Saturday, April 23, 2011

D3s: notes on ISO for optimal image quality

1. Use base ISO level (lowest number available) whenever possible.

2. Expose to the right (keep your exposure histogram pushed towards the highlights, but watch channel histograms to ensure that you do not blow out any channels; don't rely on luminosity histogram alone).

3. Increasing ISO is preferable to underexposing and correcting in post.

4. When using LO ISO values, underexpose slightly to avoid clipping highlights.

5. ISO 800, 1600 and 3200 are perfectly usable on a D3s, though dynamic range when using them is somewhat lower.

6. ISO 6400 introduces loss of color saturation and visible noise. Set High ISO NR to Low and lower sharpening in the Picture control to minimize noise. Avoid using high JPEG compression settings.

7. HI ISO should generally be avoided. Set High ISO NR to Low and no sharpening in the Picture Control; avoid high JPEG compression.

8. Decreasing shutter speed is preferable to increasing ISO when dealing with stationary subjects, but remember to use Long exp. NR to ensure noise-free images with 10-, 20-, or 30-second exposures.

Use Nikon Capture NX2 to convert noisy NEF images taken at high ISO to 16-bit TIFF. Open the file in Photoshop and convert to Lab Color. Use the Median filter (see Filter/Noise menu) to remove noise on the A and B channels. Do not sharpen until you like the result.

1 comment:

Michael Fuller said...

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