Monday, November 14, 2011
Photo Adventure
Out one day in Oxford, I had a Prakica MTL3 and some Velvia film, but no inspiration. So I sent a text to a friend...
Friday, November 11, 2011
How to Make the Switch to Manual Non-Scary
Any amateur can switch to manual today. The secret is, it's not any harder than using aperture/shutter-priority mode. Which is barely harder than using full auto.
It's a common misconception that you have to know a bunch of stuff in order to use manual. In reality, when you're using manual, your camera still does the hard stuff for you.
In your viewfinder, you will see something like this:
- 2..1..v..1..2 +
|
When shooting manual, all you have to do is click the dials until you get that bar to line up with the centre. When it's to the left, it's under-exposed, and if it's to the right, it's over-exposed.
This will give the same results as shooting in automatic. Just more control.
That's it. Go have fun in manual now.
Friday, April 8, 2011
Camera Basics, or Why You Want Manual Controls
The way digital cameras work is that there's a sensor that gets exposed to light, and records whatever light is let into it. You can control how much light gets into it in two ways: shutter speed, and aperture.
Shutter speed refers to the 'shutter', which is a thing that blocks light from reaching the sensor until you're ready. (Well, technically in digital compact cameras, there's a digital equivalent, namely the sensor turns itself on and off instead of having a physical thing blocking it. But it's the same principle.)
When you take a picture, the shutter will go up, letting the light through, and then when it's done exposing the light, it'll go back down again. If you have the shutter speed set to a long time, that means it's open for longer and more light can get in.
Incidentally, this means that if it's set for a long time, and you move the camera, you'll get what's known as camera shake: the image will get blurred because light will be coming from different places. It also allows you to hold the camera still but blur movement, creating cool effects.
Imagine what would happen if there was a fairly dark (though not pitch-black) scene, such that you had to keep the shutter open for, say, 15 seconds. Now what would happen if you quickly came on the scene, waved a small light around like a torch or an LED, and jumped out again? This is called light painting. There are a bunch of fun tricks like this you can do with long shutter speeds.
Aperture means how big the hole is in the lens that lets light through. When it's very small, not much light gets through, but when it's very big, lots of light can get through.
Aperture also affects the depth of field: how much is in focus. For example, if you wanted to make a blurry background for your portrait, you would open the aperture up as much as possible. Or, if you wanted everything to be in focus, you'd close it down and make it as small as possible. Example.
If you want to make sure your picture is properly exposed (as in, make sure it has enough light and doesn't look dark), you have to either open the aperture wider or have the shutter stay open for longer. But there is a third thing you change do in low-light conditions: ISO.
ISO (occasionally called 'ASA') refers to how sensitive the sensor is — how much light has to hit its pixels until it 'counts'.
Changing the ISO is nice because it doesn't change the image much except to make it lighter or darker. The problem with raising the ISO is that higher ISO settings can make the image come out very grainy. (Example. Varies by camera. D-SLRs can usually do up to 1600 without much quality loss.)
Now, there's one more special thing that ties these three together:
Aperture, shutter speed, and ISO all change something called stops. Essentially, the way light is measured is that whenever you go 1 stop down, that means you're halving the amount of light, and when you go 1 stop up, you're doubling it.
Even though the notation for the measurements and what they refer to is different — aperture is measured in f-stops "f/number", shutter is measured in time "number of seconds" or when it's "1/30" that means "one 30th of a second", and ISO is numbers like 100, 200, etc. — they are all equivalent in some sense.
The sense is: if you put one up by 1 stop, and another down by 1 stop, you have exactly the same amount of light. So the picture won't get darker or brighter. The exposure (exposure means the total of all this light exposed to the sensor) remains the same.
For example, a picture taken at ISO 100, at 1/30, with f/11, looks the same light-wise as the same picture taken at ISO 200, 1/60, f/11. Because you're stopping up ISO (doubling it to 200) and stopping down shutter speed (halving from 1/30 to 1/60).
Here's an example of doing this to get a different depth of field. It's the same picture, same amount of light, but because they balanced the aperture and shutter speed in different ways, it gave quite dramatically different looks.
Lots of good photographers work in Aperture Priority mode (you pick the aperture, the camera does the rest): so long as the shutter is 'fast enough', it doesn't make much difference in terms of effect. With aperture, you can tell straight away whether it's wide or not from the blur.
Going into full manual mode is very useful for any tricky light situations.
