ISO, noisy photos, and things of that nature...

First things first! Wanted to apologize for slightly lengthy posts for the first few blog entries. They should be shorter for future posts, but I first need to lay the groundwork for the basics of photography which require a bit more explanation, and thus longer posts. Thanks for your patience!

Todays topic is ISO. I'll discuss what it is, when to increase it, and the negative effects it can have.

I'm going to start by just copying and pasting my prior written definition from my second blog post...

"ISO - or International Organization for Standardization, refers to the sensors sensitivity to a given amount of light. This relates to film speed in non-digital cameras. The higher the number the faster the film. 100 being low speed, and 800 or more considered high speed film. By increasing the sensitivity of the image sensor, you are making it more sensitive to a given amount of light. So for example lets say you need to take a photograph in a dark room. You may start by trying to make the aperture it's largest possible size to let the most light reach the sensor. You may then try to make the shutter speed longer to get the light you need. Well if you have the shutter speed to slow (or open longer) you may capture the image at a proper exposure but your image will likely be blurred if you were hand holding the camera (as opposed to mounting it on a tripod). So what can you do about that? Increase the sensitivity of the sensor. By bumping up the ISO to a higher number, one can shoot at a shutter speed that wont cause any motion blur. Without adjusting the ISO, the image will look dark and underexposed. By increasing the ISO, the light that is available in the room will seem more apparent in your photos because of the increased sensitivity to light."

So we now know that if a situation occurs where it is dark and we need to handhold our camera for a shot, we can bump up the ISO to allow us to shoot at a faster shutter speed as to not blur the photo. Increasing ISO may also prove useful if you have a situation in lower light conditions where you would otherwise already have a fast enough shutter speed for handholding, but your subject is actually moving which may require an even faster shutter speed. Below is an example of this type of situation:

I was photographing a bridge opening on the York River where a boat was passing through the bridge. In the first photo I wanted to show the blur of the boat. At an shutter speed of 30 seconds, all you see is the blur of the lights from the boat. For the second photo I needed to freeze the movement of the boat so that you could still tell what it was. I quickly bumped up my ISO so that I could hopefully freeze the action. The photo didn't turn out all that well, but I think it helps demonstrate the concept (oh, and I had to use a tripod for the first photo in order to keep the bridge sharp because it's humanly impossible to handhold an exposure of 30 seconds)-

ISO-100, 30 seconds, F/9

ISO-3200, 1/4 second, F/2.8 - In this case I should have shot at an even faster shutter speed and a higher ISO to compensate. However, I was trying to avoid image noise as much as possible. We'll get into that in just a minute.

Similar to yesterdays post, I want to give you a stop chart to show what amounts of ISO represent one full stop of light.

• Low ISO, Less image noise, Lower sensitivity to light
• ISO-100
• ISO-200
• ISO-400
• ISO-800
• ISO-1600
• ISO-3200
• ISO-6400
• ISO-12800
• High ISO, More image noise, Greater sensitivity to light

it should be noted that your camera may have ISO settings between the ones listed above. again, many cameras let you increase or decrease your ISO in 1/3 stops of light where those listed above are full stops. if your camera allows 1/3 increments, 3 clicks of the ISO setting wheel will increase or decrease your ISO 1 full stop.

So now we've added a third and final way to adjust our exposure. Let's say we have our settings in such a way that your photo is properly exposed by only changing aperture and shutter speed. You can then increase or decrease your ISO one full stop and would in return have to increase one of the other two settings one full stop to maintain the same original exposure.

Example 1: ISO-100, F/5.6, 1/125

You can increase the ISO one full stop to ISO-200 (see chart above) and then change either the aperture or shutter speed one full stop. So let's increase the shutter speed for this example.

New settings: ISO-200, F/5.6, 1/250th second

Example 2: ISO-100, F/8, 1/250th

You can increase the ISO let's say 3 full stops and then decrease the aperture (or make the hole smaller to compensate for the increased sensitivity to light) 3 full stops.

New settings: ISO-800, F/22, 1/250th

In both examples you were able to change settings and end up with the same exposure.

