Fast lenses, and why again?

I regularly mention that the lens is the most important part of your equipment. Great lenses especially add to your photo-taking capabilities. Now let’s look at one aspect of that greatness again: the “speed” of a lens.

Speed is of course a misnomer. When we say “a fast lens” we simply mean “a lens with a large aperture (low “f-number”). This large aperture lets in a lot of light, which makes it possible to shoot at faster shutter speeds at the same ISO, hence the word “fast”. So a low f-number means you can obtain faster shutter speeds under the same conditions.

Like the 50mm f/1.2 lens I am selling (sadly; but I bought the 85 f/1.2 and I cannot financially justify keeping both these lenses; and for wedding portraits, the 85 will be more useful).

Here’s student Becky with the 50 f/1.2L mounted on her Canon 6D last night:

I was able, by using the large aperture of my own f/1.2 lens, to take that picture at a fast shutter speed, handheld. And I get a blurry foreground and background at the same time,  which helps me to emphasize the subject.

How fast? Let’s look at a real example from last night.

A shot of a glass of wine. That is what I focused on, so that is, of course, sharp:

I shot that at f/4.5, which is typical of the kind of lowest “f-number” that a kit lens would allow you to use. At 1600 ISO, that necessitated a shutter speed of 1/30th second. That is at the limit of what I can hope to do handheld; in fact it is beyond that “rule of thumb” limit, with an 85mm lens. So I am lucky that the shot is sharp. Also, I am lucky that nothing in the photo moved, because pretty much any motion would show, at that slow a shutter speed. And yes, the background and foreground are blurry – but they could be blurrier.

Now the f/1.2 lens, this time wide open at f/1.2:

The “f/1.2″ means that:

  1. At the same ISO value, I now needed only 1/320th second shutter speed. I.e. a much faster shutter speed (i.e. less time; shorter time period; all these mean the same thing).  That means I can easily hand-hold, and also I need not be afraid of motion.
  2. The lower f-number also allows me to through both Becky and the chips in the foreground way out of focus. The glass is still sharp (I am, after all, focusing on it!), but the depth of field at this low f-number is extremely shallow; meaning that foreground and background are very blurry indeed.

Now, I do not of course always want shallow depth of field; but the point is, that with a fast lens, I can. And that expands my picture abilities; in a dark evening setting I can shoot handheld without flash, and if I want, I can get extremely blurry backgrounds. And that is one of the reasons that I use an SLR in the first place. And any SLR would do this – it’s the lens, not the camera, that determines these things.

Which is why I am happy to spend on lenses. What’s not to love?

And a good lens lasts decades, both in technical terms and in value. So if you are going to spend, and why not; then spend mainly on lenses.

 

Learn Focal Lengths

One thing that good photographers know is  ”what focal lengths do”. There is such as thing as “the right focal length for a picture”, or perhaps better, “the right types of picture for a given focal length”. And a good photographer knows these. The pictures tend to then fall into place.

We all know – I hope – that you do not do a headshot with a 16mm lens. And we all know that landscapes and travel do like that focal length.

But in general, what is appropriate?

It depends. On you and your taste. But there’s often a good range. Look at the following examples – and keep in mind, the lengths I mention are for a full frame camera. If you have a crop camera, divide by 1.5/1.6. So a 35mm lens in my examples would need you to use a 24mm lens on a crop camera.

With that in mind, let’s look at some portraits.

35mm:

50mm:

65mm:

85mm:

200mm:

Are you beginning to see patterns? Develop your own preferences and “usual lenses” – they probably will not vary much from mine – and you will be much quicker deciding how to shoot what. A prime lens is a great way to learn, by the way. It’s why we love primes.

 

Another note on primes…

“Why should I buy a prime lens”, I am asked often. The answer is always the same: sharp, small, fast, and consistent. Oh – and fun.

Look at this photo:

A typical prime shot: 50mm lens on a crop camera (meaning a “real” 80mm). In available light, I used the following settings:

  • Manual exposure mode.
  • 800 ISO
  • 1/80th second shutter speed
  • f/1.6 aperture.

