Question on 18-55 mm kit lens

I bought my first DSLR [Nikon D3100] with standard 18-55 mm F3.5-5.6 lens.

Now as per my understanding, I should get aperture of only F3.5 to 5.6

However, while at get only at most F/3.5 in lower range, I do find I can go far beyond F/22 in upper range.

How can it be possible?

mobi said:

I bought my first DSLR [Nikon D3100] with standard 18-55 mm F3.5-5.6 lens.

Now as per my understanding, I should get aperture of only F3.5 to 5.6

However, while at get only at most F/3.5 in lower range, I do find I can go far beyond F/22 in upper range.

How can it be possible?

Click to expand...

The f/3.5-5.6 represents the smallest aperture at the range of focal length of the lens...

at 18mm, 3.5 and at 55mm it can go to 5.6... again range of largest apertures..

You can still stop down to f/22 the minimum aperture throughout the range...

so, at 18mm, 3.5 to 22 ... 55mm 5.6 to 22

Hope this helps,

Pat in NH

Lens apertures are given in a way that allows you to assess their "brightness" - how much light will be let through in their maximum setting. All of them are adjustable from there to limit light, but you cannot adjust them beyond that to allow for more light. With less light (smaller aperture - higher number) comes more depth of field.

Prime lenses will have a fixed maximum (like a 50mm f1.8) while zooms may have a fixed or variable maximum. The 18-55mm gets "darker" as you zoom in, so at 18mm you can achieve f3.5, but at 55mm you can only achieve f5.6. This is because the lens elements move and change the light characteristics.

Here's a decent overview on what aperture is and how it works. Understanding Aperture - A Beginner's Guide

Good explanation Jake, Thank you!

Pat in NH

Thanks, I now understand it.

Oops - that previous post should say maximum instead of minimum in the second paragraph. Fixed now. I always get those words backwards since the number gets smaller and the aperture gets bigger. LOL

That used to get me all the time when I first bought a DSLR. People used to word it " you need a larger aperture " and so I'd increase from f4 to f8 and wonder what happened