I managed to find it using this guide:
The number before the first _ is the photoID
Append this to http://flickr.com/photo.gne?id=
And you get the full flickr URL for the image.
In my case http://flickr.com/photo.gne?id=14742720206
Which has a non-commercial CC BY-NC-SA 2.0 license.
Credit: Norbert Hülsmann
This seems likely to qualify as fair use, by several of the four factors used as tests.
"The purpose and character of your use" — educational and as part of commentary on educational article
"the nature of the copyrighted work" — the work itself was used as an educational illustration and you're extending that
"the amount and substantiality of the portion ...
So who exactly do I have to get permisssion from to use photos froma shoot
Simply, the person who owns the rights to the image(s) under question.
The vast majority of the time, and absent contractual language otherwise, the photographer is the rights holder.
And in general, to determine who owns rights to individual photos, it's easiest to start with the ...
@atomheels's answer is great (I'm glad to learn about the photoID URL hack). Here's how I found the answer:
Perform a Google "Search by Image".
The search results led me to a couple articles using the same image. Hopefully, I'm looking for a page or article that credits the photographer and links directly to the hosted image (Flickr, in this case)...
This is a situation where any legal situation/case would be tested on it's merits and would depend entirely on the image.
In most jurisdictions if the arrangement of the products and their lighting show an artistic intent then you are in 'fair use' territory. Even if that work is sold for profit.
In this situation it's probably better to ask forgiveness ...
Is modifying a photo to educate generally fair use?
In general, no.
For example, if I made copies of your photos and used them as part of an educational course in which I charge students, even if I modified the photos to add arrows that identify relevant elements, you might argue that my modified versions of your photos were derivative works not fair-use ...
IANAL, but I think it'd depend on how you use the photo. If your photo just happens to include someone's sign because it was there in the scene, that should be fine. Many cities have signs that have become icons in their cities, and nobody would reasonably claim that you couldn't photograph them. Here are a couple examples:
Baltimore's Domino Sugars sign: