03-07-2013, 03:16 AM
There are several reasons telling someone else what's a significant difference in image quality is nearly impossible.
1. Different people have different standards for what's acceptable image quality.
2. Different people have different end uses for their pictures. Some just upload to Facebook, some view only onscreen, some make large gallery prints. (I just sold an image that being used as a backdrop 9x11 feet in size.)
3. Different images demand more sharpness or less distortion. A portrait can been less sharp that a cityscape for example. An architectural image might need less distortion than a landscape.
4. Different people post process their images differently. Skill levels, software, and time available all differ. Intensive post processing can sometimes make an inferior lens look acceptable.
You might try renting a lens first to see if it meets your standards. But, even then, be careful, because your own standards will likely change over time (the bar usually gets higher, not lower.) I've been a pro for 40+ years, and I cringe when I see some of my work from decades ago, even stuff published in national magazines. As the technology moves forward, everyone's standards seem to go up. (Take a look at an old Life Magazine or National Geographic and you'll see what I mean.
All that said, I love the new 70-200 f4. One of the most usable lens I've ever owned. (Usability for me=Image quality+size+weight+handling)
1. Different people have different standards for what's acceptable image quality.
2. Different people have different end uses for their pictures. Some just upload to Facebook, some view only onscreen, some make large gallery prints. (I just sold an image that being used as a backdrop 9x11 feet in size.)
3. Different images demand more sharpness or less distortion. A portrait can been less sharp that a cityscape for example. An architectural image might need less distortion than a landscape.
4. Different people post process their images differently. Skill levels, software, and time available all differ. Intensive post processing can sometimes make an inferior lens look acceptable.
You might try renting a lens first to see if it meets your standards. But, even then, be careful, because your own standards will likely change over time (the bar usually gets higher, not lower.) I've been a pro for 40+ years, and I cringe when I see some of my work from decades ago, even stuff published in national magazines. As the technology moves forward, everyone's standards seem to go up. (Take a look at an old Life Magazine or National Geographic and you'll see what I mean.
All that said, I love the new 70-200 f4. One of the most usable lens I've ever owned. (Usability for me=Image quality+size+weight+handling)