Photography 101

[xoxoxoBruce]

Mayhaps, because it's behind the lens?

[footfootfoot]

Originally Posted by Clodfobble

I understand those to be true facts. I just don't understand why the size of the opening doesn't affect the angle of view.

Let's say you are the retina or film plane and a window in your house is the aperture. Stand as far away from the window as possible and look outside. That is like a long focal length or telephoto lens. Now walk right up to the window and look out at the same thing you were looking at before. Your angle of view is much greater now. I'll make a little drawing.

[footfootfoot]

here you see the same aperture, but different aperture to film plane distances, in other words different focal lengths and different angles of view.

[Clodfobble]

But my retina doesn't move like the left-side line in your picture. What about when the left line sits still, but the two lines on the right move farther apart from each other (up and down, respectively)?

[footfootfoot]

Originally Posted by Clodfobble

But my retina doesn't move like the left-side line in your picture.

That's right. Your eyes have a fixed focal length and thus a fixed angle of view.

Originally Posted by Clodfobble

What about when the left line sits still, but the two lines on the right move farther apart from each other (up and down, respectively)?

That doesn't affect your angle of view, that changes your depth of field, or degree of sharpness.

degree as in extent, not fraction of a circle.

[Clodfobble]

Originally Posted by footfootfoot

That doesn't affect your angle of view, that changes your depth of field, or degree of sharpness.

Yes, I know that is a true fact. But I don't understand why. Why isn't it like this:



OH WAIT I FIGURED IT OUT! It's because the rays aren't determined by the moving lines (pupil), they're only determined by the lens in front of it. It's like this:



Okay. I'm happy now. Carry on.

[xoxoxoBruce]

That's right, because it's behind the lens.

[Clodfobble]

Yeah, looking back I realize now that's what you were saying, but at the time the only lens I was thinking of was the camera lens.

[xoxoxoBruce]

Works the same way. The lens controls what you see, and the shutter speed & aperture, how well you see it.

[footfootfoot]

Well, not so fast CF, you are right in some sense. The examples I gave were when the lens is focused at optical infinity or about 50'. In the example you cite, focused at 2" there is actually a shift in angle of view although slight.

In fact, I was recently on a shoot where the (video) camera had a pretty crappy lens and when you changed focus, the entire framing of the picture would change.

The AC pointed out to me (I was pulling focus) "be careful when you focus this lens breathed like an asthmatic smoking a cigarette and running up a flight of stairs."

I had never seen such an extreme case as that.

So, for the most part angle of view or field of vision doesn't change with changes in aperture or focus distance.

[BigV]

Thank you all for the enlightening discussion. I like the story about the view from a window at close range and the different view from the same window from a greater distance. Interesting and helpful, thank you.

I took over 500 pictures this weekend on a short camping trip. There were some wide shots of the beautiful scenery, a number of extreme close ups in manual macro focus mode, some action shots, some nightime shots, some long exposure shots (the maximum exposure, maximum time the shutter can be open on my camera is 15 seconds. what's that called?)

My current question is about editing. I take a lot of pictures, but I don't discard many of them. I want to have a greater percentage of good pictures. That means taking more better pictures, but also greatly reducing the number of poor pictures I keep.

I recently read of a method, one that reinforced something a photographer friend of mine had told me but I wasn't ready to learn. This method divides the pictures into three groups: delete, maybe and keepers.

The delete group, just delete them right away and empty the trash early and often, reducing the temptation to keep them. "Be brutal", I've been advised. out of focus pictures, ones that are obviously useless. Those are pretty easy for me.

The keepers subset is also pretty easy, I anticipate. I have taken a number of nice shots I'm very happy with. You've all seen some of them.

The maybes.... Right now, they're all maybes with a hasty exit for the obvious deletes and rapid promotion for the keepers. Then I only have to cull the maybes. I just checked my first pass through using this method... I'm not on the wagon yet.

I make a folder for the pictures of a given theme, Scenery, Misc, Family, or a specific event. I make folders like this for each month, in each year. The new twist I'm applying is to make a subfolder of each of these theme/event folders called "keepers". Then I triage from there, deleting and keeping from the maybe folder.

The first pass through looking for deletes yielded 19 deletes, leaving 569 keepers. Next I want to go through looking for, and MOVING the keepers. I want to move them so I don't have to look at them a second time. I want to reduce the number of maybes. I'll make another pass through and report the results.

[xoxoxoBruce]

Every "maybe" should be addressed with the question WHY?

Why are you considering keeping it? Is there someone you want to show it to? Do you want to look at it again for reference? Do you just want to keep it because you might not have a chance to get a better shot of the same subject?

If you show it to someone, and can't spiel three or four sentences why the picture is worth their time to look at it, what's the point? Handing them a bunch of pictures, each accompanied by the words, "more scenery", is mean.

You're not saving pictures, you're saving memories, chuck the ones that don't invoke memories.

In addition to the categories of photos that xoB mentions, create an "Examples" folder with sub-folders for different subject matter (e.g. nature photography, architectural photography, sports photography ... etc.). You're developing your eye for aesthetics (identifying compositional elements that are pleasing to you) by looking at many different compositions for each of various subject matter. A surprising number of pictures that are not intrinsically keepers will have a common element of composition that you either liked; or, disliked (it's fine to save examples of both). By identifying those, you can select just one example to save and label while discarding redundancies. This process will help you cull many of the maybes while preserving guiding examples of your preferences (especially for subject matter you may not revisit frequently). All of that information could be reduced to writing; but, why bother when a picture is worth a thousand words. Didactic study of compositional elements in photography will make this process much easier and your photo reviews go much faster. The number of pictures you take will go down while your percentage of keepers goes up.

[footfootfoot]

If you had to spend a half an hour printing each of those pictures you'd have a much easier time culling them.

[TheMercenary]

Eyes work completely differently. Not as simplistic as a camera.