Why is it that I have never read a consumer camcorder review which said much about the optical quality of the lens?
I read every review of the Sony PC-9 that I could find before buying one, and not one of them mentioned the noticable vignetting at the extreme telephoto and wide angle settings, or the barrel distortion (is that the right term?) which can be seen when the subject has vertical lines near the edge of the image. I know that some people will say that I cannot expect much from a camcorder which is designed to be small and is built down to a price, but there was still no easy way for me to compare the lens quality with other cameras in the same price bracket.
My suggestion is that every review should include a still image (taken from the video footage) of a test card at the extreme telephoto (not digital zoom) and wide angle settings. If these stills were printed at the same size for every review, this would allow readers to make a rough-and-ready comparison between lenses. At least the real stinkers would be obvious!
I know that there are other lens abberations that my suggestion would not show, but surely anything is better than nothing? Manufacturers will have no incentive to improve lens quality unless prospective purchasers have information on which to make judgements.
What do other people think?
I think you're right that most camcorder reviews tend to be a re-write of the features list rather than an appraisal of how the camcorder actually performs.
But if your PC9 is noticeably vignetting at full telephoto then something is dreadfully wrong and I'd ask for a replacement camera. Vignetting at wide angle is far more common but remember that ALL lenses vignette, from Schneiders to Cosinas. It's the laws of optics. Compact cammeras suffer dreadfully in this respect, but most people seem to care little. They'd rather have a small, light, cheap and 15x zoom, thank you.
The barrel distortion you mention is rife with camcorders at the wideangle end, and the much heralded Leica Dicomar on my MX300 suffers the same failing. Barrel distortion affects the whole picture of course, not just straight lines near the edge. Any straight line will be bent unless it passes directly through the centre of the frame.
tom.
Tom,
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I think you're right that most camcorder reviews tend to be a re-write of the features list rather than an appraisal of how the camcorder actually performs.
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I thought your read Computer Video magazine!!!
Grrr!
Bob C
And might I add...
Grrrrr!
Any more camcorders coming in for review, Bob?
Pete
CV is the only magazine I bother to read for reviews etc. As for being a re-write of the features list, how many glossies slag of the camcorder for having bottom tape feed ?? I still have the January edition sat on my desk and both camcorder reviews in that issue contain negative, as well as positive, comments.
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Regards
Keith
Hey Bob - I said "most" not "all".
Trying to drag the topic back to lenses...
I occasionally read Amateur Photographer where SLR lenses are extensively tested an compared, and this is what prompted me to start this topic. I wondered why mags dont attempt any objective testing of camcorder lenses.
Is everyone completely happy with whatever the manufacturer chooses to stick on the front of the camera? Would you not like to know if a rival model had a better lens? Or is ignorance bliss?
quote:Originally posted by tom hardwick:
Hey Bob - I said "most" not "all".
Tom,
Yes you did, but you might notice that this forum is run by Computer Video magazine and what you did not say is "reviews in most magazines except Computer Video".
The difference between what you said and what I think you meant is quite profound.
Hence the double "Grrrs"
Bob
I'm hiding under the table Bob. I'm not coming out.
Now, testing camcorder lenses is a mighty complex issue, not helped by the fact that the "film" is so coarse as to enable it's grains to be counted by the unaided eye. Go close to your TV and you'll see what I mean.
Most TVs distort a lot more than the camcorder's lens and cathode ray tubes are never as sharp or as well aligned (RGB) in the corners. So where shall we start?
Test charts are a "good thing" in as much as they can show the differences between various focal lengths, apertures and zoom lenses. But test charts invariably show that the lower resolution of Canon's pixel shift technology is a no-no, whereas in fact Canon lenses can produce spectactularily good and sharp results. The test chart winner utilises electronic "sharpening" that can seriously degrade real life images, so where to now, St Peter?
If you want the sharpest results out of your camcorder the main thing to remember is to avoid smaller apertures. If you have a 1/4" chipped camcorder don't allow the aperture to close down beyond f 4.5, and if you have a 1/6" camcorder think of f2.8 as your sharpest aperture. Yes, difraction is that harmful.
I haven't come across a modern camcorder that has a bad lens. When you think of a 20x zoom woth it's 15 to 18 elements being waved about by Joe Bloggs on full auto, I'm constantly amazed at the quality per pound he can get.
tom.