From a future slide, the higher ISO numbers mean that the image is initially less-exposed but then the brightness is digitally scaled up to "normal" exposure. This means that at higher ISO levels, less light reaches the sensor in the camera, which is why the image gets noisier; it's similar to using fewer samples in the project 3 renderings.
bbtong
Also interesting note on lenses, there's often a tradeoff between Fx.x rating, shutter speed, and lowest ISO possible. A low ISO requires a lot of outdoor sun, and f1.4 lenses (large aperture) with a very fast lens often means you lose the zoom capability and it costs quite a pretty penny.
eric99ying
If I am understanding correctly, we are only controlling the amount of irradiance falling on our sensor by changing the aperture. The higher the ISO, the lower the F stop, and the more light we allow enter our sensor.
x-fa19
I was a little confused about the term "aperture," so I went and looked it up a little. Aperture refers to "the opening of a lens's diaphragm through which light passes," and as illustrated pretty clearly in the lecture slide, affects the depth of field, as we observe in the sharpness of the background of the subject. A low F stop means more light is entering the lens and the shutter doesn't need to stay open as long to correct the exposure, so the shutter speed is faster. The reverse is true for high F stops.
serser11
I am a bit confused by this diagram. Does it mean that all of them are chain effects, so that if we change one of them, all of them change accordingly? Or can we, for example, increase the F-number and also increase the exposure time?
henryzxu
I don't believe the diagram is referring to chain effects--we can definitely increase the F-number and also separately increase the exposure time (edit: this should be shutter speed, F-number directly impacts exposure time). To that extent, however, there are tradeoffs as mentioned above, so an adjustment we make to one control typically is compensated for in the adjustment of another, which can potentially be thought of as a manual "chain effect".
chenwnicole
It was really interesting the way how each level change can be offset by another change in a different setting (e.g. increasing shutter speed by 1 level would decrease brightness, but we can change the fstop to be bigger [smaller in number] to bring that brightness back). This was pretty fun to re-think about how we can approach taking photos.
jeshlee121
Here's a helpful resource I found on camera exposure! https://www.cambridgeincolour.com/tutorials/camera-exposure.htm
From a future slide, the higher ISO numbers mean that the image is initially less-exposed but then the brightness is digitally scaled up to "normal" exposure. This means that at higher ISO levels, less light reaches the sensor in the camera, which is why the image gets noisier; it's similar to using fewer samples in the project 3 renderings.
Also interesting note on lenses, there's often a tradeoff between Fx.x rating, shutter speed, and lowest ISO possible. A low ISO requires a lot of outdoor sun, and f1.4 lenses (large aperture) with a very fast lens often means you lose the zoom capability and it costs quite a pretty penny.
If I am understanding correctly, we are only controlling the amount of irradiance falling on our sensor by changing the aperture. The higher the ISO, the lower the F stop, and the more light we allow enter our sensor.
I was a little confused about the term "aperture," so I went and looked it up a little. Aperture refers to "the opening of a lens's diaphragm through which light passes," and as illustrated pretty clearly in the lecture slide, affects the depth of field, as we observe in the sharpness of the background of the subject. A low F stop means more light is entering the lens and the shutter doesn't need to stay open as long to correct the exposure, so the shutter speed is faster. The reverse is true for high F stops.
I am a bit confused by this diagram. Does it mean that all of them are chain effects, so that if we change one of them, all of them change accordingly? Or can we, for example, increase the F-number and also increase the exposure time?
I don't believe the diagram is referring to chain effects--we can definitely increase the F-number and also separately increase the exposure time (edit: this should be shutter speed, F-number directly impacts exposure time). To that extent, however, there are tradeoffs as mentioned above, so an adjustment we make to one control typically is compensated for in the adjustment of another, which can potentially be thought of as a manual "chain effect".
It was really interesting the way how each level change can be offset by another change in a different setting (e.g. increasing shutter speed by 1 level would decrease brightness, but we can change the fstop to be bigger [smaller in number] to bring that brightness back). This was pretty fun to re-think about how we can approach taking photos.
Here's a helpful resource I found on camera exposure! https://www.cambridgeincolour.com/tutorials/camera-exposure.htm