spot meter

[Nomadr]

probably been asked loads of times but here goes, if i spot meter on a persons face will that give me correct exposure ? not bothered about anything in the background being over/under exposed, i remember reading once that spot meter on a white subject will give you a mid grey reading so you should increase by two stops, i am thinking about shooting some tennis action and the mainly dark background will throw my metering out (i reckon),cheers martyn

[bambleweeney]

A spot metered reading on a person's face will render the exposure as mid grey or zone 5 (if you use the zone system). A caucasian face is actually about zone 6 so you need to compensate by about a stop (-1 stop) unless they're tanned. An african or coloured face reads about zone 4 so for a correct exposure compensate again by a stop (+1 stop). You need to be careful where you spot meter a face though, obviously depending on the light. It's up to you where you place the spot depending on what you want the 'mood' of the picture to be - you might decide to meter the highlights and the shadows and choose a value in between the two to avoid burning the highlights or blocking the shadows if the person is in strong directional light. If you're shooting tennis then presumably you'll be a little distance away from the action and may not have the whole face in the spot (especially if you're using the in camera spot metering and not a 1 degree spot meter) so your reading may well be a little off. If it's a grass court then metering off of the grass will get you pretty close (grass reads about zone 5). Plan B - if you are in the same light as the tennis players then take a meter reading off of the palm of your hand (zone 5 again). Plan C - bracket and check the histogram, if you can zoom in to the image on the camera back and look at the histogram for that area you can nail it. Plan D - any of the above to get close and adjust in post processing. Main thing I'm guessing for tennis is not to blow the whites (assuming the players are wearing white). A slightly underexposed face will be better than blown out tennis whites so that's worth checking on the histogram.
Possibly better not to use spot in this instance unless you're really close and it's the face that's important - go center weighted or matrix and take a shot or two before the action starts and see what the exposure looks like and use exposure compensation if necessary. This advice from a landscape photographer by the way - may need to be taken with a pinch of salt.

[Nomadr]

thanks for the indepth reply, the idea was to spot meter the player rather than the whole scene, i will try a few of your ideas to see which works best, i had forgotten about meter reading off green grass, the reasoning behind it is because i want to shoot in manual mode with 1/1000th sec shutter speed,by metering first i can set the iso high enough to give correct exposure on the subject and only have to worry if the light changes,cheers martyn

[bambleweeney]

Good luck with that. The problem with manual I would imagine is that changing light is going to mess up your exposure somewhat. I shoot landscape mainly and nearly always on manual - sometimes changing light is frustrating but as landscape is pretty static I rarely miss 'the action' :-)
Never used it myself but what about shutter priority mode ?

[Nomadr]

i did think about shutter priority and will probably have a go with it,my main concern was getting the metering right on the player against a dark background,i would guess if i used spot meter on the player with -1 stop comp it should all work out ok, at the end of the day if i shoot matrix it might even be ok without any adjustment, will suck it and see what the histogram tells me,cheers martyn

[Colin Southern]

i did think about shutter priority and will probably have a go with it

Hi Martyn,

All that will achieve is depths of field that are "all over the place".

I'd suggest Aperture Priority, followed by an ISO that allows the shutter speed to be high enough to freeze the action (if that's what you want) and/or kill camera shake.

In terms of metering, just use whatever mode works best; it may well be a case of just using matrix / evaluative with some exposure compensation. Yes, a dark background may throw it off - but - it should throw it off consistently (and vary according to changing lighting condition) - so it (a) may well accomplish the objective and (b) be a lot easier to get right that trying to spot-meter a player (especially if you camera doesn't link spot-metering to the selected AF point).

[Graystar]

What brand and model camera do you have? If you have a Nikon DSLR then you can set the Auto-ISO function to maintain a shutter speed of 1/1000s. Then you shoot in A mode and not worry about shutter or ISO, because you've already set the camera to behave as you want it to.

BTW Exposure Compensation for light skin is +1 and -1 for dark skin. Brighter tones need more exposure. Darker tones need less exposure.

[Nomadr]

thanks for your comments, yep colin thats something i never thought about, i usually shoot portrait mode and have focus point in upper third on the face (well i try),i will check up on that,
graystar yep this is one of the problems, i can set my camera to auto iso but that doesnt give me any control over aperture, at least i dont think it does until i try it, i normally set the priority on either shutter or f stop and leave the iso to whatever i have set it to so to do this would be a whole new ballgame,
in my mind i imagine that my camera would choose a really high iso and give me an f stop of F16 at 1/1000th, obviously i want as low an iso as i can get,i am unsure if even by setting a fairly low iso in the auto mode if it will judge the iso as the last thing to get altered (ie drop the F stop to wide open then as last resort lift the iso to still retain 1/1000th sec),cheers martyn ps yes i use a nikon and high iso isnt a problem but i would prefer low iso,
pps another question, if i spot meter on the whites rather than the faces (i use a 70-200mm zoom which is very accurate for spot metering) will that rending the whites medium grey ?

[Colin Southern]

in my mind i imagine that my camera would choose a really high iso and give me an f stop of F16 at 1/1000th,

Maybe yes - maybe no. What it WILL do for sure though is complete the missing leg of the exposure - or put another way, you get to control 2 of the three variables directly (aperture and ISO), and the third indirectly.

If it were me, I'd use Av mode - choose the aperture I wanted for DoF control - and then choose an ISO that gave an acceptable shutter speed.

[Graystar]

Which Nikon do you have? If you tell me then I can tell you how to set up the Auto-ISO.

With Nikon's Auto ISO there's a setting called Minimum Shutter Speed. This is the slowest shutter speed that you're willing to use for your current subject matter. The camera will keep ISO as low as possible (you can set this too) unless a shutter speed slower than your MSS is necessary for standard exposure. At that point the camera will increase ISO in order to maintain your MSS. You can also set the highest ISO you're willing to use, at which point the camera has no choice but to drop the shutter speed to get standard exposure.

So you can set the MSS to 1/1000s and you can use A mode to shoot. As you shoot and change your aperture (or lighting changes), if a shutter slower than 1/1000s is necessary then ISO will increase instead, maintaining a shutter of at least 1/1000s. ISO will increase until the max ISO is reached, at which point shutter speed will drop if more exposure is necessary. It's a very good way to control your shutter speed because, at any given moment, you're using the lowest ISO possible within your shooting constraints.

[Nomadr]

thanks for your tips everyone, Graystar i have a D3,i tried a few different techniques,spot metering on face didnt work at all, it would probably have worked if the players were filling the frame and not moving about,matrix tended to make the image dark if there was any sky in the pic (even with EV comp),in the end i found centre weighted worked the best,
it was really sunny so i didnt have to worry about slow shutter speeds,what i did find was that some of the shots the face would be slightly out of focus compared to the rest of the body, (had that before with white water rafters where helmet is pin sharp but face is fuzzy),heres a few pics darkened down a touch for bright screens,cheers martyn ps last one was more to get sponsors in the frame too,