Why is this underexposed?

[Mum2J&M]

I took this picture late afternoon yesterday. It was somewhat overcast and in the shade. I used aperture priority at f/4. The 40D chose a very fast shutter speed. My ISO was at 400. Did the camera think it needed to underexpose due to his bright shirt? Should I have upped the exposure comp? I know I was using a very long lens (200mm prime), but that shouldn't have mattered, right? I wish it had been exposed properly because I like the composition, but I'd like to know how to correct it for next time. Thanks for any suggestions. Here's the image and the exif is (I'm also pretty positive I was in evaluative metering mode):

40D
ISO: 400
shutter speed: 1/1250(!?)
aperture: f/4
focal length: 200mm
aperture priority
no flash - 0 ev

http://Priors.smugmug.com/photos/274812222_cXYZX-L.jpg

[Gary Lindquist]

Why do you think this is underexposed? Looks pretty good to me.

[Mum2J&M]

Really? Well, I had to bring up the shadows a little in Photoshop. It just seemed pretty dark. Maybe it's my uncalibrated monitor. I'm just used to brighter images. Any other thoughts?

[FlyingPhotog]

If you were using evaluative metering, It's entirely possible your meter was fooled by the white shirt.

ISO 400 explains the shutter speed...

[mnealtx]

How's the histogram for the shot look, Mum? The spike for that white shirt should be pretty close to the right edge of the histogram.

[Mum2J&M]

If you were using evaluative metering, It's entirely possible your meter was fooled by the white shirt.

ISO 400 explains the shutter speed...

So the camera is seeing the higher ISO and upping the shutter speed to compensate? Should I have used spot metering? And is this a good idea whenever anyone is in a bright white shirt? I took some spot metered shots with a bright background in our kitchen and everything was blown out except for the kids. It was okay, but isn't that sometimes not okay? Thanks for your input. Here's an example of spot metering in our kitchen...

http://Priors.smugmug.com/photos/269431664_UYsBv-M.jpg

[FlyingPhotog]

Really? Well, I had to bring up the shadows a little in Photoshop. It just seemed pretty dark. Maybe it's my uncalibrated monitor. I'm just used to brighter images. Any other thoughts?

If you post an image that you've already corrected, how is anyone else to know how it looked straight from the camera?

Kinda not fair, ya know? ;)

[Mum2J&M]

If you post an image that you've already corrected, how is anyone else to know how it looked straight from the camera?

Kinda not fair, ya know? ;)

Well, unfortunately, I struggle to post anything that's not on our family website because my resizing techniques aren't the greatest. I will try to find it straight out of the camera, but I may have deleted it already. I think it still looks kind of dark, though, and posted the exif and image as a reference point.

The way I edit is this - I get the pics off my camera, I bring them into Photoshop, edit them, then save them. Then I resize them in Lightroom and post to the website. So any of the original images are gone. Maybe not the best way, but it's what I've become used to and old habits die hard.

[John_B]

Mum2J&M,
I think your over processing your photos.
ex. the first photo you posted seems over saturated in red, it doesn't look under exposed. Which could because of your monitor and your software editing or because of your white balance/saturation/color tone settings in camera. Of course like FlyingPhotog said, we don't know how it looked out of your camera only how it looks after you did software editing ???

You also can resize rather easily in photoshop elements. Just click image then resize then select your size...

Regardless of what metering system you use on your camera you can override it by either shooting in M or using exposure compensation. ;)

[cdifoto]

Maybe it's my uncalibrated monitor.

Ding ding ding! We have a winner!

[S.Horton]

Ah, when I need to do that I upload the original JPG to Smuggy in an unlisted gallery to keep it out of the 'real' family galleries. Within smugmug, if you're on a picture, click [share] and then post the link here for the [L]arge size -- in that case, it does not matter how big the original was.

When you mention having to resize, I think you may not be aware of exactly how to do that using Smugmug + posting on POTN.

Here's a visual how-to.
http://midnightblue.smugmug.com/photos/274984856_2iZ4n-XL.jpg

Posting the above JPG is a real example of letting SmugMug handle my resize for the forum.

