canon Lee

How accurate would it be to use the "P" mode as a light meter? I never use "P" mode and use M or A for my shoots, but what if I need a light meter to measure, lets say a window, and then use flash for the room? How accurate is the light meter in a camera in that mode?

sirlensalot Loc: Arizona

One of the busiest wedding photographers in the world uses P mode almost exclusively. Respectfully suggest asking Joe Buissink your question.
Sounds like you may want a light / flash meter? That said, the camera light meter does a pretty good job.

CHG_CANON Loc: the Windy City

Given P is for professionals, it should be perfect.

More seriously, the meter is the meter and does not behave differently based on the shooting mode. Auto = Program = Manual = etc, the meter just meters and spits out an exposure, within any limitations of the control parameters set by the photographer. The meter will behave differently based on the metering mode, something that is independent of the shooting mode. But even then, the difference is the breadth of data used for calculating an exposure, the meter still calculates the same. The same light level for spot and for center weighted will result in the same exposure, assuming that same light / light level fills where the meter measures. Evaluative takes more of the entire frame and in an effort to brighten the shadows, it may overexpose the brightest portions of the frame when there is a wide dynamic range within the image.

Longshadow Loc: Audubon, PA, United States

joer Loc: Colorado/Illinois

The spot meter on the window will work.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Personally, I usually don't go to a fully automated programmed mode unless I know there is absolutely no time, in capturing extremely rapidly unfolding action, to make any kind of adjustments or precise settings. Since I do come or the very old school I have learned to anticipate action, in most cases and pre-set certain parameters and shoot quickly. With static subjects like landscapes, architecture, still life, formal portraits, casual shots- I don't see any reason to shoot in "P" mode- I have plenty time to make all of my settings.

To address the question, if you were gonna do that and depend on the "P" mode, much would depend on knowing exactly how your camera actually operates in that mode as to the selection of shutter speeds, apertures, and ISO settings. Another question is the metering mode. A "matrax" or integrated reading may lead to subject failure in some circumstances such as backlighting, flash exposure in dark surroundings, etc. A center-weighted reading may sample light from the wrong zone.

I'm sure, the wedding guy who uses his programmed mode knows exactly what to expect from his camera set up under a wide variety of shooting circumstances.

Problem is, many photographers spend a lot of time trying to compensate for automatic functions such as using exposure compensation in some high contrast situations like shooting a spotlighted actor on a dark stage. It would be easier to and more accurate to make a spot reading on the main subjects and lock it in.

So...if you really want to use your camera in "P' mode, work backward and first find out what you camer is "thinking" in that setting and see if it jibes with the results you want. If it selects an aperture or shutter speed that won't address your needs for action stopping, depth of field, "bokeh" or a noisy IOS setting- you are out of luck. If you need to spend more time compensating and working around the system, having g to defeat the camera's decisions, you are better off shooting in one of the priority settings or shooting manually. There is nothing wrong with using your camera's great internal system as a spot meter and determining your own exposure settings by sampling the light from where you deem it to be appropriate.

I oftentimes use the camera as a spot meter, taking various readings, averaging them out, figuring flash fill ratios, creating multiple images for post processing insertions. Very handy for "hot" washed out windows and restoring detail by balancing the situation with indoor fill or post processing montaging.

Photocraig

Lee, if you're solving the Real Estate interior problem with window vs interiors, the spot function in any mode, but manual yields the easiest to use results, will work opewwrfectly fine. Meter the window, shoot, meter a middle lit interior shadow, shoot, meter a dark interior shadow, shoot. Blend ALL three in LR. You should be great.

khorinek

Good answer!

Pablo8 Loc: Nottingham UK.

As a Professional Real Estate Photographer, you seem to show unusual naivety, in lighting situations which must crop up every day, and every, or most shoots. You have the equipment, and 10 minutes testing (Trial exposures)for yourself, will surely give you the answers. Doesn't seem like you have done a lot of work in this field of photography, if you haven't got the basics sorted yet.

foathog Loc: Greensboro, NC

LOL

khorinek

Everybody has to start somewhere. IMO, the "P" mode should be the last resort Mode to use on today's digital cameras. It is misleading. Everybody thinks the camera will always get the images correct when in P or AUTO Mode. The camera detects motion but can't tell you how fast that motion is or how fast to set the shutter speed or ISO, etc. Most cameras will default to the lowest shutter speed or lowest ISO and that isn't always what you want in some circumstances. I have a few colleagues that live by the "P" Mode and they are always complaining about how blurry or how under exposed or over exposed their images are and spend a lot of time editing. Old habits are hard to break, I guess.

Blair Shaw Jr Loc: Dunnellon,Florida

AMEN PAUL

Pablo8 Loc: Nottingham UK.

Thanks.

DavidPine Loc: Fredericksburg, TX

Set your exposure for the brightest ambient spot in a room. Usually a window or light fixture. Then use a flash to make your image. This is a typical real estate scenario. Use ISO 320, f.7.1, 1/160-1/250. A reflected flash will most likely do the rest. Quit over thinking it. You cannot adjust everything (blown-out windows) in post-processing. Shoot RAW and get the best exposure you can to begin with. Don't worry about using a light meter. The camera's exposure meter is all you need. I think your problem is that you don't really, really grasp the relationships of ISO, SS ns f/stops and using a flash. Expose for the brightest ambient light and then overcome the lack of ambient light in the darker areas with the flash. It's sorta like making two exposures. When you really get the relationships you will be on your way. You do need to pay strict attention to white balance in my opinion even though you should be shooting RAW.

BermBuster Loc: Hi Desert S.Cal

Unless things have changed(Canon anyways), "M"mode is the only mode that is really a "Light Meter".."reflective light meter"...
the other modes I believe the meter shows 'exposure compensation'.
I used to use my camera a lot as a "light meter"..by putting it in "M"mode and measuring light. Then change to whatever Mode I wanted to set exposure for chosen subject.
If something is far off or really important not to blow out... I put it on 'spot meter', as the metering modes will affect the meter reading.

To verify... put your camera in "M"mode, point it at something and set exposure to dead center..now start pointing camera in different directions and notice how the meter moves up or down as the light changes.(make sure auto ISO is off).
Try again in "P"mode... you'll see settings change, but not meter.