paulso

<p>Hi All,<br /><br />thank you for your reply. I really appreciate it cause it really frustrate me a lot for spending 10 times the money to buy a worst lens.<br /><br />I try the suggestion of some of yours -- shoot distance object, here is the low left corner crop for both lens with F5.6 roughly 50mm range.<br /><br />http://picasaweb.google.com/paul.so/IQ#5509603452870111298<br /><br />http://picasaweb.google.com/paul.so/IQ#5509603452673429810<br /><br />I am not sure with one is sharper, what do you guys think?</p>

<p>Thanks everyone for your reply.<br>

Would anyone happen to have an image of something lots of black and white details (like a newspaper), took by 15-85 at around 50mm, from a distance of around 4 feet?That will help me do a good comparison of my lens to see if it's a bad copy.<br />Thanks a lot in advance.</p>

<p>sorry, i should say I focus and comparing the top right corner, not the top left corner.</p>

<p>Hi All, I used a Gitzo carbon fiber tripod with arca swiss ball head, I used live view manually focus the top left corner in 10x magnification. I was suspecting my 15-85 is decentering, but sharpness of the top right corner seems the same as the top left corner.<br>

One thing I did not mention is the 18-55 IS is made in Japan but the 15-85 is made in Taiwan.</p>

<p>I bought a 15-85 2 weeks ago trying to replace my 18-55 IS. While the 15-85 is almost 10 times more expensive, I surprisingly found that their IQ are roughly the same at most of the range and at around 50mm, the 18-55 IS is significantly sharper at the corner (try the top left corner).<br>

http://www.dpreview.com/galleries/4359850282/photos/489589/18-55 <br>

http://www.dpreview.com/galleries/4359850282/photos/489386/15-85 <br>

This result is very different from here:<br>

<a rel="nofollow" href="http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=675&Camera=474&Sample=0&FLIComp=4&APIComp=1&LensComp=455&CameraComp=474&SampleComp=0&FLI=5&API=1" target="_blank">http://www.the-digital-picture.com/...74&SampleComp=0&FLI=5&API=1</a><br>

In fact, it is closer to what described here:<br /><a rel="nofollow" href="http://www.photozone.de/canon-eos" target="_blank">http://www.photozone.de/canon-eos</a><br>

The photozone said they have QA issues with their 15-85, I suspect I may have the same issue. I can think of 2 possibilities, either:<br />1. I am having a exceptionally bad 15-85 and a exceptionally good 18-55 OR<br />2. the-digital-picture have an exceptionally good 15-85<br>

Can anyone tell me they also found that their 18-55 IS is better than their 15-85 so that I know it's not an QA issue cause otherwise I will have to figure what to do with this 15-85?</p>

<p >Thanks a lot in advance.</p>

 

<p>Dear everyone,<br>

These questions have been circulating in my head for years:<br>

In the past several years, I have sold the medium format, bought the DSLRs but still keeping the large format camera with the hope that, one day, there will be affordable 4x5 inches sensor for large format camera. But I wonder will it happen in the coming 20 years? Also, seeing how close IQ is the medium format digital compared to the large format film, do we really need a sensor as large as 4x5 inches?<br>

Thank you in advance for clearing out my head for these questions.<br>

Paul</p>

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