Sigma/Foveon Questions
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From: nospam on 17 Apr 2010 13:25 In article <d30541a2-c904-4aef-84de-433f9a99d7ef(a)k41g2000yqf.googlegroups.com>, Bubba <digitalrube(a)yahoo.com> wrote: > At the risk of getting a rain of more invective on a day that's rainy > enough in my parts, does this mean that you can't...focus?! focus and zoom are separate things. assuming you are talking about the dp1/dp2 series, they can focus (slowly), but there is no zoom. there is auto-focus, but as i said, it's slow. > If you can > focus, there has to be *some* zoom (or is it just digital)? there is no optical zoom. it's a fixed single focal length lens. the dp1 has a 28mm equivalent lens and the dp2 has a 41mm equivalent. if you want a focal length other than either of those, you're need a different camera. sigma's strategy is to have you buy multiple cameras for every focal length you want. however, there is digital zoom and the sigma fanbois even claim that the sensor is *so* good that digital zoom is just as good as optical zoom (they really do say that). > These > Sigma owners, and the gentleman on another thread who recommended a > camera with a Foveon sensor to me, seem to use it for what I want it > for: nature photography in low light, foveon is one of the worst choices for low light. it's noisy to begin with but it gets really bad beyond iso 200. > without the artifacts that I > suppose you all here are calling "aliasing." (I've called it red > flare, because that's what I was told it was by the British folk on my > Serif editing software sight--a nicer bunch of people, I have not met > on any forum--including those on which I've tangled with nospam.) red flare is not aliasing, however, the dp1/dp2 series have a red dot problem, although the latest versions have minimized it.
From: Rich on 17 Apr 2010 13:58 On Apr 17, 3:52 am, nospam <nos...(a)nospam.invalid> wrote: > In article > <5ab4f313-32df-4173-8c58-018f330c1...(a)c21g2000yqk.googlegroups.com>, > > Rich <rander3...(a)gmail.com> wrote: > > It's no worse than Fuji claiming the S5 was 12 megapixels when it > > clearly wasn't, > > yes it is. > > > but at least when you sharpen an image from a Foveon, > > it doesn't develop those horrible halos that Bayer/AA filtered sensors > > do. > > nonsense. if you oversharpen any image, you'll have problems. > > > Pretty much every reviewer has stated that the actual resolution > > of a the 4 meg Foveon is on-par with an 8 megapixel Bayer sensor. > > which means it's competitive with cameras from 4 years ago. that's not > very compelling. > > meanwhile, canon has an 18 megapixel slr that costs *less* than the > sd15 will and it won't be stuck with sigma lenses either. Yes, it is cheaper, it has a plastic body, they are cheaper. True, you aren't stuck with Sigma lenses with the Canon. Let Sigma believe it can sell the thing for a price in the mid-range of DSLRs, Reality will bring them down to Earth.
From: nospam on 17 Apr 2010 14:07 In article <1837c0cd-399b-4ff6-aff2-a1b64f04ad0b(a)r1g2000yqb.googlegroups.com>, Rich <rander3127(a)gmail.com> wrote: > > meanwhile, canon has an 18 megapixel slr that costs *less* than the > > sd15 will and it won't be stuck with sigma lenses either. > > Yes, it is cheaper, it has a plastic body, they are cheaper. there's nothing wrong with plastic. the images are what matter. > True, > you aren't stuck with Sigma lenses with the Canon. Let Sigma believe > it can sell the thing for a price in the mid-range of DSLRs, Reality > will bring them down to Earth. like the sd14, the price will drop after a few months. the sd15 is not competitive at 900 bucks.
From: Ray Fischer on 17 Apr 2010 14:32 Chris Malcolm <cam(a)holyrood.ed.ac.uk> wrote: >Ray Fischer <rfischer(a)sonic.net> wrote: >> Bubba <digitalrube(a)yahoo.com> wrote: >>>I don't understand how a sensor can claim 14 pixels, and the photo >>>itself be 4. > >> That's easy - Sigma lies. They pretend that you can take a single >> pixel and split it up into three colors and have that be three pixels. > >They don't lie. It's a different kind of sensor with sufficiently >different kinds of pixels and properties that the sensor megapixel They lie. When you measure the size of the image it produces you see that it is 4.6 mega pixels. That is the cold, hard fact. No amount of sophisty, lies, or self-serving bullshit will alter that fact. -- Ray Fischer rfischer(a)sonic.net
From: Bubba on 17 Apr 2010 15:46
On Apr 17, 1:25 pm, nospam <nos...(a)nospam.invalid> wrote: > > red flare is not aliasing, however, the dp1/dp2 series have a red dot > problem, although the latest versions have minimized it. If you're not yanking my chain and are serious when you use the term "red flare"--which no one on the threads I've started has even acknowledged exists-- In a $500-$600 range, is a camera available that will lessen or do away with red flare without the purchase of additional lenses or filters? There is no need for me or anyone to post a photograph in this situation (which my friends in the UK are very familiar with). "Red flare" (or "orange," or "pink," or even "yeller") means that if you take a picture of vibrant cherry blossoms with pitch-perfect exposure, the green leaves, and brown bark, and blue sky in the photograph will be as pitch-perfect as you worked to make it. Any color that is red or a cousin twice-removed will appear the way a four- year-old child does after stealing its mother's tube of fire engine red lipstick: a blotchy mess, with the red way way WAY outside of where it belongs. So if these wacky Sigma cameras have no zoom except digital, but if their partisans swear by the cameras' sensors' ability to get rid of/ diminish this flare, that makes me ask Why would these people not want another P&S camera that *has* optical zoom (or at least the ability to attach a lens) AND a CMOS sensor. |