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Old Mar 1, 2007, 12:07 AM   #1
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Hey everyone,

I'veread articles saying stuff like"you'd really like to use 1/15 second at f/4 for..." or "If I use my 28-200 I use shutter priority and select 1/200th second or 1/300th second if I might be zooming out to 200mm."What does this mean? When someone says, 1/15 second or 1/ 40 second, what does this mean?Is there anyway that I can adjust this in the D50? If so, how? Please someone describe this to me. I'm totally confusedThanks. God bless!

- TheCartoonist
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Old Mar 1, 2007, 4:20 AM   #2
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Those fractions refer to shutter speed, which is how long the shutter remains open during an exposure. This along with aperature (f-stop) and ISO, are the three main elements that determine exposure. Fast shutter speeds help freeze action, and slower shutter speeds can accentuate action. There are many books and articles written on the three elements of exposure...just use google or use the forum search functions. Typically, to prevent camera shake, you'd want to use a shutter speed of at least 1/over focal length.

Shutter speed can be adjusted while in shutter priority or manual mode by using the command dial.
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Old Mar 1, 2007, 6:59 AM   #3
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Just to add to what rjseeney said, if you do use a slow shutter speed like 1/15, 1/4 or slower with a 200mm lens, you will get very poor images due to 'camera shake'. So, again, at 200mm, minimum shutter speed should be faster than 1/200th. Indoors with average room lighting, this probably won't work out, so flash becomes necessary. All these settings would be at full aperture for the lens, BTW. If this is confusing, try to do some reading about the effects of shutter speed and aperture settings. Not to confuse you further, but ISO settings can effect your ability to capture images in various lighting conditions. Higher numbers mean you can shoot in less light while maintaining the necessary shutter speeds, but with loss of picture quality. Lots to learn, hey? Just keep trying different settings to see how they actually work out for you. That's the beauty of digital photograpy, you have instant feedback on how these things affect your picture.

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Old Mar 1, 2007, 10:51 AM   #4
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What do you currently use when shooting? I suggest you get away from all the auto scene modes, and start using A, S and M mode.


Here's a nice site for DSLR, it's not Nikon, but it's very helpful. When I first got my D50 I would read this everyday, until I fully understood it:
http://www.canon.co.jp/Imaging/enjoydslr/p_1_001.html

This page talks about the three things mentioned that affects exposure:
http://www.canon.co.jp/Imaging/enjoydslr/p_2_005.html

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Old Mar 1, 2007, 10:14 PM   #5
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OK, I've kind of grasped what Aperture, Shutter Priority and F-Stop means. I've still kind of confused though. Someone said you can adjust the Shutter Priorityin M mode and in S mode only. I was testing the camera out and whenever I try to adjust the F-Stop, the Shutter Speed changes too. I know that the Shutter Speed has to be higher then the focal length. (For example, when you're shooting at 20 mm, the Shutter Speed needs to be higher, like at 1/30 second.) When you're adjusting the F-Stop, it's needs to be at a high setting like, f/4 to let light in. My complaint is, that when I'm adjusting the F-Stop, it changes the shutter speed too, and it is not the speed that I want. Is there anyway I can change this separately? I hope that I'm making sense. God bless!

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Old Mar 1, 2007, 10:38 PM   #6
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TheCartoonist wrote:
Quote:
OK, I've kind of grasped what Aperture, Shutter Priority and F-Stop means. I've still kind of confused though. Someone said you can adjust the Shutter Priorityin M mode and in S mode only. I was testing the camera out and whenever I try to adjust the F-Stop, the Shutter Speed changes too. I know that the Shutter Speed has to be higher then the focal length. (For example, when you're shooting at 20 mm, the Shutter Speed needs to be higher, like at 1/30 second.) When you're adjusting the F-Stop, it's needs to be at a high setting like, f/4 to let light in. My complaint is, that when I'm adjusting the F-Stop, it changes the shutter speed too, and it is not the speed that I want. Is there anyway I can change this separately? I hope that I'm making sense. God bless!

- TheCartoonist
What he meant was you can adjust the shutter speed "directly" on S and M mode only. When you are in Aperture mode, you are picking the Aperture, and the camera is picking the shutter speed needed with that Aperture to maintain an exposure level.

