Dropping Ambient light compared to flash light

subseasniper

subseasniper

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Hey all.

I am awaiting delivery of a Canon Speedlite 430 EXII and, being a complete greenhorn when it comes to Speedlites, have a quick question.

I like to try and drop ambient light levels in my shots by one or two stops (as per Strobist's recommendations) and was wondering if I am shooting with the 430 EX either on camera or an off-camera cord, do I just dial in -1 or -2 ev when shooting in aperture priority mode to drop the ambient light levels?

Or, will this affect the flash lit portion of the picture?

Cheers.
 
Not done a great deal in this but im learning shoot in manual and your shutter speed will change the ambient light and ** aperture will change the flash light. i.e if u put ** aperture on 4.5 and ** subject is over exposed drop down a stop or 2. same with shutter speed if u shoot with shutter speed 200 you will pritty much knock most ambient light out s drop that down to 100 and its a bit better. im no expert and i might be totaly off track here but hope it helps
 
I hear you. TBH I never use Exposure comp on my 40D. I'm assuming that if I am shooting in AV mode then the only change the camera makes when I dial in exposure comp is to the shutter speed.

I thought that if I had my flash attached and dialled in say -1ev the camera would adjust the shutter speed appropriately whilst keeping the flash at the right intensity for the subject. Maybe not, I don't know but can't wait to get the flash to have a play.
 
Shoot in manual mode. Take a shot without flash - change the shutter speed to underexpose the scene by 1,5 - 2 stops - depends on the exact effect you want - take another shot withouot flash to check. Now shoot with the flash - the flash will expose for the aperture you have chosen - provided it is within range - shutter will control the ambient light.

If you are using fill flash - i.e. where you want the ambient light to be the main source and the flasha fill to reduce contrast for example - you will often have to dial in a minus on the flash to reduce the level of the flash output without affecting the overall scene. For outdoor fill in flash I usually use -1 - -1.7 compensation on the flash - otherwise the flash can be overpowering but it all depends on the subject, the working distance and the conditions. PRACTICE!
 
awp said:
Shoot in manual mode. Take a shot without flash - change the shutter speed to underexpose the scene by 1,5 - 2 stops - depends on the exact effect you want - take another shot withouot flash to check. Now shoot with the flash - the flash will expose for the aperture you have chosen - provided it is within range - shutter will control the ambient light.

If you are using fill flash - i.e. where you want the ambient light to be the main source and the flasha fill to reduce contrast for example - you will often have to dial in a minus on the flash to reduce the level of the flash output without affecting the overall scene. For outdoor fill in flash I usually use -1 - -1.7 compensation on the flash - otherwise the flash can be overpowering but it all depends on the subject, the working distance and the conditions. PRACTICE!
Click to expand...

Nice one, I've got it locked into my brain now. Cheers.
 
Canon flash systems have the ability to balance flash and ambient exposure. On the back of the camera is the * button. With the flash attached ( and switched on) select the exposure method you want , Tv Av. Make sure the exposure time is slower than the sync speed. Then press the * button. This will cause the flash to pre fire, and the camera will calculate the exposure accordingly. However this will simply balance the camera exposure and the flash.

Now you may need to reduce the exposure from the flash to get the lighting ratio as you like it, but you can dial this in either via the camera or flash.

A little bit of practice and you'll come up with settings that will do you most of the time
 
You want to balance ambient and flash so that the flash is the dominant light source.

Set the camera to -ve EV comp and leave the flash alone. JOb done. The camera will underexpose the AMBIENT by how much you dial in, and the flash will be "correct" - although it probably won't be, it will probably be a bit too bright. You may have to adjust your flash down 1/3 or so too.
 
You're better shooting manual camera and manual flash in these situations in my opinion rather than leaving anything to the camera to decide what it thinks is best.
 
i get that now, i just didnt recognise the way it was written! silly me.. carry on..:LOL:
 
Here is what I did.

Get a sheet of paper and write down all possible configurations of exposre mode/camera exp comp and flash comp

eg
MODE/EV/Flash EV
P/0/0
P/-1/0
P/-2/0
P/-3/0
P/0/-1
...
...
...
M/-3/0
M/-3/-1
M/-3/-2
M/-3/-3

Once you have this, go outside with willing partner/wife/girlfriend etc and take a shot at each setting in the order that they are on the sheet. This sounds time consuming but once you get into it, it doesn't take too long (15 mins or so). My wife sat in the garden reading a magazine, it doesn't matter the composition is not important. If you want to do it properly you could do the whole lot with sun behind and in front. I then uploaded to computer and added the settings as keywords in Lightroom. You can then see what each combination does. On mine the best was about -2 on the camera and -1 on the flash in Av mode on an overcast day.

I did this and then went to photograph a christening intending to take photos outside. When I got there it rained heavily all day and I had to take all the photos inside the church which screwed up my plan completely
 
Cheers guys, this is pretty indepth stuff. I got the flash today and had a very brief play with the flash. I am pretty impressed, I set the camera to manual, exposed for ambient then increased the shutter speed until the ambient was -2ev. I then left the flash to its own devices (ettl) and took a couple of pics of my daughter. It came out pretty much as I had hoped, the on camera flash is a little bit in your face but the flash output balance pretty well with the ambient and seemed to make the subject 'pop' as they say.

I was doubly impressed by the fact that my daughter had on a white top and there was no blown highlights with the flash. Next step is to hit Ebay for a cheap off-camera cord then get the flash off axis for prettier light.

I am amazed at how flash has come, my previous flash was a throwback Centon model from 19 canteen that basically involved guesswork. We are pretty lucky nowadays.
 
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