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Any telephoto zoom 4/3 Lenses for E-M1 that are much better than similar m4/3?

Started Mar 9, 2014 | Discussions thread
Anders W
Anders W Forum Pro • Posts: 22,144
Re: Where does the 70% number come from?

DonSC wrote:

I've never heard this before and based on my experience with TCs it seems unbelievable. Even a 2X TC wouldn't degrade the image by that much. Just thinking about it, the 50-200mm is only ten or fifteen percent better in the center than the m.43 75-300mm, and when you add the 1.4 TC to the 50-200mm I don't see the image being any worse than what you get from the 75-300mm.

It's the laws of physics. The only thing the TC can do is to magnify the original image circle. When you magnify the image circle (and do it perfectly, all TCs are not perfect regrettably), the resolution of the lens as measured in lp/mm falls in direct proportion to the magnification (and stays constant for the image circle as a whole, but we are using only part of it now). What helps a bit in counteracting the problem is that the crop of the lens image that you are effectively dealing with utilizes the full resolution of the sensor and the image resolution is of course a product of lens as well as sensor resolution.

See here if you don't believe me:

http://en.wikipedia.org/wiki/Teleconverter

 Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus PEN-F Olympus E-M1 II Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH +20 more
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