100-400L Overblown whites

Trying to get the camera/lens settings right for whitewater kayaks going through a rapid.
There's not much white at the top then 2 seconds later the water is really churning and splashing even with some foam.

With the sun at that moment, looks like white paper.

So I set the lens to f13 or f14,
point it at a whitewater area at the top of the rapid, half press then hold half press and put it on the person in the kayak. (should have read something on metering)

Focus set to AI Servo, Auto ISO and try to stay close to 1/400 SS with burst mode on.

I'll get several shots in thru the rapid but at the bottom whites get blown out. Now thinking on it, maybe I should have set up for the bottom of the rapid and just use that setting all the way through.

And what else am I doing wrong? Is there a good method for this type of shooting? The camera is a T2i.

I would like to get the drama (for the lack of a better word) of the water splashing around the kayak yet keep the person in it as the subject without being under exposed.

I believe the metering will be set when you half-press at the start, and assuming you don't let go of the shutter because you are in AI Servo mode, the metering will remain constant through-out.

You could try letting go of the shutter mid-way through the sweep past and re-press, but you might lose focus and/or IS will get gnarly.

Hmm, need to read-up on metering...but it is late and I have the attention span of a zzzzzzzzzzzzzzz.....



shinksma

This scenario is a bit hard to meter and adjust for because of the variables and how fast they change.

This is not a lens issue as it really is just an issue nailing the exposure. Once you find the settings that work, it will be easy.

You didn't say if you were moving around or pretty much shooting from one place.

If you are shooing from one place, I would set the camera to full manual mode. Adjust the shutter for the speed and the ISO and f-stop for the light. Take some test shots and chimp (look at) the histogram on the LCD to check for blown highlights.

If you need to move around or don't want to shoot full manual then you can try using exposure compensation and back it down by about a stop or so. Also play with the metering modes. The two modes to try would be either Evaluative or Center Weighted. I'm not sure if it works the same on the XXXD line but this will usually put the most emphasis on the light level at the selected focus point. As a result, you may want to try Center Weighted as it will take the average of the center of the viewfinder. Again chimp the histogram to see if you are getting blown pixels.

I would also suggest shooting RAW where you can go back in post and recapture some of the blown out areas and adjust exposure a bit better. Also keep in mind that outdoors the rule of thumb is that the exposure of the person will define if the photo is properly exposed. Shooting RAW will help you adjust some of these finer points in post.

It really all comes down to finding the right ISO, shutter and f-stop settings. I would read up on metering modes for that particular camera.

If the scene is dominated by dark water with bits of foam, the camera meter will try to make the water 18% grey and in the process, it will blow out the white highlights.

Try dialing in -1 EC to get the water as dark as it should be and your whites shoud become more manageable.

Have you tried the exposure lock button? Expose the bright spot(s) ahead of time and apparently hold the AE Lock (*) button and then recompose for the top of the rapid. It will probably under expose the top, but if that isn't too bad, you could probably recover those easier when you process the images.

I'll have to read more on the AE lock, is this good for one shot?

I thought exposing for the bright areas with a half shutter press and (spot meter) would take care of it but not completely. Now, it looks like its just such a drastic change that it is going to be one of those things a person has to deal with.

I got better the last time. It's a learning process and I'm new to everything, photo.

You have a lot of variables that can change making it tougher to dial in.

Try going manual, at your aperture you want (13 you said?), and at the shutter speed you want (1/400 you said?). Adjust the ISO up or down to get your exposure. If you are at ISO 100 and you still are overexposing, you can increase your aperture number or your shutter speed to help.

The more variable you set, the less you have to hunt for when trying to dial yourself in.

Could the OP post some samples please?

Hard to diagnose without pictures!

Ok I tried to upload and got this

"Your submission could not be processed because a security token was missing or mismatched."

I'm not sure why you are having the problem with uploading, but a few thoughts.

First off, with a scene like whitewater rapids, you will get the most latitude with those highlights if you shoot Raw. Just sayin'.

Second, make sure you are shooting "with the light", in other words, with the sun lighting up the scene from behind you if possible. Otherwise you will be battling with exposing the kayakers/subjects and losing the whitewater.

If it were me I'd take some time to set up a Manual exposure for the scene. Get some shots with whitewater, chimp, and if the highlights are bad, back off on the exposure. Do this before the kayaks show up and then you can just shoot, since the scene lighting will not change. Using Av or Tv or Auto ISO for this type of thing can work if you know what you are doing, but still will tend to change exposure at the drop of a hat, whereas with Manual you can nail the exposure before the "action" happens.

But that's just how I would do it!

Ok see if the first two made it

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And for the second two, the last one always gets blown out.

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And these are RAW no PP or sliders used. Someone that can see the data might confirm that.

First three look ok to my eye...

Fourth one simply has a very wide dynamic range from foam in front to shadows under big rock. Really hard to expose for either correctly in the middle of the day. I'd concern myself with the exposure of the peeps in the raft and move on from there.

Probably no need to be at ISO 400 in broad daylight though.

Are you still using Auto ISO? The ISO on the EXIF data is 640. You probably don't need it that high unless you were trying to increase the shutter speed.