Anyone who has ever tried to take a good photo of their dog, can testify; it is not easy to do! Try telling your dog to hold still so that you can frame the shot. LOL! That's not going to happen no matter how hard you try. Dogs are always on the move, always wanting to see what is going on elsewhere. If you are going to get a good photo, you are going to have to have a lot of patience. You are also going to have to take a lot pictures, just to end up with one or two "keepers".
I can't over emphasize the importance of a good camera. If you want a good photo of your dog, you are going to need a good camera. That makes sense doesn't it? You would not believe the number of people who send me photos of their dogs. They generally want my opinion on how their dog looks and if they should breed it. In most cases the photos are so terrible and sometimes blurry, that you cant tell anything about the dog. Get a good camera. Not just any camera either. You want a camera that has a "fast lens". This means that the camera can takes burst of pictures very quickly. Because the dog is always moving the camera has to be very fast at focusing too. It doesn't matter if the camera can take 20 photos in one second if they are out of focus because the dog has moved. So when purchasing a camera, to take pictures of dogs, spend extra to get a fast camera and lens. As you read reviews on cameras, get the one that the reviewers says focuses fast.
I don't care how good a camera you have or how good a photographer is, you are not going to get a good photo of a dog, if it is hot. The only photo you are going to get of your dog is one with his or her mouth hung open drooling. In many areas, especially in the Summer, the only time you are going to get a good photo is early in the morning. There is a park I like to take the dogs to in order to get some good photos. If I can't get there by seven in the morning, forget it. When you know that you want to get some pictures of your dog, pay attention to the weather forecast and look for the coolest days. Anything over seventy degrees, and it is very tough to get a good photo. Temperatures in the forties and fifties is perfect.
You can try tying your dog off to a tree, but that seldom works very well. Having someone who is a good dog handler, is as important as having someone who knows how to take good pictures. The dog is always wanting to sit or even lay down, without a good handler. The warmer the temperature the more this becomes a problem. A good dog handler is able to keep the dog standing properly and in a "stacked" position. So too, having another person who can create interest for the dog to focus on is also very important. Someone standing off to the photographer's side or behind the photographer with a toy or something else that the dog is interested in, will help to set up the right kind of shots that are important for good photography.
This can be a catch-22. Good sunlight is important in many ways in photography. But it can also cause the dog to be too hot, and looking for some shade to lie down in. Yet good sunlight makes for more vivid and clearer pictures. If the light is lacking, the photos will tend to look grainy and lack the punch that only good sunlight can provide. The cheaper the camera being used, the more important this is. If you have a good camera with a large aperture lens, you can get some good photos of your dog even when it is shaded or overcast. But even with the best of cameras, sunlight is always helpful. If a cheap camera is being used and/or there is not good lighting, the photo will look grainy as it is cropped especially.
The absolute best dog photos are always when the background has been blurred out, and the dog is the only thing in focus. This draws all of the attention to your subject; your dog. Photographers use a special lens for doing this, often referred to as a Portrait Lens. These lenses can be very expensive, but are able to create stunning pictures. When using a portrait lens to take a picture, your dog being still is especially important, because the area in focus may only be a few inches. Outside of a few inches the photo starts to blur. Taking this kind of a picture of a dog is not easy because they are always moving in and out of focus.
When taking portrait photos of my dogs, I generally will take about 500 photos and end up with a handful of keepers. Here is what will help. Find a spot where the dog can stand, where the background is far away. Doing this allows you to set your aperture for a greater depth of field and still effectively blur out the background. So instead of having an area in focus of a few inches, you can increase the focus area to a foot or two. This will help when your dog moves slightly. Still pick a background free of distractions, such as people. If you know someone who is an experienced photographer, if they will show you the tricks of the trade, combined with what I have mentioned, you should get some good dog photos. If you do, I would enjoy seeing the fruits of your labor and meeting your dog too.