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Old Oct 21, 2004, 11:22 PM   #1
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Hello im pretty new to the digital camera world and im looking for a camera that can take pictures quickly with no motion blur so i need to know wat i should look at this to tell wats fast and wats not. Also i need a camera that can take good night pics so id need to know wat specs to look at .

1) What determines the speed from when i press the button to when it takes the picture?

2) What effects the Motion Blur?

3) What effects how good it will work at night?

Thanks
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Old Oct 21, 2004, 11:38 PM   #2
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ok,

1) focusing..click the shutter it focuses, and takes the picture...most cameras allow focus locking, so you can hold the shutter button halfway down to focus, then it'll take the shot much faster...

2) slow shutter speed....lighting...ok...for further information on how to avoid motion blur, you'll want to look up some books...practically any photography book will help you there...even old film ones, as long as they have a section on "Exposure"....the shutter speed will probably have to be as fast or faster than 1/60th of a second, but, your lighting situation won't always allow that, so you have to learn how to compensate for bad lighting...

3)tripod.....

lol..ok, other than tripod, you'll want shutter speeds to go slower than 10 seconds...i've seen them with 15 and 30 seconds...but, if you really want to take NIGHT shots...you'll want a "bulb" setting...

well, hope this helps!

Vito
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Old Oct 21, 2004, 11:57 PM   #3
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Here's a couple of good resources to find the information you're looking for.

http://www.photo.net/

http://www.photonotes.org/

Use the search option for Photo.net and you'll find a lot of what you're looking for. As for Photonotes, it's more like a terminology information site, but has much more too.

As recommended, read a few photography books from your local library. That's what I did when I started and it helped a lot. After you've read a bit and have a better understanding, you'll be able to ask more specific questions that are more able to be answered without a long winded answer (such as this one :? ).
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Old Oct 22, 2004, 11:19 AM   #4
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whats the F thing in camera specs i always see them saying like F2.8-F4.7 or something like that and also wats wide and wats tele mean?
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Old Oct 22, 2004, 12:14 PM   #5
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If you want the basics, it would be better if you head to the following site which will cover all the basics for FREE:

http://209.196.177.41/

To go into all that here would take too long esp. without pictures.

Basically F is a ratio of the lens opening to the focal length of the lens. Larger the number, the smaller the opening. The F2.8-4.7 means that when your zoom is in your widest position, the largest opening is 2.8...as you zoom in it changes (in stages) down to 4.7.

A wide lens shows a wide picture. A tele lens shows a close up. A zoom lens is adjustable between these two extremes.
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Old Oct 22, 2004, 12:15 PM   #6
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kfuchs wrote:
Quote:
Hello im pretty new to the digital camera world and im looking for a camera that can take pictures quickly with no motion blur so i need to know wat i should look at this to tell wats fast and wats not. Also i need a camera that can take good night pics so id need to know wat specs to look at .

1) What determines the speed from when i press the button to when it takes the picture?
This is how fast the camera's autofocus works. This will depend on the amount of available light, the amount of contrast in the subject, and the quality of the camera's autofocus algorithms.

Steve usually discusses low light focus ability in each model's review conclusion section. An Autofocus Assist Lamp can help in low light. However, these have a very limited working range. So, in some situations, manual focus is preferrable.

Quote:
2) What effects the Motion Blur?
This one is more complicated. You have blur from camera shake, and blur from subject movement. In both cases, faster shutter speeds are needed to prevent it (although a tripod can work well for a non-moving subject).

Also, as more zoom is used, you'll also need to increase shutter speed to prevent motion blur from camera shake (because camera movement is magnified with more zoom).

A "rule of thumb" is that shutter speeds need to be 1/focal length (for example, if your camera's wide angle position is 35mm equivalent, then you'd want shutter speeds of 1/35 second or faster; or if your camera's full zoom is 200mm equivalent, then you'd want shutter speeds of 1/200 second or faster if you're not using a tripod at full zoom). This is only a rule of thumb, as some users hold a camera steadier than others and vice-versa).

