The only time you really need to wait is when your paid for assignment work. While every publication is slightly different, the “rights” that you sell to use the images will fall into one of two categories.
The right to be the first publication in NA to use the image. Otherwise known as FNASRs. This leaves you free to do whatever you want. The image remains yours to do with as you please. They have just bought the right to use it once, and to be the first publication to do so.
Exclusive rights.
Can have any number of conditions. For the pub’s I do assignment work for I’m accepting payment for work not published. I’m also getting paid whether I get any images or not. Basically Im paid go to X and shoot Y, but if the weather goes south and I come back with nothing Im still paid.
In return the publication has exclusive rights to any and all resulting images for 1 year or until the article/images are published, which ever comes first. After which I am free to do as I please, but during that time I cannot display, redistribute etc. That includes showing them online either on forums, websites, etc.
In both cases the images remain mine to do with as I please.
Display, alter, sell rights, delete, etc. All I’ve done is sell the rights to use the images once. But in the case of assignment work where Im paid for “my time” regardless….They have “dibs” on any and all images for 1 year
If what your doing is gratis…(no compensation) do whatever you like, when ever you like.