</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (tschmid @ May 14 2003, 09:37 PM)</td></tr><tr><td id='QUOTE'> BTW: the 180mm lenses officially do cover 13x18cm (which equals 5x7" quite exactly) - so it's not really the same situation here </td></tr></table><span class='postcolor'>
Just to add a note of confusion: 13x18cm measures exactly 5" by 7", but 5x7" film is measurably smaller. Take a look at Schneiders spec's for f:6,8/120mm Angulon... They claim it covers 5x7", but not 13x18cm!
There are also different lens series, with different coverage. Most 180mm cover 5x7, some do not. Some 135mm's cover 4x5", some only 9x12cm, some do not...
Besides, we're not talking about infinity here. This far the biggest enlargement I've made from a 5x7" neg is 11x14", just a bit more than 2x (and that's big enough for me). Whether the lens covers 5x7 when enlarging 20x is irrelevant to me, as I'd have to rebuild the entire house to get the working distance!
Check the specs for the lens you're thinking of buying before you buy.