What are your rules for correct exposure?

Quite often I'm finding that what I think I should be correct way of exposing for something is in fact incorrect.

For example, an area with lots of green in needs to be underexposed by a stop. Same for something that's mainly being metered as black.
White should be overexposed by a stop, such as snow or wedding dresses.

The thing is, what do you do when your'e in a church with a white dress and a black suit with brown seating yet you are focusing on the couple.
Do you change the metering to spot, take an exposure from the church walls, lock in and refocus?

It seems there must be an easier way, or rule of thumb. I've read and taken onboard the book 'understanding exposure' which was great, and for the majority it's been a great help. Maybe it's the metering I choose that throws me sometimes. But I am a little lost on this.

This may confuse more than help, it is certainly not easier, but just for the hell of it:
My philosophy of exposure is derived from the Zone System principle that exposure and development are an integrated whole and, therefore, exposure needs to be set with the treatment the latent image will receive later firmly in mind. I shoot RAW and I know that my image's next station is Lightroom. If you shoot jpg, stop reading; your exposure will be different.
In order to do the best possible conversion and edit in LR I need to feed it the maximum amount of image data possible. My exposure is therefore designed to maximize data capture. I find the brightest significant highlight in the frame, spot meter it and add 2.5 stops. RAW will give a 3 stop headroom above medium grey but on a white fabric folds and reflections can make it difficult to put the meter circle on the absolutely brightest spot, so I leave a half-stop safety net. This method has been immortalized as ETTR and it requires the appropriate post-processing.

I use most of the metering modes on occasion, depending on what I am shooting, but find evaluative is where I am most of the time.

Having said that, I never rely on the meter alone and will add some modification to allow for subject and background differences. This can be done just by experience (if I am in a hurry) but more likely I will set what I think will be the correct settings, based on the meter reading and corrected with a 'fudge factor' for bright, dark areas that may throw it out. Then, I take a test shot and check the histogram. That tells me exactly where my exposure should be and I can adjust either way as desired.

In the white dress / black suit situation (always a tricky one) I check the histogram and move it over to the right as far as I dare without risking blowing out any of the detail on the dress, then rely on the cameras dynamic range to hold what it can in the suit. In general, a suit can be allowed to lose detail more than the dress (if necessary) as the wedding dress will have more important detail. Ideally though, shoot where the contrast is lower and detail can be held in both.

Whatever metering / corrections you choose, it is always handy to just double check them on the histogram.

Without going to the extent of the ETTR approach or going to the extent of light meters or grey cards, one that works pretty well is the palm method.

If you meter on your hand in the light at which your subject will be (with your palm filling the viewfinder), it will register approx one stop higher than a grey card (depending on ethnicity - it can vary slightly). Reduce by that stop and take your shot in Manual. Ignore the meter until the light conditions change! Only change your settings if the light conditions change (i.e. going from sunny to shade or inside to outside).

Every other mode relies on the meter which can (and will) be fooled by reflected light (and the light/dark skin/suit/dress/buildi​ng etc).

Once you have your "adjustment factor" for your hand it will register the same no matter what the lighting conditions are and you will always have it with you!

Use an incident light meter.

"White dress/black tux" problems will go away.

Expose as much as you can without blowing out the textured highlights. Simple as that. The blinkies are the curbs on your highway to exposure utopia.

Expose for the dress. Far better to get a perfectly exposed dress at the expense of a dark suit than vice versa , trust me

JoYork wrote in post #10948470
Expose for the dress. Far better to get a perfectly exposed dress at the expense of a dark suit than vice versa , trust me

+1 to tzalman, RDKirk, and JoYork. I'd use tzalman's ETTR approach to ensure you get a good exposure on the dress (i.e., use the white dress to set exposure and bump it up a couple of stops, maybe even a little more), which should also maximize the dynamic range so the blacks shouldn't be under-exposed (unless the overall dynamic range is too great for the camera to handle). Also consider using HAMSTTR https://photography-on-the.net/forum/showthre​ad.php?t=744235 and raise the ISO if necessary to maintain appropriate f-stop and shutter speed - with the cameras in your gear list you shouldn't have much if any issue with image quality using higher ISOs (say ISO 1600 and up). The only caution is to make sure you don't inadvertently overexpose the dress to the point of "blinkies," as mentioned by RDKirk.

sandpiper wrote in post #10948159
I use most of the metering modes on occasion, depending on what I am shooting, but find evaluative is where I am most of the time.

Having said that, I never rely on the meter alone and will add some modification to allow for subject and background differences. This can be done just by experience (if I am in a hurry) but more likely I will set what I think will be the correct settings, based on the meter reading and corrected with a 'fudge factor' for bright, dark areas that may throw it out. Then, I take a test shot and check the histogram. That tells me exactly where my exposure should be and I can adjust either way as desired.

In the white dress / black suit situation (always a tricky one) I check the histogram and move it over to the right as far as I dare without risking blowing out any of the detail on the dress, then rely on the cameras dynamic range to hold what it can in the suit. In general, a suit can be allowed to lose detail more than the dress (if necessary) as the wedding dress will have more important detail. Ideally though, shoot where the contrast is lower and detail can be held in both.

Whatever metering / corrections you choose, it is always handy to just double check them on the histogram.

I'd go for the white dress, too. Nobody cares what the groom's suit looks like... not even his mother.
Need an exposure crutch?

PhotosGuy wrote in post #10948562
I'd go for the white dress, to. Nobody cares what the groom's suit looks like... not even his mother.

.

Keep in mind that the ideal exposure is fundamentally that which records black as black, and white as white, and 18% gray as 18% gray...and that is what a reflect light reading from an 18% gray card (and the incident reading from a handheld meter) is intended to do. ETTR modifies that starting exposure a bit, so that white-with-detail is moved to the right of the histogram so that it still captures detail yet provides more of the 4096 tones to capture shadow detail.

So in the case of white wedding gown and black tux, the wisdom of getting the bride's dress right, and letting the groom's tux fall wherever it may is the underlying principle which even overrides ETTR! After all, the paying customer is the bride's mom or the bride herself, and they likely spent $5k - $50k for that gown.