Canon Speedlite 580EX

Discussion in 'Canon' started by Jim Redelfs, Jan 12, 2005.

  1. Jim Redelfs

    Jim Redelfs Guest

    It's been a month since I got my 20D and 580EX flash. Since then, I have shot
    my granddaughter's second birthday and two family Christmas gatherings, among
    other things. Much of what I have done so far was done using mostly
    program/default settings on both the camera as well as flash.

    I'm not really seeing the flash underexposure issue.

    The other night, I was at the monthly meeting of a group of friends. With the
    20D and 580EX on a tripod and using the timer, I shot this pic. (Broadband
    Junkies BEWARE!: Please be patient. I'm using a "good buddy" server
    [translation: free/slow] feeding a 144k image. It's gonna feel like you're on
    dial-up again. Sorry.)

    <http://www.redelfs.com/IMG_0963.jpg>

    I think the camera and flash did a pretty decent job of taking the photo,
    particularly the good depth of field. The folks in back are exposed well
    enough to be easily identified by a familiar viewer while, at the same time,
    the folks in the foreground are not badly over exposed.

    Comments? (Yeah, like I have to ask!<g>)

    :)
    JR
     
    Jim Redelfs, Jan 12, 2005
    #1
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  2. Jim Redelfs

    jfitz Guest

    Certainly some individual EX flash and camera combos are at opposite ends of
    the manufacturing tolerances and have e-ttl issues. However, in my
    experience with a variety of EOS equipment, e-ttl is not the design problem
    some would have you believe.
    Yep! On my monitor it looks as one would expect a properly exposed photo to
    look from an on camera flash in that environment. I am sure a histogram
    will indicate a bias towards underexposure which belies the reality of the
    environment and what constitutes an ideal exposure.

    Are you really sure you want to identify yourself with those guys?? ;)
     
    jfitz, Jan 12, 2005
    #2
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  3. Jim Redelfs

    Colin D Guest

    Sorry to say, Jim, but your shot is considerably underexposed. I
    imported the image into Photoshop and looked at the histogram ... it's
    heavily biased towards the black end, with no tonal value above 205 (top
    is 255). I would estimate about two stops underexposed, maybe 2 1/2.

    Colin.
     
    Colin D, Jan 12, 2005
    #3
  4. Jim Redelfs

    Digi - Reb Guest

    Jim,

    You could tweak that image quite easily by opening it in Photoshop Elements
    which I believe shipped with your 20D. Once you have the image open, in the
    toolbar click Enhance>Adjust Brightness/Contrast>Levels. Drag the black and
    white Output Levels sliders (at the bottom of the dialog box) to adjust the
    shadow and highlight range, then slide the grey slider to the left to
    brighten the midtones. I took the liberty of tweaking your image, check here
    for comparison.
    http://mysite.verizon.net/vze1vv9n/IMG_0963_.jpg

    John
     
    Digi - Reb, Jan 12, 2005
    #4
  5. Jim Redelfs

    Alan Browne- Guest

    Nobody seems to be overexposed at all. The phot illustrates the problem
    of lighting a dark area with depth to the scene of interest from a
    single light, however. There is no way you can get even depth of
    lighting pointing a flash from the camera in such a scene. If the
    ceiling were white, you could ahve bounced it there and gotten more even
    illumination in depth. But this venue appears to be rather dark painted.
    Histogram shows little info in the highlights so another stop of
    exposure would have been better... but then the grey sweater would have
    been washed out for sure.
     
    Alan Browne-, Jan 12, 2005
    #5
  6. Jim Redelfs

    Bub Guest

    I would think that a $1500 camera and a $500 flash should do allot better
    than that. Its pretty bad when a $6 throw away film camera can take a
    similar picture. We should not need any computer to make a good shot, only
    just to edit the picture.


     
    Bub, Jan 12, 2005
    #6
  7. Jim Redelfs

    paul Guest

    Yeah what is it with flash dropping off so quickly? The problem is the
    folks in front are much brighter than in the background. Is there a
    technique with flash to improve that?

    I played with it by erasing out a curves adjustment layer to different
    degrees and got the histogram looking pretty decent even if it was
    sloppy (blotchy) work. I actually do this all the time in high contrast
    images.

    Here's an example:
    <http://www.edgehill.net/1/?SC=go.ph...an-Francisco/our-garden/more/2005-01-10-view>
    Those dark clouds are the original, the hillside is lightened. I
    probably screwed something else up on that, I went through a bunch of
    contortions playing with adjustments heh. One nice thing with a DSLR is
    there is lots of room to play with bringing out detail from shadows.
    It's just incredible.
     
    paul, Jan 13, 2005
    #7
  8. Jim Redelfs

    paul Guest

    paul, Jan 13, 2005
    #8
  9. Jim Redelfs

    Crownfield Guest

    damn physical rules of the universe.
     
