Low Light, Digital Noise and What We Forget

My first DSLR was a D5000, a very capable crop frame camera. It was cheap, tough and did a good job. Regardless, low light was always a weak point. Then I bought a D700, two years into its production life and according to rumors (8 months later, still just rumors) “about” to be replaced by the world’s new best camera. The replacement would be able to shoot in total darkness with no noise. It would be able to beam your images straight to getty with a guarantee of sales. Best of all, it would be able to make you a cup of coffee while doing all of the proceeding.

I waited several months (which was a mistake) before buying the “old” D700. When I did get it, I couldn’t resist comparing it to my D5000. The results told me what I already knew. The D700 is a low light monster and the D5000, not so much. More importantly, I also learned that the quality of the noise makes a huge difference.

Newer cameras, like the D7000 (also DX crop) have started to have reasonable low light capabilities beyond ISO800. I’ve seen claims that the D7000 is “better” than the D700 or even the D3s in low light and I’ve looked and compared. I wish it were true, but it isn’t, at least to my eye. I wish it were true. An $1100 camera that can shoot low light as well or better than my $2600 D700 would be AWESOME. Never the less, the noise in the D7000′s images isn’t totally bad.

And that brings me to my main point. I said “to my eye.” I can’t say if there is more or less noise from the samples I’ve seen and I don’t have any objective way of measuring. Even if I did, it would be irrelevant. Reducing noise isn’t the only goal. Producing pleasant noise is just as important, if not more, than reducing noise. If you only worry about quantity, the top half or two thirds of your ISO range is useless.

Reducing noise isn’t the only goal. Producing pleasant noise is more important than reducing noise.

I actually like noise. “Sacrilege!” you scream. “Get a rope!” you yell.

In the “old” days of film, high ISO film had grain. This was a manifestation of making it more sensitive to light (larger crystals, etc, etc, etc). This was a given. Grain could add to the artistic merit of an image and we chose film based on its character, including grain. It was just another quirk of the system to be exploited to produce beautiful images by those clever enough to do so. The digital world need not be so different. For that to happen, manufacturers have to allow different bodies to behave in different ways, just like different speeds and chemistries of film.

The ironic thing today is that we strive for no noise, instead of the right type of noise. You can always simulate film grain using one of many photo editing suits, but that isn’t photography in a pure sense. It is photo-art. Photography is about exploiting the image systems available to you, including (and especially) its imperfections. Pleasant digital noise should not be looked at as a wholly bad thing. Some noise can be beautiful.

The point of all this is that in discussions of low light and noise we often get caught up on quantity, however it is measured. We want a perfect imaging system. I think that is a mistake. I want an imaging system with pleasant flaws I can exploit, and I want different cameras to have different flaws that I can be exploited to different ends. I don’t want a perfect camera with no noise. That would be boring. For a photographer, the real discussion should be about the character of images the camera produces, instead of the technical details of minimizing or maximizing one aspect of the system, like noise. I think that gets forgotten very often.

Posted in Photography

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