Please help explainthis description.....

[ThePhotoKid]

"ISO 25-5000 automatically set in 1/3-stop increments according to DX code. Can also be set manually from ISO 6-6400 in 1/ 3-stop increments."

Can someone explain what this means? I'm so sorry, but its in the specs of a camera I'm researching, but I don't understand it.

Also, whats an f stop?

Thank you.

 

[ksmattfish]

That means it'll automatically set the meter to the manufacturer's recommended ISO for any film between ISO 25 and ISO 5000 with a DX code (bar code type thing on film cassettes).

You can override this or set manually for cassettes without DX code any where from ISO to ISO 6400 in 1/3 stop increments.

It just means that it'll read the DX code or you can set it manually. Every camera should have this; most do.

 

[mrsid99]

Also, whats an f stop?

Thank you.

It's a stop that doesn't work when you want it to.

 

[Big Mike]

While researching a camera, take some time and research basic photography. You should have at least a basic knowledge of exposure before you compare the features of different cameras.

Basically...F-stop is the number assigned to the size of the lens aperture (or opening). The smaller the number, the bigger the opening (called faster). The larger the number, the smaller the opening (called slower). The size of the opening combined with the shutter speed, will determine the exposure of the photo.

When comparing lenses, the max aperture (low number) is fairly important. For example...a 50mm F 1.8 lens has a max aperture of 1.8...which is quite good. This means that the lens can open up really wide and let in lots of light...therfore giving you the option to use a faster shutter speed to obtain the proper exposure. This is good for low light situations. You want to have a faster shutter speed if you are holding the camera in your hands because the picture will be blurry if the shutter is slow and the camera shakes even slightly. If you use a tripod and a remote release then it does not matter because the camera wont shake.

A lens with a max aperture of 3 or 4 does not open up very wide which means that you will have to have a slower shutter speed to get the proper exposure. This is OK for bright situations where the lens can be closed down to F16 or so but not for darker lighting where opening the lens would really come in handy.

I did not even mention Depth of Field, which is controlled by the aperture.

Sorry I rambled on...

 

[ksmattfish]

A "stop" is the doubling or halving of the amount of light needed for proper exposure. This is controlled by shutter speed and aperture. Aperture size is identified by it's "f/stop".

f/stop = lens focal length divided by actual size of the aperture (in mm).

 

[ThePhotoKid]

Oh man thanks guys. You are a plethra of information I have 2 books on photography at home that get pretty in depth. But I'm at school now and won't be hme for break till this weekend. I will read up. Thank you very very much.

 

[ksmattfish]

To add more confusion, I know that the term "f/stop" comes from music, but I don't know enough about music to know why.

 

[voodoocat]

Well... there is an f hole on the violin...

f stands for forte which means loud. ff is louder, fff is louder and so on. maybe thats where it comes from.