setting the flash.

[EmmaR]

So I've heard a few lines lately about setting your flash to f5.6 or f.8 etc.

How do you do this?

I have a canon speedlight 430EXII. I know how to dial it up and down, but when someone says to set the flash at a particular ap - I get confused.

Any help?

[i speak in math]

Originally Posted by EmmaR

So I've heard a few lines lately about setting your flash to f5.6 or f.8 etc.

How do you do this?

I have a canon speedlight 430EXII. I know how to dial it up and down, but when someone says to set the flash at a particular ap - I get confused.

Any help?

You can figure out for yourself how to set the flash to those levels. Put your flash and camera in manual mode and try it out.

Put your camera at ISO 100 and at your shutters sync speed (likely 1/250). Put your aperture at f/8. Now set the flash to 1/32 power and take a shot of something plain like a wall.

Read the histogram. It should be underexposed.

Crank the flash up to 1/4th or so power and take a shot again (without moving the flash or camera closer or farther away) Read the histogram. It should be a lot closer to middle grey.

Keep adjusting the flash until you get a middle grey exposure. Then remember what setting the flash it at. Once you know, you can set your flash to that setting, and your camera to f/8 and always get a perfect exposure (as long as the distance from flash to subject is the same as the test)

[Skyyton]

Are you sure they're not talking about setting your camera to those values? If you're using the TTL function of the flash, you would set the aperture on your camera. You use the aperture to control ambient light and the effective range of the flash. If you set the aperture small (ie f16) the effective range of your flash will be very small. If you set it wide open (ie f2.8), the effective range will be a lot further.

[i speak in math]

Nope. They aren't using TTL. With off camera lighting, when you set the light to f/8, that means it is bright enough to give your camera a proper exposure at ISO 100, a high enough shutter like 1/180th and f/8. Usually there is a guide on the back of the flash to help you figure out how to set it to that level. http://www.mpex.com/graphics/LP120d5.jpg

[Skyyton]

Originally Posted by i speak in math

Nope. They aren't using TTL. With off camera lighting, when you set the light to f/8, that means it is bright enough to give your camera a proper exposure at ISO 100, a high enough shutter like 1/180th and f/8. Usually there is a guide on the back of the flash to help you figure out how to set it to that level. http://www.mpex.com/graphics/LP120d5.jpg

I understand about getting the light set for off camera flash. I'm curious how you know they're using off camera flash vs on camera with TTL. I didn't see it mentioned in the post. I'm new on here and may have missed something.

[i speak in math]

Originally Posted by Skyyton

I understand about getting the light set for off camera flash. I'm curious how you know they're using off camera flash vs on camera with TTL. I didn't see it mentioned in the post. I'm new on here and may have missed something.

Any pro that is giving directions to set his/her lights to a certain ratio will not be letting the flash guess at what they want. They have a specific image in mind and they know how to set the light quickly and efficiently to get the image they are after. Using TTL would be light pointing the flashes in the general direction of the image and letting them guess what light the photographer want. How does the flash know what is in his head?

watch these Dean Collins behind the scenes clips
Strobist: Five-Minute Portrait, Dean Collins Style
Strobist: Back in The Day...

[Skyyton]

Originally Posted by i speak in math

Any pro that is giving directions to set his/her lights to a certain ratio will not be letting the flash guess at what they want. They have a specific image in mind and they know how to set the light quickly and efficiently to get the image they are after. Using TTL would be light pointing the flashes in the general direction of the image and letting them guess what light the photographer want. How does the flash know what is in his head?

watch these Dean Collins behind the scenes clips
Strobist: Five-Minute Portrait, Dean Collins Style
Strobist: Back in The Day...

I understand. I shoot in a studio and know all about lighting ratios. I'm only asking how you knew that the OP was asking about off camera flash. My original answer was just asking for clarification of the question.

[i speak in math]

Sorry, I mentioned OCF but in this case, it didn't really effect the subject matter. You could be setting the flash on or off camera. But most pro's aren't using an on camera speedlight. They are using off camera studio strobes. I just started discussing that type of shooting since you are more likely to hear them "setting" the light to a certain f stop.

[Skyyton]

Originally Posted by i speak in math

Sorry, I mentioned OCF but in this case, it didn't really effect the subject matter. You could be setting the flash on or off camera. But most pro's aren't using an on camera speedlight. They are using off camera studio strobes. I just started discussing that type of shooting since you are more likely to hear them "setting" the light to a certain f stop.

Your information is good. I just wanted to make sure I wasn't missing something since I just joined this forum this morning and didn't want to start out by making a fool out of myself. I totally agree that the very best lighting will be off camera flash using lighting ratios that you can control. There are times when TTL is the answer because off camera flash is not practical. Even then I would never point a flash at a subject unless for fill flash outdoors. Thanks for clarifying.

[Chip]

Emma - I'm by no means a flash guru, but the only time I've ever seen an aperture setting on a flash is with my wife's old Nikon (SB-10) flash. It has (basically) a circular slide rule that lets you set the "aperture" on the flash in relation to film speed and distance to subject. So, for example, if you set the flash to f5.6, then the aperture on the lens should also be set to f5.6. The "aperture" setting on the flash doesn't control the aperture on the lens - it's just a way to get the right power in the flash.

I assume that other, older flashes also have this same type of system for setting the power of the flash? And I don't think that your new Canon flash has any type of setting that will let you set the "aperture".

If this is helpful, then I just got lucky. If not, I'm sure someone will correct me.