    Crownfield, Jan 13, 2005
    #9
  10. Jim Redelfs

    Jim Redelfs Guest

    Thanks, John. It did (does).
    Of the two follow-ups that included re-done versions of the image, I like
    yours the best.

    I'm pretty impressed, overall, with the NEWSGROUP! What's with you? All the
    opportunity in the WORLD for flames and nit-picking but only legit criticism,
    if a bit adament by some, but nary a flame.

    (Good Morning, Your Worm - Your Honor! The prisoner who now stands before you
    was caught red-handed! Red-handed showing FEELING! ...of an almost HUMAN
    NATURE!! This will NOT DO!)

    I'm learning a lot just lurking. Carry on.

    (Thanks, again)

    :)
    JR
     
    Jim Redelfs, Jan 13, 2005
    #10
  11. Jim Redelfs

    Alan Browne Guest


    Ahem. The photo is a classic illustration of expecting the camera to do what
    the phtographer needs to do: consider the situation and light for it. It would
    have been much more effective, with a single flash and nothing to bounce light
    off of, to move everyone to a more shallow composition, crop the group tightly
    and hence get more even illumination. OTOH, the casual pose of a group having a
    drink together is better coveyed with this snapshot.

    If you can get everyone to hold still for 10 seconds (more or less), a non-flash
    shot would have worked better too. But nobody can hold still very long.
     
    Alan Browne, Jan 13, 2005
    #11
  12. Jim Redelfs

    Alan Browne Guest

    As I said in a prior post, one can bounce off the ceiling (if it is white) and
    get better distribution than a direct flash. But a direct flash drops at 1/r^2
    from the camera ... objects twice as far receive 4x less light (2 stops).
    Nature's like that.
     
    Alan Browne, Jan 13, 2005
    #12
  13. Jim Redelfs

    paul Guest


    Heh... what about a more expensive flash?
     
    paul, Jan 13, 2005
    #13
  14. Jim Redelfs

    Alan Browne Guest


    More expensive errors.
     
    Alan Browne, Jan 13, 2005
    #14
  15. Jim Redelfs

    Lionel Guest

    That's pretty much a fact of life with direct flash in a dark room.
    Inverse square law: "I canna change the laws of physics, Jim!"
    I find that a diffuser helps a lot, but it won't perform miracles. As
    someone else has pointed out in this thread; bounce flash would've been
    the ideal solution, but the room doesn't seem to have any white surfaces
    to bounce it from.
    Same here. In shots like the example, I overexpose a little (shooting
    RAW), then tweak the gamma or curves a little when processing to even
    things out a bit.
     
    Lionel, Jan 13, 2005
    #15
  16. Jim Redelfs

    Jim Redelfs Guest

    Oh, fer pete's sake! ...and I had it on a TRIPOD! Why did I forget THAT?!

    Ain't it the TRUTH?!?

    Anyway, I'll do what I can to recreate the shoot at our next meeting and see
    what I can improve on, including a couple of non-flash frames. Stay tuned...

    :)
    JR
     
    Jim Redelfs, Jan 13, 2005
    #16
  17. Jim Redelfs

    Jim Redelfs Guest

    Oh, right. That's the solution! ARGH!!

    [wandering off muttering $500 over and over]

    :)
    JR
     
    Jim Redelfs, Jan 13, 2005
    #17
  18. Jim Redelfs

    Skip M Guest

    Oh, right. That's the solution! ARGH!!

    [wandering off muttering $500 over and over]

    :)
    JR[/QUOTE]

    We rent Quantum T4D flashes for our 20Ds to use on paying assignments.
    Better characteristics than the 580, except for one. That we rent them is a
    clue. The flash head retails for $575 at B&H, which wouldn't be too bad,
    except you have to buy a battery pack for it too, no internal batteries like
    the 580EX. The pack we use retails for $485. And then there's the charger,
    which bumps the price of the pack to $504.95. But! B&H will sell you a
    package deal, all of the above for 999.95! And, since both of us shoot, we
    need two of them! 500 bucks, indeed! <G>
     
    Skip M, Jan 14, 2005
    #18
  19. Jim Redelfs

    Patrick Guest




    The shot is underexposed by about one stop, maybe a little more, no doubt
    about it, and the histogram tells the tale.


    Patrick
     
    Patrick, Jan 14, 2005
    #19
  20. Jim Redelfs

    Patrick Guest

    If he took the shot at ISO 800, it would have allowed more ambient light in
    the shot. Try it. But the exposure has to be right on, or you might get
    too much shadow noise.

    I'm in the wedding business, and I encounter dark areas a lot, and the one
    solution is using slaved flash, both powerful, one undiffused aimed at the
    ceiling at a 45 degree angle, and the other diffused aimed at the subjects.
    One bounced flash can do a good job if the cieling is not too high. If
    there is no bouncable cieling, two diffused flashes, one mounted high on a
    pole (held by my assitant), and the other on a hot shoe or bracket.



    Patrick
     
    Patrick, Jan 14, 2005
    #20
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