Photography Explained

Camera Lenses Explained For Beginners - 15 Things You Need To Know

April 22, 2021 Rick McEvoy Episode 57
Photography Explained
Camera Lenses Explained For Beginners - 15 Things You Need To Know
Show Notes Transcript

Camera Lenses Explained For Beginners - 15 Things You Need To Know. Hi and welcome to Episode 57 of the Photography Explained podcast.

I’m Rick, and in each episode I will explain one photographic thing in plain English in less than 10 minutes (ish) without the irrelevant details. What I tell you is based on my lifetime of photographic experience. Not Google. Well there might be the odd thing that I had to look up but mainly this is stuff that I know.

Here is my answer
Here are 15 things that you need to know about camera lenses

  1. Why are there so many different lenses?
  2. Fixed lenses
  3. Zoom lenses
  4. Standard lense
  5. Wide angle lense
  6. Telephoto lense
  7. Crop factor
  8. Specialist lenses
  9. Aperture
  10. Depth of field
  11. Quality
  12.  Cost
  13. Re sell value
  14. Does every camera have interchangeable lenses?
  15. Camera mounts
  16. What Do I Use?

(OK - there are 16 things!)

My one line explanation
Camera lenses provide endless creative opportunities for photographers.

Listen for more, or check out the transcript and even the blog post - so many ways to find out more!

What’s next?
Glad you asked! In Photography Explained Podcast 58, Prime Lens Photography Explained in Plain English In Less Than 10 Minutes.

What to ask a question?
Head over to the Want Me To Explain Something? page on the Photography Explained website and fill the form in and you are done!

Check out my my blog
Check out my photography blog where you will find lots more photography stuff all written by me.

Did you enjoy this episode?
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Thank you very much for listening and see you on the next episode.

Rick McEvoy – Photography Explained Podcast

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Camera lenses explained for beginners - 15 things you need to know. Hi, and welcome to Episode 57 of the photography explained podcast. I'm Rick, and in each episode, I will explain one photographic thing in plain English in less than 10 minutes (ish) without the irrelevant detail.

What I tell you is based on my lifetime of photographic experience, not Google, mainly this is stuff that I know.

And when I say 10 minutes, this episode is not looking good. There's quite a lot here to explaining lenses.

I am going to go into quite a few of these things in future episodes. I've spent some time on cameras. Lenses - it's a big area really. The bit you shove on your camera that you take photos through so quite important!

Anyway, this is take two. Take one I failed on the first line. So this is a big improvement already. So let's get into this

Camera lenses explained for beginners 10 things you need to know. 

That’s what it was when I started writing this, and it ended up being 15. And it could have been 16 as I forgot one thing.

1 Why are there so many different lenses?
If you look on the internet, and look at camera lenses, it's a bit bewildering. I mean, I use Canon cameras and lenses. You look at the range of Canon lenses, and it's quite, yeah, it is bewildering. There are so many different lenses.

And if you think about them, these are expensive things, so they've been made for a specific reason. Every lens that you can see, you might not have a need to use one yourself, but every lens that's ever been made (pretty much) there was a purpose for, and somebody spent a lot of time and effort and engineering genius creating it.

We have fixed lenses and zoom lenses. This is fundamental point number one.

2 Fixed lenses
With a fixed lens, you look through the lens and you see what you see. On a zoom lens, you can zoom in or out.

Okay, fixed lenses are also called prime lenses. I don't know why.

But a prime lens will have a focal length, for example of 50mm. A 50mm lens is what is called a standard lens. I'll come back to that (but use this to explain things).

3 Zoom lens
A zoom lens could be, for argument's sake, 24-70mm, a variable focal length.

4 Standard Lens
Right then. A standard lens has a 50mm (focal length) on a full frame camera, I will come back to crop factors.

This is the thing that I sort of love and hate about photography all at the same time. I can't seem to explain one thing without having to (easy for me to say) to about five other things. So I can't just explain a lens without going through these other things. 

If it sounds like I'm jumping about all over the place, there is a reason for it, and it's because none of these things are that straight forward. I'm trying to make them straightforward and understandable.

Standard lens on a full frame camera.
Now I explained in an earlier episode what a full frame camera is, but let's just do a quick recap. A full frame camera has a sensor which is 36mm x 24mm, which is the same size as a 35mm camera film.

