Metering modes

peterqd · Expire: 2014-01-04

Basic question for you guys, but having used a Praktica Nova 1B for most of my life, I don't have much experience of using a camera with auto-exposure, and I'm getting quite variable exposures with some of the manual lenses.

My Canon 400D has 3 metering modes:

Evaluative
Partial
Centre-weighted average

I think I can follow what the last one means, but what are the other two and when should I use them? What do you use?

Or would I do better to forget the camera's metering and use a hand-held meter?

bob955i · Joined: 15 Apr 2007 Posts: 2495

This may help you Peter:

http://en.wikipedia.org/wiki/Metering_mode

All the different systems have their advantages and disadvantages, despite any claims the manufacturer may make for their particular implementation, so the choice of metering can depend a lot on the subject, the light and how you want the image to look.

Generally speaking, the metering, if present, on most older cameras tended to be averaging while I believe the default mode on Canon DSLRs is evaluative - it is on the 5D so why not try the centre-weighted averaging mode to make things a little more like what you've been used to?

One big advantage of a hand-held meter is that if you have one with dial settings like a Gossen Lunasix or a Weston for example, you can see all of the available aperture/shutter speed combinations at a glance.

Orio · Expire: 2012-12-04

Evaluative uses multiple metering points scattered across the frame in "strategical" positions and creates a wieghted balance of them, that is, the points are not given all equal value, but some are more important than others. In particular, this kind of mode is able to "understand" if you are shooting a landscape or not, etc.. based on the light and colour measurements.
Partial is nothing but the old "semispot" with a different name - similar to spot metering but on a larger area (like about 15% coverage instead of the usual 3-5% of the full spot metering.
Use partial (=semispot) for portraits, flowers, etc, and evaluative or centre weighted for anything else.
Keep in mind that in order to use Evaluative and Partial, you need to have a chipped adapter. Adapters with no chip will work only in centre weigthed mode, no matter what mode you have selected in the camera's preferences.

peterqd · Expire: 2014-01-04

Orio · Expire: 2012-12-04

The best metering that you can do is by far using a manual external meter of high precision, like those made by Gossen, and shoot in manual mode.
This is what I do when I care a lot about the photograph.

BTW my Gossen also has an additional for spot metering, although when using the 5D is not necessary because the 5D has a pretty good spot meter of its own.

I agree that the rest of the modes in most Canon cameras are crappy, but have you tried the 400D? It is a HUGE improvement in exposure fidelity compared to the previous Canon cameras (including the 5D).
I can use the 400D almost in automatic mode even with manual lenses and get an almost total percentage of good exposures (and shooting in RAW helps to fix the small deviations).
With the 300D it was a pain, and so it's the 5D.
The 400D is the first Canon camera to be compliant to the international light metering standard. I don't know why canon has waited for so long.

peterqd · Expire: 2014-01-04

Thanks Orio, I'm in fact using a 400D. When I took those shots to compare the Mir-24 with the Flek 2.4/35 recently, they gradually became more and more underexposed as I decreased the aperture sizes. Why did that happen? I didn't change anything else, so why didn't the camera meter control the exposure properly? In the end I set the camera to manual and halved the shutter speed each time I stopped down. I just don't trust the camera metering, and now to find out that I have no way of knowing exactly what part of the picture is being used for metering just makes this worse.

It's probably in my genes to be deliberately awkward, but I get no fun at all out of using AE cameras, where you don't have to think much about what you're doing. Many years ago I once had to borrow my boss's brand new OM10 to take some shots at work and hated it because there was no manual mode. I guess I was left behind in the early 70's Smile

Orio · Expire: 2012-12-04

Canon cameras do not actually meter the light through the lens at all apertures, they make math calculations and offer you a value based on the full aperture metering.
This is set for Canon EF lenses. Canon EF lenses respond well to these preset values. Manual lenses require often an adjustment. But with my 400D I only need to adjust about 1/3rd stop less for stopped down aperture values (around f/8 ). If your 400D requires more adjustment, then it's probably not well calibrated, you should send it to Canon and have the light metering be recalibrated.

peterqd · Expire: 2014-01-04

Orio · Expire: 2012-12-04

bob955i · Joined: 15 Apr 2007 Posts: 2495

naplam · Expire: 2013-11-30

peterqd, i think you'll be more comfortable with the centre-weighted average mode, because it resembles the traditional metering of analog cameras. I use it a lot because it's quite predictable, with the evaluative mode you never know for sure what it's looking at. Evaluative is like the "intelligent" point-and-shoot mode; should work better if you never adjust the exposure. centre-weighted is more predictable if you want to tweak the exposure. Partial mode is the poor man's spot metering mode, it uses the area in the center of the viewfinder.