Sekor Z 50/4.5 W infinity focus

[martin_n1]

<p>Hello<br>

I have aquired a RZ set with some lenses. After testing the different lenses I am VERY disappointed with the Sekor Z 50/4.5W. When I set the focus on RZ to infinity (bellows all turned to minimum extension) I get very soft pictures with the lens. However it seems that with some bellows extension and near-subjects I could get acceptable results in the near field. Is the lens faulty or is it normal behaviour for this lens ? Have anyone examined scans at 100% magnification taken with this lens focused on infinity ? I cannot think my RZ is faulty or the bellows rack because with 110 and 180 lenses and infinity focus I get sharp results. Should I perhaps buy another sample of the 50mm or fork out money for the 50mm ULD when I can find one ?</p>

[enrico_pocopagni1]

<p>Hello Martin,<br>

this is my same experience, and the reason I switched for the 50 ULD too.<br>

50 ULD is sharper by far, another breed.<br>

Enrico</p>

[martin_n1]

<p>It's good to have confirmed the behaviour of this lens. I really think Mamiya should have left the lens on the design table until a better lens could have evolved. Good that the ULD seems to be a better lens, hopefully producing acceptable results. Some of the webstores I usually visit don't have used ULD lenses for now, so they seem to be put to good use. Maybe I will somehow find an acceptably priced copy.</p>

[mag_miksch]

<p>maybe you have to set the floating element</p>

[martin_n1]

<p>I don't have the ULD - yet. I'm discussing the old 50 Z-W lens.</p>

[miesnert]

<p>I have printed some 100x80cm wide c-prints with the 50mm and have no problems with sharpness to be honest, I do mind the distortion, and that's why I'd want to change to the ULD, but sharpness is not a great issue when stopped down to f11-f16 I think.<br>

<br />This is one image I shot with the 50mm:<br>

<a title="White noise #18 by Sander Meisner, on Flickr" href="http://www.flickr.com/photos/miesnert/7304291006/"><img src="http://farm9.staticflickr.com/8003/7304291006_c95ab1fe3e_z.jpg" alt="White noise #18" width="640" height="512" /></a></p>

[martin_n1]

<p>Great sample pic, Meisner.<br>

Thanks for sharing.<br>

Sound really great to be able to print 100x80cm.<br>

I have not yet printed bigger than a3+ but my opinion is still that when looking at 100% scan with my lens there is a big difference in sharpness between the 50mm non ULD and the 110mm for example.</p>