You put a 50mm (standard) lens on a full frame camera and what you see through the viewfinder is pretty much how humans see the world (certainly me – I cannot vouch for you!).

Now as I explain this I have just seen an error in my list.

So a standard lens is you photographing things, how we see them as we walk about our day to day business.

5 Wide angle lens.
A standard lens on a full frame camera is 50mm.

A wide angle lens is less than 50mm (focal length), common focal lengths are 24mm, 28mm, 35mm. Anything beyond 35/40mm and you're getting towards standard but 24mm and 28mm are very common. wide angle lenses.

Now what does this mean?
With a wide angle lens, because your field of view is wider you can see more. So rather than what you're looking at and you can generally see, you've got a wider view, there's more to be seen there's more in the scene.

5.5 Telephoto lenses
Okay, so the next one telephoto lens that's not on my list, which is a little bit of a concern. I've missed that one.

A telephoto lens has a focal length which is longer (larger) than 50mm. With a telephoto lens, common focal lengths could be 135mm, 200mm, 300mm, 400mm. The bigger the number, the more magnification, the closer you get to things, and the less your field of view (and the more they cost).

So that's a telephoto lens.

Sets of lenses
So if we go back to fixed lenses, like I say, you could have a set of lenses which are 24mm, 28mm, 25mm, sorry, 35mm, 50mm, 85mm, 135mm, 200mm, 300mm.

Before zoom lenses that would have been quite a common set of lenses.

You could however get a zoom lens, I've got a Canon 24-105mm lens which goes from wide to telephoto, which is a really good all round lens and that's why we have zoom lenses as they give you more options than having fixed lenses.

Post episode recording note – My Canon 24-105mm lens replaces in theory the 24mm, 28mm, 35mm, 50mm, 85mm lenses – get the point? Ok – back to the recording.

6 Crop factor
Okay, let's move on number six (which we should know should 7 but I made telephoto 5.5!).

Now I said at the beginning 50 millimetres on a full frame camera is (pretty much) how we see the world the same aspect ratio, same everything.

Now if you get a cropped sensor camera, also known as APS-C (check out previous episodes for more on this) there is a crop factor applied because the sensor is smaller.

So on a cropped sensor camera, the common crop factors are 1.5-1.6 x.

What that means is this.
You times the focal length on a full frame camera (50mm) by 1.5, and that gives you an effective focal length with a 50mm lens (on a cropped sensor camera) of 75mm.

How did we end up with this - baffling isn't it?

Micro four thirds, cameras have even smaller sensors. And the crop factor on a Micro Four Thirds camera is two.

So a 50mm lens on a Micro Four Thirds camera gives you an effective focal length of 100mm.

Okay, I'll come back to some of these in more detail (in future episodes not here).

8 Other specialist lenses

Number seven (we should be eight) is specialist lenses. There are specialist lenses, which are not that common, which I've owned and used and sold again.

Fisheye lens
They give you a circular image. I spent about a grand on a fisheye zoom lens and it was a (Canon) 8-15mm lens. So at 8mm you get a full circular image, at 15mm you had a normal full frame aspect ratio image (but very wide).

Sure, I got some funky effects with it, I didn't really get it, so I sold it.

Tilt Shift Lens
I've also had a tilt shift lens, complicated, manual focus, big, heavy expensive. I had a go with it, but it's also been sold on, which is a shock considering I'm an architectural photographer.

But I get by.

8 Aperture.
Another thing in a lens. Now when you buy a lens, and I'm going to stick with my 50mm example, you have a maximum aperture, and the maximum aperture is the maximum opening that lets light in.

So if you have a 50mm lens. Let's go with a 50mm F1.8 lens. F1.8 is maximum aperture, the minimum aperture, the small hole will be something like f 22.

So that lens will cost you more than a 50mm F4 lens. The bigger the maximum aperture, the more light that gets in through the lens of the sensor, the faster the lens, and the more expensive it is, and bigger and heavier and what have you.

If you take photos on a tripod like me, it's not a big issue anyway. So yeah, the larger the maximum aperture, the bigger and more expensive (and perceived higher quality lenses - don't necessarily believe that

9 Depth of field
Depth of field is a term I hate. It's the amount of the photo that's sharp from front to back.

Now the aperture (of the camera lens) is a factor, the aperture, and the lens (focal length) have an impact on the depth of field.

