Availability of WA lenses

Discussion in 'Digital SLR' started by Robert Coe, Nov 21, 2009.

  1. Robert Coe

    Bruce Guest


    Buying Sigma makes no sense at all.

    You are obviously a Sigma user. ;-)
     
    Bruce, Nov 21, 2009
    #21
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  2. Robert Coe

    Bruce Guest


    You can easily prove it yourself, but it involves doing some simple
    lens tests rather than blindly accepting what you read about Sigma
    lenses in magazine and web site reviews.

    Have you ever tested the lenses you bought? No, I thought not. ;-)
     
    Bruce, Nov 21, 2009
    #22
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  3. I do test them in the shop before buying them. After that, I only test
    them in the field. I don't buy them to shoot test charts; flatbed scanners
    can do a much better job at that kind of subject.
     
    Robert Spanjaard, Nov 21, 2009
    #23
  4. I am. And an Tamron and Canon user.
     
    Robert Spanjaard, Nov 21, 2009
    #24
  5. Robert Coe

    J. Clarke Guest

    i'm sure they all pick the best to send to reviewers. why wouldn't
    they??

    the issue is that sigma has a much wider variability than nikon/canon
    and fails a lot more.

    <http://www.lensrentals.com/news/2008.09.20/lens-repair-data-20>[/QUOTE]

    Now let's see, they list only the lenses for which more than 10 percent have
    had problems and on those lists there are more Canon models and more Nikon
    models listed than Sigma, so, while two specific Sigma models do seem to be
    having problems, that doesn't support the contention that Sigmas "fail a lot
    more" across the board.
     
    J. Clarke, Nov 21, 2009
    #25
  6. Robert Coe

    ColinD Guest

    That shot would have been a snap as a two- or three-shot composite, and
    with much better quality. With the easy availability of stitching
    software there's now little need to get the image in one shot, unless
    the subject is moving.

    I would have taken the shots at ground level or maybe one floor up, and
    stitched the image. Best part is, you can do it again, coz the building
    is probably still there <g>

    Colin D.
     
    ColinD, Nov 21, 2009
    #26
  7. Robert Coe

    Ray Fischer Guest

    For the price of one of those lenses you could get a copy of Photoshop
    and either do perspective correction or stitch multiple photos.

    Sure, the lens will last longer, but you may use Photoshop more.
    And if you're using a 50D then the 17-40mm and 16-35mm aren't really
    super wide. An equivalent of about 26mm for a full-frame.
     
    Ray Fischer, Nov 21, 2009
    #27
  8. Robert Coe

    Bruce Guest


    I'm sure you don't need me to tell you that you are being taken
    advantage of, however willingly. I'm also sure that the City will be
    very happy to get some highly competent images for free. Presumably,
    the alternatives are that they pay $$$ to a professional to take them,
    or accept snapshots from a less able member of City staff using a
    cheap point and shoot digicam. This way, they get great results for
    nothing. I bet you don't even assert copyright - the City certainly
    isn't entitled to the copyright of these pictures unless they formally
    commission you to do the work and pay you a consideration for taking
    them.


    Have you tried altering the perspective in image editing software? All
    you need to do is make minimal adjustments to compensate for
    converging verticals - no more. Photoshop Elements makes this very
    easy - there's no need for Photoshop CS4,


    Canon's L wide angle lenses are plenty good enough for professional
    use. I used Carl Zeiss (for Contax) and Leica R lenses on my 5D, with
    adapters, but they wouldn't have been wide enough because of the 1.6X
    crop factor. So I understand your problem. But I wouldn't spend a
    single cent on a lens for use on the City's assignments. I think they
    should pay at least something towards it, and given the savings they
    are making on photography because of your good nature, they owe you -
    big time!
     
    Bruce, Nov 21, 2009
    #28
  9. Robert Coe

    Guest Guest

    they have stopped carrying many sigma lenses because they can't afford
    to maintain them and fewer copies will skew the statistics.

    they also had a page called the sigma saga (no longer there) where they
    explained that sigma lenses account for most of their repairs. many are
    dead on arrival and some break while they test them in preparation for
    sending to the first customer. when they send them to sigma for
    warranty repair, they are refused due to customer abuse, when many
    times, only thing that was done was unboxing them, and repairs took
    weeks when they were done.

    because of that, they only carry sigma when there's no alternative.
    sigma has a few unique ranges that nobody else offers, however, for
    something like a 70-200, there's no point in a sigma.
     
