cgardner wrote:
They do the same thing, but the control on the flash takes precedence over the one set on the camera. Once the flash is set on anything other than 0 it takes over. When the flash is set back to FEC=0 whatever was set on the camera kicks back in. That can get confusing so use one or the other. I prefer using the flash because its easier to see what the setting is.
FEC only works if the flash has a reserve of power left. The problem in ETTL mode is a lack of feedback, apart from recycle time, what % of full power is being used.
Say for example your ETTL exposure caused the flash to fire at 50% of capacity at FEC=0. In that case raising FEC to +1 will increase output to 100%. Increasing FEC beyond +1 will have no additional effect because FEC+1 in that situation = Full Power. To get more exposure you'd need to either open the aperture or raise ISO speed.
"What you need to do is move AF lock the the * button. Focus with * then recompose before half-pressing shutter, which locks AE, then push fully which fires the pre-flash, meters and compares ambient and flash, then takes the photo."
So, I tried this last night for fun... I was in Av mode and I pointed the camera up at the sky to get the meter from it, then I pressed the * button (AE-Lock) and I saw the * in the viewfinder stay on, and the settings stayed the same now no matter where I pointed the camera.. But now, I am confused when you say focus with the * button? Because if I press it again, it will take a new reading, and lock it.. I have to press the shutter 1/2 to focus now.. no?
- (thanks for holding my hand here... like I said shooting in this mode is all new to me..)
sharp_glass wrote:
"What you need to do is move AF lock the the * button. Focus with * then recompose before half-pressing shutter, which locks AE, then push fully which fires the pre-flash, meters and compares ambient and flash, then takes the photo."
So, I tried this last night for fun... I was in Av mode and I pointed the camera up at the sky to get the meter from it, then I pressed the * button (AE-Lock) and I saw the * in the viewfinder stay on, and the settings stayed the same now no matter where I pointed the camera.. But now, I am confused when you say focus with the * button? Because if I press it again, it will take a new reading, and lock it.. I have to press the shutter 1/2 to focus now.. no?
- (thanks for holding my hand here... like I said shooting in this mode is all new to me..)...Show more →
He's talking about using a Custom Function to swap the function of the buttons. I never understood that advice. As you found, the * button holds the exposure without you having to keep your finger on it. Why move that function to the shutter button so you do it on every shot? And it's simply awkward to do. You have to keep your thumb up on the back edge of the camera, and also keep your finger balanced half-pressed on the shutter to lock exposure, while you're trying to recompose. I'd drop the camera.
The * button also does flash AE lock. So, say in your beach scene, you want the people off-center. Point directly at the subject, and hit * to pre-flash meter them. Then re-compose, and it should balance correctly. If you didn't *, the camera would try to flash to the horizon.
Move FOCUS lock to the * button, not exposure. CF.N 04 = 1 on most bodies. That will put AF lock on * and keep AE lock on the shutter button (at the point of half press). The reason is that you don't want to lock ambient EXPOSURE until after you have focused and recomposed. That allows evaluative metering to compare ambient and pre-flash on same scene.
Workflow is:
1) Frame to put center AF point on eyes. Press * to lock AF but keep finger OFF the shutter.
2) Reframe as you plan to shoot. Half-press the shutter. That will lock the ambient exposure reading in Av mode (AE lock).
3) Then without releasing the shutter from half-press, press it completely to take the shot. At full press the pre-flash will fire. The metering will compare it zone-to-zone with the ambient reading stored at the point of AE lock (half-press).
Shifting FOCUS LOCK to * allows you to focus/recompose without screwing up the metering as it would be if you lock AF and AE at the same time, before you recompose.
The AE lock and pre-flash need to occur with the camera pointing at the same place. That is a critical piece of the puzzle of learning to make evaluative metering work effectively and predictably.
1) Meter ambient and pre-flash in the same place
2) Adjust ambient for TECHNICALLY correct highlights (i.e. no clipping anywhere except specular reflections)
What Canon evaluate metering tries to do is determine which highlights are specular and which have detail. For example of you have a mirror in the background of a shot taken with average TTL metering the flash reflecting back off the mirror will result in gross underexposure. But evaluative can determine by comparing pre-flash reflection over 35 zones when a reflection is specular and will do a better job of exposing the scene. But a critical part of making that work in Av mode is getting the ambient exposure correct because the ambient baseline is used for comparison. If you start with blown highlights in the ambient exposure adding flash will just blow them more. Click the WWW button and see my high speed flash test which illustrates this.
