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Baadil
9th of July 2007 (Mon), 15:32
Hi,

This past weekend I attended a wedding. I took my camera with me and took lots of pictures. I used my XTi with Canon 28-135 IS and 430EX. Most of the time I bounced the flash from ceiling.

I know I am going to embarass my self but I have to ask, how do you get the proper exposure when in manual mode? Like most wedding halls, this was pretty dark as well so I used 1/60 shutter with widest F stop I could used in my zoom range. I set my camera to single focus point (instead of 9 point). If I took a shot it would come dark but if I pointed my focus point towards some dark object (i.e. black clothes or black hair), pressed and held my exposure lock button and then took the shot, it would come out decently lit. What gives? During most of the wedding, I kepp manually locking exposure for darker objects and taking shots but I know I am missing something here. Any help?

Thanks.

poloman
9th of July 2007 (Mon), 16:52
Your exposure lock button wouldn't do you any good in manual mode. But your description doesn't make sense in this context. Are you sure you were shooting in manual mode?
When using a flash the background exposure is based on ISO and shutter speed. The subject exposure is based on ISO and shutter aperture in addition to flash power. Maybe if you posted a shot with EXIF data, people can be more helpful.

Baadil
9th of July 2007 (Mon), 17:10
I know it does not make sense but here are the steps I was following:

Flash set to Zoom/Auto (incorrect terminology?)
Camera Dial set to Manual (M)
Setup Focus to single point (Center)
Set ISO to 800
1/60 - F3.5-5.6 depending on zoom
Point single-focus-point towards a dark object (Black hair?)
Press and hold Exposure lock button
Point Single Focus point to subject's eyes for focus
Re-compose and take the shot

I hope this is clearer.

Thanks.

Hermeto
9th of July 2007 (Mon), 17:18
There is NO Exposure Lock in Manual mode!
You dial in aperture and shutter speed values yourself, and that's what is 'locked'.

Pressing * button in Manual mode does NOTHING.

Baadil
9th of July 2007 (Mon), 17:25
Could it be a combination on that lens, and flash along with this camera? I had never used that flash or the lens before (borrowed it to try it out).

thanks.

rammy
9th of July 2007 (Mon), 17:30
Just to make it a little easier to understand ;-)

In AV or TV or any other creative or auto mode, except manual, when you frame a certain area of the scene, the camera will decide at that point what judgement it needs to make to expose it correctly. So when you then move the camera away or recompose, the exposure settings it decided at that time, will now change for the new framing. This is when you would use the exposure lock.

In manual, you decide everything. So if you frame for exposure, set the aperture and shutter speed and ISO, when you then recompose, the camera will not change the settings because you set it. It dare not second guess you! It becomes your slave and will always default to the master (you!) :-)

This is what manual is, you control everything :-) So there is no need to lock the exposure because you have already locked it as soon as you decided on the aperture, shutter and ISO.

cosworth
9th of July 2007 (Mon), 17:30
There is NO Exposure Lock in Manual mode!
You dial in aperture and shutter speed values yourself, and that's what is 'locked'.

Pressing * button in Manual mode does NOTHING.


Exactly. I try and stress to people that M mode is like SUPER exposure lock. No extra button to press or guessing.

rammy
9th of July 2007 (Mon), 17:33
Could it be a combination on that lens, and flash along with this camera? I had never used that flash or the lens before (borrowed it to try it out).

thanks.

No it is not. It is all to do with having the main command dial in "M" mode and what that actually means. You have ultimate control and whatever you dial in, will never change unless you change it. Therefore the exposure lock button becomes redundant.

Baadil
9th of July 2007 (Mon), 18:13
Thanks guys. I guess I need to figure out why did it make any difference in my case. It could be something external but nonetheless I need to find out what it is. I did think that manual mode was for, well, manual controls but I was unable to figure out why it would make difference when I used that button.

rammy
9th of July 2007 (Mon), 18:23
Ok so now you're not making sense :confused:

Try this:

Slap the flash on your camera and switch it on.

Set the command dial on TV or AV. Meter correctly on a bright part of a scene so the light meter in the view finder reads "ok" - I don't mean the words ok, I mean the line is in the middle. Now move the camera around the scene whilst you keep looking through the viewfinder. See how the Aperture or the Shutter speed changes as you move around the scene?

Now, set the command dial to "M". Set the aperture, shutter speed and ISO when you frame the light area of the scene. Now move the camera around as you move it around the scene. Nothing changes right, the aperture, shutter speed and ISO is as you set it right? But in the first test, either the aperture or the shutter or the ISO changes?

Ta da! No? Then slap Debbie Maggie.

