Help. Is this normal for the DA 18-135?

Started Dec 30, 2012 | Discussions thread
DS21 Senior Member • Posts: 2,084
Re: Help. Is this normal for the DA 18-135?

mr_blocher wrote:

I just acquired a used DA 18-135 and noticed right away that after zooming it is necessary to refocus. If so, this is not a true "zoom" lens, but a "vary-focal" lens. I have a Katz-eye split image focusing screen so the focus change is very obvious as I zoom.

Is this within design specs, or should I return it?

-- hide signature --

Jonathan Blocher
Instructor of Art, Design, and Humanities

Very few modern AF zooms today are true parfocal zooms, especially with more zoom range like the 18-135. With AF most users never notice this, so this is a non-issue for manufacturers. I would say this is normal.

 DS21's gear list:DS21's gear list
Fujifilm FinePix S100fs Pentax MX-1 Pentax K-x Pentax K-01 Pentax K-5 IIs +6 more
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow