I've just gotten a Nikon D3100 and I'm trying to learn it! I don't aspire to be a great photographer, but I would like to get the most out of my camera on a beginner level. I'm trying to learn what aperture is and how to set it. I guess it makes a more blurry background if the number is lower?
Is the only way to change that by using the Guide? I went there and selected "soften backgrounds." Then lowered the number to 4.5 just to see what it would do. I selected that I was ready to shoot and when I took a picture, it seemed to take it really slowly and everything was very blurry. Does the shutter speed change when you change aperture? I thought shutter speed was related to your ISO setting?
#1. "RE: please help a newbie (aperture question)" In response to Reply # 0 Tue 05-Jul-11 10:20 PM by SheriB
I do not have a 3100 but..I think I can explain in simple terms..becuse thats how I learned ans I am sure more experienced people will jump in and fill in my holes aperture is what lets the light into the camera (think of it like your pupil) Aperture, shutter speed and ISO can all be connected and can all affect each other. Both lower aperture and/or higher ISO numbers let you shoot in lower light conditions,by allowing a faster shutter speed .Using a high ISO can cost you with the introduction of some 'noise' though. The less light coming in,( larger aperture numbers like 22, 16) the slower your shutter has to open and close to get a correctly exposed picture.The larger numbers allow faster shutter speeds, yet you loose depth of field( less blurry backgrounds) Now, not knowing what you were shooting, what your other settings were( iso and shutter speed) its hard to say exactly why it seemed that your camera actually had to choose a slower shutter speed (unless your original settings actually had a wider aperture that you dialed in?)
#3. "RE: please help a newbie (aperture question)" In response to Reply # 0
ISO is the "sensitivity", so to speak, of the sensor. The higher the ISO, the less light it takes to correctly expose the image. The aperture is the opening in the lens. It is variable from "wide open", which can be anywhere from f/1.2 to f/5.6 commonly, to a small opening such as f/16, f/22, etc. Changing the aperture, changes the amount of light striking the sensor. The shutter speed is how fast the shutter opens and closes. It also controls the amount of light striking the sensor. The correct exposure is controlled by a combination of the aperture, shutter speed, and ISO. There can be several combinations of all three that all give the correct exposure. For example, if the correct exposure for a scene is f/8 at 1/125 of a second at ISO 200, an equivalent exposure that would also give you a correct exposure would be f/5.6 at 1/250th second at ISO 200. If you make the aperture wider(letting in more light), you need to make the shutter speed faster (to let in less light) so the exposure stays the same. You can change the ISO, also, to keep the exposure equal.
You can use aperture priority or manual exposure mode to set the aperture you want for "blurring the background" or what's call shallow depth of field. A large opening (small number like f/1.8) gives you shallow depth of field (DOF).
#4. "RE: please help a newbie (aperture question)" In response to Reply # 3
"1) f stop stands for full stop. it is a unit of measurement. a full stop up or down will affect your aperture, and the number f stop tells you by how much. if you want to know what your aperture is you look at your current f stop settings. that is what your aperture is. its like if you want to know what your weight is, you get on a scale and measure in pounds. there is no metric system for aperture, world wide it is only f stops. if you stop down from 2 to 4 you have stopped down. a small number (2-11) equals a shallower depth of focus (DoF). this means that the lense can focus on one item very sharply and with great detail. the rest of the items in the picture have less detail and may be blurred. photographers use this technique artistically to isolate a subject so that the viewer will focus on the subject and not on all the less important things in that background that can distract from the main subject. shooting at the smallest number your lense will go to at its focal length (f3.5 @ 18mm, f5.6 @ 300mm, etc) is called shooting wide open. that phrase particularly applies to the absolute smallest number on the fstop range for your lense (in this case f3.5) a big number (16-36) captures more detail than a small number will and brings more of the picture sharply into focus. usually the fstop that will bring the sharpest detail over the entire picture image will be f22. often you will not have to go to that big of a number to get the level of detail you want through out an entire picture. the smaller the number the bigger the aperture. the bigger the aperture the more light will go through the lense allowing for a brighter image, but this will allow less detail throughout the over all image. the bigger the number the smaller the aperture allowing less light to go through the lens, making the image darker, but more defined and sharper detail. aperture's like f1.8 or f2.8 are used for shooting in very poor lighting because they allow much more light in through their lense. this will provide more light, but sometimes at a cost of a slightly less defined image. apertures like f22 are often used for distant landscapes to capture all the detail when shot using a wide angle lens. this will provide maximum detail, but since a big number like f22 allows less light in it is best to shoot images under these settings in bright light or during the day time. f8 is often used for street photography and f11 for portraiture where sharp detail along the face is important. hope i answered your question."
#7. "RE: please help a newbie (aperture question)" In response to Reply # 0
I have a D3100 and took me a little to figure it out on how to control it on a D3100.
The easiest way to experiment it outside doing closeups of flowers.
I'm assuming you have the 18-55mm lens.
Follow the following steps Set ISO to 100 (also set ISO to auto overide) Set camera to A for aperture control using the dial, set the aperture to F3.5 (what ever smallest number is) get as close to a flower as you can get it in focus at 55mm. Take image.
Set aperture to F16 or larger. get as close to a flower as you can get it in focus at 55mm. Take image.
Compare images you will see that the background will be softer in one and sharper in the other.
#9. "RE: please help a newbie (aperture question)" In response to Reply # 7
Not only does aperture control the amount of light falling onto the sensor, but also affects the sharpness of area near the exact focus distance. Aperture also has a side affect at very small openings or large f stop numbers and that is diffraction or the bending of the light waves around a small slit or circular opening. The point at which diffraction occurs varies by the size of the media. For the DC format diffraction is noticeable at f stops larger than f 11 and for FX or 35mm film the f stop is usually f 16. Diffraction looks a softening of the recorded image but could also look like chromatic aberration.