This sort of relates to the post from DiD. I saw that the D200 will have the ISO all the way up to 3200. It is my understanding that the higher the ISO the grainier the picture. When the ISO is set to 400 on my Coolpix 8800 the pictures turn out too grainy for my taste. Am I doing something wrong, or is this just my "artistic preference" to have a sharper picture?

In other words, when increasing the ISO, what changes need to be made to shutter speed and aperture settings?

 

This higher ISO allow you to capture low lighting object without flash. However the draw back is the picture will be grainy. That's why in sunny day, you want something like 100ISO, indoors with flash usually use 200ISO

 

ISO200 is the lowest you really need...www.dpreview.com has tested many nikons with iso200 being the lowerst point in direct sunlight and the results are no different from using iso100 on canon's... when you have a higher ISO you can use shutter and aperture to get the best photo...the trade off is grain ...but iso100-200 you wont notice the grain at all on a SLR

NIkon's get more grain than Canon's but NIkon cameras produce sharper and Crispier images than the Canons...


Ever since I have switched to the D70 and I have never missed the lower ISO feature that I used in the past.

 

When you increase the ISO, probably you need to adjust to increase the shutter speed or increase the aperture. Since the camera is now more sensitive to light and you need to increase either one to limited the exposture.

 

You manage light in three ways: ISO, Aperture, and Shutterspeed. No matter how many modes your camera has, you're fundimentally adjusting those three things.

• ISO 100 means it has the sensitivity dialed down, and it takes longer for each pixel to gather enough light (color information) before it knows what color to turn.
• ISO 1600 would make the sensor 4-stops (16 times) more sensitive than ISO 100 and result in each pixel needing less exposure to light to collect enough information to determine the color it should turn

• F/2.8 - would be a big opening for a lens, meaning it lets a lot of light in and as a result of the large opening you have a shallow depth of field (a thin focus plane). Using the lens at it's biggest aperture will result in the fastest possible shutterspeeds.
• F/22 - would be a tiny opening in the lens, meaning light would have to bleed it's way in through the hole before it could get to the sensor. Using a small aperture also increases depth of field, so more of the image will be in focus (at F/22 all of it should be).

• This one is pretty self explanitory

• Each time you double or halve the ISO, Aperture, or Shutterspeed, it's referred to as a stop. Making changes in one area necessitates changes in one or both of the others in order to maintain the same exposure.

Say you have a photo that is ISO 100, F/2.8, 1/10 shutterspeed. At 1/15th of a second you probably can't handhold the camera to take a clear shot. The Aperture can't be opened any further since we're shooting with a F/2.8 lens and it's already wide open. So, the only option here is to adjust the ISO up.

• ISO 200 (1 stop or 2x the sensor sensitivity), F/2.8, 1/20 shutter (1 stop or 2x the shutterspeed)
• ISO 400 (2 stops or 4x the sensor sensitivity), F/2.8, 1/40 shutter (2 stop or 4x the shutterspeed)
• ISO 800 (3 stops or 8x the sensor sensitivity), F/2.8, 1/80 shutter (3 stop or 8x the shutterspeed)
• ISO 1600 (4 stops or 16x the sensor sensitivity), F/2.8, 1/160 shutter (4 stops or 16x the shutterspeed)

Which do you choose? The common rule of thumb would be that you can only hand hold down to about 1/30th of a second. So we need to go to at least ISO 400 to not get camera shake to show up in the picture.


As a result of boosting the ISO to increase the shutterspeed, we also introduced more digital noise into the image. There are sofware programs that can help reduce the amount of noise, by sampling the noise in an image and then processing for it. I use Neat Image but there are other software solutions out there. Keep in mind that this will only help with the noise, it won't eliminate it. That said the results can be impressive. You will also want to do some sharpening after the noise processing otherwise the image looks a little plasticy.

 

Ok, so let me get this straight. The higher ISO numbers react faster to the light input.

Using the above explanation from DiD I could also choose to increase my ISO to 400, leave the shutter speed at 1/30, but change the apperture to something like F5.6. So let me use the bellow picture as an example:



The settings for this picture were:

ISO 100
Shutter 1/30 sec
Apperture F7.1

Since F7.1 is almost at the limit of my particular camera model, if I chose to go to ISO 200, would I than change the shutter speed to 1/60? What would be the advantages or disadvantages of doing that?

 

Yes

In this case i wouldn't change it. From the lighting and what not, I'm guessing your camera is tripod mounted, so I wouldn't worry about it. If you got that hand held, your hands are a little more steady than mine. If there had been visible camera shake, pushing the ISO would have allowed you to get a stable picture.

The disadvantage would be more noise at higher iso.

 

Thanks for the advice Dave. Just wanted to make sure. Good eye, by the way. It was on a tripod with a coule of small hot lights.

 

ISO is really a film standard, and unfortunately it's been up to the manufacturer of digital cameras to loosly translate it.

All it really is to the digital camera is more amplification and different paramters for some software algorithms. ISO 200 on one digital camera does not mean it is as sharp ISO 200 on another brand's. Too bad there's no real standard for measuring this.

For example my pentax does ISO 40 but my canon is sharper at ISO 400...a lot comes down to quality of the sensor.

But their purpose is to be used as is in film cameras. Lower is sharper but needs more light. You have the option to give up sharpness for ability to capture in less light.

*and by sharpness, I mean, less grain. Not lens sharpness or resolution.

Dpreview.com is the place to go to compare varios cameras' handling of ISO and grain vs. their competitors.

 

(supergimp imagines Goaljnky at home playing with his pretty ponies)

 

 

Ugh, that triangle again. When I first learned it, it was so much more tough because with a normal SLR I couldn't just swap out my film for a different ISO between pictures. I had to work around it with my shutter speed and apature. Now with my DSLR I have so much more fun, not to mention some of the automated features. (just to note...I'm happy about the auto stuff because I came from an OLD Cannon AE-1...post-Vietnam era camera...it was my dads. So I never had anything remotely like my Olympus E-300 until recently. It made my job so much more fun when I was just wanted to take a picture)