Baadil
9th of July 2007 (Mon), 18:37
You are correct, in M mode none of the settings change, and I never said they change. What I don't get is why were my images were brighter (in light not color) when I pressed that silly button. the only thing that changed automatically in M mode was the F stop when I zoomed in since it was open all the way.

rammy
9th of July 2007 (Mon), 18:46
Both your Sigma 55-200 and the Canon 18-55 have what is called variable aperture ranges when the lens is zoomed.

On your 55-200, the F/4-5.6 means that the aperture on the lens will automatically change form F4 (zoomed out to 55mm) to F5.6 (Zoomed in). Your 18-55mm lens will do the same thing.

Only where your lens says ONE number such as F2.8 or F4 does it mean that regardless of what you zoom setting is, the aperture will always stay at F2.8 or F4.

Look at my lens list in my signature below. None of the zooms change the aperture when I zoom in or out, that is because they only have one number in the F-Stop part.

Make sense?

BTW - You never said that you zoomed in or out otherwise we would have worked out the "cause" much sooner :-)

Baadil
9th of July 2007 (Mon), 19:02
You look like L-coholic :-)

I do understand the difference between fixed and variable aperture on difference lenses (I just can't afford the fixed ones yet :-) ). I never zoomed in after the 'exposure lock'. hehe. Perhaps I was drunk without drinking anything.

rammy
9th of July 2007 (Mon), 19:12
You look like L-coholic :-)

I do understand the difference between fixed and variable aperture on difference lenses (I just can't afford the fixed ones yet :-) ). I never zoomed in after the 'exposure lock'. hehe. Perhaps I was drunk without drinking anything.

Not really, some have over 10!! But that's POTN for you :lol: No regrets though! They help in better quality pics.

So are we cleared up on the aperture changes and the exposure lock button in "M" mode? Have you tried out the examples and learnt how it all fits together now?

Oh, and stay away from the Lens Forum until you think you have exhausted your capabilities!!!! :lol:

canonphotog
9th of July 2007 (Mon), 19:24
You are correct, in M mode none of the settings change, and I never said they change. What I don't get is why were my images were brighter (in light not color) when I pressed that silly button. the only thing that changed automatically in M mode was the F stop when I zoomed in since it was open all the way.

I thought something might be amiss here so I checked the 30D manual. Your manual should be similiar.

In the reference section in the back it clearly shows that exposure lock is not available in manual mode, however, FLASH EXPOSURE LOCK is available.

So what you were doing pressing "that silly button" was giving your E-TTL system a chance to calculate the right amount of light from your flash for a proper exposure using your manual settings.

Therein lays the difference.

DDan
9th of July 2007 (Mon), 19:25
With a flash attached, the * button is flash exposure lock (FEL). The flash will prefire and record the amount of flash needed.

E-K
9th of July 2007 (Mon), 19:26
Flash exposure lock is still available even in manual mode. If you were using the flash then this is likely what was happening. By pressing the FEL button when on a dark subject you were telling the camera that more flash was necessary.

e-k

bieber
9th of July 2007 (Mon), 19:29
The reason you get more light when pointed at dark objects is because the TTL flash metering sees less light coming back, so it puts more out. In largely white or light-colored scenes, you need to add flash exposure compensation so that the flash puts out more light. For really dark scenes, you may need some negative compensation.

pigtailpat
9th of July 2007 (Mon), 21:03
There is NO Exposure Lock in Manual mode!
You dial in aperture and shutter speed values yourself, and that's what is 'locked'.

Pressing * button in Manual mode does NOTHING.

Does the Xti have the CF-4-3 function? On my 30d, I use this button to focus, but not exposure lock, when in manual mode with flash attached. Is this what the OP was after perhaps or no?

E-K
9th of July 2007 (Mon), 21:28
Does the Xti have the CF-4-3 function? On my 30d, I use this button to focus, but not exposure lock, when in manual mode with flash attached. Is this what the OP was after perhaps or no?

I think the OP was just looking for an explanation of why the exposure was different when pressing * with focus point over a dark object versus a light object.

This is because the * button functions as a FEL even when in manual exposure mode. The ambient exposure was locked in but the flash exposure was locked when the * button was pressed.

I do believe the XTi has CF-4 (the XT does for sure). On the XT, CF-4-0 would need to be set for * to act as FEL.

e-k

BillMarks
9th of July 2007 (Mon), 22:53
It's amazing--the information one finds in those manuals...

