I want to start photographing horses for a side income and was wondering how to keep them posed. I mean, you can't just tell them to stand still and smile. Is it worth trying or should I just go for natural shots, like running and grazing, rather than portraits?

If the owner is nearby they may be able to hold the horse's attention for long enough with a tempting treat, or a clicker if they've been clicker trained. If your camera is digital be prepared to take heaps of shots and then just select the best ones.

I'm a parttime photographer, though I do mostly children and family portraiture, I do some animal/pet. They are hard! My advice is get back and zoom in, use at least an 85mm lens, but a 300mm is better. Have the owner in the area, just far enough out to keep them out of the shot, but close enough to keep the horse happy and entertained. Move yourself around to get different angles, and like the pp said, use your multi-exposure option to take a lot of shots.

Depending on the quality of horses you are aiming to take photos of it may be easier than you imagine. Many horses that show halter are quite adept at posing and staying that way. Other horses may be caught in good poses using noises or rattling grain in a bucket. Otherwise freedom shots of the horse in a field might work better. You're going to take alot of shots, but even the pros do this since the shot you think it perfect isn't necessarily the one the owner is going to like.

Sometimes the best photos just happen, when we least expect it - it's one of those 'always be prepared' moments, with camera nearby, ready to snap THE photo! My daughter got some great horse photos in Portugal - I'll have to see if I can snag a few to share! :D

I imagine you'd have to sit waiting for the right moment when the horse focuses on something off screen for a second, and then snap. However, action shots may better capture the horse's personality, especially if it's a cheeky thing.

I think natural photos would be absolutely beautiful. There's nothing prettier or more graceful than a horse who is quietly grazing in a pasture. I have seen many photos just like this that looked so elegant.