What’s the difference between F22 and F5.6?


Q. One thing I just can’t understand – how can everything be in focus (in landscape photography) at say F16 – F22 but yet recently when I was shooting a landscape in low light someone told me to go to way lower F/nr than F16 as “there’s no need to be up there, you need more light now” – I thought the lower the F/nr the less detail in the photo would be in focus so why would I want that for a landscape shot? Hence I’m not quite sure if F22 lets in less light and F5.6 lets in more light – then how the heck does that affect the amount of detail that’s in focus in the photo?  Well… you did ask for questions, stupid or otherwise. Lol 🙂 – Kerry-Anne O’Donnell, Northern Ireland

A. Hi Kerry-Anne, There is a relationship between the amount of light coming into the camera and how you set the f-stop and speed – which is confusing sometimes.  Basically if you want to get everything in focus, then you are right – you need to be on the F22 side of things (F16, 11, etc.).  If you want the background out of focus you need to be at the other end – F5.6, 4, 2.8, etc.

The way to remember this is “the bigger the number, the more in focus.” However if there is not much light, it’s twilight for example – then this is difficult, because F22 “closes down” the aperture – therefore not enough light can get into the camera if there is not much around.  So you might have everything in focus but your shot will be dark because the camera can’t see the light!   In low light – you need to “open up” the aperture – which means putting it up to 5.6 or 4, allowing more light in.  Of course this means the background will go further out of focus – you can’t win! But keep reading…

That’s why it all gets so technical – because basically if a landscape photographer is in this situation – i.e. it’s a sunset or something – the only way to keep everything in focus is to keep the aperture at F22 – and the only way to let enough light in to the camera whilst using F22 in low light, is to keep the aperture open for a long time – which means you use a very long exposure – which involves putting the camera on a tripod (or it may blur because of movement) – so you have to alter the shutter speed to do that – you make it several seconds long (or even minutes in some cases) – now the aperture is now open for a much longer time, which means that more light can get in.

Yes – what a faff.  This is why I don’t do it!  I take landscape pictures in good light – or I take them at 5.6 because I love bits of them not being in focus!  I decided years ago that it was far too complicated to do landscape shots that involve loads of equipment, time and a good brain – so I worked out that I could get lovely pictures of things I had seen by thinking about them in a different way.  I see them as shapes in nature – rather than “chocolate box” pictures.  I leave that stuff to those who want to trek up mountains and sit there for 3 weeks waiting for the light!  Me – I want to shoot something as I’m walking past it and then go and have a coffee!

Also – just to be even more complicated – it also depends on the type of lens you use.  If you use a fixed lens – say 50mm or something – then the background will be more in focus (whatever aperture you use) than it will be if you shoot it on a long zoom lens like a 70-200.

If you are using a compact camera, then you can set it to Portrait setting (symbol of a head usually) to get the background a little more out of focus, or set to Landscape (symbol of mountains), and get more detail in the background. Hope this helps!

I’ve added some pictures below which were ALL shot on F5.6 with a compact camera – I like to focus on one part of the picture and let the rest do it’s own thing – which usually makes the pictures softer and more interesting – but this is just my take on it! Do whatever makes you happy!

Annabel x




Hi Annabel, Thanks so much for taking the time to give me such a comprehensive answer, I really do appreciate it and more importantly I do understand it a lot more now.  I couldn’t quite grasp why anyone would want to use the likes of F5.6 for a landscape shot – I think what I need to do in future then is stay between F11-F22 but will need a longer exposure if I want more of the photo to be in focus in low light. Thanks a lot for the explanation Annabel, very clearly explained and easy to understand! – Kerry-Anne