More on Canon Rebel XT noise at high ISO - 2 main new data points

Discussion in 'Canon' started by All Things Mopar, Dec 30, 2005.

  1. I went to another camera store earlier this afternoon mainly
    to look at the Canon 430 external flash, which I did buy.

    While I was there, I talked to the manager, whom I know well
    and trust, about the (apparent) noise I'm seeing with my XT.
    Like most everyone else, he was incredulous, then strongly
    suggested that my particular camera was defective, as his
    experience was 100% the opposite.

    Since I had my camera around my neck, I asked if I could try
    one of his, that he knew to be working correctly. "Sure, have
    at it!". So, I pumped off about 30 shots, some with the built-
    in Speedlite and some available light, across subjects with a
    lot of detail and both light and dark backgrounds (the latter
    to better pick up any inherent noise).

    When I got home, I took another series of pictures with my own
    camera, then loaded the whole mess onto all 3 of my PCs. One
    of my PCs is quite old, still running Win 98, with a 17" CRT
    with brightness and contrast cranked down because my wife says
    the glare hurts her eyes. The 2nd one is my old Win XP SP1
    machine, also with a 17" CRT that I know is showing images too
    dark. Finally, I put them on my new Win XP SP2 box with a 21"
    Samsung LCD which I know is properly calibrated for both
    brightness/contrast and RGB. Please don't go off on the
    monitors, just yet, OK?

    By this time of day (4:15PM EST), my fav store manager had
    left for the holiday weekend, so I'll talk to him on Monday.
    But, the bottom line is this, 2-fold:

    1) /Both/ camera's, my "defective" one and his "working" one
    showed the /same/ amount of noise at /all/ ISO from 100 to
    1600 on /all/ 3 of my PCs. Naturally, no noise is readily
    apparent until ISO 400 on both cameras.

    2) Despite being careful on Programmed Auto in both flash and
    available light, some of the pics I took with the store's
    camera and pics I took in my house with my own, are a stop or
    2 underexposed. Please don't debate this yet, either. The more
    the underexposure, the higher the noise. Well, Duh?! I already
    knew that, and that explains the extra noise I got Wednesday
    at the WPC Museum - but which I've already explained I
    understand.

    I /will/ investigate this further, you can trust. But, so far,
    it still looks like the medium 5.5 MP images saved on both
    cameras with the highest quality (least JPEG compression)
    /all/ show about the same amount of noise.

    As I do not understand RAW, and do not have Canon's RAW
    converter on my PC to avoid invalidating the store's return
    policy, I cannot evaluate that. Suffice to say that there /is/
    a problem with the Rebel XT - from my perspective.

    Now, you can all write me off as just another
    nutbag/troll/incompetant/inexperienced/closed minded/asshole
    if you like. But, as the saying goes "I don't know anything
    about art, but I know what I like." And, I recognize noise
    when I see it, as well as I understand what makes it worse.

    Calm, rationale, non-insulting comments are welcomed. Insults
    to me or my intelligence will be ignored. And, please
    everyone, have a very Happy New Year!

    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Dec 30, 2005
    #1
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  2. All Things Mopar

    G.T. Guest

    There is no such thing as a built-in Speedlite. It's a frickin' pop-up
    flash. The Canon external flash units are Speedlites.
    Known issue on Digital Rebel and Rebel XTs. Use + EC.
    Yes, most here have.

    Greg
     
    G.T., Dec 30, 2005
    #2
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  3. Today G.T. commented courteously on the subject at hand
    I thought that's what the manual calls it. But, a better
    question is, why the hell do you care, other than to make an
    ass of yourself taking me on - again?
    What means "+ EC"? Don't know it, didn't get anything
    Googling, can't find it in the manual (unless I've blind). I
    know what EV is...
    Okey, Dokey by me. You don't mind if I think the same of you,
    do you? Such as your smart ass crack at the top?

    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Dec 30, 2005
    #3
  4. All Things Mopar

    G.T. Guest

    Exposure compensation. I'm a relative newbie to photography and since
    you're an experienced photographer I thought you would know what EC is. It
    sounds like most of your noise trouble is due to underexposure.

    Greg
     
    G.T., Dec 30, 2005
    #4
  5. On Fri, 30 Dec 2005 15:29:14 -0600, All Things Mopar


    Why don't you contact Canon about this?


    *************************************
    A man said to the universe:
    "Sir, I exist!"
    "However" replied the universe,
    "The fact has not created in me
    A sense of obligation."
    Stephen Crane
     
    John A. Stovall, Dec 30, 2005
    #5
  6. Today G.T. commented courteously on the subject at hand
    Thank you, Greg. Now please re-reread the relevant portions of
    my posts. I have said, repeatedly, that I understand why
    underexposure exacerabates any inherent noise. Now, will you
    acknowledge that underexposure is /not/ the only cause of noise,
    particularly when I'm talking about only 1-2 f/stops? Yes, thank
    you.

    Since I know that you parlez vous EXIF, all you want to know is
    in my example posts, if you can get to them. Or, I would be
    happy to E-mail them. But, that's old news right now, since I
    got a significant 2nd data point trying the other store's
    "good" camera.

