Image quality 16-80CZ vs 18-250

[artington]

I am about to buy a A700 to add to my KM7D and KM Dynax 7s. As there are a few deals around right now I am tempted to include the CZ16-80 (if I can find a good one after reading David's warnings!). An alternative would be the similar size Sony 18-250 (faster than the Tamron equivalent) for the occasional long shot. However, it occurs to me that if the CZ is as sharp as it is reported to be then it may be possible to mimic the long end coverage of the 18-250 by cropping down an 80mm image from the CZ. Has anyone tried this comparison, or is it asking too much even of Zeiss glass?

[Dr. Harout]

Artington, welcome to our wonderful forum.

...it occurs to me that if the CZ is as sharp as it is reported to be then it may be possible to mimic the long end coverage of the 18-250 by cropping down an 80mm image from the CZ. Has anyone tried this comparison, or is it asking too much even of Zeiss glass?

As for your question, no, even a CZ lens cannot do that.

And for your decision to buy an A700, well, you're on the right path.

[artington]

Thank you, Dr Harout, for your kind words and useful comment. And, to forestall any riposte to my comment about relative focusing speed between the Sony and Tamron variants, I have just read the extensive dialogue on both this forum and that of dpreview so I withdraw it!