Help? Low-light, natural light, high-speed, fill flash

[juneappal]

I am having trouble getting a particular exposure with my 20D, and I would love some help. The situation comes up when I am shooting my toddler daughter in low-light situations. I want to blur out the background, so I would like to have the lens wide open - 1.8 on my nifty-fifty. Since she moves around a bit, I want to go no slower than 125, and I would prefer 250.
Often the f/1.8, 1/250 is too dark indoors, so I would like to supplement the existing light with my flash. I don't want the flash to be the only source of light, because that often turns out harsh.
I want to be able to manually set the time and aperture, then have the camera autmatically add flash until it is well-exposed. Is that possible? If so, how?


Thanks in advance,

Adam

[blue_max]

Not an answer to your question, as I don't have a flash gun to my name, but you could increase the iso a few notches, which may be all you need to get the shot without the flash at all perhaps.

Graham

[Hellashot]

Using which camera? Go to a higher ISO.

[juneappal]

(20D)

I considered going to a higher ISO, but that frankly seems like a cop-out, and it seems like it sacrifices picture quality (unnecessarily, since I have additional light available)
Is there some technical reason why what I am after isn't possible?

-Adam

[slin100]

Don't be afraid to use the higher ISOs on a 20D. You give up very little in the way of picture quality. But, frankly, 1/250 @ f/1.8 is not going let in much ambient light indoors. You'll also have to worry about mixed lighting sources (flash and tungsten/flourescents) unless you color-correct the flash with a gel.

Personally, I use bounce flash whenever possible, indoors, and give up on ambient lighting.

[Nessus]

I have found the flash on both the 20D and 1DMk II (with the 580EX) a bit confusing also. When I try indoor, low light shots, others on this site have explained that the extreme underexposure is because the camera is setting the speed/aperture based on the available light, and the flash is acting as a fill flash and is not a significant light source. The suggestion, which has worked for me, is to set the camera to manual in your case, 250th @ ~2.0 or 2.8) and let the flash determine the amount of light necessary. Otherwise, you will have to increase the ambient and let the flash be a fill flash in t or A modes.

Adam

[robertwgross]

I would suggest to go with an external flash unit, and put a soft box on it to diffuse the light. Ideally, the size of the soft box would be roughly the same size as the subject. Then crank the flash intensity down to -1 or -2.

If you don't have a soft box, you can rig up something with stiff wire and about one square foot of thin white cotton fabic, such as a man's handkerchief. Place the fabric diffuser a couple of inches or more in front of the external flash unit.

If that works for you, then you can purchase a proper soft box for future photography. I use a Lumiquest soft box that fits my flash unit perfectly.

---Bob Gross---

[cecilc]

(20D)I considered going to a higher ISO, but that frankly seems like a cop-out, ...

I don't know how you've "developed" (a little photo pun, there ...) that outlook, but it's just not right ....

And particularly on the 20D, high ISO (and I'm talking 1600 here) is not a death sentence for your shots. The 20D handles high ISO really nicely. And if your shots are properly exposed at 1600, then the "noise" is minimal - it's only on underexposed shots that the noise is going to be very visible.

As far as fill flash goes: if you're using the on-board flash, the only thing you can try is to use flash exposure compensation to try to knock the flash intensity down somewhat (I've never tried it, so I'm guessing here). If you're using an external flash, set your camera and flash in manual mode (1/250 at f1.8 or 2.0 or 2.8 ...) and manually dial down the flash to 1/4, 1/8, 1/16 power or so until you find an exposure that gets you what you're looking for.

And Bob's advice regarding a soft-box is right-on, too ....

Hope that helps ...

[BrandonSi]

diffuse the flash (soft box, as someone mentioned) or depending on your flash (and your ceilings, I suppose) you can bounce it. Personally, I'd go ISO 1600 and just shoot in RAW, and crank up the exposure in your post process, neat image/noise ninja for noise if necesssary.

[yenoram]

I agree with previous posters who've suggested increasing ISO - try it, you'll probably be surprised at the quality of a properly exposed shot. I would also add, reduce your shutter speed to 1/125 (or even lower depending on the speed and direction your subject moves) and make use of second-sync (either by adjusting your camera or flash)

[tim]

If you use a flash the light comes from straight on, which eliminates shadows. Shadows give a subject their depth. ISO800 is reasonably clean, especially if you use noise reduction software, and I use up to 1600 given I have noise ninja.

If you use a flash, just put the camera in M, set your aperture to what you like, the shutter speed to 1/250th, and play with the FEC between -2 and 0, the flash will automagically expose the subject correctly.

[Salleke]

I don't know how you've "developed" (a little photo pun, there ...) that outlook, but it's just not right ....

And particularly on the 20D, high ISO (and I'm talking 1600 here) is not a death sentence for your shots. The 20D handles high ISO really nicely. And if your shots are properly exposed at 1600, then the "noise" is minimal - it's only on underexposed shots that the noise is going to be very visible.

As far as fill flash goes: if you're using the on-board flash, the only thing you can try is to use flash exposure compensation to try to knock the flash intensity down somewhat (I've never tried it, so I'm guessing here). If you're using an external flash, set your camera and flash in manual mode (1/250 at f1.8 or 2.0 or 2.8 ...) and manually dial down the flash to 1/4, 1/8, 1/16 power or so until you find an exposure that gets you what you're looking for.

And Bob's advice regarding a soft-box is right-on, too ....

Hope that helps ...

Many times other members have told us to set only the camera in Manual mode and the external flash in auto mode and then dial down your flash output.
So now I am confused here. Can someone clearify this please?

[robertwgross]

Many times other members have told us to set only the camera in Manual mode and the external flash in auto mode and then dial down your flash output.
So now I am confused here. Can someone clearify this please?

Many members have opinions for what works best for them. Try each opinion for yourself and see which way you prefer. Different results will come from different combinations of camera, lens, flash, and subject.

There is no single solution for all flash photography.

---Bob Gross---

[cecilc]

... set only the camera in Manual mode and the external flash in auto mode and then dial down your flash output.
So now I am confused here. Can someone clearify this please?
There is no single solution for all flash photography.

---Bob Gross---

Bob's right ... you're right ... I'm right ..... ;)

Setting the camera and flash in manual mode and dialing down the flash output as a power ratio (1/2, 1/4, 1/8, etc) works for me .....

But setting the camera in manual mode and the flash in auto mode and dialing down the flash output in stops (-1/3, -2/3, -1, etc.) works, too .....

The common step in that, though, is getting the flash's output down to the point that it's just enough light to "fill in" rather than be the sole light source.

[sadanorakman]

Hi Guys, New to this forum, but I've had a 20D since last november.

I Keep a Sigma 18-50 F2.8 fitted most of the time, and on occasion a Tamron XDi 28-75 F2.8. (other than my 80-400 IS). These two lenses have given me some great portraits at or towards their maximum zooms (80mm and 120mm 35mm equivalents) at 2.8.

I have had some nice results in pretty appaling light with no flash, just by lifting the ISO. I was terrified of doing this at first expecting very 'grainy' results, but the 20D really does give low noise images.

My advice... just push the ISO to 800 and snap away. The results of the available natural light are so much nicer on the skin tones of a subjects face than all sorts of complex flash trickery that takes ages to set up. ... Your daughter would be bored within seconds if you were trying to get the flash set-up just right. You'll get more natural behaviour from her by just snapping.

Craig