I've been doing some small work as a marathon photographer and here is my struggle.
I like shooting in manual auto-iso mode since it allows me to set the aperture to f/8.0 and shutter speed to 1/400s. I quite like shooting at f/8.0, the depth of field isn't super shallow and that's important when i have multiple runners coming towards me as a group, maybe 2 or 3 friends, and i wanna take a landscape photo of them. Shutter speeds slower than 1/400s are doable, 1/320s doesn't completly freeze action on the fingers and feet but i think a little bit of movement in sports photography is nice. Since my scene is constantly changing i like using the auto-iso mode to take care of exposure for me, i don't have the time to put it in full manual, shoot, look at the histogram, make a decision and shoot. Sometimes i'll be shooting at a completely different background since i'm focusing on the subject and the subject can be anywhere in a 180º angle in front of me, the sun is also moving ( i may shoot for periods of 2 hours at a time ) and then there are clouds and whatnots so i can't say i'm so in touch with my camera that i can shoot in full manual and make adjustments without even looking at the pictures i'm taking, i'll shoot at least 5000 images in a single race, could be 15000 if it's a really big race.
For those reasons i find that Manual auto-iso works best for me, i could try AV but then i don't know what the camera is going to do with the shutter speed and i may lose a lot of pictures (i'm using a cropped sensor camera and a lens limited to f/5.6 at 55mm) so there's not a lot of light coming in. I've been considering TV mode but not only the camera would be setting the aperture to things different from f/8.0 ( i like the sharpness of f/8.0 ) but also i don't have the ability to set my iso at fractions of a stop, so i have to chose between say 400 and 800 iso and that can be a big difference in image quality, could even cause underexposure if it's set to 400 then the light changes and the lens is unable to have an aperture larger than f/5.6. Auto-iso works in fractions of a stop, fixing that issue, something that even in manual i'm unable to do.
So i have an exposure mode that will take sharp pictures, with a decent depth of field and freeze the action but in hard light ( i very often work with hard light ) the scene can have a gigantic dynamic range and what happens is that the camera can meter somewhat correctly but the subject being hit by side-hard light will end up overexposed on that side of the body, cause the camera simply can't account for that automatically. I can't even make a guess and dial down the exposure compensation cause canon didn't add exposure compensation to their manual auto-iso mode. And dialing down the shutter speed would just make the metering system decide on a higher iso, so i would have to go full manual and that's a logistic nightmare shooting in a chaotic situation with dozens of people running by me in a couple of seconds.
I've been nerding around trying to come up with a solution for this. I could look for spots where the scene has a smaller dynamic range, i could go full manual and lose my mind or i could suck it up and deal with the fact that a chunck of my shots will look kinda ugly. But i came across this function, high light tone priority. From what i've read, it underexposes the highlights and then applies some exposure adjustment in camera to bring the highlights back up without overxposing them and bringing the shadows up to what would be a balanced exposure. I can't shoot raw cause there is no way for me to process and store a minimum of 5000 raw images per race. Not to mention buffering and running out of memory cards.
So my question here is wether someone has tried using highlight tone priority to shoot jpegs and if the result was good. I've been studying photography for only a couple months now, trying to balance it with university and life, so any advice from more exprienced people is highly appreciated. I'm attaching two images, i was shooting at the same spot but you can see that the change in the scene from moving the camera to another angle makes a huge difference in how the camera chose to expose the shot. here http://imgur.com/a/brais
I'm using center weighted metering