    Guest, Nov 21, 2009
    #29
  10. Robert Coe

    Guest Guest

    I do test them in the shop before buying them. After that, I only test
    them in the field.[/QUOTE]

    how do you test them? tripod? autofocus? unless it's in tightly
    controlled conditions, there will be far too many variables. about the
    only thing you can do is weed out the true lemons.
    maybe so but test charts are an excellent way to test a lens. why do
    you think eye doctors have you read from a chart?
     
    Guest, Nov 21, 2009
    #30
  11. Robert Coe

    Bruce Guest


    As I said above, "No, I thought not. ;-)".

    Enjoy your Stigma lenses, you certainly deserve them.
     
    Bruce, Nov 21, 2009
    #31
  12. Robert Coe

    Bruce Guest


    Nothing but the best for you, eh? ;-)
     
    Bruce, Nov 21, 2009
    #32
  13. Seems to work just fine with all those variables. In fact, having all
    those variables at hand might be a good thing. It gives you the
    opportunity to check various aspects of the lens in one location.
    To measure the type and strength of correction I need, _after_ I noticed
    an error while using my eyes in the field.
     
    Robert Spanjaard, Nov 21, 2009
    #33
  14. Robert Coe

    Guest Guest

    Seems to work just fine with all those variables. In fact, having all
    those variables at hand might be a good thing. It gives you the
    opportunity to check various aspects of the lens in one location.[/QUOTE]

    but any differences could be due to *anything*. for example, camera
    shake or autofocus errors could produce blurry results from a good
    lens.
    plenty of people who don't think they have bad eyesight actually do
    have bad eyesight, and it only shows up on a chart, especially for
    something like astigmatism.
     
    Guest, Nov 21, 2009
    #34
  15. Ooh, that's exciting, isn't it?
    If you're incapable of avoiding blurry results with a good lens, there's
    no use in testing them. Unless you only use them to shoot test charts, in
    which case I'd advise to get a flatbed scanner.
    As long as it only shows up in a chart, I don't care.
     
    Robert Spanjaard, Nov 21, 2009
    #35
  16. Robert Coe

    Guest Guest

    Ooh, that's exciting, isn't it?[/QUOTE]

    it means that you can't tell whether a blurry result is because the
    autofocus was a little off or the lens itself is no good. if one side
    of the image is blurrier than the other (a common problem with the
    sigma 10-20), you won't be able to tell if it's the lens or if the
    camera was not parallel to the subject.
    better find another hobby then. there are a lot of reasons why a good
    lens can produce blurry results, sometimes intentionally.
    in other words you don't actually care about getting a top quality
    lens. that's fine.
     
    Guest, Nov 21, 2009
    #36
  17. If you find it so hard to judge quality, then how do you shoot _real_
    photographs after testing the lens? Do you always rely on auto-everything
    and hope for the best?

    Again, my way of testing seems to work just fine for real-life results.
    If you intentionally produce blurry results while you're trying to avoid
    them, then I'm not the one who needs to find another hobby.
    Not if the extra quality can only be seen in test charts.
     
    Robert Spanjaard, Nov 21, 2009
    #37
  18. Robert Coe

    Guest Guest

    who said anything about avoiding it? have you not heard of shallow
    depth of field? how about soft-focus or vignette filters? sometimes
    blur is intentional.
    if you can't see the difference between a crappy lens and a good lens,
    then by all means, don't spend extra on the good lens. it's wasted.
     
    Guest, Nov 22, 2009
    #38
  19. Drivers taking too long to read signs and so on because their eyes
    are bad are dangerous. They are twice as dangerous if they don't
    notice their eyes are that bad. Thrice as dangerous if *other*
    people start to notice them taking so long ...[1]

    It might "show up" only in a chart --- but it can cause accidents
    and fatalities outside a chart, in real life. Then it is too late.

    -Wolfgang

    [1] No, I'm not inventing that.
     
    Wolfgang Weisselberg, Nov 22, 2009
    #39
  20. Robert Coe

    Me Guest

    Isn't the Dx version of a "kit" lens, in the range of say 18-55 or
    18-85mm affordable?".
    As far as the Sigma goes, it's surprising that after several years,
    Sigma didn't really improve the lens apart from fixed aperture. The old
    version was much better at 10mm. Stopped down, which is compositionally
    where most people want to use these ultra-wides almost all the time, any
    of them are probably okay.
    I use the old Sigma 10-20, On my D300 it equalled or outperformed my
    17-40l /Canon 5d combination, particularly edge/corner performance.
     
    Me, Nov 22, 2009
    #40
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