Comparisons of metering modes - an eye opener!

[Curtis N]

Credit goes to PhotosGuy (Frank C) for the M&Ms idea, which I have shamelessly stolen. A variety of colors, and most everyone knows what they should look like. I added white tic tacs and black licorice to maximize the color gamut.

The idea was to see how the various metering modes on the 300D would read various combinations of colors. Rather than bore you with my conclusions, I'll just tell you how I set this up and let you discuss.

The 300D has three metering modes:
35 Zone Evaluative Metering, the default metering in every shooting mode except Manual. For these shots, I used Av mode at f/8 and let the camera choose the shutter speed. Edit for clarification per discussion and testing later in this thread: All shots were taken in autofocus mode with the center AF point selected. Evaluative metering is weighted according to the active AF point in autofocus mode. In manual focus mode, it is apparently centerweighted, regardless of the active AF point.

Centerweighted Average Metering, the default metering in Manual mode. I set the aperture at f/8 and adjusted the shutter speed to put the exposure indicator needle dead-center.

Partial Metering, which is activated by the AE Lock (*) button, uses a center area comprising about 9% of the frame. These were taken in Av mode at f/8, just like the Evaluative Metering shots.

Before you look at the pictures, you need to understand two vital points. First, every single shot was metered according to what the camera considered to be the "correct" exposure. There was no exposure compensation, no post-processing adjustments. What you see is what I got.

Secondly, the same pieces of candy were used in every shot. I simply rearranged them and tried to keep every piece at least partially in the frame. I did not substitute dark ones for lighter ones or vice-versa.

Every image below is from the same lens at the same distance with the same lighting. I did not move the camera or the light. Every shot was at f/8 and ISO 100. Only the shutter speed was changed via the metering methods described above. Nothing has been cropped. These are full-frame images shot RAW with custom white balance, converted and resized to 260 x 390. No sharpening, no adjustments to hue, saturation, etc., etc.

[Curtis N]

The same M&Ms, tic tacs & licorice pieces, just rearranged.

[PhotosGuy]

Good job, Curtis! If this doesn't convince some people to try using "M", then I don't know what will!

Maybe someday the geek at Canon who programs the meter software will figure a way to compensate, but until then I'll carry a white sheet of paper in my pocket & shoot RAW!

I'm going to add a link to this in my "Gray Card" threads.

[jfrancho]

All the m&m's are making me hungry! Nice test, Curtis.

[Sathi]

Thank you for doing this test. Very interesting.

[Curtis N]

Thanks, Frank. It was amazing to me how just rearranging the same colors changed the metering by a factor of ten in terms of shutter duration, about 3 1/3 stops! I was also surprised by how much the evaluative metering seems to be "center weighted." This could be quite problematic for those who try to follow the rule of thirds and compose with their subject off-center.

When I get a chance I will try to shoot some "real world" examples, like people in dark clothing in front of a bright background or vice-versa. This has really arroused my curiosity.

I think there are several lessons that could be learned from this. Anyone who shoots in JPEG mode with auto white balance really needs to see that first gray card shot.

[AjP]

Great Job Curtis!!!!!!!!!!!!!!!!!!!!!!!!!!

[jfrancho]

I have always used the "white-gray-black" card included as a pullout in the Kelby book. I assume that is sufficient? I don't think I have any problems, but if there is a better way....

[PhotosGuy]

I have always used the "white-gray-black" card included as a pullout in the Kelby book. I assume that is sufficient? I don't think I have any problems, but if there is a better way....

I don't see where it wouldn't work the same. Except that I'd always have to carry the book. I can get white (enough) paper anywhere, & it comes in handy for taking notes, too.

All the m&m's are making me hungry! Nice test, Curtis.

Why did you think I started using them? Tax deductible, too!

I was also surprised by how much the evaluative metering seems to be "center weighted."

By now, most of you know that I don't like having the cam "evaluate" anything for me & interpret the results. I make enough misTaKes of my own without compounding them with those with what I'd call a false evaluation.

YES, you can learn how to set up the cam to compensate. So you're compensating for the compensation? I want to spend my time looking at the subject & free up my brain to look for possibilities & think of variations & see what's happening in the background & forground & is this a better angle & maybe try for less DOF &... &... &..., Get the idea?
Manual settings work for me. When they don't, it's because I screwed up, & RAW will usually save me (again). There's too much going up in my brain to wonder what the cam is thinking THIS time. I want it to do JUST what I tell it to do. No more. No less.

[Curtis N]

Originally Posted by jfrancho

I have always used the "white-gray-black" card included as a pullout in the Kelby book.

I'm curious how the three colors are arranged on the card. Are they like three pieces of pie meeting in the center, or are they side-by-side? The shots above seem to indicate that would make a difference.

[jfrancho]

Side by side. But it is only really useful as a WB tool or metering close ups, since it is so small.

[Tom W]

Originally Posted by jfrancho

Side by side. But it is only really useful as a WB tool or metering close ups, since it is so small.

Unless you have spot metering.

This thread is driving me to give manual a workout - I used to shoot manual by necessity with nothing but a center-weighted match-needle light meter built into my FT-QL. I would meter around the scene a bit and get a good educated guess at what I wanted to be right. More recently, I've gotten spoiled by auto-exposure, I guess.

[Curtis N]

Originally Posted by Tom W

I've gotten spoiled by auto-exposure, I guess.

Auto exposure doesn't spoil me, it frustrates the bejeebers out of me. If it weren't for being able to adjust the RAW images later, 90% of my shots would be crap.

I haven't carried a gray card with me yet, but I have learned to find neutral targets to meter on. Since we haven't had any rain this summer, there's always brown grass around somewhere. I've also used old (not new) blacktop and brick walls if they're not too dark. This isn't a perfect solution but it gets me a lot closer than auto metering most of the time.

[PhotosGuy]

...but I have learned to find neutral targets to meter on.

I've done that. Green grass & blue sky can work too, but here's a bit of trivia: The palm of your hand doesn't tan! So it's always the same tone. Take a reading of it & figure out the appropriate compensation & you'll always have something to use for a reading. Not too hot for WB, though.

EDIT to update my palm of your hand comment: Manual exposure the quick & easy way.
First set the f-stop & shutter speed you need. Then adjust the ISO.
Need an exposure crutch?

[jfrancho]

Originally Posted by PhotosGuy

The palm of your hand doesn't tan!

I hear it get hairy, though.