Why do I get Blurry Low Light Pictures?

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I've ranted on this before but I'm back to try to give it a new spin.

Please please please please stop adding your "standard rant" on low light handheld blurry pictures. It IS the cameras fault. How do I know that? Because I can buy a Sony DCR-PC1 Digital Video camera (http://www.sony.co.jp/ProductsPark/Models/New/DCR-PC1_J_1/index.html). It is as small as a walkman, it's profile is smaller than your average passport, it as a 10x optical zoom carl zeiss lens. And it has no problems taking pictures in low light conditions. All they need to do is take out the mechanism for the DV tape, put in a CompactFlash slot and take out the 7??x5?? CCD and replace with with a 1280x960 CCD. You'd have a camera the (1) fits, in your pocket, (2) has 10x optical zoom (3) can take un-blurry low-light pictures (4) has batteries that will probably last 2 or 3 hours given that the will no longer have to drive the DV Tape motors.

The reason digital still cameras take blurry pictures in low light conditions is because people like you keep blaming the operators instead of the equipment manufactures when clearly a solution exists. If you start directing your rant to the manufactures you'd get cameras that can do this.

I'm begging you, please change your rant.

-Gregg Tavares

-- Gregg Tavares (gregg@greggman.com), December 08, 1998

Answers

Greg-

OK,OK, I'll tone down the "rant." The solution to low-light shooting isn't as easy as you think though, for several reasons. First, as soon as you go to a higher-resolution sensor, low-light performance takes a major hit, because the sensor cells are so much smaller, meaning there are fewer photons for them to collect per pixel at any given light flux. Worse, the perimeter-to-area ratio of the pixels goes up, which increases the leakage currents that set the limit on low-light signal to noise ratio. Another possibly relevant issue is that video cameras are much more tolerant of noise than still cameras, because the 30 frame/second flow of images tends to average-out the randomly fluctuating noise, so our eyes don't see just how bad the images actually are. Likewise with motion blur. I can't speak about the Sony model you mentioned, but many video CCDs that look fine in very low light look pretty poor when you view the individual frames one at a time. Finally, on battery life, two factors: 1) The larger CCDs actually consume an appreciable amount of power to clock data on/off the array. 2) Digital still cameras are generally doing much more processing internally than do video cameras, which means more circuitry eating more power. All that said, the biggest power drain is the LCD backlight.

A large part of the origin of the low-light rant is that I used to get innumerable emails from people claiming that a camera's focus wasn't working, when the pictures they were referring to clearly had motion blur problems. Many consumers assume that just because they can push the button, they should get a sharp picture, regardless of whether they're holding the camera steady. I don't know why, but people seem to expect some magical suspension of the laws of physics by their digicams that they don't with film cameras.

Despite all the foregoing, I'll modify (slightly) the rant in future reviews, in an effort to elevate the issue of low-light performance to the manufacturers. (So far, the market has been demanding higher pixel counts, and paying no attention to low-light behavior: Maybe a little more focus on that will be helpful. - But I don't think so: The mfrs are responding to mass consumer behavior, not the comments of a few reviewers.) Thanks for your input!

-- Dave Etchells (web@imaging-resource.com), December 09, 1998.


Thank you for the technical explantion. I understand about the noise but I have to wonder because (as you've heard before in my previous rants) my DSC-F1 doesn't have nearly as many noise problems as say my Coolpix 900. Of course the DSC-F1 doesn't take even close to as good a picture under reasonable lighting conditions so that makes me wonder what the difference really is.

I think all it would really take for the low-light consideration to come into play is for one or two new cameras to do it well and few a few major reviews to notice it because then it will become a feature that every other camera has to copy.

I'm guessing that you are the photographer type of person. You want the best picture at all times. I'm more on the recording my life side of things which I think is what most people do with their cameras. They take a few travel pictures and they take pictures with their friends and family at get-togethers and parties. A low-light capable camera should be a HUGE marketing advantage to some company that can wax elequent about how wonderful it is to be able to snap tons of pictures without waiting for a flash to charge, without an annoying flash bothering and blinding all their friends and also able to catch lots of candid shots without anybody knowing the pictures are being taken inside places like parties, bars, weddings, birthdays, restaurants etc.

-Gregg

-- Gregg Tavares (gregg@greggman.com), December 09, 1998.


We may start to see some improvement in this area next summer or thereabouts, in cameras using new CCDs from IBM. They announced some new 1.3 and 2.0 megapixel chips that supposedly have VERY low dark current, which should make low-light photography much more feasible. OTOH, I don't know what the basic light sensitivity is, so the ISO may still be low.

-- Dave Etchells (detchells@imaging-resource.com), December 11, 1998.

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