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BigV · 06-23-2008, 05:56 PM

temporarily changing subjects here....

After close review of many pictures, pictures I was fairly happy with, I found a new thing to be disappointed about. My composition and focus are pretty good, the exposure is ok, but sometimes, when I zoomed in on the image the noise, digital noise in the images was really noticeable. It is present throughout the image, but most easily noticed when there is a large area of one color. Black, like the night sky, is the *worst*, when it comes to noise. And noise is directly related to the sensitivity of the sensor.

I can't directly change the sensor in my camera. That would require a whole new camera basically. But I can adjust the sensitivity of the sensor--that aspect is called ISO and it is intended to behave like the different speeds of film, different ISOs of film.

The noise looks like specks when the area should be smoothly and uniformly black (or whatever color...). I'll attach a picture where the noise is a noticeable distraction from an otherwise nice picture, tomorrow.

When I went on my most recent trip, I made a conscious effort to choose settings on the camera that minimize the noise. Specifically, I shot at the lowest possible ISO setting at all times. For most of the trip, I was able to use the lowest setting on my camera, ISO 80. A few times I had to dial it up, but I moved it back down as soon as I could.

This decision had a couple of consequences. Firstly, it did reduce the noise in my pictures, yipeee! It also meant that I had to increase the aperture or decrease the shutter speed to get the same exposure. This was expected. I deliberately chose the least sensitive setting for the sensor, so to get the shot, to get the light on the sensor, I had to have more of it or take the maximum I could get for a longer time.

There is a point of diminishing returns with this plan. For one, the aperture will only open to some maximum extent. The iris can only dilate so far. And secondly, the need for a slower shutter speed means that I'm more likely to get shake-blurred photos. Not a good tradeoff.

06-23-2008, 05:56 PM	#35
BigV Goon Squad Leader Join Date: Nov 2004 Location: Seattle Posts: 27,063	temporarily changing subjects here.... After close review of many pictures, pictures I was fairly happy with, I found a new thing to be disappointed about. My composition and focus are pretty good, the exposure is ok, but sometimes, when I zoomed in on the image the noise, digital noise in the images was really noticeable. It is present throughout the image, but most easily noticed when there is a large area of one color. Black, like the night sky, is the worst, when it comes to noise. And noise is directly related to the sensitivity of the sensor. I can't directly change the sensor in my camera. That would require a whole new camera basically. But I can adjust the sensitivity of the sensor--that aspect is called ISO and it is intended to behave like the different speeds of film, different ISOs of film. The noise looks like specks when the area should be smoothly and uniformly black (or whatever color...). I'll attach a picture where the noise is a noticeable distraction from an otherwise nice picture, tomorrow. When I went on my most recent trip, I made a conscious effort to choose settings on the camera that minimize the noise. Specifically, I shot at the lowest possible ISO setting at all times. For most of the trip, I was able to use the lowest setting on my camera, ISO 80. A few times I had to dial it up, but I moved it back down as soon as I could. This decision had a couple of consequences. Firstly, it did reduce the noise in my pictures, yipeee! It also meant that I had to increase the aperture or decrease the shutter speed to get the same exposure. This was expected. I deliberately chose the least sensitive setting for the sensor, so to get the shot, to get the light on the sensor, I had to have more of it or take the maximum I could get for a longer time. There is a point of diminishing returns with this plan. For one, the aperture will only open to some maximum extent. The iris can only dilate so far. And secondly, the need for a slower shutter speed means that I'm more likely to get shake-blurred photos. Not a good tradeoff. __________________ Be Just and Fear Not.