# What's this little sign on the focal length ring of zoom lenses?

Looking at pictures of zoom lenses I've noticed there's sometimes a little sign between the two widest focal lengths:

What is the meaning of that sign?

## 2 Answers

I've always thought that it's just to indicate the position that the widest focal length (in the example pictured that would be 18) refers to, to prevent it being too close to the next widest value - e.g. 18 & 24 appearing as '1824'.

In effect the line is saying "we've written the widest focal length over here but actually it should be written here!"

I don't have any reference for this, but on all of the zooms i have used the vertical part of the symbol lines up with the focus ring's position line when the lens is zoomed out to the widest focal length (as it appears to in your picture above).

• It's always amazing to me how badly designed so many icons/symbols are that they need to be explained.
– user3739
Commented Dec 30, 2017 at 11:23
• @DrEval: not a bad design in my opinion. Zoom rings don't need to be linear but since they often act in a linear fashion, some key values get squished too close together and it feels like common sense to me. Commented Dec 30, 2017 at 14:19
• I'd never noticed that before. But if every number had a tick (or at least the one at the other end, reversed), it might be more obvious. Of course this would add 0.0000001c to the cost so it'd never happen. Commented Dec 30, 2017 at 17:19
• @progo The fact someone is asking about it shows it's a bad design. It's common sense that something needs to be done to show where 18 is, but that icon doesn't represent anything. It would literally be more clear were it an upside down christmas tree - at least then there's a chance the user would pick up on the fact that something was being pointed at. The "every number has a tick" is obviously better still. I could literally come up with 5 or 10 ideas which would be clearer than a sort of rotated letter d floating one third of the way between two numbers.
– user3739
Commented Dec 30, 2017 at 18:33
• @DrEval bad is subjective. No matter how well your design is there will be somebody somewhere that will not get it. As a result here is somebody wo it needs to be explained to. Therefore, according to your logic its bad design? But yes this is not the best design possible but not the worst either. Certainly not very bad design at least. Commented Dec 30, 2017 at 19:31

It is just to indicate where the widest focal-length is since there is not enough space to have 18 and 24 not run into each other. You will notice that you will not be able to zoom out past it.

• Given that you can't zoom past it, it's not even needed. What would happen if it wasn't there? Has a single user ever removed their eye from the viewfinder, looked at the side of the lens, twisted until the rotated letter d sort of lines up with the line below and says "There! I have now fully zoomed out!" before proceeding with composing the image?
– user3739
Commented Dec 30, 2017 at 18:36
• @DrEval I'm sure that without that line, and with that being as far as the lens can zoom, tons of people would think their lens was broken, and couldn't quite reach the end of the range. "I paid for an 18-200mm lens, but it can only get halfway from 24mm to 18mm!" Commented Dec 30, 2017 at 21:36
• ^^^^^^^^ This! ^^^^^^^^^ Commented Dec 30, 2017 at 22:35