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Old Jan 25, 2004, 8:31 PM   #1
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Default Took my first photography class last week, ???'s...

Hi everyone. I was impressed with how much I already knew about photography just by lurking on this site and reading the info presented. The instructor is actually OK, but his disdain of digicams is quite evident. He was "forced" into digital photography (his words). I, with no qualms whatsoever, showed up to the class with my little Canon A80 (supposed to bring 35mm SLR). He is actually good about helping me understand things by converting film lingo (i.e., grain=noise) into something that I can understand with my digicam.

I'm still pretty confused about the whole aperature/shutter relationship. Any good web sites you could recommend or explanations you could give (I need a good analogy)? I seem to get the concept of what each of them do (academically), but I can't seem to transfer that knowledge into practical use (i.e., how do I use these setting in real life?). Thanks in advance for helping out a newbie!

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Old Jan 25, 2004, 8:41 PM   #2
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Default Re: Took my first photography class last week, ???'s...

Originally Posted by amytude
(I need a good analogy)?
Aperture = your iris; it opens up bigger or smaller to let in more/less light. (How much light it lets in depends on its size).

Shutter = your eyelid: it opens up longer/slower to let in more/less light (how much light it lets in depends on its speed).

They also have other functions.

The aperture controls the depth of focus; how much of the scene is in good focus, from foreground to distance. Smaller (more closed) apertures increase depth of focus, while larger (more open) apertures make the depth of focus more shallow. Simple example: if you're taking a closeup of a lily against a background of a muddy pond, you might want to open the aperture up to make the depth of focus very shallow, and focus on the lily. That way the muddy pond in the background will be fuzzy and not distracting.

The shutter's other function is to stop or blur movement/action. You need very fast shutter speeds to stop a bee's wings. When you make the shutter speed very fast, less light gets in the lens, so to compensate, you have to open up the aperture more. So they work in an inverse relationship.
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Old Jan 25, 2004, 9:01 PM   #3
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I found this article very helpful.


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Old Jan 26, 2004, 8:30 AM   #4
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Thanks so much for the explanation and links. Photo.net also has some articles, but I wasn't able to clearly understand them. It is confusing when you first start out! Arrrgghh! I just have to have some patience with myself. THanks again!

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Old Jan 26, 2004, 10:47 AM   #5
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In a class I took the instructor had one of the students try this exercise. Take your camera and mount it on a tripod, shoot one 'frame' at the openest aperature (smallest number), one at f8, one at the smallest aperature (largest number) it goes to. I'm guessing that your camera will record in the EXIF data the shutter speeds. Shoot the same scene and compare the differences

Do the same but this time set the shutter speed and let the aperature be determined by the camera. A scene with some movement is a good idea.

This way you'll really see what the two settings will do for you.

One caveat - you will not get as shallow a depth of field (focus) on your camera as you would with a 35mm camera because of the smaller imaging area.

I can sympathize with your instructor's point of view. On a 35mm SLR you can (almost always) turn off all the automation and force the students to control all the settings (focus, aperature, shutter, film speed). That way you are in control and they don't have to try to understand all the nuances of each camera models auto-exposure etc. When the cameras in full-manual mode there's no one to blame except the photographer! no more 'why did my camera do this'.

In addition with a 35mm camera you can shoot slides - which is the easiest way to show a class an image for critique and analysis. Prints (either from negative film or a digital image) add one step of processing to an image so that flaws in exposure can be hidden or corrected (often automatically).

The point and shoot digicams tend to make manual control much more difficult to do versus an SLR. The same goes for film point and shoots.

A friend of mine took a digicam course at the same time as I took my 35mm course. One of her comments was that a lot of the instructor's time was taken up trying to show how to do things on individual cameras - P&S digicams are much more varied in brands, features and controls compared to SLRs.

I'm personally glad I took a course using a film camera and slide film vs. the digital camera course that was offered. I'll take it next and learn photoshop but I'll have a better understanding exposure etc.
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Old Jan 26, 2004, 12:30 PM   #6
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I agree with all that is said above. I just wanted to add a few details. You can choose to ignore them (or ask questions if you want more info) as you choose.

1) The distance to the subject also effects DOF. Really close objects end up with a very small DOF (one reason why macro photography is hard.) Really far objects have more DOF. But unless you do something like Macro or huge landscapes, its effect on the DOF isn't very much. But itís there, so I thought I should mention it.

2) The notation for Aperture and Shutter speed was chosen intentionally. There is in inverse relationship between the shutter speed and aperture. This is the relationship:

As you double (or half) the shutter speed, you need to 1/2 or double the aperture to keep the same exposure (same amount of light hitting the sensor/film.)

So if you are shooting at f2.8 1/250, then you can get exactly the same exposure with f4 and 1/500. The difference will be that you'll get less motion blur in your subjects (faster shutter speed) but you'll get less depth of field (smaller aperture.)

That is the unavoidable tradeoff. You trade shutter speed for aperture and visa-versa (sp?). So knowing how they relate allows you to capture your vision of the shot.

BTW, if I recall the A80 has fully manual, aperture priority and time/shutter priority. That should be all you need for most classes.

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Old Jan 26, 2004, 1:36 PM   #7
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Thanks, again. Yes, Eric the A80 does have all those features. I must say that I was more impressed with the little camera when I walked out of the class. It has more functions than I could have ever thought possible. What I really need is TIME to shoot, TIME to play around, etc. I'm glad I am taking this class, too. He offers a photography II course which gets more into digital and so forth. We'll see.....

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