William Gardner
February 27th, 2006, 02:38 PM
Hi Everybody,
I thought I'd share some experimental results from a quick test I did.
I have a Z1 and recently purchased the Canon 1.6x teleconverter w/ step down rings to attach it to the Z1, as described in previous threads on this site. I got the teleconverter on Ebay for $20. It is far from mint condition, but it isn't totally awful either.
I've got 5 high quality JPEG frame grabs to compare, all taken of a poorly printed res chart on a music stand. :) They're all 1440x1080 grabs, so the aspect ratio isn't correct, but for these purposes they'll do. They were all taken with default PP1 settings, F4, no gain or ND.
First,
http://dsp.ucsd.edu/~wgardner/ZT50.jpg
was taken with the Zoom at the mid setting (50 on digital range from 0-99), with only the standard Z1 lens.
http://dsp.ucsd.edu/~wgardner/ZT99.jpg
was taken with the Zoom at the highest setting (99 on digital range from 0-99), with only the standard Z1 lens (physically farther back so that the framing was similar to the first image). It's not bad, but there is noticeable chromatic aberration at the edges with a green interior and magenta exterior on black items on the res chart.
http://dsp.ucsd.edu/~wgardner/ZT99wC1.6x.jpg
was taken with the Zoom at the high setting (99 on digital range from 0-99), and with the Canon 1.6x teleconverter (even farther back). There's a slight color shift. The resolution in the center looks pretty close to the first two images. However, the resolution at the edges becomes noticeably worse. The "4:3" in the upper left corner of the chart is much blurrier. There seems to be more chromatic aberration, but then it's tough to tell if this is just a blurrier version of the CA from the stock lens.
http://dsp.ucsd.edu/~wgardner/ZT90wC1.6x.jpg
was taken with the Zoom at 90 and the Canon lens on, and
http://dsp.ucsd.edu/~wgardner/ZT80wC1.6x.jpg
was taken with the Zoom at 80 and the Canon lens on. You can clearly see the vignetting effect at these settings.
Check them out for yourselves and make your own conclusions. However, my conclusions are:
1. There is mildly annoying CA in the stock Sony lens when zoomed near the max setting (though much of this can be removed with radial CA correction software, such as what I posted on this site earlier in the week).
2. The Canon 1.6x teleconverter keeps the high res of the Z1 at the center of the image, but noticeably degrades the resolution near the edges. This might be fine for some applications, but not others.
3. The Canon 1.6x teleconverter is only useable without vignetting when zoomed in almost to the max.
So, if you can tolerate items #2 and #3, then the Canon teleconverter at $20-30 is a real option to the Century converters at much higher prices. But if you can't tolerate #2 and #3, then you shouldn't bother with the Canon option.
Cheers,
Bill
I thought I'd share some experimental results from a quick test I did.
I have a Z1 and recently purchased the Canon 1.6x teleconverter w/ step down rings to attach it to the Z1, as described in previous threads on this site. I got the teleconverter on Ebay for $20. It is far from mint condition, but it isn't totally awful either.
I've got 5 high quality JPEG frame grabs to compare, all taken of a poorly printed res chart on a music stand. :) They're all 1440x1080 grabs, so the aspect ratio isn't correct, but for these purposes they'll do. They were all taken with default PP1 settings, F4, no gain or ND.
First,
http://dsp.ucsd.edu/~wgardner/ZT50.jpg
was taken with the Zoom at the mid setting (50 on digital range from 0-99), with only the standard Z1 lens.
http://dsp.ucsd.edu/~wgardner/ZT99.jpg
was taken with the Zoom at the highest setting (99 on digital range from 0-99), with only the standard Z1 lens (physically farther back so that the framing was similar to the first image). It's not bad, but there is noticeable chromatic aberration at the edges with a green interior and magenta exterior on black items on the res chart.
http://dsp.ucsd.edu/~wgardner/ZT99wC1.6x.jpg
was taken with the Zoom at the high setting (99 on digital range from 0-99), and with the Canon 1.6x teleconverter (even farther back). There's a slight color shift. The resolution in the center looks pretty close to the first two images. However, the resolution at the edges becomes noticeably worse. The "4:3" in the upper left corner of the chart is much blurrier. There seems to be more chromatic aberration, but then it's tough to tell if this is just a blurrier version of the CA from the stock lens.
http://dsp.ucsd.edu/~wgardner/ZT90wC1.6x.jpg
was taken with the Zoom at 90 and the Canon lens on, and
http://dsp.ucsd.edu/~wgardner/ZT80wC1.6x.jpg
was taken with the Zoom at 80 and the Canon lens on. You can clearly see the vignetting effect at these settings.
Check them out for yourselves and make your own conclusions. However, my conclusions are:
1. There is mildly annoying CA in the stock Sony lens when zoomed near the max setting (though much of this can be removed with radial CA correction software, such as what I posted on this site earlier in the week).
2. The Canon 1.6x teleconverter keeps the high res of the Z1 at the center of the image, but noticeably degrades the resolution near the edges. This might be fine for some applications, but not others.
3. The Canon 1.6x teleconverter is only useable without vignetting when zoomed in almost to the max.
So, if you can tolerate items #2 and #3, then the Canon teleconverter at $20-30 is a real option to the Century converters at much higher prices. But if you can't tolerate #2 and #3, then you shouldn't bother with the Canon option.
Cheers,
Bill