If there's low light and you want to hand-hold the camera, but you don't want camera shake, you're going to have to control the shutter. If you want to make sure you get your subject in focus (especially if it's moving around), you might make the depth of field bigger by closing down the aperture. You may want to make sure the camera never produces grainy images, so you'll want to control the ISO, too. I ran into all of these at once when I tried to take photos of a very active performance at a pub. It was tricky to say the least.
Shutter speed refers to the 'shutter', which is a thing that blocks light from reaching the sensor until you're ready. (Well, technically in digital compact cameras, there's a digital equivalent, namely the sensor turns itself on and off instead of having a physical thing blocking it. But it's the same principle.)
When you take a picture, the shutter will go up, letting the light through, and then when it's done exposing the light, it'll go back down again. If you have the shutter speed set to a long time, that means it's open for longer and more light can get in.
Incidentally, this means that if it's set for a long time, and you move the camera, you'll get what's known as camera shake: the image will get blurred because light will be coming from different places. It also allows you to hold the camera still but blur movement, creating cool effects.
Imagine what would happen if there was a fairly dark (though not pitch-black) scene, such that you had to keep the shutter open for, say, 15 seconds. Now what would happen if you quickly came on the scene, waved a small light around like a torch or an LED, and jumped out again? This is called light painting. There are a bunch of fun tricks like this you can do with long shutter speeds.
Aperture means how big the hole is in the lens that lets light through. When it's very small, not much light gets through, but when it's very big, lots of light can get through.
Aperture also affects the depth of field: how much is in focus. For example, if you wanted to make a blurry background for your portrait, you would open the aperture up as much as possible. Or, if you wanted everything to be in focus, you'd close it down and make it as small as possible. Example.
(If you wear glasses, you can test this by poking a pinhole in a bit of paper and looking through it without your glasses. Stuff that was out of focus becomes sharp. This is exactly the same as a small aperture.)
If you want to make sure your picture is properly exposed (as in, make sure it has enough light and doesn't look dark), you have to either open the aperture wider or have the shutter stay open for longer. But there is a third thing you change do in low-light conditions: ISO.
ISO (occasionally called 'ASA') refers to how sensitive the sensor is — how much light has to hit its pixels until it 'counts'.
Changing the ISO is nice because it doesn't change the image much except to make it lighter or darker. The problem with raising the ISO is that higher ISO settings can make the image come out very grainy. (Example. Varies by camera. D-SLRs can usually do up to 1600 without much quality loss.)
Now, there's one more special thing that ties these three together:
Aperture, shutter speed, and ISO all change something called stops. Essentially, the way light is measured is that whenever you go 1 stop down, that means you're halving the amount of light, and when you go 1 stop up, you're doubling it.
Even though the notation for the measurements and what they refer to is different — aperture is measured in f-stops "f/number", shutter is measured in time "number of seconds" or when it's "1/30" that means "one 30th of a second", and ISO is numbers like 100, 200, etc. — they are all equivalent in some sense.
The sense is: if you put one up by 1 stop, and another down by 1 stop, you have exactly the same amount of light. So the picture won't get darker or brighter. The exposure (exposure means the total of all this light exposed to the sensor) remains the same.
For example, a picture taken at ISO 100, at 1/30, with f/11, looks the same light-wise as the same picture taken at ISO 200, 1/60, f/11. Because you're stopping up ISO (doubling it to 200) and stopping down shutter speed (halving from 1/30 to 1/60).
Here's an example of doing this to get a different depth of field. It's the same picture, same amount of light, but because they balanced the aperture and shutter speed in different ways, it gave quite dramatically different looks.
Lots of good photographers work in Aperture Priority mode (you pick the aperture, the camera does the rest): so long as the shutter is 'fast enough', it doesn't make much difference in terms of effect. With aperture, you can tell straight away whether it's wide or not from the blur.
Going into full manual mode is very useful for any tricky light situations.
If there's low light and you want to hand-hold the camera, but you don't want camera shake, you're going to have to control the shutter. If you want to make sure you get your subject in focus (especially if it's moving around), you might make the depth of field bigger by closing down the aperture. You may want to make sure the camera never produces grainy images, so you'll want to control the ISO, too. I ran into all of these at once when I tried to take photos of a very active performance at a pub. It was tricky to say the least.