1) Frame to put center AF point on eyes. Press * to lock AF but keep finger OFF the shutter.
2) Reframe as you plan to shoot. Half-press the shutter. That will lock the ambient exposure reading in Av mode (AE lock).
3) Then without releasing the shutter from half-press, press it completely to take the shot. At full press the pre-flash will fire. The metering will compare it zone-to-zone with the ambient reading stored at the point of AE lock (half-press).
Shifting FOCUS LOCK to * allows you to focus/recompose without screwing up the metering as it would be if you lock AF and AE at the same time, before you recompose. The AE lock and pre-flash need to occur with the camera pointing at the same place. ...Show more →
Which is exactly what happens if you just take the picture normally. It's not "screwing up the metering" if you use AE Lock before you recompose -- that's the only time you really need to use it. If you are metering as you take the picture, as in your sequence above, you don't need to lock anything, and you don't need to use two fingers to work two buttons to do it. And if you're trying to get best focus, it's better to choose a different AF point and NOT recompose anyway -- especially if you're recomposing so drastically that you think it would change the exposure metering.
There's some advantage to using * for focus if you use Servo (tracking) focus, it focuses faster or something. I dunno, that's for the sports and wildlife guys, I don't use it.
You simply do not understand how Canon evaluative metering works. It compares ambient readings of the 35 metering zones > at the time of AE lock < with the pre-flash returns which occur after the scene is recomposed and shutter fully pressed. An accurate ambient / flash comparison allows evaluative metering to create a virtual 3D map of what is in the viewfinder similar to radar or sonar. It then uses that map to logically deduce how much flash to add. If AE lock and pre-flash don't occur with the viewfinder pointing at the same scene then evaluative is comparing apples and oranges rather than same fruit under two different types of light.
Try this simple test. Aim your camera in Av mode and flash in ETTL under your desk where it is dark and lock AE then move it up and take a photo of the room with flash. The camera, having lock AE based on the low light level under the desk will drag the shutter and grossly overexpose the photo just with ambient alone. The evaluative flash metering, basing its calculation from the AE lock under the desk compared with the reflection of the room the camera was aimed at when you fully pressed the shutter will be incorrect also.
The bottom line if you focus / recompose and want ETTL metering to work predictably is to wait and lock AE until after recomposing. The most practical way to do that is to move AF off the shutter button and onto the * button.
use manual mode, do a few test exposures to get the sunrise right, then add flash, use a warming gel on the flash... shoot in RAW too as you can process the photo to the WB of the sunset then to the WB of the flash, and then combine them in photoshop...
I am going to go and do a "practice" session with a friend tomorrow AM. I am just going to first try to use manual mode, meter the horizon get my settings as if I wanted to take a picture of just that... then recompose using flash in ETTL mode, and see what happens.. I will play with the FEC on flash (+/-) until I get the look I want.. and or adjust my shutter speed to get a lighter / darker background.. right?? I mean certainly based on this concept I should be safe..
I will "play" around with Av mode.. and see how I like it.. I can see from what everyone is saying that it might be nice because of the fast changing ambient light at this time of day... but I see that if I use Av mode, meter the horizon, lock the exposure, then re-compose and turn on flash.. I lose the AE-lock.. and it looks like the camera is then going to lock flash instead? thus by background will be all screwed up.. ? (I am sure something has already been said here) but I guess I am trying to grasp too much too fast or something..
You simply do not understand how Canon evaluative metering works.
I understand how it works, I'm just saying that changing the buttons and thus the sequence of taking a picture is a way of adjusting for a situation that you shouldn't be having in the first place, plus it prevents you from using it when it could be helpful. First, focus-and-recompose is an easy way to get lousy focus. Better to choose another focus point. Second, if you're recomposing so much that the exposure would be drastically different, that's the only time you need to lock AE, and it doesn't matter which button you do it with, so you might as well use the one that's already there. It's uncommon to need to separate your exposure and focus points, so keep the uncommon function on a separate button.