Let’s say I had used a consumer lens: f/5.6 at 50mm. That’s almost four stops slower, so I would have had to use either:

  • A slower shutter, like 1/6th second; meaning a shaky picture;
  • Or 12,000 ISO, meaning a grainy picture;
  • Or a combination, meaning a little of both.

And the background would not have been nice and blurry, and simple.

Even an f/2.8 zoom lens would have meant 1/25th second or 3200 ISO, or a combination. And again, less blurriness.

So in real life available light situations, a fast prime can be invaluable. So you can document everyday moments and tell everyday stories, which are often the best. Here, the storytelling is done by the simple composition, the leaving out of the face, and the fork hovering expectantly.

 

 

Prime primer

I teach “Lenses” this afternoon (Saturday) at Vistek in Mississauga before leaving for the Sunday workshop in Timmins, Ont.

So while I am on it, let me see if I can give you some input as to why you might want a prime lens. I have explained before of course (consistency, sharpness, size, wider aperture..) but a picture, well, a picture tells 1,000 words.

Here’s my kitchen island:

Now let’s look at 1:1 pixels. Straight out of camera, and pixel for pixel; 1/80-th second at 800 ISO.

First, the 24-70 f/2.8 zoom at f/2.8, set to 50mm:

And the 50mm f/1.2 lens, also set to f/2.8:

Both are good. But when you look closely, really closely, especially at the cloth material, you see that the 50 is much sharper.

No surprise, it is stopped down while the 24-70 is wide open. But that is the point, isn’t it? In real life use the prime often gives me sharper pictures.

This fact, and a million others, in the “Lenses” course at Vistek Mississauga (after “Flash”, also a great course, if I say so). See you there perhaps!

 

Michael’s Top Ten Dicta

Legally speaking, a Dictum is “a statement of opinion or belief considered authoritative though not binding, because of the authority of the person making it”. More generally, it is “a noteworthy statement: as (a) : a formal pronouncement of a principle, proposition, or opinion; (b) : an observation intended or regarded as authoritative.” Google it if you want.

So, assuming you know me and trust my judgement, you may well be interested in my Top Ten Dicta:

  1. Bright pixels are sharp pixels. The more you make your subject bright pixels, the more it will be sharp and crisp. Noise hides in the darkness, like cockroaches. Light your subject and it becomes sharp.
  2. Go wide and get close. Wide angles combined with proximity to something introduces depth and perspective into y our images.
  3. Indoors flash: point your flash up, 45 degrees behind you. This gives you the correct light angle for close-by portraits, like in events.
  4. Indoors flash: Use the “4-4-4″ rule” as your camera setting starting point: Camera on manual, 400 ISO, 1/40th sec, f/4. Then adjust for brighter or darker rooms, to give average ambient exposure of around -2 stop.
  5. Turn baby turn. Feel free to angle your shots whenever you like. Composition, simplifying, energy: whatever your reasons. It’s cool, it’s allowed.
  6. You, and the lens, make the picture. Cameras are cool – I buy a lot of them – but the picture is made by you – even an iPhone can produce cool shots – and more technically, by the lens. A good lens on a cheap body is great. A cheap lens on a good body, not so much.
  7. Go Prime If You Can. Prime lenses lose on convenience but win in every other way. I love my 35mm f/1.4 lens.
  8. Use off-centre composition and the rule of thirds in your compositions.
  9. Get close: fill the frame. This so often makes your images better, it is worth stressing as a Dictum.
  10. Simplify! Ask yourself: is everything in my image the subject or the supporting background? If not, get rid of it. A circle has 360 degrees.

That’s my wisdom in a nutshell. Do you know, understand, feel, and above all use all ten principles above?


Learn about these and much more in one of my training or private coaching sessions. There is 10% December Discount – this is a great time to consider buying a friend a session with me: buy a Gift Certificate for the holiday season!