Baadil
9th of July 2007 (Mon), 23:16
Thanks guys. I feel much better now that I know I wasn't insane. Yes, it probably, most likely is Flash Exposure Lock because no settings were changed on the camera yet this single button made images brighter :-)

Now having said that, what can I do in future to get the flash to expose with proper power without having to do what I had been doing for every image? I am more interested in learning any additional capabilities of the camera/flash more. I understand I can probably take better images from a faster lens but what to do if you do not have a big lineup of expensive lenses?

Thanks.

E-K
10th of July 2007 (Tue), 08:19
If you cannot get faster lenses then the only option would be to improve the light -- assuming of course the light wasn't sufficient in the first place ;). If you're shooting indoors then this likely means flash. You can take a look at the "Small flash and Studio Lighting" forum for ideas on making better use of your flash.

e-k

totalbeginner
10th of July 2007 (Tue), 09:08
There is NO Exposure Lock in Manual mode!
You dial in aperture and shutter speed values yourself, and that's what is 'locked'.

Pressing * button in Manual mode does NOTHING.

Yes it does, it activates the FEL (Flash Exposure Level)

When pressed, the strobe will fire and then the reflected light is measured by the E-TTL system and is used to control the flash output for the next shot.

This can be a handy feature considering that the rebel xt line of SLR's don't have Flash Exposure Compensation.

Baadil
10th of July 2007 (Tue), 09:34
Is FEL (Flash Exposure Level) same as FEC (Flash Exposure Compensation)? I have FEC in my menu.

Thanks.

Yes it does, it activates the FEL (Flash Exposure Level)

When pressed, the strobe will fire and then the reflected light is measured by the E-TTL system and is used to control the flash output for the next shot.

This can be a handy feature considering that the rebel xt line of SLR's don't have Flash Exposure Compensation.

Baadil
10th of July 2007 (Tue), 09:37
Well, I can get faster lens but I am thinking I am still missing something here. For some reason, I am having to manually trigger (newly found :oops:) FEL button before each shot. Does this mean either camera or flash is not metering light properly and I am having to force it to re-evaluate it for flash level purpose?

Thanks.

If you cannot get faster lenses then the only option would be to improve the light -- assuming of course the light wasn't sufficient in the first place ;). If you're shooting indoors then this likely means flash. You can take a look at the "Small flash and Studio Lighting" forum for ideas on making better use of your flash.

e-k

PhotosGuy
10th of July 2007 (Tue), 10:32
what can I do in future to get the flash to expose with proper power See post #4 here: Settings?? Help Needed! (http://photography-on-the.net/forum/showthread.php?p=2953374)

tmanAg08
10th of July 2007 (Tue), 12:07
This can be a handy feature considering that the rebel xt line of SLR's don't have Flash Exposure Compensation.



Hmm. My XTi sure does.

sixsixfour
10th of July 2007 (Tue), 12:19
Is FEL (Flash Exposure Level) same as FEC (Flash Exposure Compensation)? I have FEC in my menu.
Thanks.

Nope.

FEL (I believe it is Flash Exposure Lock) "locks" the information needed to correctly expose the subject with flash by firing a preflash and storing that data into memory. the camera then adjusts the flash output to get a proper flash exposure.

FEC (Flash Exposure Compensation) lets you change the power output of the flash in 1/2 or 1/3 increments. it lets you adjust the output so you can get more flash fires for a given amount of time or do a few max power flashes to light up a scene.

totalbeginner
10th of July 2007 (Tue), 19:30
I stand corrected, from what others have said it looks like the new 400D has FEC?

StewartR
11th of July 2007 (Wed), 05:18
This can be a handy feature considering that the rebel xt line of SLR's don't have Flash Exposure Compensation.I stand corrected, from what others have said it looks like the new 400D has FEC?The 350D aka Rebel XT also has FEC.

totalbeginner
11th of July 2007 (Wed), 05:46
The 350D aka Rebel XT also has FEC.

Really? My goodness, I'm ashamed to say that I had that camera for nearly a year and I had no idea it has this feature.

How is it contolled?

StewartR
11th of July 2007 (Wed), 05:51
Well, I can get faster lens but I am thinking I am still missing something here. For some reason, I am having to manually trigger (newly found :oops:) FEL button before each shot. Does this mean either camera or flash is not metering light properly and I am having to force it to re-evaluate it for flash level purpose?I don't think "not metering light properly" is quite the right way of looking at it. I think it's perhaps more accurate to note that you have identified some of the limitations of the camera's metering system, and you need to work out how to overcome them.

Here's a thought experiment I've used before. Set your camera to an automatic mode such as Av or Tv, using evaluative metering, and take photos of [a] a black cat in a coal cellar, and [b] a polar bear in a blizzard. What happens?