In your example above, if I *want* to get the right exposure for under the desk, then that's exactly what pressing * does for me. Yes, it would grossly overexpose the room when I recomposed. If I want the room to be correct, I point and shoot normally. I don't see what moving the buttons does there. Without flash, AE lock is already on the shutter (which I've realized is why the sports guys move focus to *: they want to keep it pressed for focus tracking without the exposure locking until they want to shoot).
Here's an example: subject off-center to the right. You'd point the center AF at him and focus with *, then swing back (now it's probably out of focus) and AE lock (on the BG) and fire. Hope the 35 zones pick up the subject over there. Now try: center the subject and * to FEL (Flash Exposure Lock), then recompose and use the right AF point on the subject. Shoot, and the subject which is pre-flash-metered and the BG which is metered at exposure are both correct, and your focus is correct because you've focused in your actual composition. I don't see how you do that unless you have the AE/FEL on the separate * button, not the focus. (The pre-flash with * don't work with the 420/430 flash, only the big ones.)
Here's an example: subject off-center to the right. You'd point the center AF at him and focus with *, then swing back (now it's probably out of focus) and AE lock (on the BG) and fire. Hope the 35 zones pick up the subject over there. Now try: center the subject and * to FEL (Flash Exposure Lock), then recompose and use the right AF point on the subject. Shoot, and the subject which is pre-flash-metered and the BG which is metered at exposure are both correct, and your focus is correct because you've focused in your actual composition. I don't see how you do that unless you have the AE/FEL on the separate * button, not the focus. (The pre-flash with * don't work with the 420/430 flash, only the big ones.)
Ah, yes this makes sense to me... but I want to make sure of something....
That - I *first* metered the horizon in manual mode get my settings... lets say (1/200 @ 2.8 100ISO) then turned to my right and used the center point to FEL... then move back to the left (recompose) select the point on the right (cause it's closer to them) and take the shot...
sharp_glass wrote:
That - I *first* metered the horizon in manual mode get my settings... lets say (1/200 @ 2.8 100ISO) then turned to my right and used the center point to FEL... then move back to the left (recompose) select the point on the right (cause it's closer to them) and take the shot...
or.. does FEL not work in manual..
You probably wouldn't want, or need, to keep using the FEL-recompose technique for a series of shots. You'd probably find it easier to do as we said above: shoot normally, then adjust FEC to get what you want as far as balance between the BG and your flash-lit subject. After that, you can put them anywhere in your composition and the flash exposure would be correct, as long as they're the same distance from your flash.
FEL and FEC work in manual, and actually even better, since the ambient exposure and thus the ratio to the flash isn't floating. You always know what you're getting once you set it.
I am just going out, relax.. take a breath shoot manual expose the sky, then add some fill flash while riding the FEC button on the flash. ETTL mode.
The bigger issue I may have.... oh, boy... is that I have no CTO gel sheets.... and there is NO camera store here in Miami that has ANY in stock.. that I can get to in time.. ARARRRGGG.. any way to substitute gel on the flash with something else?
sharp_glass wrote:
I have no CTO gel sheets.... and there is NO camera store here in Miami that has ANY in stock.. that I can get to in time
Theater supply houses are where to get gels, and BG paper, and diffuser material, and lots of other "photographic" supplies.
fizzy wrote:
Here's an example: subject off-center to the right. You'd point the center AF at him and focus with *, then swing back (now it's probably out of focus) and AE lock (on the BG) and fire. Hope the 35 zones pick up the subject over there. Now try: center the subject and * to FEL (Flash Exposure Lock), then recompose and use the right AF point on the subject. Shoot, and the subject which is pre-flash-metered and the BG which is metered at exposure are both correct, and your focus is correct because you've focused in your actual composition. I don't see how you do that unless you have the AE/FEL on the separate * button, not the focus. (The pre-flash with * don't work with the 420/430 flash, only the big ones.) ...Show more →
In your example there's no reason you can't select and lock AF on the right point with * if you feel it will it will yield better focus, so that's a "straw man" argument. You also seem to justify your method on a lack of faith in evaluative metering.
