550 EX flash

Discussion in 'Wedding and Event' started by melissa_downham, Jun 1, 2005.

  1. My 550 EX speedlight usually works great with all my Canons--I use a
    10D and an Elan 7. But I've been noticing an inconsistency in a lot
    of my flash pictures at weddings...The problem is this: Canon flash
    TTL works with the focusing point on the camera. I always have the
    focusing point set to the middle point because my camera tends to
    focus on the wrong thing sometimes--like the background behind the
    people I'm taking a shot of. Therefore, if that focusing point is
    focused on something dark, I tend to get an overexposure or if it's
    focused on something light, I get underexposure. Am I making sense?
    Either I have a blurry shot or my shots are not consistenly lit
    correctly. Has anyone else experienced this and how do you solve
    it? For posed shots, it's easy to use flash exposure compensation,
    but not those really quick shots that are so often at weddings.
     
  2. Most people end up using old-fashioned auto thyristor flashes, such as Vivitar 285s or the Metz 54MZ-4, which has both E-TTL and auto thyristor. With that flash unit, you can conceivably go back and forth between the two flash modes. Be aware that the SCA modules for the Metz have various versions, and some of the versions don't allow certain features, so do your homework on that. Ben Rubenstein, who is active on this forum, uses one.
     
  3. Move AF activation from the shutter release to the * button using custom function 4. When you want to take a shot, focus with the * button and release it just before pressing the shutter. Alternately you can switch the lens from AF to MF, but this is not as convenient. In both cases the 10D will no longer use the focus point to bias the flash exposure and it will be easier to get consistent results. You still need to be aware of high/low key scenes though, just like you do with the ambient metering. Move FEL to the 'assist' button and you can still get the benefit of spot-metering for the flash exposure when you need it.

    Canon bodies with ETTL-II (Mark II bodies, 20D, 350XT) remove the focus point bias for flash metering.
     
  4. Chris, does that really work? I tried it out on my Elan IIe (same kind of focus point bias) and it didn't really change much.
     
  5. Chris gave the answer IMO.

    I use the * button for focus and it does help in getting the exposure more accurate. You can do it on the 10d too. OTOH, the use of it takes some adjustment in the way you tink. I would practice with it until your thumb automatically uses that button when your mind says 'focus'.

    it works v.well.
     
  6. Nadine, the trick is to either

    1) FOCUS on the subect and at the last instant press the shutter button all the way down in one smooth action.

    2) METER the scene you want to expose for by half pressing the shutter button, then compose the shot as you focus. When you are in focus you simply complete the shot with the other half of the shutter button action.
     
  7. Chris - it will use the focus point to bias exposure if you have it set on anything other than evaluative correct? If one does the "*" for focus as you explained, and you are shooting w/ partial metering, it will use the center focal for exposure correct? It's funny that Melissa asked this question because i'm finding the focus lock/recompose technique giving me less than satisfying results - when i lock focus/exposure and then recompose.....i'm finding that the focus does not lock......it shifts as i pan for compsition. It has become such a problem that i did tests on it last night where my subject was shaded with backlight, using partial metering/focus lock on my subject, then recomposing - the focus then went to the backlit areas everytime - are you having this problem michael and melissa? I switched focal points to the top/center one and i'm having much better results. Can the focal points go bad?
     
  8. Thanks for the info, Michael, but it isn't getting used to focusing with the * button that I had a problem with, it was that I didn't notice any difference in flash exposures. The theory behind putting the focus on the * button (in this case) is that if the camera thinks you're using manual focus, it will not bias the flash exposure to the active focus point, because it has no active focus point to bias to. So it's important that you completely let go of the * button before pressing the shutter. The flash metering pattern is supposed to revert to an averaging pattern, supposedly much like the averaging pattern option with the 20D and E-TTL II, which does not use a focus point bias.

