Phil posts SD9 review!
By
Dave Etchells
(Tuesday, November 26, 2002 - 21:28 EST)
Friendly competitor Phil Askey has posted his review of the controversial Sigma SD9 SLR, with more than a few different findings...
Well, I guess this proves the value of having more than one digicam review site: My friendly competitor Phil Askey of DPReview.com has just posted his review of the Sigma SD9 SLR, using Foveon's X3 sensor technology, and some of his conclusions just a *little* different from mine.
Without further ado, here's a link to Phil's SD9 review, as detailed and pleasing to look at as any of his are.
As it happens, I'm just about to update the "test results" section of my own SD9 review. (It should be up by the end of the day tomorrow, just in time for the Thanksgiving holiday here in the US.)
I've only had time to skim Phil's review, but on the face of it, it's hard to believe we were actually testing the same camera. Some of the differences are simply that we noticed different things (he caught a chroma problem in overexposed highlights that I missed, I found greatly elevated image noise in red hues that he apparently didn't notice), some of it is interpretation (resolution and aliasing, for instance, see below). Some of it's that he simply appeared not to encounter some of the problems that I did (the uncertain and sometimes completely confused autofocus). A lot of the differences can perhaps be ascribed to differing attitudes and approaches: Phil's always been a strong proponent of the X3 technology, whereas I've adopted more of a "wait and see" attitude towards it. Certainly though, the differences between our two reviews will make interesting reading, and fruitful fodder for internet discussion groups. ;-)
One area where Phil and I have very different views has to do with aliasing: The SD9 has no anti-aliasing filter, and so can produce very strong moire patterns with fine, repeating detail. This didn't seem to bother Phil very much (he went so far as to count the aliased patterns on the resolution target as a positive characteristic), while I feel it's a pretty serious limitation. Individual photographers will have to decide how they feel about aliasing of this sort, which also shows itself as "jaggies" in gently sloping lines and curves. There's no question that the SD9's images have a sharp-edged quality that's unlike any current camera built with a striped array. (Most of which have anti-aliasing filters in front of their sensor chips.) It'll be up to each potential purchaser to decide whether they're willing to accept the tradeoff of jaggies and aliasing in exchange for sharper edges.
One thing I was greatly surprised to see in Phil's images though, was what looked like some color aliasing around fine text in one of his test shots. - Supposedly, this is exactly the sort of thing that can't occur with the X3 technology, but the SD9 showed it, while the Canon D60 that Phil compared it to didn't. I'm a bit at a loss to explain how this could occur, other than being some sort of a blooming problem in the sensor, but the exposure levels weren't anywhere near what should be required to produce blooming.
I was also surprised by Phil's observation that the SD9's raw files had a lot of headroom in the highlights - he felt there was a full f-stop of exposure latitude in the raw file beyond what a default extraction to JPEG would reveal. I haven't yet done a careful measurement of this, but in my own test shots to date, there seemed to be very little actual headroom present. - This is an area where I hope to have some actual test images shortly. It's quite possible that the shots where I didn't see any remnant highlight detail were simply too overexposed in the critical areas for any detail to be left, regardless. (It's also possible that our two cameras are behaving differently in this respect, but I've been told that all review units were very carefully checked out before they were shipped to us.)
Our differences of opinion and our different experiences of the camera's behavior aside, Phil's done his usual bang-up job in his SD9 review - Definite "must" reading for anyone contemplating purchase of a digital SLR in the SD9's general price range.
Check out Phil's SD9 review!
Oh - and for a somewhat contrasting viewpoint, here's a link to my own review of the SD9, from a couple of weeks ago:
Dave's SD9 Review
(As noted, stay tuned tomorrow, I'll have a few updates to the Test Results section in my SD9 review. I doubt I'll be able to manage it before taking off for the Thanksgiving holiday, but I hope to have a controlled test of highlight headroom posted fairly soon as well.)
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