up to 1600 or faster, and expose for 1...8 seconds (depending on how much magnification the lens provides... at 85mm, 4 seconds is good. At 400mm, about one second is all you can go before the starts begin to trail.) Personally, I like 85mm; it's enough mag where with a modern sensor (15mp for the 50D) you get a goodly amount of detail, but it's short enough that you get some exposure time.
So with this setup, shoot multiple shots, then align and "stack" them using pretty much any image processsing software that lets you rotate and translate, preferably to sub-pixel precision. The more images you stack, the better the result will be. The rule is, random noise reduces to the square root of the number of frames, so you can get a 4:1 noise reduction with only 16 shots. To get 10:1, you need a hundred. For impulse noise, like a satellite track, averaging gets you reduction of N:1 where N is the number of frames... BUT... if you use median instead of average, odds are excellent that impulse noise will disappear completely. I always try both, just to see which looks better.
There are dedicated programs out there than can stack and align for you, too. A little googling goes a long way.
The biggest challenge has little to do with the camera, and more to do with where you live. Light pollution, that is, the amount of light sourced from streetlights and so forth, competes with the dim deep space objects; so someone who lives east coast, say, NJ or in the metro area... not going to do very well. Where I live - rural Montana - it's not a problem at all. If you live in an urban area, it's the kind of thing you keep in mind for when you go cross country and have an opportunity to cross some desert (or most anywhere in Montana. :) Refer to a light pollution reference, watch the weather (which can really screw up your plans.... clouds.... I flipping despise clouds at night), and then it's all down to your timing.
Anyone who has a modern DSLR, I can't recommend this highly enough. It's fun.
Re:Stunning; but compare (Score:2)
so really, from a strictly photographic perspective, yes, this guy's pictures are better, because they show what the thing *really* looks like.
Meh. True color would be relevant only if you were going to live out there and wanted your curtains to match ;-).
... space-operaish for instance ;-).
(Some of the explanations in the following are not directed to parent (who appears to already know this) but to anyone who's interested).
If you read some of the descriptions below his (quite fantastic!) pictures, you'll see something like this "using the HST palette" or "H-a, RGB" or "H-alpha, RGB". The first refers to the Hubble Space Telescope palette, which you can read about here - http://astroprofspage.com/archives/1500 [astroprofspage.com] (brilliantly written article understandable at the elementary school level - I recommend it to anyone interested in what false color processing is really all about). The H-alpha of course refers to the lowest energy line in the Hydrogen spectrum, which I would assume has been filtered out (or enhanced) during processing. A lot of false color processing is merely enhancing certain wavelengths over others because there's more interesting structure (and astrophysical processes) to be explored there and they would otherwise be swamped by high intensities of more 'boring' wavelengths (whose origins are well known - such as the H-alpha). Of course, sometimes you would do such processing for purely aesthetic reasons - to make a celestial scene look more
Re:Stunning; but compare (Score:2)
Re:Even with the smallest budgets? (Score:3, Insightful)
Jesus, some people will make up conspiracy theories about anything.
Re:Even with the smallest budgets? (Score:4, Funny)
It's all a conspiracy to make conspiracy theorist sound overly paranoid, thus removing any credibility from true conspiracy theories.