Stupid ISO....

[fischerphotos]

<p>Ok, I just ruined a perfect sunset photo because I don't no the difference in ISO speeds. Do you use the low number for dark conditions and highest for light conditions or is it the other way around. I shot the sunset at 1600 thinking that was right because it was semi-dark outside, instead, I got a very noisy photo.</p>

<p>I need to fix this because Im shooting my first soccer game at night with stadium lights and ISO is really important.</p>

[jim_momary]

<p>Colton -</p>

<p>Higher ISO = less light needed (or the ability to keep shutter speed high to stop action and its motion blur).</p>

<p>In film that = more grain.</p>

<p>In digital that = more noise.</p>

<p>At some point it is a trade off, dependiing on what you need. How much is too much, well that is in the eye of the beholder.</p>

<p>More folks will chime in I'm sure.<br>

Jim M.</p>

[lex_jenkins]

<p>As with film, ISO ratings are an indicator of sensitivity to light. The higher the ISO number, the more sensitive to light. The way it works is different between film and digital, but the concept is the same.</p>

<p>And, as with film, exposure settings for shutter speed and aperture are linked to ISO or light sensitivity (in ye olden thymes, ASA, Weston and other scales were used but now it's pretty much all ISO).</p>

<p>For bright daylight stick with lower ISO numbers. On a digital camera that's typically around 100-200 (some go a bit lower).</p>

<p>For handheld photography in dim lighting, a moderate ISO rating may be more appropriate: 200-800.</p>

<p>For handheld photography of action, especially in dim lighting, a higher ISO may be needed: 1600-6400 (some recent dSLRs may go a bit higher). Your nighttime soccer game will call for ISO 1600-6400, depending on field illumination. You'll need a fast lens, preferably f/2.8 or faster, used wide open and a shutter speed of 1/125th second at an absolute minimum - faster is better - to freeze action. Use a support if you can to minimize your own camera shake. Action photography takes practice and every bit of support helps.</p>

<p>You will get noise with higher ISOs. That's the compromise. But it can be minimized with noise reduction software. The best noise reduction packages offer options to treat chroma (color) and luminance ("grainy") noise separately. Usually chroma noise can be reduced without affecting sharpness, altho' color fidelity and saturation may be affected. When people claim that noise reduction "always" compromises sharpness, they're referring to global, non-selective application of noise reduction. Try to treat chroma and luminance noise components separately for best results.</p>

[paddler4]

<p>Because of the noise problem that Lex mentions, it is usually best to keep the ISO as low as is practical, given the lighting available. Cameras differ in terms of how high you can push the ISO before the noise becomes really problematic, at any given level of enlargement.</p>

<p>Here is the relationship among the numbers, if you are new to this and don't know them. Doubling the ISO means doubling sensitivity to light, and thefore it is equivalent to keeping the shutter open twice as long. So, for example, I find 1/60 about as slow as I can go with handheld shots with my 60mm. If there is only enough light at ISO 100 for me to shoot at 1/30 sec, I go to ISO 200 or 400 to let me shoot at 1/60 or 1/120. Similarly, doubling the ISO allows you to close the lens down one f-stop, which gives you more depth of field. f-stop numbers are confusing, however. Doubling the size of the aperature allows in 4 times as much light. (the f-stop is based on the diameter of the opening, not the area.) Therefore, one f-stop usually is taken to mean increasing the aperature by a multiple of roughly 1.4 (the square root of 2) to double the light. Doubling the aperature number is actually opening the lens 2 stops and allowing in 4 times the light. For example, a one stop increase from f/2.8 is f/4.0, not f5.6. In the old days, this was more apparent, because many cameras had click stops at half-stop intervals, and you just got used to thinking in those terms. Many digital cameras can give you all sorts of f-stop values--in fact, on lots of them, you can adjust the increment.</p>

[jkiffmeyer]

<p>The answer for the sunset photo is to use low ISO (100-200) and use a tripod or other stabilization to prevent blur. High ISO sunset photos simply are not worth it. For the soccer game you must have the faster shutter speed, so higher ISO is needed to freeze the action. (That is where you will probably need 1600) If you have to go to high ISO and don't like the noise you can try the photo in black and white, which tends to look much better with the grain and removes the issue of chroma noise.</p>

[naturetrek]

<p>You can get excellent results with a software called NeatImage. You'll most likely salvage the picture with it. Up to now I was shooting with cameras that were really bad on high ISO (Canon Rebels), and my 400mm lens was only F5.6 with no image stablizer, so I was forced to raise up the ISO to get decent shots. But this software saved me countless times.</p>

[robert becker]

<p>If you use a high ISO >400, try to expose to the right on the histogram. In other words, 1/3 to 1 full stop over exposed. But be careful not to over do it and blow out the highlights. When you under expose an image, the noise becomes more exaggerated.</p>

[fischerphotos]

Thanks guys!