Depends on the type of Photography.... Could be Art/Film, Commercial... etc. www.hottelphotography.com
Possibly by 'field' you mean a category or type, such as Photojournalism, or Portrait, or Wedding photography. Or maybe you refer to 'depth of field', which is the distance front to back in focus. Sorry to be vague, I have worked in photography for many years, and have never considered the idea of 'field' as such.
Journalism and photography
The term "depth of field" in photography refers to the range of distance in a photo where objects appear sharp and in focus.
In photography, the relationship between focal length and field of view is that a shorter focal length results in a wider field of view, while a longer focal length narrows the field of view.
Using a small aperture in photography increases the depth of field, meaning more of the image will be in focus from the foreground to the background.
Single Lens Reflex.
A. A. Blaker has written: 'Field photography'
In photography, the acronym DOF refers to Depth of Field. This applies mainly in digital photography, and is how focused the lenses are on one area or place.
One famous Japanese photographer known for their iconic and influential work in the field of photography is Daido Moriyama.
It is if you are passionate about it, but if you're not, the demand is not very high for careers in photography, so it is probably not the best choice for you.
The depth of field(focus) and exposure.
This is too general of a question and really varies by type of photography and region. Are you looking for a range in a certain field of photography? If you are looking for how to price your photography, here is an article on that: http://digitalphotobuzz.com/pricing-your-photography