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The Lytro Camera: Impressive Technology and Some Big Drawbacks
waderoush writes "The venture backers behind Lytro, the Silicon Valley startup that just released its new light field camera, say the device will upend consumer photography the way the iPhone upended the mobile business. This review takes that assertion at face value, enumerating the features that made the iPhone an overnight success and asking whether the Lytro camera and its refocusable 'living pictures' offer consumers an equivalent set of advantages. The verdict: not yet. But while the first Lytro model may not an overnight success, light field cameras and refocusable images are just the first taste of a revolution in computational photography that's going to change the way consumers think about pictures."
Right now, it seems like the majority of Lytro pictures are technology demos, a fire hydrant in the foreground and a building in the background, or some equivalent, which just invites you to click both and move on. You can just hear the enthusiastic early adopter in the background of these pictures saying "OK, _now_ click the building! Whoa! Cool, huh?!". These shots are, to my mind, the photographic equivalent of arrows or spears coming out towards the audience in early 3D movies. Gimmicks which break the fourth wall, saying "Hey, remember, you're looking at a Lytro (tm) image, not just anything!".
I can't wait for real photographers and artists to actually find situations, styles and aesthetics where Lytro sorts of cameras can be used in a way that both effectively uses the new capabilities of the format _and_ produces something artistically and aesthetically wonderful. I think the technology has a ways to go, but right now, the biggest problem facing Lytro (and light field photography) is that it's a new medium that nobody has a clue how to use effectively.
Until we reach that point where people see a great Lytro picture and actually feel inspired, it's going to be tough to sell what is currently a low-spec camera with one big gimmick. So, if you want Lytro to take off, buy one for the craziest artist you know.
DP Review has a review of this camera. It sounds like it has a long way to go. Due to the way lightfield works, the final resolution is fairly low, in this case only 1024x1024. I don't know if there's really a way around it, since they're substituting resolution for the depth of field focus feature.
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...that's going to change the way consumers think about pictures.
You're overestimating the average consumer: You believe they think prior to taking a picture. Having gone through enough cell phones left abandoned and dropped off at the lost in found before finally pressing 'm' in the phone book and calling their mom to say they lost their phone at my workplace... I can say with a fair degree of confidence most people take pictures of themselves, themselves with friends, more pictures of themselves and... (guys only)... pictures of inanimate objects that they never share or send to anyone. Ever. They're usually things like sign posts, car wheels (not actual cars, this would be too obvious), or random corners of buildings. From this, I can deduce that no actual thinking occurs for at least 95% of your everyday consumer's use of a camera.
#fuckbeta #iamslashdot #dicemustdie
My first thought was that it could be great for video; no need to bother with precise focus while shooting if you can refocus when you edit. However, I'm guessing that it would require a huge data rate.
Author here, from Xconomy. I changed the headline to make it shorter and catchier, that's all. I'm not of two minds. I was impressed by the technology, but I said that Lytro needs to make some changes such as enlarging the screen before the value of the device will be completely obvious to consumers.
For those more interested in the technology, Ren Ng's thesis is available on Lytro's website (at the bottom of the "Science Inside" page). I read much of the thesis at it the other day after reading an article about the camera in the New York Times. It's a well written thesis and explains the technology in a few simple ways and more rigoroursly.
The best explaination to me was that the microlens array is effectively reimaging the lens onto a small array of pixels under each microlens. (The micolens is placed at the usual focal plane of the camera and the # of microlenses is what determines the resolution). Each pixel therefore sees only a small aperture of the lens. A small aperture gives a very large depth of field. You could just use one pixel under each microlens to create an image with a large depth of field, but you'd be throwing away a lot of light. You can be more clever, however, and reconstruct from all those small aperture images the image at any focus. At different focuses, the light from any location is shared among multiple microlenses. (i.e, it's out of focus - so it's blurred at the focal plane). However, it's not out of focus at the pixels, since remember each pixel only sees a small aperture and has a large depth of field. It's then just a matter of adding the right pixels together to create an in-focus image at any effective focal plane.
Unfortunately, though, the move to release it at a (barely) 'consumer toy' price point really led to a product slightly too compromised to be useful: The optics you need for the light field capture eat so much of the sensor's available resolution that the resolution of the images you can get out of the thing is hovering slightly below 1 megapixel.
