Ideal Aperture

The ideal aperture is like really large, yes, a small F-number?

Depends.

Well then, at least in a portrait it is, yes?

It can be. But you need to think about this carefully.

Look at this image of some students who kindly volunteered the other day:

f/5.6:

f/3.5:

f/1.8:

f/1.2:

Which one do you prefer?

I think you may agree with me that a blurrier background is better. But so is a sharp face. Often, the extremely shallow depth of field (e.g. the DOF you get at f/1.2) is too shallow for comfort. Personally, I would say that for this kind of close-up hand-held available light portrait, f/2.8 to f/4 is great.

Reader question

Today, another reader question that I think may interest others. Reader (and student in one of my workshops) Chuck asks:

I wanted to ask you a second question since my class – this time about Canon lenses:

I’m looking for a wide angle Canon EF lens, and I’m seeing two choices:  17-40MM L F. 4.0 lens and for literally twice the price, a 16-35MM F2.8 lenses.

Having heard you educate about ISO abilities & Lightroom capabilities and seeing your picture of lenses ( http://mvwphoto.files.wordpress.com/2009/10/lenses.jpg) I’m wondering why you choose the more expensive 16-35MM F 2.8. over the 17-40MM F 4.0  I read a lot of praise for the F2.8 lens and mixed praise for the F4.0 lens…. but just wanted your perspective please on these two L series lens before I make the purchase.

Thx!

Great question, Chuck.

First of all: either lens would be superb. They are both high quality “L” lenses. On a full frame camera like my 1Ds this is a very wide angle lens; on a crop camera like my 7D this is a wide-to-standard lens. All great.

So why do I go with the 16-35 f/2.8 instead of the 17-40 f/4?

Two reasons.

  1. A wide lens is easy to keep in focus all over the place, i.e.in focus from the tip of your nose to infinity. The wider, the easier this gets. But what if I do not want that? What if instead I want selective sharpness, with a really, really blurry background? Then on a wide angle lens I need very low f-numbers to achieve that. F/2.8 is better than f/4 (which is better than f/5,6, and so on). ISO will not help here.
  2. Light. A wider lens lets in more light. One more stop may not seem much, but in the low light environments I often shoot in, that extra stop can be the difference between a lost shot and a good shot. ISO can of course help, but in that case the more expensive lens can be the difference between me having to shoot at 3200 ISO and being able to do it at 1600.

That’s why I chose the 16-35. The 17-40 would also be a super l;ens, and if you do not need the extra depth-of-field control and you do not shoot very dark environments all the time, the 17-40 will be great as well. I used to own one and loved it.

Why is the 2.8 twice the price? It has literally twice the glass in it, that’s why (a larger aperture means more of that expensive optical glass). So it’s not just marketing!

Advice: go into your camera store and hold both, feel them, try them out. Then, you will know. And since either choice will be superb, you will be happy!

Michael

Guess what.

Two techniques today that I have pointed out before, and I will do it again until everyone uses them regularly.

  1. Close-Far
  2. Selective focus with supporting background elements

Like here:

Food, and food

Food, and food

And here:

Cigar and person

Cigar and person

These pictures:

  • Make the foreground subject really stand out
  • Achieve perspective (close-far: get close to your close object!) and
  • Provide environment, or context, where theuser has to put two and two together to create the story. The eye goes to close object – background – back to close object.

One more example – then go out and shoot some!

Cheers (Teen with orange juice)

Cheers (Teen with orange juice)

Instuctions, should you need them:

  1. Wide lens, often the wider the better
  2. Get close!
  3. Focus on the close object.
  4. Use the largest aperture (smallest “f-number”).

Have fun!

Wide, and wider

Wide angle lenses are good, you have heard me say this many times.

Not just for travel. Also, for instance, for “event background shots”, like this recent picture taken at a corporate event:

Bar Lemons

Bar Lemons

Or for this:

Montreal Plateau Tree

Montreal Plateau Tree

Wide angles because:

  • You get more in (d’oh).
  • They are easy to focus – if you wish, you can get it all in focus (but see the note below).
  • It is easy to avoid camera shake (a safe-ish shutter speed is “1 divided by the lens length”, after all, so shorter lenses are easier).
  • You introduce depth (“close-far” technique).
  • You can exaggerate perspective, if you wish.

So how wide is “wide”?

I would say 16-35 mm on a “full frame” camera – that means 10-20 mm for those of you who use a crop camera, like a Digital Rebel, 50D, D3000, or D90.

Now I promised you a footnote. Wide lenses make it easy to focus on “everything”. So what if I want selective focus, like in the bar or in the following shot? Selective focus is oh so important in photography, as it helps you tell a story:

Buffet

Buffet

Well, then I need to have a wide open aperture. Wider than on a longer lens.

And that is why I use a 16-35mm f/2.8 lens, and if I could find a faster one I would get it, too. The faster (i.e. the lower the “F”-number), the better. So when some say “a wide lens does not need to be fast”, they are wrong.

Why is my picture blurry?

Why is my picture all blurry?

I hear this all the time from both experienced and new photographers.

Well, here’s why.

Focus:

  • You have not focused properly. Solution: select ONE focus point; focus; hold it; and only then shoot.
  • You are using a shallow depth of field. At f/1.4, it is hard to focus.

Subject:

  • Your subject is moving fast. Solution: pan with the subject or increase ISO, open aperture, or shoot the subject at the apex of its jump, say.

Shutter speed:

  • You are using a slow shutter speed (slower than twice the lens length, say, so on a 100mm lens you are using a shutter speed slower than 1/200th second). Solution: open the aperture or increase the ISO).
  • You are using a long lens (say a 300mm lens). On that lens, fast enough shutter speeds are hard to obtain). Solution: Zoom out, increase ISO, open the aperture, or use a tripod.
  • You are not using a tripod when you ought to. Solution? use a tripod!
  • You are using a slow lens. An f/3.5-5.6 consumer lens will never do as well as an f/2.8 pro lens. Solution: need I say?
  • You are using a small aperture, like f/8, when you should be using f/2.8. Solution: open your aperture.

Miscellaneous technique:

  • Your subject is in the dark – where it is muddy and blurry. Solution: Light your subject well.
  • You are not using flash when you should be. Solution: need I say?
  • You are  not using IS/VR. These are great features: stabilized lenses are superb and give you several stops. Solution: get an IS/VR lens.

Equipment:

  • Your camera is faulty – this is very unlikely, but have it checked out.
  • Your lens is faulty – this is also rather very unlikely, but have it checked out.

Clear? (Pun intended). Try all these and you will see your images improve amazingly.  Yes, I know, there are a lot of them. Yes, it’s complicated. But yes… you will take brilliant images once you get all of these right.

Remember these tips:

  • Bright pixels are sharp pixels (that is Willem’s Dictum);
  • Flashed pixels are sharp pixels;
  • VR/IS works;
  • Use one focus spot;
  • Hold the camera right;
  • A tripod is a good thing.

Have fun – a crisp, razor sharp picture really is a joy.