Jump to content
Sign in to follow this  
Chris Lambert

18-55mm stock lens with Canon 550d/T2i issue

Recommended Posts



Firstly I don't shoot too often with this lense generally I use Nikon manuals but haven't coughed up for the anything wider than 24mm at present. I was using the 18-55 stock lens today and was wondering if anyone else has seen or experience this when zooming to the long end of the lens I am experiencing a weird iris issue even on apertures slower that the long end of the lens 5.6 it seems to ramp up and down throughout the range with a noticeable shift in light. Is this normal iso and shutter were not set too auto or anything like that. tried both the switches on the lens IS and Auto focus but I am still getting the issue as well as hearing the opening and closing of the iris.


Is this normal?

Share this post

Link to post
Share on other sites

If you look at the front of the lens, if it's the one I'm thinking of, it says "F=3.5-5.6", so at the wide end, it has a maximum aperture of 3.5; at the long end, 5.6. So yes, it's normal.


An F stop is nothing more than the ratio between the diameter of the aperture and the focal length, so if the aperture stays the same diameter and you zoom in, the image will get darker due to the increased effective stop. This is why stop numbers get bigger as the image gets darker, which is counterintuitive.


Many lenses also insist that you stop down at the long end of the zoom to maintain optical quality, which may actually be more of an issue in that sort of lens.



Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Glidecam

    Wooden Camera

    Gamma Ray Digital Inc

    Ritter Battery

    Metropolis Post


    Rig Wheels Passport

    Paralinx LLC

    Tai Audio

    Media Blackout - Custom Cables and AKS

    Serious Gear

    Broadcast Solutions Inc

    Just Cinema Gear

    Abel Cine

    New Pro Video - New and Used Equipment

    FJS International

    Visual Products

    G-Force Grips

  • Create New...