| Joined: | Mon Apr 2nd, 2012 |
| Location: | South Lakeland, UK |
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Hello everyone!
Some of you are probably cringing while reading this! Any input on how to create a more efficient setup, better/easier focus, or anything else that might be of value would be great to know. I will post two pictures I took in the gallery.
This turned out kind of long, sorry about that!
Thanks for the explanation, no cringing here.
Aperture controls the amount of light entering the the camera through the lens. It's just about the most important control on the camera (in my opinion).
Not only does it control the amount of light, it also controls the depth of focus. That is how far in front and behind the point of the pen you used to focus on is acceptably sharp. When the lens (aperture) is wide open it lets maximum light through BUT your depth of focus is at it's shortest. When the lens (aperture) is closed right down you get least light and greatest depth of focus. That is fact of life in photography for every lens no matter what.
To throw spanner in works... Lenses have a sweet-spot in their aperture range, where the best image quality is usually to be found. In most cases that is usually around f8.
Set up a row of bean cans, say 5 or 8 in a line on a table and take a picture along the row focusing on the middle one. Try wide open, then f8 then f16 look if you can see the change in the depth of focus.
This is an important lesson to learn, say you are taking a photo of a group of people with the lens wide open, unless they are all the same distance from the camera some will be out of focus. To fix that you need to close the lens down a bit, but not too much because that might make it too dark.
By the way we are talking about Aperture priority here, with the top dial set to 'A'.
Below I will try to demonstrate the principle. Unfortunately we can only inset one image per post.
The images were taken with a D3100 with an 18-105 lens zoomed to about 35mm. at f3.5, f8 and f22.
Note the increased depth of focus and the darkening in the background with the smaller apertures.
Focus was on the front of the red Ravioli can.
Attachment: Cans a f3.5.jpg (Downloaded 64 times)
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Robert.