So I'm hoping at this point you're starting to get the concept of ISO and how it effects your photograph. In that last photo, and in the chart above, you may have noticed the comments regarding image noise. What is image noise? Image noise is a negative side effect of increasing the ISO. The more you increase the ISO, the more image noise or graininess you'll notice in your photos (especially in the shadow areas).

Examples of noise at different full stop ISO settings (missing ISO-6400, accidently deleted it before uploading..again, I think you still get the idea though). In these examples I changed the shutter speed accordingly to maintain the same exposure when I adjusted the ISO. I left aperture the same for each photo.

ISO-100

ISO-200

ISO-400

ISO-800

ISO-1600

ISO-3200

ISO-12800

It should be noted that the greater the ISO and noise level, the less sharp your image will be. You can also reduce the noise in post processing with noise reduction software, but that's another days topic. If you want to get a jumpstart though, one of the best programs for this is called Noise Ninja.

So that's ISO in a nutshell. It can be a bit confusing, but the best way to learn it is use this guide and go out and play with the settings. Just remember if you've got your slowest possible shutter speed that you can hand hold and your widest aperture for the most light and you still can't get enough light....increase the ISO until you get a properly exposed photo.

There's your ISO "From The Ground Up!"

View the full post here...

Automatic Vs. Manual

So you've just gone out and bought yourself a shiny new DSLR (digital single-lens reflex) camera to replace that point and shoot you've been using for the longest time. Sweet better photos are on the way.

Or are they?

That will greatly depend on a few things...mainly if you intend to use your DSLR as a fancy point and shoot.

Some aspects of your photos will likely improve just with the purchase of your DSLR. Some of these things include:

-Better Image Sensors (better resolution [Megapixels], color accuracy, tonal range, etc)

-Better Dynamic Range (better ratio of light to dark to capture more detail in the highlights and shadows in the same photo)

-No Shutter Lag (helps to not miss that once in a life time shot due to a delay from your camera)

-More Frames Per Second (more photos shot in a short period of time - up to 10 fps in some camera models)

But aside from these few things, if you shoot on automatic mode with your DSLR, you're losing out on the best features built into your new toy.

Automatic modes choose all your in camera settings for you in an attempt to get a properly exposed photo every shot. Wow! That's great! Exactly what I want! Or is it?

By doing this, the photographer (you) loses control of the artistic effects that you'd be capable of achieving by shooting in manual mode.

With that said, lets define the different things that the camera is deciding for you.

Aperture - The opening in your cameras lens through which light passes through that in turn reaches the image sensor. The size of the hole is adjustable to let more or less light reach the sensor. In addition to changing the amount of light coming in, it also has an added artistic effect. The bigger the hole, or the wider the aperture, the more blur will be added in front of and behind your focal point. The smaller the hole, or the smaller the aperture, the more that will be in focus in front of and behind your focal point. This matter of focus in front of and behind your subject is referred to as Depth of Field (DOF).

Shutter Speed - For starters, the shutter is the mechanism in your camera that blocks light from hitting the sensor when a photo is not being taken. When you click the shutter button, you send a signal to open the shutter for a preset amount of time to allow light to pass through the aperture to reach the sensor. When this preset amount of time elapses, the shutter closes, blocking further light from reaching the sensor. The amount of time the shutter is open is referred to as shutter speed. The shorter amount of time the shutter is open, the less light is allowed to reach the sensor. The longer it's open, the more light reaches the sensor. Faster shutter speeds (1/250, 1/500, 1/1000, 1/4000, etc) allow you to capture something moving and prevent motion blur from occurring. Slower shutter speeds (1/25, 1/8, 1/2, 1 sec, 30 sec, etc) allow motion blur to occur. The fractions above are fractions of a second.

ISO - or International Organization for Standardization, refers to the sensors sensitivity to a given amount of light. This relates to film speed in non-digital cameras. The higher the number the faster the film. 100 being low speed, and 800 or more considered high speed film. By increasing the sensitivity of the image sensor, you are making it more sensitive to a given amount of light. So for example lets say you need to take a photograph in a dark room. You may start by trying to make the aperture it's largest possible size to let the most light reach the sensor. You may then try to make the shutter speed longer to get the light you need. Well if you have the shutter speed to slow (or open longer) you may capture the image at a proper exposure but your image will likely be blurred if you were hand holding the camera (as opposed to mounting it on a tripod). So what can you do about that? Increase the sensitivity of the sensor. By bumping up the ISO to a higher number, one can shoot at a shutter speed that wont cause any motion blur. Without adjusting the ISO, the image will look dark and underexposed. By increasing the ISO, the light that is available in the room will seem more apparent in your photos because of the increased sensitivity to light.

