Exposure question

Despite reading in manuals and some websites about Evaluative, Spot and partial, I tend to leave my camera just on Evaluative ? I never really get the difference, just thought out of all the members out there, that have much greater knowledge than me, can you tell a simpleton when and where I should use these different type settings ?

Thanks again in advance ?

Using the evaluative setting is essentially turning over control to Canon's programmer's whims about how to measure the light in a scene. For typical outdoor snapshots, it will work just fine. However, when you get into any more difficult situations - high contrast and/or backlit scenes, for example - you will not have the necessary control to get consistently good results.

I always leave my 20D on "partial" mode - the closest thing I can get to "spot". That lets me choose the part of the scene that I want to use to measure the light level rather than having the camera essentially average the whole scene and make up its own electronic mind about the results.

That said, I use a handheld meter far more often than the camera's meter and the camera's exposure mode dial is almost always set to to "M" for manual control.

Evaluative is good for most general situations. Where you have a scene that has fairly even illumination, evaluative should work fine.

Where it might struggle is where you have vastly differing areas of illumination, especially if one are is much bigger than another; eg a performer at a concert standing in a spotlight. Evaluative will look at the entire scene when determining what exposure to give. The result is very likely going to overexpose the performer. To counter this, you can switch to spot metering, which measures a much smaller area to determine exposure. If you spot meter off the performer, he/she will then be correctly exposed.

naford wrote in post #9275039
Despite reading in manuals and some websites about Evaluative, Spot and partial, I tend to leave my camera just on Evaluative ? I never really get the difference, just thought out of all the members out there, that have much greater knowledge than me, can you tell a simpleton when and where I should use these different type settings ?

Thanks again in advance ?

Evaluative = This is the metering mode to use when you want the camera meter to make the decision for you how to expose the scene. It's usually pretty close to correct unless the scene is really 'off' (heavily backlit, snow etc). It's the mode for when you do not want to think.

Center Weighted Average = Evaluative mode from the 1970's. They keep this mode so the old guys feel comfortable.

Spot - This mode allows you to directly take meter readings of specific tones in the scene and then select an exposure based on those readings. If you don't understand what I just said, don't use spot metering. For sure spot meter is not for when you just want to point the camera at things and take pictures without thinking.

Partial - Same as spot metering with a bigger target area. This mode is even more useless than Center Weighted Average. Don't use it.

Just to completely confuse the situation...

I was strictly using spot metering. Then I added a split prism focusing screen and the camera meter was all over the place. After finding a post on this forum, I changed to Partial Metering and I was able to get some consistency again with the on camera meter. Yes, I loose the benefits of a 3 degree spot meter, but now I have a consistent guide to start with.

diputs wrote in post #9275718
Just to completely confuse the situation...

I was strictly using spot metering. Then I added a split prism focusing screen and the camera meter was all over the place. After finding a post on this forum, I changed to Partial Metering and I was able to get some consistency again with the on camera meter. Yes, I loose the benefits of a 3 degree spot meter, but now I have a consistent guide to start with.

If you want to use a split screen, consider getting a handheld meter that can take incident readings as well as spot reflective.

I use an incident meter, and I almost never use the meter in my camera anymore.

JeffreyG wrote in post #9275758
If you want to use a split screen, consider getting a handheld meter that can take incident readings as well as spot reflective.

I use an incident meter, and I almost never use the meter in my camera anymore.

Interesting that you mention this as I keep looking at the Sekonic 358. I was all ready to get a meter until I started watching some videos on using Flash.

On the Strobist Lighting DVDs, and on the Joe McNally and David Ziser videos on Kelby Training, they are all chimping and using the histrogram as the method of metering. I am sure there is one out there, but so far I have not seen a video on using a flash that uses a non camera meter.

Is Joe McNally, David Ziser and David Hobby doing it wrong?

diputs wrote in post #9275791
On the Strobist Lighting DVDs, and on the Joe McNally and David Ziser videos on Kelby Training, they are all chimping and using the histrogram as the method of metering. I am sure there is one out there, but so far I have not seen a video on using a flash that uses a non camera meter.

Is Joe McNally, David Ziser and David Hobby doing it wrong?

Flash uses E-TTL metering unless you shoot manual flash power. E-TTL does use the camera meter, but not in the same way as you meter ambient light.

Get a high end handheld meter and you can use it to meter ambient and manually set flashes. Or you can use the meter to measure ambient and then still let the camera manage the flashes via E-TTL.

I have no idea what affect your focus screen will have on E-TTL though.

My old T90 use to let you take several spot readings and would then average them for the final exposure. Useful in situations where you had more than one backlit subject for example. Do any of the modern digital cameras have this ability?