Answer: They both come out grey. The camera's meter doesn't know that the cat is supposed to be black and the bear white, so it meters the scene to get a mid-grey (18% grey) on average. The cat will be overexposed (grey instead of black) and the bear underexposed (grey instead of white). In order to get the exposures right, you need to set some Exposure Compensation (EC): negative EC for the cat to make it black instead of grey, and positive EC for the bear to make it white instead of grey.

With me so far? That thought experiment, and the concept of EC, is probably quite familiar to most non-beginners.

Right, here's the second thought experiment, which is new. Set the camera to M mode, fast shutter speed, low ISO, small aperture - so that any exposure using just the ambient light would be underexposed, and you need flash. Then take the same two photos using the flash. What happens?

Answer (I haven't actually tried this, so if anybody thinks I'm wrong, please say so!): They both come out grey again. The camera is now using ETTL-II metering to determine how much power to use on the flash: it fires a test flash and evakuates the results to calculate the exposure, and fires again to take the photo. But it still doesn't know that the cat is supposed to be black and the bear white, so once again the cat will be overexposed (grey instead of black) and the bear underexposed (grey instead of white). In order to get the exposures right, you need to set some Flash Exposure Compensation (FEC): negative FEC for the cat to make it black instead of grey, and positive FEC for the bear to make it white instead of grey.

Of course real-life situations aren't quite so black-and-white. (Sorry.) But my point is that, just as we expect to have to learn how to cope with the meter's limitations for "ordinary" (ambient light) photographs, we should also expect to have to learn how to cope with the limitations of ETTL-II for flash photography.

Does that make sense?

StewartR
11th of July 2007 (Wed), 06:04
The 350D aka Rebel XT also has FEC.Really? My goodness, I'm ashamed to say that I had that camera for nearly a year and I had no idea it has this feature.

How is it contolled?It's a bit clumsier than on your 30D. It's one of the menu settings, just under AEB. Check it out on the DPReview review of the 350D (http://www.dpreview.com/reviews/CanonEOS350D/page10.asp).

I imagine the reason Canon didn't enable it through one of the buttons on the camera, as on the 30D, is to keep the 350D simpler for beginners.

pigasus
11th of July 2007 (Wed), 06:19
For some reason, I am having to manually trigger (newly found :oops:) FEL button before each shot. Does this mean either camera or flash is not metering light properly and I am having to force it to re-evaluate it for flash level purpose?

You said that you were bouncing the flash. And maybe this has caused the problem. My first thought was maybe your flash isn't powerful enough. But as you are able to get a good exposure by locking on a dark area, then this would not appear to be the problem.

But why does this happen? And what can be done? With my 5D and 430FX, it doesn't matter whether I use my flash directly or bounce it. In manual mode my camera gets the exposure right. But I used to have a Nikon D200 and this camera always gave me underexposed results when I bounced the flash. Maybe your camera also operates this way.

First thing I'd do is check whether using the flash directly works as you would expect and if the problem only appears when bouncing the flash. If the problem occurs in all cases then there might be a fault in how your camera (or flash) is metering for flash. If the problem only occurs when bouncing, then it's more likely that this is just a "feature" of the camera model (or perhaps of some settings). It would be interesting to find out whether others with similar cameras also have this issue when bouncing.

So if this is a "feature" and not a fault, what can be done so that you don't have to FEL for each shot? With my D200 I used to set my flash exposure compensation to +1 to +2 when I was bouncing. You can do this on the camera or on the flash (I find it easier to do on the flash). And some experimentation should help you determine the right amount of compensation needed for a given situation.

I hope this helps a bit.

tzalman
11th of July 2007 (Wed), 07:13
Pigasus has it right, or at least partially so. E-TTL II figures the required exposure not only from the preflash reflection but also (even primarily) from the distance to the object on which the lens is focused. That is, it assumes that the distance the light will travel is equal to the focus distance. However, when you bounce the flash you invalidate that equation. The light travels a longer path, not all of it is reflected - depending on the color of the ceiling, and it is dispersed over a wider area. Although the preflash data will cause a partial compensating adjustment, the distance data will still be wrong. So a bit of FEC is neccessary.

Baadil
11th of July 2007 (Wed), 10:49
Thank you everyone for all your help. This, for sure, gives me some pointers. Do you guys think synching with second curtain might help here? I am thinking perhaps light is falling off too short for distance when bounced?

StewartR
11th of July 2007 (Wed), 11:40
Second curtain synch makes no difference. All it means is that the flash fires just before the shutter starts to close, rather than immediately after the shutter has opened. No impact on exposure.

Baadil
11th of July 2007 (Wed), 11:50
cool, thanks.