Photography exposure help!?

Question

for my photography class we were given an assignment to shoot one normal exposure one exposure one stop down and one exposure one stop open, i have 24 exposures on my film so i should have 8 picture but the example on what my data sheet should look like is different is has 1/125 shutter with 5.6 fstop 1/125 with 4 1/125 with 8 1/250 with 5.6 1/60 with 5.6 1/125 with 5.6 and so on so i dont really know what im supposed to be doing. if you could just help me to understand what stop open and stop down mean and how i shoot them and what exactly this data sheet he gave us means!!!! this is like super important i only have a couple of days to get in the darkroom!!!

Answer 1

Hi,

You have a reference shot of a picture with shutter speed at 1/125sec at f-stop of f/5.6. Assume that is your base exposure.

One stop down means one f-stop smaller, so that would be 1/125sec at f/8 (f/8 is a smaller aperture than f/5.6 - half the size in fact).

One stop open means open the apeture larger by 1 stop, so that would be 1/125sec at f/4 (f/4 is a larger aperture than f/5.6 - twice as big).

Note: the scale of apertures is a little confusing. It goes, from largest hole to smaller hole:

f/1.0  f/1.4  f/1.8  f/2  f/2.8  f/4  f/5.6 f/8  f/11  f/16  f/22  f/32 ....

f/1.0 is the largest aperture (wide open)

f/32 is the smallest aperture (tiny hole)

Note that the scale is double the second number (ie: 1st, 2nd, 2x1st, 2x2nd...), not double each previous number. This is because the numbers represent that area of a circle.

The second set of values you were given is with the aperture constant, adjust the shutter speed.

Your reference is f/5.6 at 1/125sec.

One stop down is would be f/5.6 at 1/250sec (1/2 the time the shutter is open, which results in 1/2 the light coming in ).

Open stop open would be f/5.6 at 1/60sec (2x the time the shutter is open, which results in 2x the light coming in).

The scale of shutter speeds is pretty simple, it's either double or half the previous value (depending on the direction). Note, it's not always exactly 1/2, but pretty close.

30 15 8 4 2 1 1/2 1/4 1/8 1/15 1/30 1/60 1/125 1/250 1/500 1/1000 1/2000 1/4000

Hope that helps,

John.

Answer 2

Ok so stop open is the f stop like 5.6 and stop open would be making it bigger so a smaller number like f 4 and then 2.8 and then 2. Stopping down would be making the hole smaller like f 8 then f 11 and so on... look at your camera the numbers are in order. I still have to stop to think about it. You could also think of it like a pie chart... 2 is a big piece of pie where 22 is a small one.

Hope that helps

Answer 3

The aperture is the opening in the lens to let light into the camera to expose the film, when you press the shutter button.  It has settings called "f stops."  Think of the aperture as like the iris in your eye.  The size of the opening determines how much light comes into the camera.  It's a little confusing, but a smaller F-stop number actually means a bigger aperture.  So F-5.6 is actually a larger aperture than F-11.  A larger F-stop number means a smaller aperture.  So, F-16 or F-22 (if your camera goes down to F-22) is the smallest aperture.

The two ways you control exposure are with the aperture setting and the shutter speed.  The shutter speed just means how long the shutter stays open when you press the button.  It's usually measured in fractions of a second.  So 1/250 is a faster shutter speed than 1/125.  A faster shutter speed will expose the film less, and a slower shutter speed will expose the film for longer.  The shutter speed you would want to use depends on the light and whether you want to freeze motion or show motion in your picture.

The overall exposure of a picture is determined by both the shutter speed and the aperture.  It's the combined effect of how much light comes into the camera, and the length of time you expose the film.  Also, shutter speed and aperture can compensate one another.  So you can either use a faster shutter speed with a wider aperture, or a smaller aperture with a slower shutter speed.

The numbers 5.6, 8, and 4 just mean your aperture setting.  Those are F-stops.  To change the F-stop, there should just be a dial on the lens of your camera.  The numbers that are in fractions like 1/125 mean the shutter speed.  You should be able to change the shutter speed with a k**b or dial that's by the shutter release button.    

For the "data sheet" you just record what shutter speed and aperture you used.

Answer 4

Follow the shot list and all will be reviled to you once you develop and make contacts of the film

These technical assignments are supposed to teach you a number of things.  How to adjust your shutter speed and f/stop, determine how accurate your cameras meter is (you didn't mention the lighting prescribed in your assignment) and once in the darkroom prove to you how important getting the exact exposure and developing the film properly is when you start trying to print the over or under exposed negatives.

Answer 5

Ok, if you double the f/stop and half the shutter speed that is the same exposure.  For instance-

If you set the aperture at f/8 and a shutter speed of 1/500 that is one exposure

If you open up one stop (f/5.6) and set the shutter speed at 1/250

guess what- that is the same exposure.

The same amount of light is hitting the film plane thus the exposure will be identical!