This is an agreement between a model and photographer where the model trades her time (the session) for no fee, and the photographer gives his time and expertise for no charge. Basically, it’s intended to be a win-win situation. The details may vary between photographers so what follows is my version (and is likely fairer than most).
The model will give her time and best efforts to the photo session (which will include preparation, punctuality, and most of all a positive attitude). In return, she will receive a digital low-res proof of all reasonable shots (i.e. excluding the obvious out-of-focus, badly lit, or badly posed shots that no photographer would want to show) – typically this may be half of the shots taken. These would be made available online or emailed.
Later (typically within 1-2 weeks), the model will receive a CD/DVD of a selection of hi-res photos selected by the photographer (but the model may suggest some from the low-res proofs). These will have been edited, cropped and finished as appropriate. (See my separate comments on photo-shopping and my preferred style of editing). Depending on the quality of photos produced from the shoot, this could be anything from 10 to 30 shots (sometimes more). But since editing each photo typically takes a minimum of 5-10 minutes, it should be realized that editing 30 shots could take 5 hours or more – so it’s unreasonable to expect any more.
The model will have the right to use all finished photos for any non-commercial purposes. In other words, they may be used digitally or in print form socially or for promotional purposes (websites, portfolios) but may not be used for financial gain.
The photographer brings his time and expertise to the session as well as providing use of often expensive equipment both during the session and after (editing).
The photographer retains copyright to all images and will be free to use all images for promotion work, portfolios and other non-commercial uses. In addition depending on the agreement, the photographer may retain the right to use images for commercial purposes (including but not limited to Stock/Microstock agencies, direct websales (digital or print) or any other outlet but not including any pornographic or similar uses. The model will be expected to sign a model release form.
All details of this will be specified on the Model Release/Agreement form and may be modified/negotiated. For instance, specific uses of any type of nude or semi-nude photos may be limited by agreement.
Bottom line is – both parties should benefit from the arrangement and be appropriately rewarded for their time and effort.