When to use different 10D metering modes?

[DLopez]

Hello all, first time poster here, so I hope this isn't too basic of a question!

I've tried different kinds of searches, with not much luck, about when to use the different metering modes available on my 10D (Evaluative, Partial, Center-weighted).

When I've experimented with them, I've not seen a whole lot of difference in the exposure, but it could be the subject and composure didn't lend itself to making a big difference.

Anyhow, just wanted to pick the brains of those who've familiarized themselves with the different metering modes, and when it is best to use each one.

TIA!

[dsze]

Welcome! This is not a basic question at all, as far as I'm concerned. Metering is not a simple issue...Well, metering isn't that difficult, but knowing when to use the 10D's different methods (and remembering to change the mode) is the difficult part. Personally, I almost ALWAYS use partial metering for what I do, but I almost always shoot in manual mode. I am typically shooting people (faces) and or specific (small areas) that I want to be sure I have the detail captured (correct exposure), so partial seems to work best for me. If I were shooting in one of the auto-modes, I would probably be more inclined to use evaluative metering. I'm no metering expert...maybe someone else will jump in and enlighten us both :)

-daniel

[CyberDyneSystems]

This may seem totally obvious.. but sometimes it confuses, tgus the first thing to keep in mind is that all metering modes will bring you to the same exposures. (ie: there is no exposure that "evaluative mettering" will provide that partial won't.

The basic ocncept for the differrent metering modes is.. is there a specific part of your image frame that is more important to get correct exposure than thean the rest of the frame? And if so ,.. how large is it?

Thus..

Evaluative will try to get as much of the full image size exposed correctly as possible. Usefull for landscpes and other images that do not contain specific subjects.

Centerweighted is usefull when there is a large sibject for which exposure on that aspect is of greater concerne than the background. Portrait work is a good example.

Partial is goos for the same sort of reason as centerweighed.. but it will isolate more secifically the center area.. and a smaller part. This is good for wildlife much of the time.

Again.. in the end.. any metering mode and judicious of the review LCD and histogram can eventually bring you to the best exposure for your image,.. but sometimes using one mode will get uou there faster than another,..

[scottbergerphoto]

Choosing a metering mode involves understanding how your camera sees and meters light. As you go from Evaluative to Partial to Spot, less and less of what you see in the viewfinder is measured by the camera's meter. In addition in Evaluative Mode, the camera while biasing the metering at the active AF Point, takes into consideration the rest of the lighting using a computer algorithm. If your subject is evenly lit, then all three modes will give nearly identical results. If you have a scene with uneven illumination, the three can give very different results. My advice is to walk around with your camera and select different scenes to try all three metering modes for each one. See how the choice of metering mode and where you place your partial metering circle or spot metering point affects the resultant exposure.

Spot metering or partial metering take the most experience as they require that you not only take a reading at a point you think is most important, but also requires that you correct that reading for 18% grey. If you spot meter a bright white object, it will come out grey in the image unless you correct the spot reading by adding 2 stops of exposure. Black would require 2 stops underexposure.

I suggest: http://www.amazon.com/exec/obidos/tg/detail/-/0966081714/qid=1103660884/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/002-7964141-6862432?v=glance&s=books&n=507846
Regards,
Scott

[Persian-Rice]

Partial is a very primitive version of spot metering. Very good for getting, as dsze put it, metering of a specific area. When people say meter the sky, or meter the face, they are usually talking about this form of metering. I would say that you will need to practice with spot. An inexperinced photographer will overexpose/underexpose many of the images if they are not good with spot metering. It's a fine art of recognizing what to meter and if you need to compensate etc etc.

There are many situations that, you metering something other then the subject.

Evaluative metering will almost always give you a proper exposure, but there is far less control. It is Canons answer/equivalent to Nikons matrix. If you need to shoot fast and not time to meter, your best bet is this. It calculates an average of sorts based on several readings from several different areas of the image to give you a proper exposure setting.

[DLopez]

Excellent replies, all! This is the sort of info I've been looking for! :D

And Scott, I did not know about the metering being biased at the active AF point in Evaluative metering... BONUS!

Please, if any more readers have insight, feel free to add your input too!

Thanks again everybody!

[RDKirk]

Excellent replies, all! This is the sort of info I've been looking for! :D

And Scott, I did not know about the metering being biased at the active AF point in Evaluative metering... BONUS!

Please, if any more readers have insight, feel free to add your input too!

Thanks again everybody!

More on Evaluative Metering:

Canon really needs to do a white paper on this. Back when they first came out with it in '87, the magazines described how EM (and Nikon's matrix metering) worked in detail, but I haven't seen a good explanation since then. I still have my old magazines, though.

Simply put: With evaluative (matrix) metering, the camera attempts to match the image in the viewfinder to an image formula stored in its database.

Canon and Nikon took thousands of actual properly exposed pictures (Nikon claimed 90,000 pictures) and reduced them to mathmatic formulae according to proprietary algorithms (the formulae store smaller and can be searched quicker than image files). When you take a meter reading, the camera first notes what you've identified as the subject according to the active focus point (in autofocus modes, or the central point in manual focus mode), then checks the light levels in each of the viewscreen segments. It reduces that information to a formula pattern and seaches its database for a matching light/subject pattern. When it finds a matching pattern, it corrects for actual exposure level of the subject and shoots.

When evaluative metering goes wrong is when for some reason it selects the wrong pattern. That's why you can't just "add half a stop"--you don't know which wrong pattern it actually selected.

It can also go wrong because like every meter, it will still try to reproduce the subject as a medium gray. For instance, if you focus on an entertainer wearing a white gown on stage under spotlights, the camera will conclude: "Subject is brighly lit, background is dark...and the subject is medium gray." So you still have to compensate as with a spot meter.

[scottbergerphoto]

There is a Canon paper on Evaluative Metering on the WEB. I found it a while back using a Google Search.

Here's a link:
http://www.camera.canon.com.my/archive/photography/art/art14/
Scott