When FEL is used there is no evaluative metering. FEL overrides the evaluative metering process for flash and instead bases flash what is in the center metering zone. As with any spot metering method whether or not the metering results in correct exposure or not at FEC = 0 depends on how close the object reflecting the pre-flash is to middle gray. So on average it is probably no more or less accurate than evaluative.
One problem conceptually with FEL is beginners, not aware of the laws of physics, will use FEL to lock on a face 10ft away and then be puzzled why stuff 5ft away is blown out. The solution of course, regardless of flash metering method, is to put what needs to be correctly exposed closest to the flash. What evaluative can do, which other metering methods can't, is make an educated guess how far things are away from the camera based on the relative amounts of ambient and pre-flash that is reflected.
Regardless of what mode is used for exposure the camera, being a dumb machine, will repeat it consistently. Automatic exposure systems only get ambient and flash exposure both correct right at EC =0 and FEC =0 at best half the time for an average scene. When you add variables like pointing the camera at a horizon where the ambient level will be constantly changing the odds go way down. So regardless of what workflow used the process is always shoot, chimp, adjust EC and FEC as needed.
You are going to be just fine. I would do it exactly as you planned and basically the same way chuck is telling you to do it but I would change two small things, Chuck already suggested one.
I would do it in Av mode and turn on Hi-Speed Sync on the flash. You are underestimating how quickly the light will change during a sunrsie. Av will help with this because it will increase your SS as the sunrises (which is good for you because you don't have to worry about camera shake once you establish our baseline). Once you've got the ISO as low as it can go and the SS pushes past you normal sync speed you'll need Hi-speed sync unless you want to change the aperature. Shooting into the sun this can happen a lot sooner than you'd think.
With your method, you'll have to check ambient, set the camera in manual, shoot a few shoots, adjust the poses, switch people, adjust hair etc. Oops, time to check ambient again....adjust the camera. Not a huge deal but Av can get rid of some of this.
Well, I went out this morning, and played around at the beach. I got some great results that I for one was happy with. I was able to locate some CTO gel (sheet) last night, so I was able to make (2) strips of it (it is 1/4) this way I can start with one strip @ 1/4... then add another to be at 1/2. I found that I liked the warmer temp using 1/2 much better.. so I just shot everything that way..
Things I noticed... well, I used "M" mode for 99.9% of it... but I do see the issue with fast changing light... after the sun pokes it's head up...WOW lookout..
Q: When (if) I use Av mode, wont the camera constantly me metering the subject (not what I want).. in other words, in manual I can meter the sun / sky behind my model, then recompose on my subject (meter showing WAY underexposed because I want to expose the sky behind her) then I shot with ETTL flash (most of them were ETTL +3 by the way... (which = 1/1 in manual?).. anyway.. I can not use AE-lock when metering in Av mode because I am using the flash.. see my point? So I am a little confused about this..
I would LOVE to use Av, mode when the sun starts coming up though...need better workflow understanding first.
Other observation maybe someone can help with... later in the day I practices shooting in "mid day" harsh shadows.. and applied the f16 rule. This time I did it right by having my "model" have her back to the sun, and I used my fill for shadows (just like at the beach).. For the most part I was happy... I really had to play with settings to get both background and subject the way I wanted but I can see this is THE ONLY way to go. Anyway... I noticed that because of the BRIGHT sun an aperture sometime in excess of f/16 was needed (especially because of the 1/250) limit on flash sysnc.. to keep things exposed in the background... however I can see that even with my flash at full power or ETTL +3 I was underpowered. Funny because when I got closer to the subject it was okay... but as I got farther away (10+ feet) I could se the flash power diminish.. so I would increase to f/9 ish.. to get my desired result still at 1/250... But I can see that if I need to shoot a group of people 4 or more... that I need to be back in order to get them all to fit in the frame (24-70 lens) thus... I need a more powerful flash to project OR.. better yet this is where off camera lighting would come in... right... thus I can have the light MUCH closer to them, while I take the shot where I may.
In some shots, I can see where increasing the flash rage to say... 70mm was helpful to narrow down my light, thus making it "appear" more powerful. Cool stuff...
Let me know I am on track here...lol.... I want to get this stuff nailed down. Tomorrow IS the big day....
.. how very helpful. Now thats shallow depth of field!