ISO and aperture

[xolotl]

A quick technical question here. About ISO, Shutter speed and aperture.

Assuming natural light is the same. Would I get the same shutter speed with a lens at f/2.8 and camera at ISO100 as I would with a lens at f/5.6 and the camera ISO400?

Does upping the ISO give you essentially an extra stop of light?

[Falkon]

http://www.camerasinteractive.com/index.php#

http://www.photonhead.com/simcam/

I like the second one the best. I hope this helps you understand it.

[SkipD]

A quick technical question here. About ISO, Shutter speed and aperture.

Assuming natural light is the same. Would I get the same shutter speed with a lens at f/2.8 and camera at ISO100 as I would with a lens at f/5.6 and the camera ISO400?

Does upping the ISO give you essentially an extra stop of light?Yes and Yes.

However, it would be better to phrase the question (to yourself) - instead of Would I get the same shutter speed - as Could I use the same shutter speed?. What I am hinting at is the mindset of you making the camera do what you want it to do instead of letting it do it for you.

One of the best tools (other than computer software) that I have found to learn about various combinations of settings for the same exposure reading is a handheld light meter. You can take a reading and then visualize all the combinations on the meter.

[Robert_Lay]

A quick technical question here. About ISO, Shutter speed and aperture.

Assuming natural light is the same. Would I get the same shutter speed with a lens at f/2.8 and camera at ISO100 as I would with a lens at f/5.6 and the camera ISO400?

Does upping the ISO give you essentially an extra stop of light?

Assuming natural light is the same. (As what?)
Would I get the same shutter speed with a lens at f/2.8 and camera at ISO100 as I would with a lens at f/5.6 and the camera ISO400? Yes.
Does upping the ISO give you essentially an extra stop of light? No - it gives you an extra stop of sensitivity, which can be indirectly equivalent to an extra stop of brightness in the image.

[Robert_Lay]

Yes and Yes.

However, it would be better to phrase the question (to yourself) - instead of Would I get the same shutter speed - as Could I use the same shutter speed?. What I am hinting at is the mindset of you making the camera do what you want it to do instead of letting it do it for you.

One of the best tools (other than computer software) that I have found to learn about various combinations of settings for the same exposure reading is a handheld light meter. You can take a reading and then visualize all the combinations on the meter.

I agree 100% with everything that you say. However, even though I personally am a fan of the Pentax Spot Meter, the EV scale that such instruments use becomes a problem in itself. I spent about a year researching EV before I finally found a set of consistent derivations for EV. In other words, once you accept EV, you're OK, but for many people, the EV itself becomes another stumbling block.

[SkipD]

I agree 100% with everything that you say. However, even though I personally am a fan of the Pentax Spot Meter, the EV scale that such instruments use becomes a problem in itself. I spent about a year researching EV before I finally found a set of consistent derivations for EV. In other words, once you accept EV, you're OK, but for many people, the EV itself becomes another stumbling block.I guess I should have been a little more explicit - the meters I had in mind (several that I have used over the years) show shutter speeds and apertures as well as ISO settings (or ASA in the old ones).