Shutter speed and aperture

hamlet · Oct 25, 2013

Lets say i have two prime lenses:

one with an maximum Aperture of f1.8

and one with an maximum Aperture of f4

I am about to take a picture at the same exact conditions with both cameras set to f8. Will the shutter speed of both these lenses differ in speed? or will their shutter speeds be equally fast within a margin of error?

480sparky · Oct 25, 2013

F/8 is f/8 is f/8 is f/8.

All else being equal, the shutter speeds and ISO of both images will be the same.

hamlet · Oct 25, 2013

Thanks Sparky.

Josh66 · Oct 25, 2013

If this were not the case, hand-held light meters would not work.

hamlet · Oct 25, 2013

So now its that time again to create a thread and ask what hand-held light meters are. :popcorn:

Josh66 · Oct 25, 2013

hamlet said:
So now its that time again to create a thread and ask what hand-held light meters are.

2011121511 by J E, on Flickr

hamlet · Oct 25, 2013

Its always fun to learn, but i'm not even going to bother with something like that. Yet.

Josh66 · Oct 25, 2013

They do make life easy... Especially with flash.

The meter in your camera is measuring the light being reflected by the subject. That ^^^ measures the light falling on the subject. It can also measure reflected light with an accessory that I do not have (it replaces that white dome).

edit
Actually, I do have the reflected light attachment, but there is *another* attachment (a few of them, actually - 5, 10, and 15 degrees, I think) for spot metering reflected light - I don't have *that*.

hamlet · Oct 25, 2013

Here i thought that all you needed was a camera.

astroNikon · Oct 25, 2013

hamlet said:
So now its that time again to create a thread and ask what hand-held light meters are.

It's a light meter ..... that's hand held

astroNikon · Oct 25, 2013

hamlet said:
Here i thought that all you needed was a camera.

If you point your camera into various subjects .. some in light, dark areas .. just slowly move it around and watch your exposure meter in your viewfinder or live view. You can see those bars move from left to right. As they move from left to right and you stop, you need to adjust something (such as shutter) to compensate for a properly exposed photo. So the light meter states that you are over or underexposed to that item. Remember, it adjusts based on the reflected light unless it generates it's own light.

Now the hand held light meter is kinda the same thing except much better. Then you make adjustments on your camera to what the light meter states.

Light meters were used all the time by photographers in the ice age .... (waiting for a response) :popcorn:

hamlet · Oct 25, 2013

Do you have to use it with a flash? How about building? Does it work on that?

Josh66 · Oct 25, 2013

astroNikon said:
Light meters were used all the time by photographers in the ice age .... (waiting for a response)

HAHA! They're still pretty useful in the digital age.

hamlet said:
Do you have to use it with a flash? How about building? Does it work on that?

You don't "have" to, but it lets you get everything dialed in right much quicker.

The next best thing (for getting it right the first time) to using a flash meter would be calculating the proper settings using the Guide Number of the flash. For that you need to be at reasonably good at estimating distances though - many people aren't (in my experience, that's the part people have the most trouble with - accurate distance estimation. I measure stuff every day though, so I'd say I'm pretty good at it, lol.). And being able to do simple math in your head quickly would help too. (Most modern flash units have this built in though, so all you really need to know is how to estimate distance.)

What a lot of people do is just guess, check the LCD, change some settings, check the LCD again, etc...

edit
Not sure what you mean by building? Taking pictures of a building? Sure, it would work for that. If you're metering the incident light (using the white dome thing) the meter will need to be in the same light as the subject though.