Re: Test : Teleconverters vs Enlarging in Photosho
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Hi, Terry,
If you didn't upsize the TC-less image but just cropped it and viewed it at the same size as the (entire) TC image, or printed it to the same size, how would it have looked?
The underlying question here is of course "does upsizing it do anything beneficial?".
Doug
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Hi Doug:
Not entirely sure what you mean. If you mean just using the magnify tool to "blow" the 1.4X image up 140% and compare it on the screen to the 2X image, it still looks clearer (better contrast) than the 2X image, but there are discernible "jaggies" too.
I upsized using bicubic smoother in CS at 110% intervals to make the 1.4X image the same size in pixels as the 2X image, so they would print at the same size. You can be sure it makes a huge difference over just blowing the image up on the screen.
As the link states, I have had doubts about using the EF2X II for quite some time. After doing these tests, it is not going back in my bag. I truly consider it "worse than useless!" I remain very happy with the EF1.4 II.
I recall using a Nikon TC14B TC on the 800mm f5.6 IF-ED Nikkor. That makes for 1120mm equivalent FL. The results, as I recall, were far better than what the EF600mm/4L IS plus EF2X II gives me.
White Balance so easy, even our 5 year old can do it.- Melissa Strickland
Re: Test : Teleconverters vs Enlarging in Photosho
I've also re-converted 10D RAWs from early 2003 with both the latest Abode CS converter and DPP 1.5. The improvement with both converters varies from photo to photo but is definitely there. Higher acutance, fewer artifacts.
I sold my 2x converter earlier this year after using it a bit on a weekend shoot with my 200mm and noticing that all photos I'd taken with this combo looked equally low in contrast no matter the aperture I'd used. [img]/ubbthreads/images/graemlins/shocked.gif[/img] So I then did a more formal test with much the same result Terry reports. With non-zooms I do get marginally better results with my Tamron 1.4x than with upsampling. With zooms, especially the 70–300mm DO, the converter stays in the bag.
-Dave-
White Balance so easy, even our 5 year old can do it.- Melissa Strickland
Re: Test : Teleconverters vs Enlarging in Photosho
Very interesting and useful tests, Terry. You just saved me some money!
While on the topic of interpolation, check out this new article by Jack Flesher on interpolation. You might even be able to get even better results with the interpolated images than shown in your original test ...
Re: Test : Teleconverters vs Enlarging in Photosho
I live and die with the teleconverters on my 500 f4. While I may conceed that the 2x is not optimal on the 300f2.8 which I also have, it does very, very well. My observations, (non scientific) are that the 500f4+1.4x is almost identical to the 500 alone, with the 2x-II, still very, very good, and with the 2x and 1.4x stacked just about as good as the 2x alone. All of which is a testimonial to the exceptional quality of the 1.4x converter when used on long glass.
White Balance so easy, even our 5 year old can do it.- Melissa Strickland
Re: Test : Teleconverters vs Enlarging in Photosho
Methinks if the lens is just barely able to focus an image well by itself, the teleconverter will make it visibly less sharp. Even the best teleconverter will magnify the defects. Less than the best will add aberrations.
It's quite possible the Canon 500L is so good a lens that the teleconverter doesn't push its sharpness beyond the single pixel level.
-Noel
White Balance so easy, even our 5 year old can do it.- Melissa Strickland
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