Throwing the background with flash?

[TheNissanMan]

Is it possible to blacken a background using an off camera flash?

Was thinking of taking some shots of a flower that was given to us but it would look much better with a black bg. Is it possible to blacken a backround using the flash?

 

[Dan_H]

Yes. Kind of

Get your camera and take a picture of your background, like a wall or something. Keep adjusting your settings until the image is just black.

Then use your flash to light the flower.

Not sure if there are other ways you can do it but I'm sure someone will know if there is.

 

[MatBin]

I'm no expert but I usually expose for the foreground (flower) and ensure there's insufficient light to expose the background, usually this means moving the flower close enough to the camera/flash so the light falloff doesnt light the background. If you have a background that is close to the flower it will be almost impossible (I think) to acheive this.

Matt

 

[MadWoman]

I did a fill-in flash course (at the Cotswold Wildlife Park - long time sine we met there, Ryan) and to achieve this effect we were told to dial in the maximum amount of negative exposure compensation, then a degree of positive flash compensation. The amount comes from the LCD image NOT the histogram, and is quite easy to judge. I can't really say how but even I was guessing spot on very quickly, so it isn't complicated to estimate.

 

[TheNissanMan]

Thanks peeps will have a play this week


Madwoman, been ages since I visited CWP, tend to hang out at the hawk centre as a lot closer

 

[RJL2005]

Funnily in macro it's usually the other way around. I'd use some pretty std macro settings manual, iso100, 1/200, f16. If you're using the flash off camera then try positioning it at about 45 degrees to the subject. It should be simple to adjust the flash power to achieve well lit subject and black BG. Attaching a piece of black card to the BG side of the flash will also help keeping light where you want it.
HTH