Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Canon Lenses

Thread Tools Search this Thread
Old Nov 4, 2005, 10:39 PM   #1
Join Date: Jan 2005
Posts: 70

Well, here goes the public display of my ignorance. Just got my 28-135 IS lens and can find nothing in the booklet about the distance scale. Can anyone explain it's use for me? I've searched around and found no info so far.

dlw is offline   Reply With Quote
Sponsored Links
Old Nov 5, 2005, 12:14 AM   #2
Senior Member
NHL's Avatar
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,567

For decoration??? :blah:

Seriously... Most Canon zooms if not all are varifocal in design which means the focus changes as you zoom in or out (Yes - the 'L's too which is why I prefer Nikon/Sigma/Tokina zooms because most are parafocal instead, i.e. theses lenses hold focus when the focal lenght is changed)!
-> Do this as an experiment on your 28-135:
1. At the widest zoom setting (28mm) focus on something up close and record the distance scale by the white marker
2. Now zoom to 135 without touching the focus ring on the same object and notice how the lens goes out of focus
3. Do another AF lock @ 135mm instead and check the distance scale again - not the same as before (@ 28mm) right?

The object hasn't move (and you didn't move) so which distance scale to use??? :?

The red zoom ticker marks are normally use for infrared film, but for dSLRs which are almost blind to this frequency spectrum they become even less relevent... :sad:
NHL is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 11:59 AM.