    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Dec 30, 2005
    #6
  7. All Things Mopar

    Chrlz Guest

    For the sake of completeness, mainly that someone else may stumble on
    this thread looking for useful information...
    Given that later he establishes that the store-owner's 100% good camera
    and his 'bad' one behave identically, what would a normal person infer?
    In other words he went looking for noise in dark areas...
    Good-oh. No real surprises there.
    Oh dear. Here we go back to square one. I've never yet met a
    camera/flashgun combo that had infallible auto-exposure. In
    particular, and as stated MANY times, if the subject has significant
    refelective areas that bounce the flash back at the sensor/s.. You
    can't be 'careful' in auto mode. Manual mode, or proper flash
    metering, is being careful.
    When should we? It's directly relevant. Even at a single stop
    underexposure, noise problems will be exaggerated, and at 400 ISO will
    be by far the most significant cause. And on auto mode, he is asking
    for wrongly exposed images, especially if there is anything even
    remotely challenging in the subject. Like.. chrome and polished
    paintwork.
    And we do too.
    Fine. Point being? And why not at least use Tiff files if evaluating
    noise.
    Key words - 'from my perspective'.

    Another way of saying all this is - 'I'm not prepared to put in the
    effort to ensure my images are correctly exposed, even though I shoot
    shiny objects in dim environments, namely cars with an on-camera flash
    (yes, I'm *serious*). My images come out underexposed and noisy. It's
    the equipment's fault. I can't believe that all my cameras and flashes
    have this problem to a greater or lesser extent, and that no-one here
    will help me. It's certainly not my technique, and don't you *dare*
    suggest I'm trying to do something the wrong way. Agree with me and
    I'll be your friend. Suggest anything else and get in the neck.'
    Heavens no. Not us. Uh-uh. No way.
    The people who say that are BUYING the art, not creating it. I think
    he missed the point of the metaphor entirely. (O: (O: (O:
    I betcha he doesn't.....
     
    Chrlz, Dec 31, 2005
    #7
  8. Today Chrlz commented courteously on the subject at hand

    [snip the babble]
    'Cuz the XT doesn't save to TIFF, just JPEG & RAW? 'Course you
    knew that, right?

    [snip more babble]

    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Dec 31, 2005
    #8
  9. Today Chrlz commented courteously on the subject at hand
    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Dec 31, 2005
    #9
  10. All Things Mopar

    Chrlz Guest

    'Cuz the XT doesn't save to TIFF, just JPEG & RAW?
    I'm very surprised to hear that. I personally would never evaluate a
    camera on JPG's alone, especially if it was about noise issues. That
    would surely be a reason to borrow the owner's software temporarily.
    No I didn't. So I unreservedly apologise for my error/assumption and
    thank you for the correction.



    See how easy it is to be civil?
     
    Chrlz, Dec 31, 2005
    #10
  11. Today Chrlz commented courteously on the subject at hand
    Well, being the dummy that I am, I never shoot in anything but
    JPEG and always have. And, I never save anything in JPEG and
    always have. For my purposes as a documentary photographer of
    cars, that has worked admirably for me through film and 3
    digitals.

    So, while I wanted RAW for later once I figure out how to use
    it, and new the XT has it, I wasn't at all interested in TIFF.
    At least one reason is that the files cannot be compressed if
    EXIF is desired, which makes them way bigger than they are
    worth.

    If you want to evaluate noise in the lab or using some
    mathematical routine in your fav graphics editor, you may be
    right about TIFF vs. JPEG. But, as the old saying goes "I
    don't know anything about art, but I know what I like" -
    meaning, I can recognize noise when I see it, no matter what
    format the picture is saved in.
    You and I will get along better, Chris, as well and me and
    everyone else here, if we start off with the assumption that
    the other guy isn't a dummy, ask reasonable, polite, and
    intelligent questions, and wait patiently for an answer.

    Frankly, I was quite suprised not to find TIFF. And, I was
    also surprised not to find any 4:3 sizes. But, I've already
    figured that out. I just zoom out/stand farther back about 20-
    25% and use a PSP 9 crop preset on the 5.5 MP images I shoot.
    That way, I am assured of not chopping anything off my main
    subject and I have plenty of pixels to crop without reducing
    the resolution I want. Problem solved.
    Yes. And, I would have apologized by now to those that I
    offended if I'd have been treated even moderately well here.
    But, what happened yesterday is things went very rapidly
    downhill, so I had little incentive to be civil.

    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Dec 31, 2005
    #11
  12. All Things Mopar wrote:
    []
    Any lack of civility was purely on your part, making false accusations
    about me, and refusing to back up those allegations when challenged.
    Trying to help you was a great mistake. I await my apology.

    David
     
    David J Taylor, Dec 31, 2005
    #12
  13. Today David J Taylor commented courteously on the subject at
    hand
    You're gonna wait a long, long time then, David. At least until
    /you/ apologize to /me/ for calling me a liar and a dumb-ass,
    numerous times. I don't really care if you call those
    "allegations" or what, that's what I "heard" and "read", whether
    it was what you "said" or "meant". Got it?