I'd love to see the same technology applied at a price point and form factor where the sheer sacrifice of available pixels wouldn't be so keenly felt.
The reason the camera is only 1 megapixel has nothing to do with the optics. The technology requires many pixels in the imager for each pixel in the resulting image. So, the CCD (or CMOS imager, I don't which it uses) probably has at least 10MP, despite the output of only 1MP.
It's a fundamental limit of the technology, and it'll be a while until we see more than 2 MP using it.
Why do we need "focus" at all? Why not have photographs where everything is in focus? Depth of field is an artifact of lenses, whether they're in your eye or in your camera.
Focus can be used in composition to guide the viewer to the important elements in the story. Just as "left", "up","down", etc. define the field of view, so does focus.
The Lytro camera has special optics that basically separates the light entering the lens from different angles. Knowing the rough angle of the light rays allows you to combine them in different ways to change the focal length of the image, as opposed to a traditional camera, in which they are permanently combined as the CCD captures the light at a set focal length. This comes with a trade-offs as light from each set of angles is essentially captured as a separate image, giving you say 12x12 sub images on the CCD, so the resolution of each sub-image is much lower than you would get using the full CCD for an image.
Since Ren Ng published his seminal paper making the connection between refocusing a light-feild and Fourier Slice theory, there has been additional work which shows that you can achieve the same thing using a simple filter, rather than a whole new set of optics. The benefit of this is that it is cheaper to manufacture, and you can easily switch out the filter to adjust the trade-off between image resolution and depth of field, but come with an additional cost of a slight loss of total light (due to the filter). Here is one of those papers.
There are two basic approaches. The first heterodynes the light (a filter acts as multiplication) such that light that enters at different angles is shifted to different frequencies. So with this approach you get "subimages" in the frequency domain rather than the spacial domain, which can be seperated and recombined in software. The result and trade-offs are essentially the same but with simpler hardware.
The other is based on refocusing as a deconvolution operation, but the filter modifies the point-spread-function of the camera, such that it's frequency response doesn't have any zeros, so you don't loose data at those frequencies like you would with a simple rectangular aperture.
No you can't. You just think that because you don't understand how an aperture works.
Camera lenses focus by directing light through a small hole. At the point of focus, any light which bounces off an object then hits the lens will be directed in such a way that it hits the sensor in exactly the same place as it would have if it had bounced exactly at the center of that hole to begin with, meaning all light from that position hits the same place, giving a sharp image. Away from the point of focus, light bounces off the object, then when it hits the lens, it bends either too far, or too little, giving a soft edge. Thus when an image is out of focus, then the light projecting onto the sensor is actually wrong, no amount of sensitivity will fix that. This is why optics and focus have always been the most important part of getting a nice image out of any digital camera.
A light field camera fixes this by capturing the direction of the light and reconstructing an image of where the light actually came from, not just where it hits the sensor. Thus it can calculate a 100% in focus image covering the entire depth range without having to focus. Previously, only a relatively small range of distances could be kept in focus, and for that it was required to have a small apature and either a long exposure or a grainy image (cellphone style). Now you can have a sharp image with a wide range of focus without motion blur or grain and that's fantastic.
Resizing a 12 megapixel image into 1 megapixel will give you the same image, with less grain, exactly the same image as if you had stuck a 1 megapixel sensor in to begin with (lower resolution sensors of the same size format give less grain because of larger size per pixel and lower photosensitivity). It will never be any better than the image projected on the sensor to begin with, so it doesn't get you anywhere.
When Argumentum ad Hominem falls short, try Argumentum ad Matrem
No, it's not, it's a useful word. It generally refers to a hobbyist who has the money/dedication to use genuinely professional equipment. For example, I don't play guitar for a living, but I do own a guitar and amplifier that would be more than suitable for a professional session musician. None of "amateur, hobbyist, enthusiast" conveys that. The marketing side of it is that companies have started to target those people as a sector in their own right, for instance Canon tend to make a range of cameras that have the same features as their high-end professional models, but with plastic rather than alloy bodies so not really suitable for a photojournalist in the field. Prosumer describes that quite nicely.