White Balance - refers to the representation of colors in your image. Different light sources cast different colors on your subject. Lets say for example you had a piece of white notebook paper on the table and it was lit by a tungsten bulb (normal lamp). If there was no white balance adjustment, the image will appear to be very warm and orangey in color due to the color cast from the lamp. Your white paper won't look so white. Lets say it was under the light of a fluorescent lamp. These lights cast a blue color on your subject. The image will look cool and blue in color. Who wants blue or orange paper...or anything in between? Well you may want a color cast if you're going for an artistic effect, but by adjusting white balance whether automatically, or manually, the camera will warm up or cool down the image to bring that paper back to a nice white color.

So in automatic mode, the camera is making all of these choices for you. In manual mode you have the power to change these things individually and render the artistic effect that you desire in your images.

But this all sounds so hard. There's to many options and I'll likely mess up the image because I took to long to make the choices, or I made the wrong choices. Well let me say... you're probably right. You're going to make mistakes with your images when you first start using Manual exposure modes. That's the great thing about digital! You get instant feedback without wasting money as you screw up images. With film cameras you had to pay for the film and it was costly to make mistakes. I'm not advocating that if you choose to shoot film cameras, you should do everything on the automatic modes it may or may not give you. I'm just saying you have the ability to learn from your mistakes in an instant so why not shoot manual.

It will give you a better appreciation of your own images when you capture them well. You'll likely become a better photographer for doing so.

Well my dads reunion is tomorrow and I just got this DSLR and I can't afford to mess up the shots...Ok so shoot on automatic early on if it's vital that you at least capture keepable images from the event. But everywhere else, you should be striving to shoot manual. Before you know it you'll be able to dial in the desired settings in not much more time than it would have taken you to shoot the photo in manual.

Up until this point I've been referring to your cameras ability to choose how the photo is exposed. Another thing to think about is Automatic vs. Manual focusing.

To be quite honest, the Auto focus systems on cameras have come a long way. I shoot on Automatic focus 90% of the time. You may choose to do otherwise but I just wanted to explain the differences and let you decide for yourself.

There's not necessarily any right or wrong image to use manual focus on.

However, there are instances when manual focus will be a great benefit to you.

In my opinion, macro photography (close-up photography) is much easier by using manual focus. The DOF (depth of field) is so narrow that a slight hairs length of movement can cause the desired part of the image to be completely out of focus. This sounds hard to do by hand but it can be harder using auto focus. Auto focus in these situations tends to focus on an undesired point on your subject.

Another instance would be shooting through glass. I often find when shooting through glass, the auto focus system tends to pick up on dirt and reflections in the glass making it nearly impossible to get a subject on the other side of the glass in focus.

Fast moving subjects, or action photography can be much easier using manual focus. Let's say you're at an air show and the planes are going left to right at the same distance away from you. By setting the focus to manual and then getting your subject in focus, you'll find that every shot is in focus and you don't have to wait for your auto focus system to hunt back and forth looking for the subject every time it passes at 500-mph.

Low-light photography can prove to be a good time to shoot on manual. Many auto focus systems have trouble finding the subject to focus on in dimly lit conditions. By switching to manual, you can get the subject in focus without the headache of an unusable auto focus system.

So there you have it. Now you know the advantages to shooting with manual modes as opposed to automatic modes.

When I got my first DSLR, I just told myself to pretend that the automatic modes were broken. I never let myself resort to the automatic modes. I came home with alot of crappy photos, but when I got one right, it felt soooo good. Now manual mode is second nature to me and I couldn't even imagine shooting with an automatic exposure mode.

I encourage you to pretend your auto exposure mode is broken as well.

From now on, my entries will be based around shooting with a Digital SLR camera in full manual exposure mode.

The next entries will be going into more detail on aperture, shutter speed, ISO, white-balance, etc.

This has been Automatic Vs. Manual . . . "From The Ground Up!"

View the full post here...