Lesson 4 Did I do anything right

[barbp]

I have really been struggling with the whole Depth of Field thing. What confuses me is when the assignment says

Highest f-stop, fully zoom out and take a couple of shots.
What is full zoom out?


then zoom in and take a shot
What is zoom in?

lowest f-stop and higher focal lengths = subject isolated form background

higher f-stop and longer focal lengths = most picture sharp


higher focal lengths and longer focal lengths confuses me also???

Following is what I did and how I did it, did I do anything right? This Depth of Field is SO confusing to me.
:confused:
http://www.proudphotography.com/forum/picture.php?albumid=40&pictureid=339

[ladyups]

Hi Barb...I'm going to take a stab at this. When you do this....do not move your body. Stay in the same place for both pictures. Now...zoom out as far as your lens will go (where you are further away from the subject) and take your shot. Then zoom in on the subject (which means you are getting closer to the subject but with your lens, not your feet) and take another shot.
When you zoom in (get closer) you have less depth of field. This means things behind will be blurry. When you zoom out, you have more depth of field..image is sharper. Hope this helps...I hope I didn't explain it wrong.

[rasmussen4]

Hey BarbP, actually in looking at these shots and the kind of camera you have you don't have to do anything with zooming in closer or farther back. That really is only for people using point and shoot style cameras. A point and shoot camera is very compact, and the sensor is really close to the lens element, so the blur isn't as evident even when shooting at low f-stop numbers. But from your signature there it looks like you're shooting with a D90, which is a DSLR and the lens elements are plenty far enough away from the sensor so you don't have to zoom in or out to get a blurry background.

On a DSLR the depth of field is all about adjusting your f-stops. If you set the f-stop on a low number (like f/5.6 or f/7.1 as in your examples) you get a blurry background. The only troll doll in sharp focus was the closest one to the camera. If you set the f-stop to a high number like f/36 in your example, the trolls in the background get sharper. At such close range, however, you're not going to get everything equally sharp, even at the high f-stops like f/36. If you were shooting a landscape or something, the distances wouldn't be as close to the camera and most of the scene would look equally sharp.

So, in short, yes you definitely did something right on these shots! The top-most and lower-most shots were both shallow depth of field shots, and the middle one was the longer depth of field. Unless you decide to shoot with a point and shoot camera, forget about the zooming thing. That being said, if you wanted to add even MORE blur, yes you can zoom in on something even with a DSLR. But technically, it gets blurrier because the lens element moves even farther away from the sensor. The depth of field, though, is still being controlled by the f-stop setting, and the zoom is only enhancing the blur.

Hope that made some sense! :)

[ladyups]

I don't want to contradict you on this but this is how I was taught to do this assignment and I have a dslr.
From the assignment for lesson 4...

. Get 10-15ft from the subject. Set the aperture to the highest f-stop (f16 or more) for your lens. Fully zoom wide out (low focal length) and take couple of shots.
2. Stay where you are, now change the aperture to the lowest f-stop and zoom in on your subject as close as you can, focus and take a shot.

You'll notice that at the lowest f-stops and higher focal lengths the subject will be more isolated from it's background, while on photos with higher f-stops with smaller focal lengths most of the picture will be sharp.

[solo1]

hi,

The largest f stop is the lowest aperture number on your lens - the smallest is the the highest aperture number that your lens will go to.

with the lowest number be it 5.6 or lower you have less depth of field with a smaller aperture up to 36 or more you have a much clearer picture all should be in focus