    So Jammey, if you have a 10D, you will have focus point bias for flash exposure as long as you are engaging autofocus at the same time as releasing the shutter button (has nothing to do with being in evaluative mode--focus point bias is the only flash metering pattern you have on the 10D). The only time you supposedly don't have focus point bias for flash metering is when the camera thinks you are using manual focus (the "focus with the * button" is a trick to make the camera think this way). Partial metering (which only applies to ambient readings) does not affect flash metering at all. As for the focus sliding around, do you have the focusing set to AI Focus or AI Servo? If so, there's your problem. Set focusing to One Shot unless you really need the other modes. And focus/recompose is supposedly one of the worst things you can do with the 10D, because that does throw your metering off--both ambient and flash exposures.
     
  9. What cam are you using Jammey?

    I have had that same thing happen too. Ususally only with very strongly backlit subjects. I have only had a few that were 'bad' using the methods I employ. Are you using the * for focus?
     
  10. "Partial metering (which only applies to ambient readings) does not affect flash metering at all."

    Really? If so, you have enlightened me. I always thought that the flash would base it's reading off the partial area, expecially when you do "*" FEC lock. Am i wrong? Yes, i do have the camera set to one shot. For the focus/recomposure technique, i always meter (partial), lock the exposure ( "*" locks it for 15 seconds) then recompose. Now, does the flash not read based on the "*" of the partial meter? Thanks for the response, i'm not sure what to think.
     
  11. Michael - 10D's. No, i havent been using the "*" for focus.....i've been using it for partial meter lock.
     
  12. I think you mean FEL...but anyway, someone correct me if I'm wrong, but I always thought that when you performed FEL, the flash took it's reading off the active focus point and surrounding area. If you have partial metering engaged, it is only affecting the ambient reading. If you have focusing set to auto (the camera picks focus), then there are options, I think, to have the FEL taken off the center focus point (??). You might want to read and re-read the photonotes.org article about EOS flash. I think it is all covered there.
     
  13. I'm a little confused. If pressing the * button means that it deactivates the focus point, how does the camera focus? And more to the point, how does the flash work with the camera if it doesn't know what to meter off of?
    Manual focus does not work because the flash and camera no longer "work together" according to the handbook.
     
  14. Am i reading this incorrectly? From the manual:
    00COjU-23875684.jpg
     
  15. The more I read of trials and tribulations with these automated units, the more I think the auto-thyristor flash approach is faster and more consistent (with practice), especially if using different models or types of cameras or adding in additional lighting. Remembering the override/focus point/recompose/fec/fel/* button/ et'al issues of each camera type is boggling to me. Of course, I too use Canon dedicated flashes, and they certainly are the best option for some situations, but Im not convinced they are the best option always.
     
  16. OK, first of all, I do not own a 10D, I have a 20D. Second, it pays to keep going back to the photonotes.org article to re-read the info, because now, the article states that with the 10D, the flash pattern is supposed to be center-weighted averaging. I could have sworn that before, it said it was focus point biased. If this is true, then inconsistent flash exposures for the 10D is not based on focus point bias, but on something else--what I don't know. I do know that my Elan IIe was focus point biased for flash metering.

    Jammey, as for your instructions, what part of the book did this come from? Is this the "quick start" section or part of the instructions for the automated modes? Anyway, the instructions seem to imply that the center focus point is used for FEL (which is also stated as an option in the photonotes article), but does not specifically say that partial metering is involved in FEL. I know with my Elan, partial metering only affects ambient readings, and you do have control on whether FEL is performed using the active focus point or the center focus point.

    Melissa, in order to trick the camera into thinking you're using manual focus, you must assign auto focusing to the * button, which is accomplished using Custom Function 4. When you have done this, you can only focus when you press the * button. When you press the shutter button, you cannot focus. In order to trick the camera, you are indeed disengaging focusing from flash metering. But this might be a moot point based on the fact that the 10D doesn't have focus point bias when it comes to flash metering.

