Part 2 - Shutter Speed and Aperture
Nikon D600 Nikon 70-200 VRII | F/3.2 1/400th @ ISO 6400
Shutter Speed – You heard me mention this a bunch, so I thought this would be a good point to start discussing what shutter speed is and how it relates to what we are trying to accomplish. Shutter speed is a part of what is called the exposure triangle. Which means that if you adjust your shutter speed it can change how light/dark you photos are. When we adjust ISO, the same thing, ISO also controls how light and dark our exposures are. It does it differently though, by changing the sensitivity of the sensor to light. Aperture affects your exposure by how much light comes through the lens.
The shutter inside your camera opens and closes exposing the sensor to light. The longer the shutter is open (slow shutter speed) the more light is introduced, but any motion will be blurred. Ever see photos of waterfalls that are all silky smooth? That effect is created with a slow shutter speed. On the contrary, a faster shutter speed is what “freezes” motion in place. Like the image below:
Nikon D600 Nikon 70-200 F/2.8 VRII | F/4.5 1/800th @ ISO 5000
Sports typically any type, have fast movements we are trying to capture. For the most part, other than some “creative” type shots, we are trying to freeze that motion. So that means we need to get our shutter speed to a point where we can freeze motion. In the image below it looks like I did a good job freezing the motion:
Nikon D600 Nikon 70-200 F/2.8 VRII | F/3.2 1/800th @ ISO 3200
So what shutter speed should you shoot at? Well, in my opinion, try to get it as high as you can. Max out your ISO and try to shoot for at least 1/400th of a second. If you can’t get there, maybe 1/320th. The point is, you want to try and maximize your shutter speed or your image is going to be blurry, even with “Vibration Reduction” or “Image Stabilization” turned on. Those technologies prevent blur caused by you shaking and moving the camera while at low shutter speeds, not the blur created by the movement of your subject. The point I’d like to drive home is in these situations that you are trying to freeze motion, you need to do whatever combination of ISO and aperture to get your shutter speed up.
Aperture – Aperture in a lens that allows a certain amount of light to hit the sensor. It is represented as the “F/” number on the lens. Like F/4.5-5.6 or F/2.8. The lower the aperture number the more light is allowed to hit the senor, signifying the lens as “fast glass”. By allowing more light to hit the sensor you are able to decrease ISO reducing the amount of noise, and also have the flexibility to increase your shutter speed, making motion easier to catch.
Another neat side effect of a lower aperture is the “burry background” effect. That’s something for later as well, but just know that it’s a lot easier to make those backgrounds blurry with “fast glass”.
Fast glass comes at a cost though….literally. The faster lenses cost money. Constant aperture lenses are some of the most expensive you can buy. By constant aperture, I am referring to lenses that display apertures like: F/1.4, F/1.8, F/2.8, and F/4. As an example: my favorite portrait lens is a Nikon 70-200 VR II F/2.8. It’s a constant aperture lens. What that means is the lens allows the same amount of light to enter the lens at 70mm as it does at 200mm. A very handy thing indeed. This allows me to shoot lower ISO values and faster shutter speeds. But it costs money. This lens currently retails at around $2100. There other alternatives that companies like Sigma and Tamron make that are less expensive and are quite good, but I opted to stay with a Nikon “branded” lens. One of the reasons: I know with 100% certainty the lens is also dust/weather-sealed. I don’t know if the others are/are not…I’ve never felt the need to check. If they are, great…but I’ll still keep my Nikon. As for the Sigma and Tamron versions of the 70-200 f/2.8, they range in price but hover around $1500. We will delve into lenses in Part 3.
What lens we will touch on is the most common lens sold as an entry level “sports” lens. Typically this is the 70-300 F/4.5-5.6 and tend to hover around $550-$600. They come from a variety of manufacturers but they normally all share similar traits: most will come with some sort of vibration reduction or image stabilization (providing it's not an old used one), the most common aperture rage used is F/4.5-5.6, and they are variable aperture lenses. What the heck is a variable aperture lens? In short, the more you zoom out, the less light the lens captures.
Anytime you see a F/#- F/# it’s a variable aperture lens. F/3.5-4.5 is another common one. Don’t get me wrong, there is nothing wrong with them and they are great inexpensive lenses if you’re out shooting in certain conditions (like in the middle of the day where there is plenty of light)….but this isn’t the case with high school sports. We are shooting in low light. Low light and those lenses tend to lead to frustration and disappointment.
But Justin, I don’t have a 70-200 and I don’t see one in my near future. I’ve been there, it’s a lot of money anyway you spin it. The justification to get one shrinks more and more when you realize that maybe you won’t use it all the time. So, let’s compare the $2100 70-200 F/2.8 lens to the 70mm-300mm F/4.5-5.6 and see what makes the latter so much more expensive.
First thing I will say, in the $2100 lens, they use better glass…they have to. In order to keep the light transmitting through the lens to allow for a constant aperture the best glass is used. So, sharpness is one of the first differences you will see. My $2100 lens is sharp at 70mm all the way through 200mm. Sometimes on the 300mm end of the 70-300 lenses they get a little “soft”. It’s just the nature of the materials used. Super-zooms, like a 28-300 can even worse. That’s a long distance for one lens to cover. Try not get suckered into an all-in-one lens…you’ll get frustrated...trust me.
