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Old Aug 2, 2008, 10:38 PM   #1
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i have a nikon d40 and am a little confused on how/ when to use iso correctly.

*at what iso should i start to use a tripod??

*would shooting with an iso of 100 be suggested without a tripod?

* what are the best ways to shoot great NOISE FREE pictures in low light situations (indoor car shows with dim light)???? any suggestions on what to use (ex. lower iso/ up exposure/ aperature??/ flash etc)

*what are the best ways to reduce/ eliminate noise in low light indoor pictures?

*
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Old Aug 3, 2008, 2:09 AM   #2
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danielpouldar asks:

i have a nikon d40 and am a little confused on how/ when to use iso correctly.

*at what iso should i start to use a tripod??

*would shooting with an iso of 100 be suggested without a tripod?

* what are the best ways to shoot great NOISE FREE pictures in low light situations (indoor car shows with dim light)???? any suggestions on what to use (ex. lower iso/ up exposure/ aperature??/ flash etc)

*what are the best ways to reduce/ eliminate noise in low light indoor pictures?

The first question should be, "At what shutter speed should I start to use a tripod?"

In this case, ISO is only a tool to allow you to use a high enough shutter speed so that your shot won't be appreciably softened by camera shake.

The general rule of thumb for the minimum usable shutter speed is 1/x, "x" being the focal length in millimeters of the lens. That means that if you are shooting with a 70mm lens (1/70), you should be using a minimum 1/70th of a second shutter speed. If you're using a 200mm lens, then 1/200th second should be a minimum.

Of course, this is just a general starting figure. Some people can hand-hold shots at lower than this recommended minimum and get good results, while other people need significantly higher shutter speeds.

What you really need to do is to shoot some test pictures of a subject with a lot of detail at various shutter speeds along the full range of your zoom lens (if you have one) or using each of your prime (single focal length) lenses. Then you can look at the results on your computer monitor or test prints to see how low a shutter speed you can use at the various focal lengths of your lens(es) before the pictures start to look unacceptably sharp to you.

Now that you have a good idea what your minimum hand-held shutter speeds are, you can use your lens aperture and ISO setting to keep you shooting at or above that minimum shutter speed.

Getting a lens with built-in image stabilization will help you shoot lower shutter speeds hand-held than you could with a "regular" lens.

For the lowest noise in your pictures, try to use the lowest ISO possible. Noise only gets worse as you increase the ISO.

Sometimes, you will want/need more depth-of-field than you will get using a large aperture (small f/number). Then you will have to start increasing your ISO before you max-out your aperture.

A tripod is only required when there isn't enough light to let you shoot at your hand-held minimum at the aperture/ISO combination that you want.

The D-40 does a pretty good job keeping the noise down at high ISO's, but you might want to run a test on your noise tolerance by making some test shots at all the ISO settings your camera offers. That way, like with the shutter speed, you'll have an idea of how high you can go with the ISO before the noise level starts to get objectionable to you.

Keep in mind, though, that it's probably better to get a noisy shot than no shot at all. Also keep in mind that there are several good noise-reduction programs that can make your noisy shots look better.

The best way to keep down the noise in your pix is to shoot at the lowest ISO you can get by with under the prevailing conditions. To do this, you'll need to open up your lens aperture, add light to the scene with a flash, and/or shoot at low shutter speeds with a tripod.

A tripod can't fix all your problems. The tripod will only help cancel out blur caused by camera motion. If there are moving objects in the frame, they will be increasingly subject to motion blur as your shutter speed drops.

I hope that this addresses, in general, most of your posted questions. Feel free to ask for more!

Grant
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Old Aug 3, 2008, 5:36 AM   #3
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danielpouldar wrote:
Quote:
i have a nikon d40 and am a little confused on how/ when to use iso correctly.

*at what iso should i start to use a tripod??

*would shooting with an iso of 100 be suggested without a tripod?

* what are the best ways to shoot great NOISE FREE pictures in low light situations (indoor car shows with dim light)???? any suggestions on what to use (ex. lower iso/ up exposure/ aperature??/ flash etc)

*what are the best ways to reduce/ eliminate noise in low light indoor pictures?

*
There are three factors that affect exposure:
  • Aperture - The amount of light that passes through the lens to the image sensor[/*]
  • Shutter Speed - The length of time the image sensor is exposed to light[/*]
  • ISO Setting - The sensitivity of the image sensor to light
[/*]
In general, you should use the lowest possible ISO setting, and adjust the other two for exposure.

There are times when you need to increase the ISO setting though. In situations where the light is good but you want to use a very fast shutter speed (to capture motion) AND you want to use a small aperture (for a larger depth of field) your only option is to increase the sensitivity of the image sensor by using a higher ISO setting.

In situations where the light is poor, you can use a larger aperture (risking a smaller depth of field), a longer shutter speed (risking motion blur), a higher ISO setting (risking noise), or increase the amount of light, usually with a flash. You can apply one or more of these options to obtain a proper exposure, only one of which is the ISO setting.

A tripod, or image stabilization, only helps to make a longer shutter speed useable, and does not directly affect exposure.

And the'rule of thumb' that granthagen referred to was developed in the days of 35mm film photography, and doesn't directly apply to digital photography. In order to successfully apply this rule of thumb, you should use the '35mm equivalent' focal length in the formula. That is, on a D40, a 100mm lens would have a '35mm equivalent' focal length of 150mm. So the minimum usable shutter speed on a D40 using a 100mm lens would be 1/150 second.
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Old Aug 4, 2008, 1:02 AM   #4
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Old Aug 4, 2008, 3:50 AM   #5
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danielpouldar wrote:
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bump
What other questions do you need answered? The responses you've been given are fairly comprehensive, and cover all the bases.
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Old Aug 5, 2008, 11:59 PM   #6
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at what iso should i begin to use a tripod????
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Old Aug 6, 2008, 1:38 AM   #7
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There is no simple answer to your question because the way you have phrased it makes it clearthat you do not understand the basics of photography.

So this is as simple as I can make it:

You should begin using a tripod when your shutter speed is too low to hand-hold your camera.

ISO doesn't matter when making this decision.
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Old Aug 6, 2008, 5:51 AM   #8
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danielpouldar wrote:
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at what iso should i begin to use a tripod????
Can you tell us why you think that changing the ISO would require you to use a tripod?
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Old Aug 6, 2008, 8:08 AM   #9
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danielpouldar wrote:
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i have a nikon d40 and am a little confused on how/ when to use iso correctly.

*at what iso should i start to use a tripod??
As others have explained, ISO is a measure of the sensitivity to light. It is equivalent to film speed. If there is sufficient light, you can shoot without a tripod at any ISO setting. On a bright day outside, for example, at ISO 200, I am able to use a 500mm lens hand held. OTOH, at night, indoors, with incandescent lighting, at 18mm, I would need a tripod even at ISO setting of 800 or higher. So, the answer to your question is that ' It depends on what shutter speed you are able to use for proper exposure at the selected ISO '.

The way to have good noise free pictures, is to have a lot of light. This often requires using a flash. For reflective objects, such as cars, you may need an external flash with a diffuser or reflector to reduce harsh reflections.

Everyone is trying to be helpful, but the way you have phrased your initial question is a bit confusing, as most of us do not think of using tripods in terms of ISO settings, but in terms of shutter speed.

brian
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Old Aug 6, 2008, 9:23 AM   #10
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Just to add, while I dont have a D40, I would think the noise at iso400 is virtually nill, and very acceptable at iso800.

At iso 1600 you will still get good images if view at 40% size or so or make small prints.
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