Flash HELP

[gwendolyn_white]

Out of all the things I have been able to figure out on my own, flash is something I never understood.

Whenever I stick my Speedlite 580EX on my Canon... I'm not sure what to do. With my Digital camera I can

test out different exposures to make sure they're decent, but I'm trying to figure out how to use it with my

film camera (Canon EOS Elan 7NE). I've been back and forth between both manuals and they -- quick

frankly -- don't tell me shiat.

<br><br>

What I don't understand about flash is that whenever I stick it on, my camera meter has the exact same

(blinking) exposure that it has without the flash on. Now, is this flash not suppose to sync with my

camera? How on earth (more like <i>why</i>) would my camera's meter still be metering as if there is no

light when I now have a flash on it that should be giving enough light for me to take pictures?!

<br><br>

I want to shoot some things at night but I don't want to screw up my exposure because I have no idea how

to read my camera with my flash attached. I'll try and give a more specific example so this makes sense:

My camera's meter is telling me for a proper exposure I need to set my shutter speed to 4" and aperture to

F2.8. When I stick my flash on, it <i>still</i> says I have to be at 4" and F2.8, even though the flash is

now giving me more than enough light to shoot the subject. Why is that? Shouldn't my camera's meter

adjust to the flash being put on it? I would assume that my camera -- with the flash attached -- would

now give me a much faster shutter speed and, basically, more options since I'll have enough light once I

shoot, but it doesn't do this. Why?

<br><br>

Any useful information about this would be so greatly appreciated. I have a raging headache from going

round and round with these dumb manuals! I know how to set all my settings but I just don't understand

the way my flash 'syncs' with my camera.

[jimstrutz]

Start reading here: http://photonotes.org/articles/eos-flash/

 

But the quick answer to your question is that in TV and AV modes the camera considers flash to be used something like fill flash. And it meters ambient lighting the same with or without flash. P mode does something different though. P mode does not allow the shutter to drop below 1/60, and usually selects f/4 when used indoors.

 

The best, and easiest, thing you can do with flash is to set your camera to the M mode and ignore the meter. (Ambient and flash both meter completely separate on a Canon EOS.) Just let the flash provide enough light and meter itself. If indoors in normal low light, set the shutter to 1/30 or so, and the aperture to f/4 or even wide open if you want.

 

But do read through that link a few times to make sure you know what flash is all about on a Canon. You will need to figure out when to use Flash Exposure Compensation.

[gwendolyn_white]

I always have my camera set to M because I like to control both my shutter speed and

aperture. However, I did set it to my other settings just to see if they 'synced' better with

my camera, and I did notice the change you speak of (it set my shutter speed to 1/60 and

my aperture was around F4) but I still did not understand why it was not syncing when in

M mode. What you said about them metering separately makes sense though -- it's what

I've been experiencing; I just thought they were <i>suppose</i> to sync.

<br><br>

Now my only question is, if I'm ignoring my meter on my camera, what should I do? I plan

on shooting some things outdoors at night so I'm sure the shutter speed would be

different compared to indoors in low light.

<br><br>

I could just mess around with it but as I said, since I'm using film, I don't want to

completely ruin a roll of film simply because I greatly underexposed or overexposed. Do

you think a spot meter would do any good? I do have one of those that I use when

outdoors during the day, but I never figured out how to use it with a flash -- in fact I'm

not even sure it can be used with a flash.

<br><br>

Thank you very much for helping me here. I'm going to go and read through that page you

linked me to.

[jimstrutz]

<I>"...if I'm ignoring my meter on my camera, what should I do? I plan on shooting some things outdoors at night..."</I>

<P>

If you plan on having the flash provide all the light, it doesn't matter what you set the shutter to within reason. When flash is the only light source, all the exposure takes place in less than 1/1000 second. So setting the shutter to 1/10 or 1/100 makes no difference. There is an exception to this rule by using the flash in FP mode (high speed sync), but I won't get into that here.

<P>

There are a couple things to remember though. First the flash (if used normally) can only be used at your camera's top sync speed (I think 1/125 on the Elan 7) or slower. The reason for that is both shutter curtains have to be completely open at the same time, and faster than 1/125 the exposure is made by varying the width of the slit between the curtains.

<P>

The second issue is that if the shutter speed gets so slow that the ambient lighting starts to seriously effect the exposure you will get streaking from moving objects, and the exposure won't be controlled completely by the flash. Sometimes you actually want this, but you should be aware of what to expect. In fact, I suggest 1/30 as a better shutter speed than the 1/60 of P mode because it often picks up some of the ambient lighting in a dimly lit room, and I think that effect is good.

<P>

Anyway, you can use the same 1/30 second indoors with low light and outdoors with no light, but you don't have to. Keep in mind that any flash has a very limited range that is affected by its power, the film speed, and the lens aperture. Outdoors, you can easily get past the distance your flash can light up.

<P>

The other way to use flash is to use a shutter slow enough to get nearly a full exposure without flash (like the shutter speed your camera recommends in M, TV and AV modes), and then use flash just for a little fill. You will likely need to set the camera on a tripod and tell everyone not to move for a while, but it makes for nice images. You probably ought to use -1 FEC for this though.

<P>

A spot meter can be used with flash, but it seldom is. Generally, it's not needed, or even useful. Also many spot meters will not measure flash. Using an incident meter (as opposed to reflected metering) is more common with flash. However, the Canon 580EX will fire a metering pre-flash in E-TTL mode, and this will ruin any reading from an external flash meter, so I wouldn't bother with it.

[ralph_jensen]

Not much to add to Jim's insights, except to say that if I was shooting film, I'd do the same thing I do when I want to make sure I get the shot in digital: I'd shoot in "P" Mode, not in M, Av, or Tv. After I have the shot, I often experiment with other modes (on camera and on flash), but nothing is safer than "P" on the camera and "ETTL" on the flash.

[awindsor]

Gwendolyn,

 

Jim has given excellent answers to your original question.

 

What are you planning on photographing at night? The cameras meter is not very useful in very low light.

 

Depending on what you are interested in you might want to look at the following links:

 

http://gorillasites.blogspot.com/

 

http://www.thenocturnes.com/