Shooting Horses- Critique wanted

[MooseOne]

I'm a fledgling photographer who is new to this list. I shoot mainly family, outdoor scenery and show horses while at my wife's events.

I am fairly happy with my outdoor results, but recently I had the opportunity to shoot into a covered arena on a bright day. It was tough to say the least. I'm using a D300 Rebel with Canon 75-300mm F4-5.6 III lens. I've been using the Sports mode in daylight conditions with some success (see first sample). Under the covered arena, with bright daylight all around, I was forced to experiment. I ended up in the Manual mode with 800 ASA, 1/1000 shutter and F4.0 aperature. The images were quite backlit, and somewhat underexposed as you would expect with no artificial lighting at all. I was able to adjust a test image in Photoshop (see second sample), but it's still rather marginal.

Does anyone have any low-light, backlit, long slow lens sports photo tips? Also, how's my daylight work???

I appreciate all responses.

[Vetteography]

Use a big gun? :D

The first pic is outstanding! No clue about the other issue, sorry!

[MooseOne]

Thanks for the kind words...

[lostdoggy]

Since the subject is not moving I don't think you need 800 ISO. At 100 or 200 ISO and Manual mode take exposure of the horse. This will blow out the back light but the horse should be right. Alt same ISO in Av mode lock exposure on horse and reframe. Oh, this is just my guess I'm not a pro at it yet!!!

[MooseOne]

Well, in the sample shot the horse happened to be stationary. That was the last shot I took in a 3 minute test where the horse and rider moved in a walk, trot and canter all over that 20x60 meter arena. I was also zooming between 75mm and about 275mm. I felt I needed the 800 ASA so I could use a 1/1000 shutter speed to stop the action. My lens in also considered quite slow I believe.

Maybe there's a different metering mode that is less influenced by the bright background. Gotta read that manual again...

[lostdoggy]

Shoot in RAW set EC to +1 to +2 and shoot with ISO 800 in TV mode w/ shutter set at 1/500 This will let you shoot without suppot at 300mm, but if you have very steady hands then you can set it at 1/250.

[MooseOne]

Those are good tips. I haven't experimented with RAW files yet. Will a RAW file get me more latitude in optimizing the image in PS? Do you think I can stop action on a cantering horse with 1/500?

I need to get back out to that covered arena and do some more testing.