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in [Digital Cameras]
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From: John McWilliams on 10 May 2010 12:07 gumby wrote: > Why don't you like to take your base ISO down to below 200? I don't get > that because the lower the ISO the better the quality. Back in film days > anything above ISO 100 was considered pushing the film. I still consider > ISO 100 my base and not 200. Depends on the camera, specifically its sensor and processor. For some Canons, ISO 200 is cleaner than 100, so I keep that as my baseline. -- John McWilliams
From: eNo on 10 May 2010 12:12 On May 10, 9:02 am, gumby <gu...(a)here.com> wrote: > Why don't you like to take your base ISO down to below 200? I don't get > that because the lower the ISO the better the quality. Back in film days > anything above ISO 100 was considered pushing the film. I still consider > ISO 100 my base and not 200. Good question. If a camera supports ISO 100 as its "base ISO", then I'd use it in a heart-beat. However, many recent DSLRs, especially those that support higher ISO, set their base at ISO 200. They enable a pseudo ISO 100 mode (in Nikon speak, Lo.3), but they do so by pushing the ISO the other way you're used to. They over-expose the image at base ISO (200), then digitally process it to add -1EV of exposure compensation. This has deleterious effects on your image quality, because it essentially reduces dynamic range. You can do this yourself by taking a photo at ISO 100 (try a bright, high contrast scene), then taking one with the same shutter speed and aperture at ISO 200, then applying -1EV of exposure compensation in post processing. Even if you do this in the RAW format, the ISO 100 photo will have better image quality, especially in the highlights. ~~~ eNo http://esfotoclix.com
From: gumby on 12 May 2010 13:22 On 10/05/2010 9:07 AM, John McWilliams wrote: > Depends on the camera, specifically its sensor and processor. For some > Canons, ISO 200 is cleaner than 100, so I keep that as my baseline. > Really? How can ISO 200 be cleaner than ISO 100? The higher the ISO in digital the more noise you get, usually. I'll have to do some expermenting on my DSLR and see which is the best ISO to use now that you have told me this.
From: John McWilliams on 12 May 2010 13:24 gumby wrote: > On 10/05/2010 9:07 AM, John McWilliams wrote: > >> Depends on the camera, specifically its sensor and processor. For some >> Canons, ISO 200 is cleaner than 100, so I keep that as my baseline. >> > > Really? How can ISO 200 be cleaner than ISO 100? The higher the ISO in > digital the more noise you get, usually. I'll have to do some > expermenting on my DSLR and see which is the best ISO to use now that > you have told me this. Think a curve. If lower ISO is always 'better', why not ISO 50, 25, 10, 0, -100, -10,000 (the latter used for atomic blasts)?? No need for ND filter, huh!? -- john mcwilliams
From: gumby on 12 May 2010 13:28
On 10/05/2010 9:12 AM, eNo wrote: > Good question. If a camera supports ISO 100 as its "base ISO", then > I'd use it in a heart-beat. However, many recent DSLRs, especially > those that support higher ISO, set their base at ISO 200. They enable > a pseudo ISO 100 mode (in Nikon speak, Lo.3), but they do so by > pushing the ISO the other way you're used to. They over-expose the > image at base ISO (200), then digitally process it to add -1EV of > exposure compensation. This has deleterious effects on your image > quality, because it essentially reduces dynamic range. You can do this > yourself by taking a photo at ISO 100 (try a bright, high contrast > scene), then taking one with the same shutter speed and aperture at > ISO 200, then applying -1EV of exposure compensation in post > processing. Even if you do this in the RAW format, the ISO 100 photo > will have better image quality, especially in the highlights. OK, thanks. I will do this test because I don't even know what the base ISO of my Olympus E510 is supposed to be and had been assuming that ISO 100 would give me better quality than ISO 200 because that is always how it worked with film. In film photography I used film that was as low as ISO 25 (Kodak recording film). |