20D/420ex flash

[sheffieldbloke]

Hi, first posting,very useful forum.

I know this has probably been done to death..........but.......the more i delve into the internet the more confused i get.......the problem is underexposure using the 420ex, usually shoot in p mode and the camera reads 60th at f4,but all shots taken in a vaugly dark room are always underexposed....read conflicting opinions,some people say the 20d has a leaning towards overexposure with flash........where am i going wrong? got two 20ds they both expose on the dark side,understand that turning the fec up will help,but Why?
is there a problem with the canon flash? Surely if i "stick " the camera in p and shoot the ,exposure should be near enough spot on!

Tried both cameras on manual slightly better results,in as much as i get some background detail.

The work i do is reportage style,so i need a setting that will suit an average environment,because its often the case of shooting the subject without worrying about the camera(obviously need to change settings outdoors in daylight) think iam going to resort to shooting on p,flash up 1stop and camera set on 1600,does anybody have any thoughts on this?

My main gripe is..a camera set on programme with a dedicated flash should take a decent picture....why do i have to crank up the fec to get a decent exposure!? are all canons d's like this? (my two are )

[NickyBlade]

I have the 20D with 420ex flash... if I'm shooting indoors just snapshots and don't feel like thinking about what I'm doing my settings are

ISO 100
set the camera to M
1/125 and f5.6

I get really good results with this combo... so I've just stuck with it.

[OceanRider]

Well I hear ya man! Mine is the EXACT same. I have to pump up the FEC +1 on all indoor shots on "P" or its underexposed in both evaluative and partial metering. For the life of me I don't know why. Surley Canon could better expose on "P" at "0" FEC!

[sheffieldbloke]

I have the 20D with 420ex flash... if I'm shooting indoors just snapshots and don't feel like thinking about what I'm doing my settings are

ISO 100
set the camera to M
1/125 and f5.6

I get really good results with this combo... so I've just stuck with it.

Thats really bizarre!!!.... if i was to shoot at those settings i would be lucky to get anything at all it struggles at a 60th.........wonder why all the different combos?

[sheffieldbloke]

Well I hear ya man! Mine is the EXACT same. I have to pump up the FEC +1 on all indoor shots on "P" or its underexposed in both evaluative and partial metering. For the life of me I don't know why. Surley Canon could better expose on "P" at "0" FEC!

Frustrating as it is i'm glad you have the same problem,if you know what i mean .........it drives me crazy......hate it when something doesn't work as it should!!

[tim]

Inside rooms are often made up of a lot of white. This is where knowing the theory of how metering works comes in handy (ie the 18% grey rule). The long and the short of it is if there's a lot of white in the scene you need to use positive compensation - if you're using a flash use FEC, if not use EC. If there's a lot of black or dark colors in the scene you need to use negative compensation. There's a good book called "understanding exposure" which will be able to explain it better than I can.

[OceanRider]

yes Tim I agree, good advice. I shot a dark dog the other day and forgot to use negative EC, and it blew him out. (The camera tried to make him lighter)

MUST.....RE....MEM....BBBB......ER

[NickyBlade]

Here's an example... have you tried on M mode? I'm no flash expert, but my camera and flash seem to comunicate and I get decent results. Looking back through old shots, I've used f4-f7 and shutter speeds between 1/60 and 1/160 in various combinations with really good results. Hmmm....

[PacAce]

Thats really bizarre!!!.... if i was to shoot at those settings i would be lucky to get anything at all it struggles at a 60th.........wonder why all the different combos?
When using flash as your main source of lighting, it really doesn't matter what shutter speed you use as long as it's at or below the max sync speed. The reason why is because the duration of the flash is much shorter than the length of time the shutters stay open even at the fastest sync speed.

On the other hand, the aperture you select will affect the maximum working distance of your flash. The smaller the aperture, the shorter your working distance becomes.

[scottbergerphoto]

To add to what Leo said, when using flash, the shutter speed regulates how much of the ambient room light is recorded in the image not the flash light. In P mode, the camera programming doesn't allow the shutter speed to drop below 1/60 to prevent blurry images from the recorded ambient light and camera motion.

When you work in a small room, the light reflected back to the camera from the walls, reduces the flash output, especially if the walls are white.