Wide angle lenses and their issues.

• _brian_

  Participant

  August 17, 2006 at 8:17 pm

  I am at a bit of a dead end at the moment ,not sure what to expect from wide angle lenses ?
  I’ve got a 10-20 Sigma lens on a 350D and I have myself convinced it’s soft all round ,but I don’t know for sure.
  Almost all the time indoors with natural light ,images are soft when the subject is 6ft away and I’m lucky with the flash to get a good one.

  Question – Do I look at a wide angle image as an expansion of a standard image because there is twice as much taken in ?

  Thanks
  Brian.
  Thorsten

  Member

  August 17, 2006 at 8:34 pm

  You might want to take a look at the lens review page at Photozone – http://tinyurl.com/4ycyj. It’s a lens performance survey where the results are submitted by real world users of the lenses. Your Sigma lens scores OK – 2,4 out of 5, which isn’t all that bad. You may have a bad copy of it or it may just be technique related. What aperture are you shooting at when you get your poor results?
  _brian_

  Participant

  August 17, 2006 at 9:34 pm

  thanks for the reply ,I’ve used photozone alright and I like their site. The reason I’m paranoid is because of all the hype I think and as you say my technique.
  I bought it for landscape and scenic shots and have got some nice shots with it ,I thought there might be a straight point of comparison with WA lenses to standard ones.

  Thanks
  Brian.

  PS Guy in conns offered to check it out .
  SteveFE

  Member

  August 25, 2006 at 12:39 pm

  Sigmas are notorious for iffy QC?some people get really sharp ones, others get soft, backfocussing or decentred ones. I’d try another copy to be sure (Conns should do you an exchange if you have looked after yours).

  Beyond that, well, most wides get soft at the corners and suffer more from CA and flare etc. than longer lenses. If you can’t get a sharp shot, at least in the centre, stopped down to say f8, I should wonder if it’s a back- or front-focussing issue. Again, try another. Many people do rate their 10-20s as a pretty sharp lens if they get a good copy. Have you tried doing an AF vs MF comparison under controlled conditions? If you can manual focus sharper than the AF there’s deffo a problem, assuming you have a nice simple focus target that the camera can lock to easily.
  _brian_

  Participant

  August 25, 2006 at 4:49 pm

  thanks steve ,appreciate that info .

  Brian.