If you have the camera lens wide open, as in maximum aperture (largest opening), you will get less depth of field. If you stop down the lens to the minimum aperture, (smallest opening), you will have more depth of field.

You get more depth of field on a wide angle lens than you do on a (incoming telephone call!) telephoto lens.

You get more depth of field on a crop sensor camera than a full frame camera, I still don't understand that.

10 Quality
Okay, quality of lenses. I think in general terms, the more money you pay, the higher the quality, the better the photos, in general terms.

This is a big generalisation in photography because you can get fantastic photos with a camera costing £1,000.

So why can you buy a camera (and lens) costing £10,000? Because the quality is better, the quality is higher. So the more money you spend, the higher the quality, but you can get really good results with relatively inexpensive lenses.

These days, the optics are fantastic. There's also a lot of clever electronic stuff in the software that helps as well.

So yep, quality varies, cost varies hugely as well - it depends what the lens is. Like I say the bigger the maximum aperture, the more expensive the lens.

11 Cost - what do I use?
Now, I use a Canon 17-40mm F4 lens. F4 is not a fast lens. Because it's an F4 maximum aperture lens, the lens isn't that big, it's not that expensive.

And it takes fantastic photos, it works for me.

17mm is wide enough, just what I need, I take most of my photos using 17mm. And I I never take photos at f4.

The problem with maximum and minimum apertures

Because you do lose quality at both ends of the aperture scale, I use F8 or F16 the bits in the middle (the sweet spots for this lens).

So that's what I use.

I don't need a more expensive camera lens with a bigger aperture because I've just got no need for it. And it would just be a waste of money and it will be heavier. So think about that and the type of photography you're embarking on

12 Resale value.
No one told me this. Nobody ever told me this. I had to find this out myself. If you buy a camera lens, in five years time you might well get more money for it.

They hold their value fantastically well.

Just something to bear in mind.

I've actually bought secondhand lenses, had them for 4,5, 6 years, used them a lot, looked after them, of course so they're in immaculate condition, and sold them and got really good money for them.

So yeah, bear that in mind.

13 Does every camera have interchangeable lenses?
I've given up with a numbering of notes because it's wrong (corrected in the edit of the transcript). Now they don't you can get cameras which don't have interchangeable lenses.

Let me introduce a new unhelpful acronym ILC. Interchangeable lens camera is a completely unnecessary term, isn't it?

14 Camera mounts
Canon have their own (lens) mount, as do Nikon and Sony, and Fuji.

Now micro four thirds cameras have a universal mount so anybody could make a lens that fits on a Micro Four Thirds camera.

But there are people third party manufacturers like Sigma and Tamron who make lenses for Canon, Nikon, Sigma

15 What do I use?
I use three lenses (with my Canon 6D)

  • Canon 17-40mm F4L 
  • Canon 24-105mm F4L
  • Canon 70- 200F4L IS USM (snappy title I know)
  • I used to have a 24mm tilt shift lens - I sold that.
  • I used to have 100-400mm zoom lens – I sold that.
  • I used to have 100mm f 2.8 macro lens – I sold that.

(And I forgot to mention that I used to have a Canon 8-15mm fisheye zoom lens that I also sold).

I probably had other lenses especially in my earlier crop sensor days, but they're all gone.

I only have three lenses.

With my Olympus EM5 Mk2 I have

  • 14-42mm lens, a pancake lens. That fits the camera in my camera pocket (really)
  • 12-40mm F2.8 lens which is a brute.
  • And a 40- 150mm lens.

That's all I have.

Right? I am way over time here. I thought so.

My one line explanation.

Camera lenses provide endless creative opportunities for photographers.

Next episode is Episode 58 would you believe – prime lenses explained by me in plain English in less than 10 minutes - snappy title

Now if you enjoyed this episode, please leave a nice review and rating wherever you get your podcast from. Please subscribe so you don't miss an episode and share my podcast with anybody you think might enjoy it.

Thank you
Thank you for listening to my small but perfectly formed podcast.

My websites
Please check out Rick McEvoy Photography to find out about me and my photography blog and also the Photography Explained Podcast website where you can find out all about this podcast and ask me a question.

This episode was brought to you by the power of caffeine and the other half of the chocolate digestive (refer to the previous episode).

I've been Rick McEvoy thanks again very much for listening and forgiving me 16 ¼ minutes - longest episode ever. And I'll see you on the next episode. Cheers from me, Rick.


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