You should learn how to properly write accessible image captions as the fediverse has a large amount of blind and visually impaired users who rely on screen readers
Make it easier for everyone to enjoy your pretty Instagram posts and funny tweets.
Right now there is a bit left to be desired when it comes to lemmys accessibility features, but it's a good idea to be mindful of the fact the fediverse and its platforms tends to have pretty universal accessibility features that will likely come to lemmy sooner rather than later
Alt-text descriptions should clearly convey both the content and the meaning of the image, and should aim to use as few words as needed. Describe what's essential to understanding (and enjoying!) the intent of the posted photo — you don't need to add in a sentence for every visual element, but should include as much as you need to create an accurate portrayal of the image. Cut out unnecessary words and combine separate sentences as much as possible. One to two sentences is usually more than enough room to describe what's going on.
As mentioned before, these photos convey information to the people scrolling your page, even if you are just posting them to brighten up your feed. They have a purpose, and for that reason, alt text should focus more on the image's meaning than its aesthetics. This means you're not focused only on what the object in the photo looks like, but what it is and why it was posted.
I was hoping to see a format that people can easily follow and just fill in the blanks, but I suppose this is the gist of it: Describe the main purpose of the photo succinctly rather than each and every individual thing you can see.
Is the image purely decorative/e.g. if the picture never loaded does the audience miss out on some piece of information? If not then empty alt text suffices (this is less applicable to social media posts)
Otherwise imagine you have this picture and you’re telling somebody on the phone about it.
You’re not going to go into a full description of every element
“a small child on the left side of the picture is picking up a maple leaf with their index and thumb and handing it to the person on their right” who is a 50-60 year old woman with dirty strawberry hair and wearing horn rimmed glasses”
That’s too much and doesn’t “convey” the photo.
And you wouldn’t say “kid hands something to another person” since that’s not enough.
Let’s say you have an article about the fall and all the fun activities families can partake in. What matters is that it’s a young kid showing their grandma a leaf.
So something like this
“Young child and grandmother at City Park. He is handing her a newly fallen leaf”
Or, if it’s an article about children nature education programs then it may say
“Teacher and a student in the park. The student is presenting a maple leaf to the teacher”
If it’s a post about your kid it may say
“Timmy showing his grandma a leaf he found while playing at City Park”
I can't really think of a case where a post's image isn't relevant to the associated discussion. Even if it's just a nonsense post with an unrelated image, knowing what the irrelevant image is about would help make sense of the discussion.
Not enough info is better than nothing. Because if it's nothing, you can't tell if the person who shared the image is lazy or decided the alt text wasn't necessary for this particular picture