Flash!., Bang! What a crap picture!

[candidrachel]

Ugh! I went to my daughters school Royal Wedding Disco yesterday and thought I'd practice my photography but almost all my shots came out REALLY blurred . Luckily the school haven't asked for any photos this time but if they do I shall just explain that this time I was practicing some new technique for my own personal use (my get out of jail free card).

I thought flash is supposed to "freeze" motion. I didn't want to use too much flash as then you lose the disco light and atmosphere!

Here is an example of what I mean (straight out of camera no editing apart from changing to jpeg):


ISO 1600
f4.0
Aperture Priority
speed 1/4 sec
flash fired -3 high speed sync

The second photo you see has accidentally been taken on P mode the shutter speed (again straight out of camera) automatically sets itself at a much faster speed to ensure no camera shake or motion blur. How can I get the same effect with AP?

ISO 1600
f4.0
1/60
Flash fired high speed sync.

[LeeR]

Somewhere in the settings you should be able to tell your camera the normal shutter speed for flash photography, and the best speed will depend a bit on which camera you have. Back in the film days most cameras were set to 1/60th of a second, but nowadays most cameras operate faster, 1/125th or faster. You should be able to find this in your manual somewhere. (You have read the manual, haven't you?)
Now that you have made this mistake, keep it in your back pocket. I often use this technique when shooting people dancing to get the effect of movement. I have found that a shutter speed a bit faster than 1/4 of a second works better; I usually go around 1/15th of 1/30th. Also, you may find your camera gives you a choice of when the flash goes off. Set it one way and the flash fires first and the shutter lags behind, with the other setting the shutter opens first and the flash fires at the end. I tend to prefer the latter, but try them both and see which you like best.

[Rentham]

Originally Posted by candidrachel

How can I get the same effect with AP?

The automatic modes are always going to take at least some of the decision out of your hands. Try shooting in manual mode and dial your FEC up or down as needed.

[Niresangwa]

Use manual, and try using rear-curtain sync with your SS set to approx 0.3 sex ...the flash will freeze the objects but by dragging the shutter you'll soak up some ambient. You might have to fiddle with the flash power, but its quick to settle in...

...if you're using a zoom you can do some neat stuff with this technique by zooming the lens during the exposure. You have to brace yourself and be steady, but any shake kind of adds a dynamic element to the image.

[RichardTaylor]

@ candidrachel

What camera are you using? I am only familiar with Canon cameras.

If you are shooting with a Canon camera as soon as you put the camera into Av mode the camera will try to set the shutter speed for a correct exposure using the ambient lighting.

See your camera manual under Av

If you attach a flash the camera will still do the same setting a shutter speed (for a Canon 40D) between 30 seconds and 1/250 (Max synch speed for a Canon 40D).
In low light the main subject is exposed with the flash and the background is exposed with the slow shutter speed.

You may be able to set your shutter speed to maximum synch speed by using a custom function.
This may solve you problem of using Av and getting similar (not the same) results as using P

See your camera manual, must likely under "using the built in flash".

In P mode the camera will not shot below 1/60 second and above 1/250 seconds (for a Canon 40D)

The camera manual also explains this. It also suggests using a tripod at slower shutter speeds.

When actually shooting your viewfinder indication of the slow shutter speed should ring alarm bells that camera shake (and possibly subject motion) may be a problem.

[candidrachel]

Sorry it's taken in a little while to reply (still blown away about the Royal Wedding). Thank you for your advice. I have read my manual many times but it's just rubbish and doesn't give ENOUGH information. Its actually falling apart now so I have to stick the pages together with tape. That's now much I've read it....

I think from now on I am going to have to go Manual like it's been suggested. I got too frustrated in AV mode. Richard, I was using a Canon 550D. I didn't want to drag a tripod around the hall floor. I wanted to get in amongs the action.

I really wanted that "dragging the shutter" effect with the nice ambient background but frozen foreground. I thought I could do that in AV but I think using manual mode would give me more leeway.

It was a great learning experience and with all your lovely feedback it only gives me more tools and lessons learn for "next time".

Thank you for taking the time to reply!

[BexJarratt]

I've seen that there are manuals ( additional to the instruction manual provided) written by third parties ( such as ...for dummies) for a vast number of the major camera models now. I've not used one because they've not done one for my camera. I don't know if they're any good or if they're a bit too basic, or whether they do cover this kind of detail.

[Tiberius]

Originally Posted by Niresangwa

Use manual, and try using rear-curtain sync with your SS set to approx 0.3 sex ...the flash will freeze the objects but by dragging the shutter you'll soak up some ambient.

You don't need second curtain flash to soak up ambient light. Using first curtain will get just as much ambient light as second.

What second curtain flash does is fire the flash at the END of the exposure instead of the beginning. This makes any blur caused by movement to appear behind the subject rather than in front of it, creating a more natural look (so people don't look like they are dancing backwards).

[Niresangwa]

Originally Posted by Tiberius

You don't need second curtain flash to soak up ambient light. Using first curtain will get just as much ambient light as second.

What second curtain flash does is fire the flash at the END of the exposure instead of the beginning. This makes any blur caused by movement to appear behind the subject rather than in front of it, creating a more natural look (so people don't look like they are dancing backwards).

Normally I'd agree but for a couple of things...

when it's a dancefloor shot youre trying to get front/rear won't matter relative to 'dancing backwards'... people are generally standing in one spot waving their arms randomly... we're not trying to get light trails on a car or anything...

secondly, my own experience has shown rear curtain to produce a 'better' and more dynamic result in combination with zooming over and extended exposure. The bigger determinant of how successful the shot is for her is a matter of taste, and attenuating the aperture/flash power vs finding a controllable SS for the specific environment.

[sk66]

The main issue I see between the two (exif's) is that when you were in Av the flash EC was set to -3.
In A(Av)/S(Tv) the camera sets the flash as "fill" to balance with the ambient light levels. In aperture mode it sets exposure time for "correct exposure" based upon size of aperture. To override this you need to add flash EC.

I don't think the flash will automatically set itself w/ a minus EC..maybe you did it? And why ISO 1600? The camera should have defaulted to your minimum ISO set.

If "dragging the shutter" I always use rear curtain as a default.