Possibly stupid flash question...

[mai_lin]

I actually haven't had a problem with this yet but am wondering when my 'luck will run out'.

Scenario: Taking portraits indoors with a 28mm prime, ISO 400, 1/5 ss would be correct exposure but as its a smaller number than the focal length, I need it faster... so I add camera mounted flash E-TTL. Bump the ss up to 1/30 and let the flash figure out what it needs. Great pic.

New twist: fast moving subject (such as my 3 year old who thinks spinning around is just so much fun) - suddenly 1/30 isn't really cutting it so I bump up to 1/60 and let the flash handle its job. Great pic. (BTW both subjects are 5 - 10 feet away)

At what point will the flash not be able to handle its job? I know I can only go up to 1/200 but at some point its not going to be perfectly lit - right? What are the limitations of ETTL.

All of this is the result of me messing around in manual mode on my flash and am trying to figure out when I would actually use it camera mounted?



Jen D.

[Titus213]

Your 430EX has high speed sync so you can go to the max on your camera. Range drastically reduced.

I would move the ISO up. If you are properly lit, and the flash should insure that, you don't have to be too concerned with noise.

[Naturalist]

Set your camera to Tv mode.
Add flash.
Adjust aperture so it is good exposure and fire away.

[mai_lin]

Would going to the max be taxing on the flash unit itself (batteries aside)? I get a bit worried about doing too much with my 430ex because I'm afraid I'll burn it out... irrational thought probably but I'm more worried about breaking my flash than I am my lenses most days :oops:


Jen D.

[mai_lin]

Set your camera to Tv mode.
Add flash.
Adjust aperture so it is good exposure and fire away.


oh what's the fun in that? :p

I'm so stuck on manual - I've never shot in Tv or Av mode. I don't even know what they do. I went from green box to P to manual...

[WillMass]

That's kind of like being afraid to drive your car because it'll use all the gas. OK, that's a bad example. :D

You're not going to hurt the flash.

And really, even if you did.... what are those irreplaceable photos of your 3 year old worth to you? Amortize the cost of the flash over it's life and you'll see those treasured photos will only cost you pennies.

[Titus213]

Would going to the max be taxing on the flash unit itself (batteries aside)? I get a bit worried about doing too much with my 430ex because I'm afraid I'll burn it out... irrational thought probably but I'm more worried about breaking my flash than I am my lenses most days :oops:


Jen D.

No, your flash will be damaged more by rapid, continuous firing without letting it cool. Certainly high speed flash might put more strain on it but it's a tool so use it when you have to.:D

oh what's the fun in that? :p

I'm so stuck on manual - I've never shot in Tv or Av mode. I don't even know what they do. I went from green box to P to manual...

Good for you!

[JeffreyG]

Would going to the max be taxing on the flash unit itself (batteries aside)? I get a bit worried about doing too much with my 430ex because I'm afraid I'll burn it out... irrational thought probably but I'm more worried about breaking my flash than I am my lenses most days :oops:


Jen D.

One piece of information that you are missing is that so long as you are at the max synch speed or below the shutter speed does not affect the flash at all. In E-TTL mode the flash will fire at the same power whether you are at 1/30, 1/60 or 1/200. It simply doesn't matter.

The only things that affect the flash (for a given scene) are the aperture you select and the ISO.

[msowsun]

Set your camera to Tv mode.
Add flash.
Adjust aperture so it is good exposure and fire away.

How do you adjust your aperture in Tv mode?

If you set your camera to Tv mode, you have control of the shutter, but you lose control over aperture. The camera will always select to aperture that will properly expose with only the ambient light. It disregards the fact that a flash is connected.

Tv when used with a flash usually means wide open apertures like f/2.8 or f/4

I find Manual mode is best for flash. Even for fill flash.

[40Dude6aedyk]

At what point will the flash not be able to handle its job? I know I can only go up to 1/200 but at some point its not going to be perfectly lit - right? What are the limitations of ETTL.



I like the way you have experimented, so keep on experimenting. The point where the flash can't handle its job is when your pictures come out underexposed as you wrote.

The most output that the flash can produce is essentially a full dump of the electrons stored in the fully-charged capacitor through the flash tube. Since it takes time to recharge the capacitor, you have a built-in safety system if you wil that makes it hard to hurt your flash. But the discharge will also heat your flash, so the speedlite has circuitry that prevents it from firing if it is overheated. I'm not sure what your manual states, but a re-read can be helpful.

With camera in manual mode and a fixed aperture, the flash is probably going to fire the same duration whether your shutter speed is 1/250, 1/200, ... or 1/60th. Now that you like manual mode on the camera, you can try manual mode on the flash. This can give you an idea of what ETTL is doing for you. For example, take a flash picture in ETTL mode. Now do the same flash picture in manual flash mode. What manual flash setting (1/4, 1/32, ....) is needed to get the same exposure? You can then surmise situations when a 1/1 output might be used by ETTL.

[mai_lin]

With camera in manual mode and a fixed aperture, the flash is probably going to fire the same duration whether your shutter speed is 1/250, 1/200, ... or 1/60th. Now that you like manual mode on the camera, you can try manual mode on the flash. This can give you an idea of what ETTL is doing for you. For example, take a flash picture in ETTL mode. Now do the same flash picture in manual flash mode. What manual flash setting (1/4, 1/32, ....) is needed to get the same exposure? You can then surmise situations when a 1/1 output might be used by ETTL.

Does the exif information store what output the flash fired at? That would be really helpful but as far as I know it only stores if it fired or not.

I've actually been having alot of fun with manual mode on my flash as of late - it's really helped me learn actually... annoyed my husband to no end though :lol: (he's my model when testing as he won't fidget like my kids). I still don't think using on camera flash in manual mode will be very useful for me anytime soon. Perhaps in a few years when I have a better eye for the flash output needed for a given scene I can set manual - but for now ETTL should be able to figure it out.

Now, taking it off camera is a totally different story. I've been renting a studio for a few months and have learned alot about lighting and know exactly how I'd use my flash in manual mode off camera... in an array with other flashes probably.

Any other use for on camera flash in manual rather than ETTL?


Jen D.

[40Dude6aedyk]

Does the exif information store what output the flash fired at? That would be really helpful but as far as I know it only stores if it fired or not.Not that I know of.

.... I still don't think using on camera flash in manual mode will be very useful for me anytime soon. Perhaps in a few years when I have a better eye for the flash output needed for a given scene I can set manual - but for now ETTL should be able to figure it out.I use ETTL all the time with my "people" photos at parties, meetings and conferances .

Any other use for on camera flash in manual rather than ETTL? I use manual flash for sports photography both on- and off-camera.