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 p.1 #8 · p.1 #8 · What's your professional opinion of this lens's quality? | |
Yeah "excellent" was the feeling I got while looking through the camera. While the lens is exceptionally good for a bridge camera from it's period in history it's not as good as most slightly hi-grade ($500 ~ $1000) lenses available for 35MM DSLRs and of course the image sensor sucks terribly compared to any DSLR from the past 6 or 7 years. The very best review site I have yet to find says this of the lens:
The DiMAGE A2 appears to feature the same advanced apochromat 7x zoom GT Lens that was so impressive on previous models in the line. While this lens really stood alone in the earlier marketplace in which the A1 and other predecessors competed, other makers have now caught up with their optical designs, so the A2's lens is now less notable than it once was. (Still very good, it's just that the competition now equals or exceeds it in some respects.) Comprised of 16 glass elements in 13 groups, the GT lens has two anomalous dispersion (AD) and two aspheric glass elements for sharp, detailed images with minimal distortion and glare.
The lens consists of 16 elements in 13 groups, including two AD (anomalous dispersion) glass elements and two aspheric surfaces. All that dispersion/aspheric mumbo-jumbo is by way of explaining that this is a very high quality lens. Way back when I first tested the original DiMAGE 7, I was amazed by how little distortion and corner softness it displayed, and as far as I can tell, the A2 still uses the same lens. Images are sharp corner to corner, with very little of the softness I've come to expect from digicam lenses in the corners of the frame, although the A2 is on the lower end of the sharpness scale overall, when compared to the rest of the 8-megapixel field. - Not to the extent that I'd say it constitutes a serious reason to pass over the camera in favor of one of the others, but the softness is visible enough that I felt I should mention it.
Resolution/Sharpness: Very high resolution, 1,600-1,650 lines of "strong detail." Not as crisp as the best of the competition though. The A2 performed well on the "laboratory" resolution test chart. It started showing artifacts in the test patterns at resolutions as low as 800 lines per picture height, in both horizontal and vertical directions. I found "strong detail" out to at least 1,600 lines vertically (although there are enough artifacts at that point that I question whether I should drop back to something like 1,500 lines, per my own, fairly conservative criteria - see my added comments below), 1,650 ins horizontally. "Extinction" of the target patterns didn't occur until 1,900-2,000 lines, but even there there's some detail faintly visible in the vertical direction. Regular readers of my reviews will know that resolution and sharpness are two only tangentially related parameters though. While all the 8-megapixel digicams that I've tested delivered the same absolute resolution, I did see differences in apparent sharpness. On that score, the A2 didn't fare as well as some others, delivering roughly the same level of sharpness (to my eye, at least) as the Nikon Coolpix 8700. That said though, I think the differences between the models is relatively subtle, and depends a fair bit on the subject content as well.
Image Noise: Noise levels lower than most of its 8-megapixel competitors. On a purely numerical basis, the A2's images show lower noise levels than most of its competitors. (Tied with or just slightly better than the Olympus C-8080.) As usual though, the cost for lower image noise is some loss of detail in subject areas of subtle contrast, as well as a rolloff of high spatial frequencies in its images. While the noise levels are low though, the "grain pattern" is on the large size of average, so noise in areas of flat tint may be more evident than that of cameras with more fine-grained noise patterns.
Optical Distortion: Higher than average barrel distortion, moderate pincushion, moderate chromatic aberration, very little softening in the corners. Geometric distortion on the A2 is higher than average at the wide-angle end, where I measured approximately 1.07 percent barrel distortion. The telephoto end fared much better, as I found only 0.3 percent pincushion distortion there. Chromatic aberration is higher than I'd like, but seemingly average for its class, showing about seven pixels of moderate coloration on either side of the target lines. (This distortion is visible as a very slight colored fringe around the objects at the edges of the field of view on the resolution target.) - Compared to the other 8 megapixel models I've tested, this amount of chromatic aberration seems fairly common, more or less matching what I saw with the Canon Pro1 and Nikon 8700. The Sony F828 had somewhat less, and the Olympus C-8080 the least of all. The big plus with the A2's lens though, is that there's very little of the softening I'm accustomed to seeing in the corners of the frame, particularly with long-ratio zoom optics.
The lens amazed me when it first came out, as nothing then on the market could touch it for corner to corner sharpness and low chromatic aberration. Now, some three years later [in 2004], the competition has caught up somewhat, as several other 8-megapixel digicams now have excellent glass. That said, the lens on the A2 is still notable for how well it holds sharpness into the corners of the frame, across its full zoom range. Relative to other 8-megapixel contenders, the A2's images look a little softer overall, perhaps in some part a consequence of the lens design, but more likely the result of the camera's relatively strong anti-noise processing: The A2 shows some of the lowest image-noise figures of any of the current 8-megapixel models (only the Olympus C-8080 matches it), but this comes at the usual cost of some of the subtle detail in its images.
http://www.imaging-resource.com/PRODS/A2/A2P.HTM ...Show more →
All that just to confirm your suspicions that indeed the lens is NOT perfect! Good or maybe even great for a bridge camera but far from perfect. 
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So, what do you think? That much zoom from a lens attachment resulting in the quality you see here... Awesome, good, terrible? 