But, this only accounts for blur from camera shake, not blur from subject movement. The shutter speeds you'll need for subject movement will vary (depending on how fast the subject is moving, the direction the subject is moving, and how much of the frame the subject occupies).

The shutter speed a camera can use depends on the amount of light available (which is very low in typical indoor incandescent lighting), the aperture of the lens, and the ISO speed.

Indoors with most models, you'll need to use a flash or a tripod (if shooting a stationary subject). Otherwise, the shutter speeds will be too slow to prevent motion blur from camera shake and/or subject movement.

Shutter speed with a flash in low light is not as critical. This is because the flash burst is very short. Since the subject is not exposed well enough for proper exposure exceptfor the very short flash duration, the flash itself has the impact of freezing the action in lower light. Of course, you'll need to make sure that the subject is within the flash range.

For outdoor use, shutter speeds are usually much faster. But, the shutter speed a camera needs for proper exposure is still dependent on the available light, aperture of the lens (with smaller f/stop numbers indicating larger available apertures), and the ISO speed (which controls the sensitivity of the sensor to light).

Each time you double the ISO speed, the camera can use shutter speeds twice as fast. However, this will have a penalty. Higher ISO speeds cause higher noise levels (similar to film grain).

The amount of light that can go through the lens is based on the lens aperture rating. You'll see two numbers for most lenses. The first number is the largest aperture available at wide angle, and the second number is the largest aperture available at full zoom. A typical rating for a compact model is f/2.8-4.9. Some models have apertures that maintain a constant value throughout their focal range. These only have one number listed.

The lower the f/stop number, the larger the aperture (with more light reaching the sensor through the lens). The higher the f/stop value, the smaller the aperture (with less light reaching the sensor through the lens).

F/1.4 is twice as bright as F/2.0

F/2.0 is twice as bright as F/2.8

F/2.8 is twice as bright as F/4.0

etc.

The aperture scale (in one stop increments) goes F/1.4, F/2.0, F/2.8, F/4.0, F/5.6, F/8.0, F/11, F/16, F/22... With each one stop move to a smaller aperture, you will need shutter speeds twice as long for proper exposure.

ISO Speed is linear (ISO 200 is twice as sensitive to light as ISO 100; ISO 400 is four times as sensitive to light ISO 100, etc.)

An understanding of these parameters is very important, especially if you need to shoot in "existing light" indoors.

Here is a handy chart that shows how Aperture impacts shutter speeds needed in various lighting conditions (see the table for Exposure Values, F-Stops and Shutter Speeds). Note that the chart is based on ISO 100. So, each time you double the ISO speed, you can also use shutter speeds twice as fast for the same aperture and lighting. However, increasing ISO speed also increases noise (similar to film grain), so photo quality can degrade as higher ISO speeds are used.

http://home.earthlink.net/~terryleedawson/dcnotes/tables.htm

For existing light shooting without a flash if your subject is not stationary, the best solution is a DSLR model with a very bright lens (i.e, f/1.8 ). These can shoot at higher ISO speeds with lower noise compared to non-DSLR models.

Quote:
3) What effects how good it will work at night?
It depends on what you mean by night. Are you talking outdoors at night with no street lights, indoors at night via incadescent lighting, outdoors at night with lights in a stadium, moving subjects, stationary subjects, or what?

Most models produce the cleanest photos using their lowest ISO speed setting.

This means that shutter speeds will be slower, too. So, a tripod is needed for photos of cityscapes, etc.

If you mean photos of moving subjects, that's something else entirely. In this case, a flash is your best bet unless some light is provided. If you mean night sports in a well lit stadium, that's again something else entirely. In this case, a DSLR with a very bright lens using a higher ISO speed is your best bet.

If you mean at night with very little light of a moving subject and don't want to use a flash, you don't have a best bet. Cameras must have enough light to properly expose the image, and must keep the shutter open long enough to do so. So, for moving subjects with little or no light, you must provide the light via a flash or other means. Otherwise, motion blur will be unacceptable.
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Old Oct 22, 2004, 2:56 PM   #7
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Thanks for the info and the time u spent putting it up it helped alot. also thanks for those sites ill take a look at them.
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