Anyway, back to our comparison. Look at the image below. First I will list my specs on how I got this image, and then we will do a hypothetical situation using the 70-300 as an example.
Nikon D600 Nikon 70-200 F/2.8 | F/3.2 1/800th @ ISO 3200
So, here are the important settings from my camera and $2100 lens:
Shot at 98mm, ISO – 3200, F/3.2, and 1/800th of a second shutter speed
Nice sharp frozen action. Overall, I’m happy.
“But, I only have the 70-300 F/4.5-5.6”. That’s ok, let’s pretend we took the same picture with that lens, but see how the settings need to change to accommodate.
So, we will say it was shot at 98mm, ISO – 3200, F/…..wait the lens doesn’t do F3/.2. Crap, so now what do we do? If you said “Try to shoot the lowest aperture” you were right. So, what is that lowest aperture we should shoot at? I bet many of you would say F/4.5…and you would correct…kind of. So as I said before, this lens if variable, so as we zoom in we lose light. I want to make the least amount of adjustments possible. Why? Because, who really likes to fiddle with settings when you should be taking pictures? So, I set the camera to use F/5.6. Why would I do this? Because that way when I zoom in and out, the aperture doesn’t change. When the aperture changes my exposure changes as well. The other nice thing is: by locking in the aperture, it only leaves me 2 settings I need to worry about in order to get my exposure correct, ISO and shutter speed.
So, for this exercise, we will use the aperture of F/5.6
So at F/5.6 we are losing 1 2/3 of a stop of light. What does that mean? That means we lose half the available light for the first stop, and another 2/3rd of that half because of the 2/3rd stop…Math aside, we are looking a bunch of lost light. So, how does that relate to what we are trying to accomplish…a photo freezing motion at a hockey game?
We want to keep our shutter speed to 1/800th for this example. Why? So we are only changing one thing at a time…easier to follow that way. Since we locked in our aperture, and our shutter speed, the only thing left to change is ISO. So we have to raise our ISO 1 2/3rd of a stop of light to compensate for the smaller opening in the lens (F/5.6). So, in order to go 1 stop of light, we need to double the ISO. We are now shooting at ISO 6400. Not bad, but pretty high even though ISO 6400 has been around for a while….problem is, we still need to go 2/3rd of a stop up or we will be under exposed. ISO 8000 is 1/3rd of a stop and our other 1/3rd of a stop takes us to ISO 10,000. Wow, we got there…..but, at what cost? Unless you have a camera made in the last 4 years or so, ISO 10,000 is going to look pretty bad. That’s assuming your camera goes up that high. I know on my D600 I can go to ISO 25,600, but I never do. The images that come out are terrible.
So let’s back that down to ISO 6400, which most cameras in the last 8 years should be fine with. I have printed 11”x14” images at ISO 6400 from a D7000 (which is 8 years old) and had no issues with noise on the final print. Re-read the noise section of part one if you must. Trust me, it will be fine. Anyways….
So we got 1 stop of light in our ISO by going from 3200-6400, we still need 2/3rd of a stop of light. Because of our lens and camera, we are going to have to drop the shutter speed. 1/3rd of a stop from 1/800th is 1/640th and 1/3rd more is 1/500th of a second. So we can get 1/500th of a second in this situation, which is pretty darn good. No, you won’t probably be able to freeze the puck or some of the really fast swings...but you should, for the most part, freeze the players. So as you can see, it’s still “doable”, but of course there is a couple sacrifices to be made. The first sacrifice in extra noise because of the bump to ISO 6400 (though as I discussed, not that big of a deal) and the second is not getting to freeze the really fast action because of having to slow the shutter speed. In my opinion, these are not deal breakers. Now if we were shooting for a paper, magazine, or “professionally”, the blurrier image due to slower shutter speed may end up being a deal breaker…but we aren't shooting professionally in this article, that’s not what this is article is about. We are parents capturing our kids.
On a side note, sometimes a blurry puck/swing can look really cool anyway. If everything else is frozen and just the swing and the puck have some blur, it can give a sense of motion in an otherwise frozen photo. But getting those right can be fairly tough and requires greater understanding on what you are doing with the camera.
To conclude:
This section was pretty intense, so I am going to end it here. I encourage you to play with your settings. Go into manual mode and practice. Try out the different settings and try to shoot the highest shutter speed you can. Try shooting inside your house away from direct window light. Most houses are pretty low light, so they are good for practicing this exercise. Choose one setting and lock it in. It doesn’t matter if it’s ISO, Aperture, or shutter speed, just pick one. If it were me, I would lock in my aperture. I say that because in this instance, unless you are using a constant aperture lens, it’s going to change your exposure on you if you don't.
A little tip: If you ever buy a lens that is F/4.5-5.6, F/3.5-4.5, or any variable aperture lens, just get into the habit of changing your aperture to the second number. That way the light doesn’t change as you zoom in and out. It’s one less thing to futz with.
Next week we will be looking at lens choices and what options are out there if you don’t want to spend $1500 - $2100. We will also discuss auto-focus settings and what to use, and I will wrap it up with some things that have helped me.
Take care and see you next week.