Shooting in the dark with flash

Richard

I was out the last couple of nights shooting the Easter processions in Madrid. There was not enough light to get a reasonable shutter speed using fill flash, so I set my 20D to manual, ISO 1600, 1/100 sec and f/4, hoping that the 580EX would figure out the rest. I got mixed results--some shots looked excessively "flashy," others weren't bad. Not surprisingly, they all had quite a bit of noise. In thinking about it, I started wondering whether I could just as easily have used a lower ISO to reduce the noise. Presumably, the flash would have just put out more power, right? So what would have happened if I had set the ISO to, say, 200? Would that have reduced the noise? :scratch

Thanks,

pathfinder

If the flash has adequate power, using a lower ISO, say ISO 200, will definitely decrease noise, but will also reduce the ambient light captured in this situation, and the shot will look even more like direct flash I suspect, Richard. If the flash runs out of power ( not battery power, but light intensity ) then you risk under-exposure and your recycle times will be much longer. You might have tried a few shots at ISO 800 and ISO 400, to see how they compared. They would have a lower noise threshold, but still capture the ambient lighting as well.

Were the exposures accurate, or were they under-exposed? The noise was mostly in the shadows? With lots of shadows with noise, set your black point higher to push som eof the noise to black, it was dark out after all

Shooting out of doors you frequently have to give up good reflectors, like walls and ceilings that help produce a softer quality of light. Did you try bouncing the flash off a white wall, for a soft window effect?

Richard

Thanks, Jim, for clarifying the trade-offs. There were thousands of people lining both sides of the procession route, so I couldn't be too picky about having a wall to bounce off of nearby. I haven't processed any of the pics yet, but here's a sample, just converted from RAW to JPG, no other processing:



Here's a 100% crop:



I think the exposure isn't too bad--I didn't particularly want much of the background to show--but the noise is evident.

I didn't think to try other ISOs at the time. I always do my best thinking after the fact, when it's too late.

Cheers,

pathfinder

Call me a cock-eyed optimist, but I think this is a pretty good result, Richard, given that you were shooting in the dark. I don't know what size prints you are planning to print, but I doubt the noise will be nearly as visible on paper. In the close up, much of the noise looks to be in the red channel ( brown being a red tone too ) - NoiseWear, Neat Image or Noise Ninja will dial it back. If it is only the Red channel - a little blurring on the a channel in LAB might be enough.

With the main subject separated that far forward from the crowd, there is no way a single flash is going to be able to illuminate the foreground and the background in a similar manner. If you had used a lower ISO, the crowd in the background would have been even darker. ISO 3200 MIGHT have captured a little more of the ambient lit crowd in the background, or you could have lowered your shutter speed to 1/50th if you dared.

Maybe I am not critical enough with the small image I see on the web, but I think the close up of the cross is pretty good given that you were shooting in the dark.

Richard

I think with some processing, the pics will be OK, and I'm not unhappy with the results given the difficult conditions. The subjects were moving, if slowly, so I didn't want to lower the shutter speed. I still have a lot to learn about flash, though, as I don't use it much. I'm just trying to grasp how to analyze things properly. I think I learned a few things from this shoot.

Thanks again for your clear explanations.

joshhuntnm

Given the difficulty of the situation, i think you did great.

Does anyone now how much the newer chip -- 40D does with noise?

ziggy53

joshhuntnm wrote:

Given the difficulty of the situation, i think you did great.

Does anyone now how much the newer chip -- 40D does with noise?

I have the Canon 40D and the general consensus is that, compared to the 20D/30D, the 40D has a bit more noise at high-ISO with high-ISO noise reduction turned off. With the H-ISO noise reduction on, the noise is about the same or maybe a little less.

While H-ISO noise reduction appears to have no impact on continuous shooting speeds, it does reduce the shot buffer considerably.

rwells

I'm with Pathfinder here,

I think you and the 580EX did a good job. The flash did not over-expose the white gloves, and this would've be tough with them being so small (percentage wise) in the overall picture.

A little noise reduction, and I'd say your good to go

Richard

Thanks guys. I finished processing the first set. Here's the final version of the original I posted above:



All in all, I am happy with the results, though the processing was sometimes laborious. I posted a few more pics in this thread in case anyone is interested.

joshhuntnm

very nice!

pathfinder

Richard,

I looked at your gallery of Easter shots and was impressed that almost none of your street shots show folks smiling or happy, ( except for the street performers). I was impressed that this is a very serious, solemn time for these folks.

The costumes are quite striking.

Richard

pathfinder wrote:

Richard,

I looked at your gallery of Easter shots and was impressed that almost none of your street shots show folks smiling or happy, ( except for the street performers). I was impressed that this is a very serious, solemn time for these folks.

The costumes are quite striking.

Yep. But apparently, photography is permitted:





Regards,