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Canon S2 IS apertures and ISO
I checked out the specs this morning online and I am somewhat confused about
the listed aperature settings; maybe someone can clarify for me. Specs show range of f2.7 (wide) and f3.5 (tele) (if I recall correctly). Does this indicate a limitation for the lens? In other words, would the lens actually be able to close down to, say. f5.6 or f8, f11 or even smaller? Or not? Also, ISO ratings are also confusing to me, as my experience has been only film. I always think of ISO ratings in terms of "fine grain film" vs. less fine grain, and ability of a higher number, say ISO 800 or 1600 to be more grainy but more able to catch shots in low light or for action. I notice that the ISO rating of the S2 IS peaks at 400, yet without film to worry about, why stop at 400? Your input much appreciated. -- Judy |
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Canon S2 IS apertures and ISO
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Canon S2 IS apertures and ISO
Judith Raskin wrote:
I checked out the specs this morning online and I am somewhat confused about the listed aperature settings; maybe someone can clarify for me. Specs show range of f2.7 (wide) and f3.5 (tele) (if I recall correctly). Does this indicate a limitation for the lens? Yes, the lens can only open up to f3.5 at the telephoto end, while it can reach f2.7 at the wide end. In other words, would the lens actually be able to close down to, say. f5.6 or f8, f11 or even smaller? Or not? It stops down to f8 regardless of zoom. Also, ISO ratings are also confusing to me, as my experience has been only film. I always think of ISO ratings in terms of "fine grain film" vs. less fine grain, and ability of a higher number, say ISO 800 or 1600 to be more grainy but more able to catch shots in low light or for action. I notice that the ISO rating of the S2 IS peaks at 400, yet without film to worry about, why stop at 400? Digital cameras do not have "grain" the way film does. What they do have is noise, an unavoidable random error added to the image data. Boosting the ISO setting boosts the noise along with the image. Your Canon only goes up to ISO 400 because anything beyond that would produce really awful images. As far as we know, the only way to avoid noise in digital cameras is to make the sensor pixels larger. This makes the sensor larger, requiring the lens to be larger, and the price to be much higher. It is not currently possible to make a compact digital camera that is usable at higher ISO settings, has a long zoom ratio, and has lots of megapixels. If you want to be able to shoot at ISO 1600, you need a digital SLR. You'll spend a lot more money and give up some features like movie mode or the ability to frame using the LCD, but you'll get great low-noise images. Your input much appreciated. -- Judy Just set your camera at its lowest ISO and forget it. Use the higher settings only when the image stabilizer doesn't give you enough leeway to get the shot. Have fun! Paul Allen |
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Canon S2 IS apertures and ISO
"Judith Raskin" wrote in
nk.net... I checked out the specs this morning online and I am somewhat confused about the listed aperature settings; maybe someone can clarify for me. Specs show range of f2.7 (wide) and f3.5 (tele) (if I recall correctly). Does this indicate a limitation for the lens? In other words, would the lens actually be able to close down to, say. f5.6 or f8, f11 or even smaller? Or not? snip... Your input much appreciated. -- Judy Also, you may be used to that 24x36 cameras give best sharpness around f8-f11, but small sensor cameras, like S2IS, have small absolute sized apertues, and give best sharpness at around f4.5 - f5.6. Take some test pics on a tripod at different apertures and different zoomings and see for yourself. /per |
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