Tag: Post Processing

Microphones Part 2: The war of silence

With the levels down so low, my test recording needed post-processing. I used Adobe Audition 1.5. In most of these audio-doctoring softwares, all you need to do is to normalize the levels, so that “0” is the highest your levels should go. Audition had a “Normalize” setting, and of course that also boosted the background and electronic noise, along with my voice.

Now I needed noise reduction. Adobe has a fancy dancy noise reduction interface which is useable for the brave of heart. The main idea is to highlight “silence” (a moment of pure background noise) somewhere on your waveform, in order for Adobe to get a snapshot of the frequencies that need to be attenuated with the noise reduction. When I tried it, the noise was virtually eliminated when there was only noise, especially at the start, but the noise seems to have a reverberation, since if the noise is at the end, it fades in a stepwise fashion. The noise in the middle is reduced substantially, but not enough to compare with other noise reduction that I know about, like Dolby or ANRS. DBX would have been good, if they could have licensed it.

Audacity won the war of silence, in making the background noise pretty much inaudible, with its noise reduction scheme, which had a far simpler interface. The noise reduction was equally effective in the silent bits and the parts with talking. I used the same strategy in giving it a sample of pure background noise to its noise reduction profile. I found that only the very lowest setting on their “Less/More” slider would not make me sound like I’m living in a tin can, or even disappear altogether.

To be fair, I was using Audition 1.5, against the latest version of Audacity. I hear that Audition is somewhere around version 3.0. But I am happy with Audacity, since Adobe charges a pretty penny for its sound editing software.

Visits: 83

Getting more out of my camera

I have a Nikon Coolpix L3 that I have had for a number of years. In its day, it sold for close to 200 bucks and had a 5-megapixel resolution. These days, that level of resolution would only be acceptable for a cell phone, but I have learned to be rather happy with my purchase anyway. The color and detail are both great, and while the camera enjoys occasional but steady use, I use it seldom enough that I would forget some of its features.

I discovered this when taking photos of white paper with black print on them, under lighting I would have imagined to be more than adequate (two 300 W incandescent bulbs shining not more than 1 metre from the paper, and shining directly on the paper). What I kept getting was brownish-yellow digital photographs of these paper when they were displayed under GIMP. If I took several photographs, it took time to correct the white balance, and to remove any other extraneous color. After all, the color of the paper is supposed to be white. For about 30 or so photographs, it took over an hour to correct them all. I was even thinking to myself that I would have to get a camera that would be smarter about the lighting conditions.

And as I was pricing them out, I found that cameras half the price of my camera had over 12 megapixel resolution, and can focus optically to at least 4x (mine does 3x). In my frugal mind, that still meant an expenditure had to be made, and I needed to look more closely at some of these cameras. One helpful salesman told me that I needed a way for the camera to do the white balance internally, so I can eliminate the need for using GIMP, or Photoshop, or most other post-processing software. He showed me some cameras that can do this, and can update the image as you are adjusting it.

I left, still not making a purchase, because my instincts were telling me to check my own camera. Indeed, my old clunker L3 does indeed do white balance adjustment, and that takes care of most of the problems I had been having. I found that I could not directly control the ISO settings, which internally control light levels internally, so after correcting for white balance, my photos still came out looking dark, especially considering the strong lighting conditions I was using. I read that the L3 controls the ISO settings internally, and it is likely that it is over-compensating for the strong light, still resulting in my having to do some post-processing under GIMP. For the moment, it will be a bug in the camera’s design that I’m willing to live with for the time being. Maybe what is being indicated here is that I need not take any pains with anything other than ambient lighting (seeing that daylight pictures come out so well).

Visits: 68