The camera makes a decision on what it thinks a proper exposure should be. So in A mode, when you set the aperture, it matches it with a corresponding shutter speed. If you are shooting the same scene and you make the aperture smaller, then to maintain the same exposure, the camera will have to make the shutter speed slower.

For example, if you make the aperture half the size, then the camera will need to keep the shutter open twice as long to keep the same exposure.

If you want to control both aperture and shutter speed directly, you can use M mode.

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Old Mar 1, 2007, 10:43 PM   #7
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I have two questions.

1. How do I adjust the sensor's sensitivity? Iread somewhere that you could adjust it.

2.Whichmode (M, A, Sor P)would you suggest thatI use?

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Old Mar 1, 2007, 11:16 PM   #8
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TheCartoonist wrote:
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I have two questions.

1. How do I adjust the sensor's sensitivity? Iread somewhere that you could adjust it.

2.Whichmode (M, A, Sor P)would you suggest thatI use?

- TheCartoonist
1) That's the ISO. On P,S,A,M mode you hold the ISO button on the back and turn the dial.

2) I started with using Aperture priority first. Which one you use will depend on what you're shooting. For landscape and portrait one normally wants to control depth of field, so I use A. For shooting sports, I use S to freeze motion. M is full manual. I suggest you learn A and S first, and then you'll know when to use M. I don't use P at all.

Here's a D50 tutorial:
http://www.nikondigitutor.com/eng/d50/index.shtml


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Old Mar 2, 2007, 7:08 AM   #9
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TheCartoonist wrote:
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My complaint is, that when I'm adjusting the F-Stop, it changes the shutter speed too, and it is not the speed that I want.
If you try to use a shutter speed that's too fast for the lighting, aperture and ISO speed, you'll get an underexposed (dark) image. If you try to use a shutter speed that's too slow for the aperture, lighting and ISO speed, you'll get an overexposed (too bright) image.

So, when you're using modes like Av (Aperture Value, a.k.a., Aperture Priority) and set your aperture, the camera's metering is trying to select a shutter speed that will result in properly exposing the image (so that it's not too dark or too bright).

If you use a mode like Tv (Time Value, a.k.a., Shutter Priority) and select a shutter speed, the camera will try to open or close the aperture iris to let in the correct amount of light to properly expose the image.

But, it can only open up the aperture so far (based on your lens specs). So, if you try to set a shutter speed that's too fast for the largest available aperture (smallest available f/stop number), ISO speed and lighting, you'll get an underexposed image (and most cameras will flash the aperture or shutter speed in the viewfinder to let you know you're trying to exceed the capabilities of the lens you're using when that happens).

You can set both the Aperture and Shutter Speed using Manual Exposure. But, you still need to keep exposure in mind (using the meter in the viewfinder to see how your choices are impacting exposure).

ISO speed (how sensitive the film or sensor is to light), and Aperture (this is the iris opening in the lens that works similar to the pupils in your eyes by opening and closing with your f/stop setting) work together to get you a properly exposed image.

Your lens will have limitations (largest available aperture, represented by the smallest available f/stop number) that restricts the aperture you can use (which also restricts the shutter speed you can use for proper exposure for any given lighting an ISO speed).

That's one reason that a brighter (a.k.a., faster) lens with larger available apertures (represented by smaller f/stop numbers) is larger, heavier and more expensive. They are able to let in more light, allowing you to use faster shutter speeds for any given lighting level and ISO speed.

To get a better understanding of how these parameters work together (aperture, ISO speed, lighting, shutter speed) to control exposure, see this handy onine calculator. Note that film speed in the calculator is the same thing as ISO speed:

http://www.robert-barrett.com/photo/...alculator.html

Any good book on basic photography will also include information on exposure (and the same concepts that apply to film also apply to digital).

Note that aperture will also impact Depth of Field. So, there are tradeoffs (you will have a shallower DOF when you use a larger aperture (smaller f/stop number).

See this handy online Depth of Field Calculator for more on how aperture, focus distance and focal length impact Depth of Field (how much of the scene is in focus as you get further away from your focus point).:

http://www.dofmaster.com/dofjs.html


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Old Mar 2, 2007, 9:42 AM   #10
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Cartoonist, I also recommend a specfic book, "Understanding Exposure". It helped me a lot starting out and even now I like to leaf through it for refresher and inspiration.
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