High Key Tips
High Key photography is characterised by very light, low-contrast images. Lots of white, soft lighting, getting rid of shadows wherever possible. (Contrast this with Low Key, which is characterised by very dark, high-contrast images. Lots of black, limited light, often hard shadows.)
After searching around for some good tutorials on high-key, I found that most of them suck, and give advice that might actually be harmful. High-contrast and blown-out highlights everywhere!
The most important thing to keep in mind when doing high-key photos is to not blow out your highlights. Do not over-expose your image when you're taking it — you can lighten it with software afterwards.
Blowing out highlights means that the light parts have gone past the point where the camera can detect different shades of white, so it just registers it all as 'maximum white'. This kills any detail in that area (and can look really bad when looking at it from certain angles on your monitor). So, sure, expose as much as possible, but make sure you stop just before the highlights die. Think 'off-white'.
The second thing is that not every photo was destined to be high key.
In fact, unless you keep some principles in mind while taking the photo, it'll be pretty hard to turn it into high key after the fact. Here are some tips to keep in mind:
- Shoot in RAW, if your camera lets you. RAW allows you to mess with the photo on your computer much more before it harms the picture.
- Get lots of light. Wikipedia says "three [lighting] fixtures per person (left, right, and central)". You want to minimise those shadows.
- Shoot against a white backdrop (a white wall is perfect, but a sheet may also do). Just to make sure it's as white as white can be, put a light facing it.
- Shoot subjects that are already light. It might be hard to get the high-key effect on Rottweiler, compared to a yellow Labrador.
- And above all: don't blow out your highlights! You still need information in that RAW to mess with it in image-editing software later.
Here's my first attempt, after working all this out yesterday:
Here's all I did to the original colour image to get it like this (I used the software Lightroom):
- Converted to black and white.
- Turned up orange grey level. (This selectively lightens only orange tones. This is great for making skin lighter.)
- Made shadow tones a bit darker.
- Lightened the left side a little (it was darker because I didn't position the lights evenly).
- Cropped.
It's not perfect: the shot is a little boring, and there is slight highlight blowout (e.g. around the forehead). Also, if you look at the larger version on Flickr, you'll see the focus isn't perfect on the eye. But it's a start.
Flash 101: Sync curtain
You may have been wondering what that 'Shutter sync' flash setting on your camera is. (If you don't have one: sorry, this post is not for you. Here is a picture of a sympathetic kitten to make you feel better. It, too, does not have this setting on its camera.)
Your two options are: first/front curtain sync, or second/rear curtain sync.
The basic difference is that first curtain fires the flash as soon as you press the shutter button, and second curtain fires the flash afterwards, just before the shutter closes.
So, which do you use?
The following two pictures were both taken at 1/10, with the hand moving in the same direction each time, from left to right.
FIRST CURTAIN
Flash fires, it captures the image, I move my hand, you can see a little trail of where my hand went.
Good for: If you want to freeze the moment as soon as you press the shutter button.
Downside: If the shutter speed is slow, it can leave a streak after the action has already happened.
SECOND CURTAIN
It starts capturing the image, I move my hand, flash fires and stops the action.
Good for: Leaving a nice movement trail of light after what you flashed.
Downside: You won't be exactly sure what moment you're capturing, as it freezes the moment a moment after you press the shutter.
In both cases, it doesn't make a difference which one you set it to if the shutter speed is high enough that there's no motion blur anyway.
Blog Mission Statement
In this blog, I'll be documenting my journey as a newbie into photography. I'll share what I've learned as I learn it, DIY setups, and digital processing (AKA touching up in software).
I'll try to assume no prior knowledge on the part of the audience, so if you're a newb like me, you can understand what I'm talking about.
My goals include:
As always with tutorials written by newbies, take everything I say with a pinch of salt: look up how other people have done or explained these things, because I might be wrong. Also, please do correct me if you've noticed any mistakes, be it technical, aesthetic, efficiency-related, whatever.
I'll try to assume no prior knowledge on the part of the audience, so if you're a newb like me, you can understand what I'm talking about.
My goals include:
- Cheapness: favouring DIY, eBay, available light/lamps... anything to save those precious pennies.
- Explain how everything was done. No secret knowledge here.
- Where possible, suggest alternatives for those really on the cheap. All I ask is that you have a camera where you can control the shutter and aperture. (Got a Canon point-and-shoot that doesn't? You may be able to install CHDK, which gives you access to lots of stuff like that.)
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