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Old 07-06-2008, 08:28 AM
Dennis
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Interesting comparison - up sampling or x2 converter?

Hello,

Here is an interesting comparison between up sampling a photo versus using an x2 teleconverter. I found the results quite surprising Ė I didnít expect such a variation is overall image quality. The Canon x2 EF II certainly shows a very strong performance, converting the 400mm F5.6 into an 800mm F11 telescope.

Photos taken using a tripod mounted 40D, on 6th June 2008, within a few seconds of each other. Raw images opened and cropped in CS3 with a smart sharpen (100 at 0.5).

Cheers

Dennis
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Old 07-06-2008, 09:10 AM
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h0ughy (David)
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nicely explained to the common folk with the image Dennis (Dennis) the clarity is quite amazing with the 2x converter
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Old 07-06-2008, 04:48 PM
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sheeny (Al)
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Great comparison, Dennis. Just goes to show you can't create something from nothing!

Al.
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Old 07-06-2008, 05:18 PM
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RB (Andrew)
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Ditto, nice comparison Dennis (Dennis) !

The 2x and 1.4x T.C are very high quality.



An alternative is to use the high quality Genuine Fractal plugin although again it's not the same as using an actual T.C. and is quite an expensive plugin.

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Old 07-06-2008, 05:38 PM
Dennis
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Thanks guys, and thanks for the link RB.

I had a mediocre result with the x2 EF II on the 70-200 F4L on the single occasion that I have tried this (unlikely?) combo. Then, I used Live View with the 40D tripod mounted, so I think that mirror slap should not have been a factor in that case. Nevertheless, it can be dodgy to draw too many conclusions from a single trial.

However, enter the 400mm F5.6L and wow; I was blown away with the performance on the x2 EF II – quite a remarkable transformation into an 800mm F11 optic.

The 70-200 has 20(!) elements in 15 groups, including 1 CaF2 and 2 UD elements.
The 400 has 7 elements in 6 groups including one S-UD and one UD element.

Here is a better laid out version.

Cheers

Dennis
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Old 09-06-2008, 06:46 PM
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I've found from my own use of the Canon TC's that the 1.4 is a much better item than the 2x. however you have shown here that its quite capable of brilliant results...

This thread should serve as a lesson to others, Upsampling by 2x is a no go... When in doubt, spend more money!!

More seriously, it does show very well the degridation to data after being stretched after the fact as opposed to using either a TC for photography or a barlow/powermate for webcam imaging.
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Old 09-06-2008, 09:31 PM
Ian Robinson
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Optical multiplication is aways better than digital multiplication (because of the algorithms involved in linearisation and interpolation are still working with the original 1x digital image data and you can't get more information out if pixcelated data than was originally there in the first place.

Best to spend the extra $350 and buy the 1.4x or 2x teleconvertor in my view. Will be cheaper than buying another telephoto or telezoom.
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