I am mystified about fill flash, over/underexposure

[kristenh]

I would love any thoughts about this. I took these three shots today, all with my nikon d5000, all in aperture priority mode. i have read that the camera gets confused with a very bright background, and i've read that you can use a fill flash. but then i've also read that amateurs (which i am- i'm on month 6 with my dslr) think they're underexposing but they're not. then i've read that in shady situations, i should aim to overexpose a light subject by about a stop. so now i'm befuddled.

this is my son. he's a light subject, to my eye. so here i didn't do anything:



exif data were shutter speed 1/800, ISO 200, aperture 1.8

here i used a fill flash:



exif data: shutter speed 1/200 s, aperture 2.8, and ISO still 200

and here i went back to not doing anything, with decent lighting results (i think- unless you think it's overexposed). pardon the boogers:



exif shutter speed 1/200 s, aperture 1.8, ISO 200

can anyone explain this business of overexposing the light subjects, how to handle shade, and when i can successfully use fill flash? thanks in advance...

[autofocus]

A few simple things to remember:
1) The meter in the camera is not as smart as you
2) The meter will try to reproduce everything at 18% gray
3) That said, pure black will come out looking gray, and pure white will also come out looking gray.
4) Because of number 3 above, black items that are dominant in a photo will be overexposed, (to gray) as will all else in the photo. As for white items, as in snow, bright beach sand, and wedding dresses, they too, will be rendered as gray...or muddy white.
5) The solution to number 4 above is to underexpose when there's a lot of black/dark items in the photo (limos, tuxedos, animals, etc) and to overexpose when there's a lot of white/bright subject matter. If you want snow to look white, you will need to overexpose the image. In either case, one to two stops is usually enough.
6) Remember, any exposure changes over, or under will also effect your other subjects in the image...so, those are the times that you may need to make some decisions as to what in your composition is most important, and possibly consider use of flash or a reflector. Overexposed snow or beach sand may look great, but the kids standing in it will wind up blown out...not good.

Your first image above is very backlit. The camera's meter will make an exposure decision based on all the ambient light it's seeing, and therefore underexpose your subject. Your choices here are to use fill flash (or reflector) which will maintain your background part of the image...or you can spot meter off your subject which will blow out your background, but render OK on your subject.

Hope this helps...

Vinnie

[inkista]

Just one thing, in your second shot, the flash is actually doing what it's supposed to. It's the flare you're getting from shooting straight into the sun that's washing the picture out.

Hoods are good things.

[Sterling]

this is my son. he's a light subject, to my eye. so here i didn't do anything

I'm not sure how you can make that statement based on the first photo. Obviously he is much darker than the background. You can't look at an object or person and say, "that object is light/dark so I need to overexpose/underexpose in every situation" You have to base that decision relative to everything else in the shot. A grey cat in the snow will look a lot darker than the same cat on a pile of coal.

Look carefully at your 1st and 3rd shots. In the first, your boy's face takes up what, 5% of the frame? While in the third his face takes up about 50% of the frame. Your camera can provide a much more accurate exposure for something that fills up half the frame versus a tiny portion.

[OsmosisStudios]

The other issue you're having here is that when you use the fill flash, the shutter speed automatically drops to the sync speed of 1/200

Between 1 and 2, you're going from:
1/800, iso 200, f/1.8
to
1/200, iso 200, f/2.8.

So while you're dropping one stop (well, 1 1/3) in aperture, you're gaining 2 stops in shutter speed. So you're still over exposed.

[kristenh]

thank you all for your thoughtful replies. i feel a little clearer now.

Originally Posted by OsmosisStudios

The other issue you're having here is that when you use the fill flash, the shutter speed automatically drops to the sync speed of 1/200
.

ah, this i did not know. so anytime i use fill flash the camera will set the shutter speed at 1/200?

5) The solution to number 4 above is to underexpose when there's a lot of black/dark items in the photo (limos, tuxedos, animals, etc) and to overexpose when there's a lot of white/bright subject matter. If you want snow to look white, you will need to overexpose the image. In either case, one to two stops is usually enough.

this makes sense to me- and is more nuanced than the rather general idea that one should just overexpose if the subject of the photo is light. i'm getting that now.

Just one thing, in your second shot, the flash is actually doing what it's supposed to. It's the flare you're getting from shooting straight into the sun that's washing the picture out.

okay, makes sense. hood is on my wish list.

Look carefully at your 1st and 3rd shots. In the first, your boy's face takes up what, 5% of the frame? While in the third his face takes up about 50% of the frame. Your camera can provide a much more accurate exposure for something that fills up half the frame versus a tiny portion.

thank you.

now may i ask what you all make of this "expose to the right" idea (as in

Expose Right)

would i be doing that here? esp in the first shot ? i have been savings raws and jpegs for each shot...

[OsmosisStudios]

Originally Posted by kristenh

ah, this i did not know. so anytime i use fill flash the camera will set the shutter speed at 1/200?

Not necessarily. The camera will set the shutter speed to any speed SLOWER than 1/200. The camera can only sync the shutter to the flash up to 1/200s, but any slower speed also works.

[AdrenoJunkie]

Originally Posted by autofocus

A few simple things to remember:
1) The meter in the camera is not as smart as you
2) The meter will try to reproduce everything at 18% gray
3) That said, pure black will come out looking gray, and pure white will also come out looking gray.
4) Because of number 3 above, black items that are dominant in a photo will be overexposed, (to gray) as will all else in the photo. As for white items, as in snow, bright beach sand, and wedding dresses, they too, will be rendered as gray...or muddy white.
5) The solution to number 4 above is to underexpose when there's a lot of black/dark items in the photo (limos, tuxedos, animals, etc) and to overexpose when there's a lot of white/bright subject matter. If you want snow to look white, you will need to overexpose the image. In either case, one to two stops is usually enough.
6) Remember, any exposure changes over, or under will also effect your other subjects in the image...so, those are the times that you may need to make some decisions as to what in your composition is most important, and possibly consider use of flash or a reflector. Overexposed snow or beach sand may look great, but the kids standing in it will wind up blown out...not good.

Your first image above is very backlit. The camera's meter will make an exposure decision based on all the ambient light it's seeing, and therefore underexpose your subject. Your choices here are to use fill flash (or reflector) which will maintain your background part of the image...or you can spot meter off your subject which will blow out your background, but render OK on your subject.

Hope this helps...

Vinnie

Great explanation! That just helped me understand why so many of my pictures that the camera said were properly exposed came out looking gray and dull to me.

[autofocus]

Originally Posted by AdrenoJunkie

Great explanation! That just helped me understand why so many of my pictures that the camera said were properly exposed came out looking gray and dull to me.

Always happy to try to help when and where I can... Remember, photography like so many other things in life, is an ongoing learning experience, and we all can learn from each other's experience regardless of how long you've been doing it.