m_barbu1 Posted May 30, 2007 Share Posted May 30, 2007 <p><i>The flash will take care of freezing the subject</i></p><p>That's not always true. There are cases where the exposure will be slow enough to register additional motion, which would appear like ghosting.</p> Link to comment Share on other sites More sharing options...
joseph_lasker Posted May 30, 2007 Author Share Posted May 30, 2007 Due to popular demand here is a sample: This pic is unedited exept for file raw->jpeg and size convertion Lens: efs 17-85mm f4-5.6 is usm Body: Canon 30D Flash: Speedlite 580EX II 1/5 sec, shutter priority, f4.5, @ 30mm, ISO 800, metering-patern. Never mind the composure, I was too frustrated that I couldn't get the shutter speed high enough. I welcome your insight. Link to comment Share on other sites More sharing options...
m_barbu1 Posted May 30, 2007 Share Posted May 30, 2007 First, if your camera is set to shutter priority, the exposure is fixed (unless you change it). You need to use aperture priority. Second, I believe that if you shot the same photo at f/1.4, you would have been able to use a shutter speed of at least 1/40 sec, all else being equal. Third, you've got a very powerful flash, but that doesn't appear to be the case if you look at the photo. Are you diffusing or redirecting the light? Link to comment Share on other sites More sharing options...
joseph_lasker Posted May 30, 2007 Author Share Posted May 30, 2007 Correction: Aperture Priority Link to comment Share on other sites More sharing options...
ni_gentry Posted May 30, 2007 Share Posted May 30, 2007 At wide apertures, your depth of field is smaller (also dependent on your subject distance and focal length). So not everything is going to be sharp, especially when you have multiple people arranged so that they are not all in the same plane. Also, using Aperture priority or Program mode in dim lighitng like that will always result in a slow shutter speed because the camera is trying to expose for the ambient light. Either dial down the exposure compensation or better yet, learn to shoot in manual mode. With your flash, you should be bouncing the light to give a softer effect and light up more of the area around the subject as well as fill in the shadows. Next time in the same situation, try arranging the people in a better fashion, set the camera to manual mode f/4 (or f/2.8), 1/60th sec, ISO 800 ~ 1600, flash on ETTL and bounced off the ceiling with the little built-in bounce card raised up. Guaranteed better results. (of course not all situations will be equal) Link to comment Share on other sites More sharing options...
ni_gentry Posted May 30, 2007 Share Posted May 30, 2007 To add... You could probably also bring the shutter speed down to around 1/30th sec since again, the flash will freeze motion, and in this case your subjects are pretty stationary. But since you are essentially "dragging the shutter" you don't want to go too low unless it's for effect. The flash freezes motion, but the ambient exposure still can creep in. <p>Also, try adjusting your white balance to fix those colors. Link to comment Share on other sites More sharing options...
joseph_lasker Posted May 30, 2007 Author Share Posted May 30, 2007 Ni Gentry: That is my question. Which lens will let me do what you sugest? The lens that I'm using now, will let me go down to f4, as long as I don't zoom. And at f4 800 it gives me 1/8 sec. Link to comment Share on other sites More sharing options...
joseph_lasker Posted May 30, 2007 Author Share Posted May 30, 2007 As far as white balance I'm shooting RAW. (for now I let the camera decide on white balance) The white balance is not adjusted for purpose of showing you the lighting situation. Link to comment Share on other sites More sharing options...
brucecyr Posted May 30, 2007 Share Posted May 30, 2007 Joe, That's actually not too bad a picture -- guess my standards aren't that high! However, Manual mode with bounced flash would certainly go a long way towards fixing your problem WITHOUT a new lens. In manual you could shoot at a higher speed and a smaller aperture. Check out the EOS flash bible: http://photonotes.org/articles/eos-flash/ If you do go for a new lens, the one you pick depends on your relative valuations of weight, speed, etc., and whether or not you plan to also keep the 17-85. Link to comment Share on other sites More sharing options...