    I think the best thing to do at this point is to wait for people who actually own the camera to weigh in. I can only report from my own experience, which is with my focus point biased Elan IIe. Everything else I know about EOS flash metering is from reading about it over time and from the photonotes article.
     
  17. In the index, look under FEL and it takes you to page 100. This is the instructions when using FEL for the canon 10D; which states to use partial metering to lock "*" on a paticualr area (partial area) before composing the shot. My understanding is that this reading works in conjuction with the flash to expose properly. The reading is put into memory and will not change while recomposing.
     
  18. Jammey is reading the manual correctly regarding the * button and FEL. However the answer regarding focus point bias was to use the * button for focussing which removes the camera bias for the flash exposure on the active focus point. Forcing the camera into partial metering of the FLASH exposure, this doesn't change the metering pattern of the ambient exposure.
     
  19. Jammey--while the instructions do say to use the partial metering circle to aim with, they don't say that partial metering is used to FEL. I suspect the center focus point and the area around it is used, which may or may not correspond with the partial metering circle...but what do I know? Canon is pretty secretive about what exactly is happening with E-TTL, both plain and II.
     
  20. Hi.

    Although photonotes says that the 10D balances flash with center weighed (I bought my 10D based on that fact after giving up on a D60 after two jobs), I don't particularly believe that it is accurate. From my experience using the Sigma ef 500 super, the 550ex and the 580ex, the flash metering is heavily focus point biased. That is after using ETTL with the 10D for over 6000 frames in the field (wedding/barmitzva work).

    I also use the center point exclusively and focus recompose as I find this to be the only way to reliably and correctly focus with split second timing. When I was shooting with ETTL I would underexpose heavily to protect the highlights and rely on pulling the exposure up in RAW, and yes it did infuriate the hell out of me.

    If you have time to plan the shot in that you know where your focus point is going to land after recomposing then you can guesstimate the FEC needed. For example if you are taking a 1/3 shot of a speaker at the wedding then you know that the focus point will land on his tux after recomposure so you dial in a FEC of -1.5 and theoretically the exposure will be right. This was made easier with the superb wheel controlled FEC of the 580ex.

    I never bought the CF4-1 trick, for split second shooting it's too many steps and not particularly comfortable with the camera at your eye, if you can make it work then good luck.

    I bought the Metz 54 MZ-3, had it upgraded for free to MZ-4 (it's flash upgradeable) and as I gave up totally on ETTL had it downgrade, again for free to the original version which allows auto flash in Av and Tv modes.

    With auto flash you expose the flash as you expose the ambient with center weighed metering. If there is a lot of black infront of you then dial in a -1.5 stop, if there is a lot of white then overexpose by a stop. I find with the 10D that it is at least 1/2 a stop more sensitive than it's meter, my flash or even my ambient meter. Coupled with a fear of overexposing the highlights I have it set on a -1 stop as standard and use that as a base exposure. Black goes down to -2 stops, white goes up to '0' or gets recovered in RAW and fill is -2.5 to 3 stops under.

    The advantage of the auto flash is that it is CONSISTENT. Two photos taken one after another with the camera in pointed in the same direction will have the same exposure. With ETTL it's anyone's guess what the camera will do from shot to shot. That doesn't mean that the auto flash always gets it right, it often doesn't, but once I've seen the histogram and changed the settings I can rely on every photo taken afterwards in similar conditions unlike the yo yo of ETTL. Another advantage is that I can use the flash with strobes in the hall, although I often need to dial in a serious minus to the flash (it doesn't really shut down fast enough), when I have the setting right I can rely on great, even exposures throughout the evening. With ETTL the preflash will not see the strobes output and cause the flash to overexpose even when using radio slaves.