The original is too large to post

[Cody21]

Mum, are you shooting in RAW ? You wold have better WB & Exposure control in PP if you work with the RAW image.

[Mum2J&M]

Yes, I definitely need to start shooting RAW. I'm thinking sRaw might be better for me as my photos are only for the web and it won't take up the space, but I can still fix wb in pp. As for the over-saturation, that has to be in camera as I never boost saturation in pp anymore. Hmmm. Thanks, Sam, for your tut. I will definitely start using smugmug more. I just find myself with less and less time to learn it because I'm chasing my kids most of the day.

[S.Horton]

^^ I know exactly how that feels!

[egordon99]

That's kinda the point of ISO! :)
To keep the same exposure value (EV), changing one of the three parameters (ISO/shutter speed/f-stop) a stop in one direction requires changing one of the other parameters a stop in the other direction.

So if you are in a dark environment and you set ISO to 800, select f/2.8 (say you're in Av), the meter selects 1/50 for the shutter speed. If you bump up the ISO to 1600, the shutter speed will increase to 1/100s. If you keep the ISO on 800, but open up to f/2.0, you'll also get 1/100s. If you go to ISO800 AND f/2.0, you'll get 1/200s!
Exposure 101 ;)

So the camera is seeing the higher ISO and upping the shutter speed to compensate?

[Mum2J&M]

That's kinda the point of ISO! :)
To keep the same exposure value (EV), changing one of the three parameters (ISO/shutter speed/f-stop) a stop in one direction requires changing one of the other parameters a stop in the other direction.

So if you are in a dark environment and you set ISO to 800, select f/2.8 (say you're in Av), the meter selects 1/50 for the shutter speed. If you bump up the ISO to 1600, the shutter speed will increase to 1/100s. If you keep the ISO on 800, but open up to f/2.0, you'll also get 1/100s. If you go to ISO800 AND f/2.0, you'll get 1/200s!
Exposure 101 ;)

Ok, yes, I suppose I knew that. :rolleyes: Sometimes it takes me a minute to chuck it all together in my brain. It is the right combination of all those that throws me. I know higher ISO means more light, which means this needs to be compensated by either faster shutter speed, or a smaller aperture. And it's about how all these things work together successfully to create the image you desire. I also think the choice of shutter priority, aperture priority, and ISO are doing me more harm than good. I'm going to start considering manual again. That way, if I screw up, I know it's me. Not guessing what the camera is guessing.

[tdodd]

If your lighting conditions are not changing then, in my opinion, manual is surely the way to go. Once you have the exposure dialled in correctly you can dress up your subject in whatever you like - dark clothing, light clothing, different backgrounds, one kid, several etc. and your exposure will still be correct. Often, manual exposure can simply be so much easier than the auto modes. You just have to decide how to meter your exposure initially and chimp the histogram to make sure you have it right before launching into a session.

[lungdoc]

I think there's some confusion here about ISO - ISO would have no contribution to over or underexposure; the camera's meter will call for the same net exposure for a given scene regardless of ISO - picture will be just as dark and only the shutter speed would have changed.

I think the original picture looks fine; but the slight underexposure is almost certainly related to the white shirt that camera will try to make 18 % grey - which is why snow picture look underexposed and black dogs get overexposed. This level of exposure difference is very easy to correct in RAW processing; I use Bibble but any tool would do it.

Manual is fine for keeping exposures constant; but for any one shot it's knowledge of the camera's meter and how it will interpret a scene that matters - and if you don't know that you should adjust for these things it won't matter if you are doing it via manual setttings or by adding +/- EC.

[Bamamike]

Yes, I definitely need to start shooting RAW. I'm thinking sRaw might be better for me as my photos are only for the web and it won't take up the space, but I can still fix wb in pp. As for the over-saturation, that has to be in camera as I never boost saturation in pp anymore. Hmmm. Thanks, Sam, for your tut. I will definitely start using smugmug more. I just find myself with less and less time to learn it because I'm chasing my kids most of the day.
Why giving away the information of a picture by using sRaw? Memory is so cheap right now, take everything you can get and decide later to throw away information, but not upfront. And use the histogram to rate the exposure, then go manual to compensate.