ni_gentry Posted May 30, 2007 Share Posted May 30, 2007 >> "That is my question. Which lens will let me do what you sugest? The lens that I'm using now, will let me go down to f4, as long as I don't zoom. And at f4 800 it gives me 1/8 sec."<p> Hi Joseph,<p> Again, the lens (of the 2 you mention) doesn't really matter too much in this situation... f/2.8 or f/4... it's only one stop difference. If you're bouncing flash properly, then that will be your main exposure. The lens aperture will do basically 2 things... 1) control your depth of field, and 2) effect your ambient exposure (along with shutter speed and ISO)... So if you are at f/2.8, all you need to do to get the same ambient exposure is to slow down the shutter speed or bump the ISO (one stop for either, 1/2 stop each, or whatever). To re-iterate, the flash exposure (set to ETTL) is your main exposure. Letting in ambient light via the camera exposure will provide additional fill and background ambience for a more natural look..... remember, flash exposure will be auto/TTL. The flash output will be set automatically based on subject, distance, aperture, and ISO (NOT shutter speed).... The camera exposure will be set manually to let in just enough ambient light to suit your taste for a "natural" look... that ambient exposure will be based on aperture, shutter speed and ISO. <p> Now if you really want natural... then get a fast prime (f/1.4 or faster), which will allow you 2 or more stops of available light. You can then drop your flash exposure compensation a stop or two so that the ambient light is your main exposure and your flash just acts as your fill. Or if the lighting is good enough, turn off the flash completely. Of course, this means you're shooting at an even smaller aperture and possible on the edge of a fast enough shutter speed for handholding. So you have to have your technique down for nailing your focus point and holding the camera steady. Also, shooting at high-ISO's you'll have slightly less lattitude for underexposre because of the added noise. Link to comment Share on other sites More sharing options...
rtrace Posted May 30, 2007 Share Posted May 30, 2007 "To re-iterate, the flash exposure (set to ETTL) is your main exposure." Not in aperture priority mode, which is I think the problem here. In Av mode, flash is fill, and the camera meters the subject and thus gives you the small shutter in low light situations. So in this case, it's better to use manual (M) mode, in which case the flash will be your main exposure and set the shutter to 1/30 - 1/90 depending on how stationary your subjects are and how much you want to expose the background. Bogdan Link to comment Share on other sites More sharing options...
rtrace Posted May 30, 2007 Share Posted May 30, 2007 For that picture, I'd use f/5.6, 1/30, & ISO 400 for instance. Flash on ETTL auto. M mode. Simple as cake really. Maybe up the ISO if really dark. Bogdan Link to comment Share on other sites More sharing options...
rtrace Posted May 30, 2007 Share Posted May 30, 2007 M mode on the camera that is - not to confuse with flash on auto ETTL. Again, I think the real problem here is using Av mode. Bogdan Link to comment Share on other sites More sharing options...
ni_gentry Posted May 30, 2007 Share Posted May 30, 2007 >> "Not in aperture priority mode,..."<p> Yeah, that and the rest is basically repeating what I said. Link to comment Share on other sites More sharing options...
joseph_lasker Posted May 30, 2007 Author Share Posted May 30, 2007 You guys are hitting the nail right on the head. I've been reading a link that Bruce C has sent and it basically says the same thing about the Av mode and E-TTL. I think that this is exactly the problem here. Thanks for everything...PS I'm still debating about the two lenses.... Link to comment Share on other sites More sharing options...
rtrace Posted May 30, 2007 Share Posted May 30, 2007 "Yeah, that and the rest is basically repeating what I said." Yes - but it's breaking it down and making it simple and making a distinction between Av and M mode and how flash operates in both modes. I know you understand it, but I just put it more succintly :) "Thanks for everything...PS I'm still debating about the two lenses...." Again, you need to decide what is more important for you - extra 35mm on the telephoto end that the 24-105mm has, extra stop that the 24-70mm has, weight factor, IS vs non-IS (this was explained quite well in this thread), etc. As Ni said, either lens is fine for this type of shot, and not the problem. And again, if your objects are stationary and you want to handhold at low shutter speeds, then IS makes sense. If on the other hand your subject are moving and you want to freeze them, then IS won't help and you the extra stop of the 24-70mm will help. The decision should really not be a complicated one. Just take these things into account and go. Both are fine lenses (Internet forum nitpicking aside ;) Bogdan Link to comment Share on other sites More sharing options...
William Michael Posted May 30, 2007 Share Posted May 30, 2007 >> The decision should really not be a complicated one. Just take these things into account and go. Both are fine lenses (Internet forum nitpicking aside ;) << Hoo Ya WW Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now