    It's not all great news, the auto flash can not shutdown fast enough with certain apertures. Unlike ETTL which used the actual picture data and can therefore work out fill at fast apertures, the auto flash will not allow more than a -1.3 setting at f2.8 iso 400+, and no minus at all with f1.8 iso 400+. That means that when shooting with fast apertures at high iso's you cannot use fill, whatever the distance! You have to drop the iso to 200 and lower the shutter speed by a stop. You also lose high speed sync in auto mode so you are stuck with a 1/200 max shutter speed with flash. Not a huge problem unless you shoot outdoors with fast apertures and I have a good quality 2 stop ND filter in my pack for such situations.

    Another problem is that auto flash outdoors, especially for fill can be problematic if your subject is over 3-4 meters away. The auto flash relies on light reflected back from the subject and outdoors the light dissapates faster causing the flash to overexpose, you should use faster apertures and not longer lenses to control DOF (85mm not the long end of your telephoto). With groups it isn't that much of a problem as there is a large surface to bounce light off. A connected problem indoors is that auto flash is not that good for distant subjects. If you are framing a speaker from 5 meters away with your 70-200 then the same problem applies in that the flash hasn't got enough surface to bounce back off, or it's bouncing off the nearest table and causing underexposure.

    If these things worry you then it not be a good idea to be as drastic as I was and have the flash downgraded. That way you will keep ETTL for when you need it. You lose Av and Tv mode in auto flash but then you can use manual and twiddle the exposure till the lines match up in the viewfinder or use an ambient meter as I do, if you know that you have to do it then you will always be prepared, it's not like shooting car racing...

    I've come to the conclusion that for all pro wedding photographers winge about the newcomers with their DSLR's, I am of the opinion that there is nothing like a DSLR to take someone back to the very first principles and techniques of photography so as to achieve the same results that someone could manage with a Rebel 2000 loaded with NPH....

    For all that I heartily reccoment auto flash, although there is a learning curve, once you know how to use it, you can trust it and a photographer needs to be able to trust his equipment to do the job. I never was able to rely on ETTL with the 10D, hell half the time now I don't bother looking at the review....
     
  21. BTW as far as your Elan 7 is concerned, as far as I know the focus bias is nowhere near the extent of the DSLR's. I have two Elan II's and used to do all my shooting with them for event/wedding work using NPS/NPH. I used focus recompose with the center focusing point and under/overexposed the FEC as with an auto flash. The exposures were always consistent through and through. I'm assuming the Elan 7 is the same.

    I know how to read negs, I used to manage a photo lab, plus you can tell from the balance of foreground/background exposure, those pictures were well and consistently exposed film after film. Digital was a huge shock, whose stupid idea was it to tell pro's that they had to select the focus point for each shot, make sure it's over the face (not all shots have faces big enough to fill the whole focus metering point, get some tux in there and you're screwed) and only then take a picture as the flash was spot metering the focusing point? If I wanted to work that slowly then I'd be shooting my beloved A-1 and working out the flash distances in my head....

    I thought that ETTL II would be the answer to my problems till I had to fix an entire wedding shot with a 20D by an amatuer friend, the flash exposures were awful, totally all over the place, give me auto any time!
     
  22. That's interesting, Ben, about the focus point bias, and sorry that I spelled your last name wrong. I think for Melissa, there may be another consideration beside the focus point bias. I think it should be stressed here that you can't ever get your camera/flash to the point that it will produce perfect flash exposures without your thinking about your subject matter and tweaking it. Even if you are able to get a better handle on flash exposures via the CF4 trick, or whatever, you still have to deal with lightness/darkness of the subject matter/background if you are using automated systems like auto exposure and auto/TTL flash. So for those fleeting moments where you are just grabbing shots, it comes down to whether or not you have the time to tweak the setting, however you tweak. For me, if I don't have time, I just shoot and deal with it later. If I have the time, I tweak. This assessment happens very quickly. My reasoning is, if something is happening and I don't take the shot immediately, I'll lose any image I could have gotten. If I just shoot, I may get the shot and not have another chance. If I get another chance, I tweak and re-shoot.

