Welcome to Photo.net: A Community of Photographers

Community > Forums > Casual Photo Conversations > How to meter off the sky?

How to meter off the sky?

Kiran S , May 14, 2007; 12:20 a.m.

Hello All,

I encountered a situation where in I was asked to take a picture of a group of people (31 people) standing in front of water and blue sky. I switched camera to Av mode set f10 and WB => daylight and took the shot, Evaluative metering. I got the picture but then the people faces turned out blurry. I think if i had switched to M and metered off one persons face it would have got better.

First question is how do you meter off the sky. Camera wont focus on just sky as there is nothing to focus on. So how do i focus sky and get meter reading. Second question: if i do get to meter sky and then change ISO, to get the correct compensation as displayed in the meter. Do I have to lock the exposure and then move the focus to the bunch of people and take pic? because if I moved the focus to the group of people after metering sky the pointer in meter points to the extreme right . Should i again adjust ISO to make it come back to the point which denotes the correct exposure?

Here is the URL to the picture which i am referring to

http://farm1.static.flickr.com/220/496576014_a7beb3bce5_b.jpg

- Thanks - Kiran

Responses

Bob Atkins , May 14, 2007; 01:09 a.m.

What makes you think different metering would have made the faces any less blury?

If you want to meter the sky for some reason, switch to manual focus.

I really have no idea what you are trying to do. If you have a backlight situation, just dial in +1 or +2 exposure compensation or meter a gray card in the same light.

Alternatively, just do some post exposure correction.


fixed

Kiran S , May 14, 2007; 01:14 a.m.

Thanks for the inputs Bob. Mind sharing the technique you used to post process the picture. It looks better than what i achieved after post processing.

Bob Atkins , May 14, 2007; 01:15 a.m.

Simple shift of the histogram. I used PSP v9, but any image editor should do it. I pushed the center slider of the histogram a bit to the right.

You could also do it with curves.

Kiran S , May 14, 2007; 01:24 a.m.

Thanks for the info Bob. So I guess what i have heard about Xti and underexposing is right.

Can you tell me how to achieve this in manual mode?

if i do get to meter sky and then change ISO, to get the correct compensation as displayed in the meter. Do I have to lock the exposure and then move the focus to the bunch of people and take pic? because if I moved the focus to the group of people after metering sky the pointer in meter points to the extreme right . Should i again adjust ISO to make it come back to the point which denotes the correct exposure?

Steven Bakalis , May 14, 2007; 01:30 a.m.

The answer to the second part of your first question is to set your camera to manual focus and set the focus to infinity. This will keep the sky in focus.

The answer to the first part of your first question requires you to do some practicing. If the sky is the subject of your photo then the first thing you need to learn is how to meter off an object and set the camera to render the image at the brightness that you desire. To start with set your camera up for manual operation and set the camera?s light meter to spot. Second, when your meter is set to spot or center weighted modes, the meter will tell you how to set the camera up for that object to be rendered as neutral gray in your photo. For example if you meter off white snow on a bright sunny day, and you set up your camera up to expose the scene according to what your light meter tells you, the white snow will be rendered neutral grey in your photo. Thus, you need open up you camera a stop or two to render the snow white. What this means is that you need to learn what neutral gray looks like and ask yourself what in the scene you are looking at is neutral gray and set your exposure off that. If as in the case of the white snow scene there is no neutral gray in the scene then you will need to learn how to adjust your exposure accordingly. This take practice, and since you have a digital camera, go out and practice with it and taking notes.

With respect to the sky, pick a place that looks neutral gray and expose off that. If you what the sky to appear brighter open up a stop, and for darker reduce a stop. You can also bracket. It takes practice to learn to use your light meter as guide to exposure.

Because you have set your camera up for manual operation and have set up your exposure then you can aim your camera any ware and the settings will not change. If you want the people to be in focus then manually re-focus on the people. Stick with one ISO setting for the entire shoot to reduce the number of variable you need to deal with.

Take an afternoon to play, experiment and practice with exposure. The more you do the better you will get.

Frank Uhlig , May 14, 2007; 09:50 a.m.

Focus and exposure are two different things! They both somehow fall onto those pesky red bracketed squares inside the viewfinder and that confuses you, it seems.

You can focus on the sky or better the faces and meter the sky or the people, both independently of each other. Try it out!

But if you do a group portrait, why not focus AND meter on the people?

Doug Smiley , May 14, 2007; 10:54 a.m.

The "fixed" image looks between one-half to one stop too bright on my monitor.

Bruce C , May 14, 2007; 12:26 p.m.

Kiran,

I think the root of your problem is that you're not clear on what you want to do. If you want to photograph the sky, get all those folks out of the scene -- they're distracting attention from the sky!

But since you did assemble those people, I assume that they at least wanted you to take a picture of them and didn't give a fig about how the sky looked. So you need to focus on them and expose for their faces. Once you get a few group shots down, you can then turn to work on the sky at your leisure.

Basically, you seem to suffer from smart person think -- you're thinking about too damn many peripheral things instead of focusing on the essentials.

Kiran S , May 14, 2007; 02:00 p.m.

First : I wanted to take a picture of the group of people. ( For some reasons it has turned out to be grainy and i want to know the reason why ? )

Second : I think I've read some where on net that when you want to take picture of a person in front of a sky or water there are chances that cameras meter might be fooled so one has to meter of the sky take reading and then focus on the person to get a proper exposure. If this is right how do i do that ?

Doug Smiley , May 14, 2007; 02:24 p.m.

Kiran, if you had moved in a lot closer to the group so that no sky and very little of the water showed, metered and locked your meter reading in, then stepped back, composed the photo, focused, and took the picture, your exposure should have been just about right.

Barry F - Oklahoma , May 14, 2007; 02:45 p.m.

Second : I think I've read some where on net that when you want to take picture of a person in front of a sky or water there are chances that cameras meter might be fooled so one has to meter of the sky take reading and then focus on the person to get a proper exposure. If this is right how do i do that ?

You may be getting confused with something you read about using fill flash, but if you meter off the sky, and let's say you get an f-stop of 16, and then you move down to the people and take the shot at f-16, the people will be under-exposed because, in simple terms, they don't reflect as much light as the sky, and you've set your camera to expose for the sky. Your desired f-stop for the people might be, for instance f-8, or even f-5.6. The darker your subject, the more light it's going to need.

Cheers

Notify me of Responses


Photography