    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Dec 31, 2005
    #13
  14. As I have said before, if I have called you a liar or dumb-ass at any
    time, then it was without intent so to do and, if you can quote my exact
    words where I do this, I would have no hesitation in publicly apologising.

    I do care about what I say, otherwise I would not wish to bore everyone
    with repetition of the above. You continue to accuse me of things and
    present no evidence. No-one else perceives that I have called you such
    names.

    David
     
    David J Taylor, Dec 31, 2005
    #14
  15. Today David J Taylor commented courteously on the subject at
    hand
    I don't have to prove the obvious and it matters not what your
    apologists say. As I've already stated, it is what /I/
    perceived as an unsult. You've done it here, repeatedly,
    you've done it to me on CNews, and other places. The only time
    we've been on the same page, and polite to each other, is in
    the few private E-mails we've exchanged.

    I suggest you go back and re-read /your/ words in context, and
    in the way I might've viewed them. One hint: you lectured me
    on image size, JPEG altering noise, underexposure exacerbated
    noise and more, when you are damn well aware I know this
    stuff, then you denied everything when I confronted you.

    I'd like to keep on reading your comments, to others, because
    I can and do learn from you. But I will neither tolerate the
    continued attacks on me, your refusal to acknowledge them, and
    your continued "I know everything" attitude. 'Nuff said.

    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Dec 31, 2005
    #15
  16. Jerry,

    I would not write differently to you privately than I do here. I'm
    genuinely sorry that despite a common language, our communication is
    faulty. When I post on a newsgroup, I may say more than is strictly
    necessary as I know that others without your background or understanding
    read the messages, and I don't see it as a strictly one on one
    communication. No-one can carry a knowledge profile of every newsgroup
    participant. Perhaps if you re-read my comments in that light, you will
    see that I have never intended to call you either a liar or a dumb-ass.

    David
     
    David J Taylor, Dec 31, 2005
    #16
  17. All Things Mopar

    G.T. Guest

    If you knew this shit then why are YOU SHOOTING UNDEREXPOSED JPGS? Are
    you a completely obstinate moron? If you had shown even the slightest
    bit of awareness to the above suggestions DJT wouldn't have bothered
    giving that advice. Your credibility is seriously lacking when you
    admit you can't figure out what EC is.

    Greg
     
    G.T., Dec 31, 2005
    #17
  18. All Things Mopar

    C J Southern Guest

    David,

    There is an old saying that goes like this ...

    "you can't please all of the people all of the time"

    "All Things Mopar" is obviously one that you (nor anybody else) are/is never
    going to please. You're attempting to communicate in a rational manner with
    someone who's behaving irrationally - someone who's basically "lost the
    plot". I'm sure we've all realised now that this just isn't going to get us
    anywhere.

    I can appreciate that this is frustrating and perhaps embarrasing, but by
    now we've all figured out that it's nothing you've done - and that you have
    the support of the rest of the group on this.

    Who can say what the gentleman's problem is? However it seems to me that
    he's "feeding' off all the attention - my suggestion to one and all is to
    simply ignore him from now on - it's pretty hard to have an argument when
    there's only one person involved in the conversation.

    Kindest regards,
     
    C J Southern, Jan 1, 2006
    #18
  19. Today G.T. commented courteously on the subject at hand
    Look, numb nuts, if /you/ know as much as you spew, /you/ would
    know that TTL flash /will/ underexpose on Auto or Programmed
    Auto if /anything/ catches the flash pulse and incorrectl
    reflects it, such as paint on a car. So, why did I take
    underexposed pictures, because the F__king camera made a
    mistake, then compounded /its/ mistake by being noisy. Don't
    like that, huh? Well, it is true.

    Nobody intentionally takes underexposed images except for
    "dramatic" reasons, and then, they don't complain about it. I've
    got 1,000 more images under my belt today so I know more than I
    did when I started this thread, but you have been zero help to
    me because you've been too damn busy being an asshole to be
    helful. so F__k off.

    --
    ATM, aka Jerry

    "I disagree with what you say, but I will defend to the death
    your right to say it." - Evelyn Beatrice Hall under the
    pseudonym Stephen G. Tallentyre
     
    All Things Mopar, Jan 1, 2006
    #19
  20. All Things Mopar

    Prometheus Guest

    Obviously, that is why photographers have brains. It is little different
    in principle to having a strong (back) light in the frame, except you
    have to think about reflective surfaces instead of just seeing a light.
    Good question, perhaps you failed to understand that the subject was not
    'average' and tell the camera that your intelligence is better than its.
    No, you failed to understand the scene you were photographing was not
    "average' and the camera did what you chose to let it do.
    The camera did what you told it to do, treat the scene as average (or to
    be more accurate failed not to tell it to do); when you tried to correct
    that in the image you enhanced the noise.

    *****************************
    Not wanting to just criticize you I need to offer you a solution.
    =============================

    You could always try offsetting the flash and using AFB in such
    circumstances, one of a sequence at 0, +1, & +2 should be correct. You
    will need to experiment a little and think about the results and how to
    apply your new skill in future.
     
    Prometheus, Jan 1, 2006
    #20
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