    Also, I don't understand the part about blurry shots. If you are setting your focus to always use the middle point, and you are focusing and recomposing, how does this result in blurry shots? Maybe you should try the CF4 trick, not for tricking the camera, but to improve your focusing. I have my 20D set this way, not for the flash exposure pattern, but because I got tired to having to always deal with the focus on the shutter button. I tend to be a "wait for the moment" kind of photographer rather than the "shoot a lot" photographer, and also "old school" when it comes to using zone focus. So setting focus with the * button came very naturally to me and I can perform focus very quickly, and perform a kind fo pseudo zone focus, although I don't have to worry about taking my finger off the * button before pressing the shutter button.
     
  23. Ben, if you're talking to me about the Elan 7, I have an Elan IIe, and I did find that it consistently underexposed and the flash exposures weren't that reliable. I find the 20D and 580EX flash exposures very reliable, but still needing tweaking. If the flash is the main source of illumination, averaging mode with maybe 0 or +1/3 compensation is very realiable. For fill flash, evaluative mode with +2/3 compensation is very reliable.
     
  24. whew, lots of responses on this thread....

    When I first went through this with the 10D I did a bunch of test shots and was abel to
    convince myself the AF/MF * button trick with C.Fn-04 is effective. It was hard to evaluate
    just by looking at my actual work because I got better at compensating exposure over time
    (same way you get used to a camera's metering pattern reacts). In the end, here's what
    worked for me with the 10D:

    A) C.Fn-04 set to 1 - This makes the * button the AF button instead of the shutter release
    B) C.Fn-13 set to 4 - This move FEL to the assist button (the one that looks like an x to
    the left of the * button). You need to do this if you want to keep the ability to FEL if you
    have set C.Fn-04 to 1 because that overrides the normal behavior of the * button in flash
    mode which is to FEL.

    NOTE: setting the custom functions as described above changes the instructions on page
    100 of the 10D manual which Jammey quoted above (there is a footnote on the bottom of
    p.100 that notes the change in behavior with C.Fn-13 however.

    With the 10D, much of the time, I will just focus with the * held down, and take the
    picture when I wan. I don't often focus and recompose, I move the focus points instead, so
    the focus point is on my subject. When exposure is more critical and the focus point is
    over something very light or very dark (or very reflective!), then I am careful to release
    focus (*) before pressing the shutter. It's harder to explain than to do once you get used to
    it.

    ETTL-II in evaluative mode on the 1DsII (and I'm sure for the 20d, 1DII) is much more point
    and shoot and works very well. ETTL-II in averaging seems closer to the 10D in
    performance when used as described above.

    I use FEL on the 10D more than the 1DsII, and this is what I've found helpful...
    Many times there will be a consistent and BIG target in the scene that you can FEL on with
    a certain compensation factor. Like a dark tux at - 1 1/2 or a white dress at + 1 1/2. Or
    smaller but still consistent like a face at + 1/2. ETTL on the 10D is actully very
    CONSISTENT, it's just a bit tricky to use in practice because it's basically spot metering for
    you.

    Two more things that help... 1) bouncing and/or diffusing flash indoors (I like stofens, but
    use whatever modifier you like) helps even out flash exposures a great deal. 2) I tend to
    shoot fast lenses wide open and higher ISOs if needed so ambient light is often a large
    percentage of the overall exposure, and that tends to even things out as well.
     
  25. The best way to radically improve the performance and accuracy of a 550EX flash is to put a 20D under it.
     
  26. Nadine, the bit about the Elan 7 was for Melissa. I had my Elan II on parital metering which locked exposure for ambient with focus (oh how I wish the other canon cameras would do this!), I assume that the flash exposure was balancing the ambient/flash ratio based on the partial metering which was over the face.
     
  27. Ben--never tried that. Maybe I'll try that next time. I do notice that the auto fill flash reduction on the Elan IIe was way more than on my 20D, so maybe that has something to do with it.
     

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