1 stop

400dabuser wrote in post #10267829
How about the 50D?

Page 93.

400dabuser wrote in post #10267763
Can you explain what is program shift is?

It simply changes aperture and shutter speed in opposite directions. So the exposure remains correct while you vary those parameters.

-js

400dabuser wrote in post #10265798
Not quite sure how to put the title of this thread

Say for example, I adjusted the aperture by 1-stop from f/5.6 to f/8.0, and then I adjusted the shutter speed from 1/125th sec to 1/60th, does that mean
a) I have adjusted the exposure by 2-stops
or
b) I have cancelled out the stop of the aperture?

Again, I do apologise about the lack of understanding about the 1-stop procedure, I have had a kind of an epiphany in the aperture understanding

Have you read Bryan Peterson's "Understanding Exposure" ? It's a good book that explains some of the fundamental concepts of photography.

egordon99 wrote in post #10269001
Have you read Bryan Peterson's "Understanding Exposure" ? It's a good book that explains some of the fundamental concepts of photography.

I should put that book under my equipment list (joke)

egordon99 wrote in post #10269001
Have you read Bryan Peterson's "Understanding Exposure" ? It's a good book that explains some of the fundamental concepts of photography.

That specific concept is on pages 32-33 of the book
FYI

I just passed it in my own reading of the book

ceriltheblade wrote in post #10270163
That specific concept is on pages 32-33 of the book
FYI

I just passed it in my own reading of the book

Oh I see now, thanks:o

images by Paul wrote in post #10267354
except depth of field

Yep, and the possibility of motion blur caused by a moving subject or shaky hand, but i'm guessing the OP was asking about exposure only.

TristanCardew wrote in post #10270238
Yep, and the possibility of motion blur caused by a moving subject or shaky hand, but i'm guessing the OP was asking about exposure only.

I was indeed talking about exposure only

TristanCardew wrote in post #10265848
B) You've cancelled out the stop of the aperture, and effectively adjusted nothing.

That should read, "effectively adjusted nothing as far as the exposure goes". What you have adjusted is the amount of depth that is sharp in the shot.
Virtual Camera
Notice the background change when you use his "Shutter and Aperture" settings!

That's why they're called creative controls. Think of it this way, for a good starting point, first set the f-stop OR shutter speed you need for the effect you want. Then the other parameter: shutter speed or f-stop. Then adjust the ISO.
Need an exposure crutch?

PhotosGuy wrote in post #10271074
That should read, "effectively adjusted nothing as far as the exposure goes". What you have adjusted is the amount of depth that is sharp in the shot.
Virtual Camera
Notice the background change when you use his "Shutter and Aperture" settings!

That's why they're called creative controls. Think of it this way, for a good starting point, first set the f-stop OR shutter speed you need for the effect you want. Then the other parameter: shutter speed or f-stop. Then adjust the ISO.
Need an exposure crutch?

I had see that virtual camera website, but not understood about what is a stop, that is until nearly two weeks ago, but thanks again

Full stops are all about halving and doubling the amount of light. Closing down one stop lets half as much light. decreasing the shutter speed a full stop lets twice as much light. Increasing the ISO one stop means the sensor "absorbs" twice as much light. (And vice versa)

So...f5.6 to f8.0 means -1 stop. 1/125 to 1/60 shutter speed is +1 stop. Add them together you get 0 stops - so there's no change in the amount of light hitting the sensor.

(Thought I'd add this even though 400dabuser figured this out two weeks ago.)

I was taught that the term for what you have done is "equivalent exposure". changing the shutter speed, aperture size, or sensor sensitivity to light by going one direction with one variable and compensating by going another direction with either of the other two will give "equivalent exposure".
Of course, wider apertures mean narrower depth of field, slower shutter mean camera shake and motion blur, and to different degrees depending on mfg. ISO increases can cause image noise.
Although the qualities of the image may change, the term used for changing variables in a way that offsets one change with another is called "equivalent exposure".

The law of reciprocity and when talking film reciprocity failure or as Adams called it the reciprocity effect in which the law no longer applies. Reciprocity failure is not a real issue with digital.


Reciprocity Law (Exposure)
Exposure = Intensity x Time.
In photography, reciprocity refers to the relationship whereby the total light energy – proportional to the total exposure, the product of the light intensity and exposure time, controlled by aperture and shutter speed, respectively – determines the effect of the light on the film. That is, an increase of brightness by a certain factor is exactly compensated by a decrease of exposure time by the same factor, and vice versa. In other words there is under normal circumstances a reciprocal proportion between aperture area and shutter speed for a given photographic result, with a wider aperture requiring a faster shutter speed for the same effect. For example, an EV of 10 may be achieved with an aperture (f-number) of f/2.8 and a shutter speed of 1/125 s. The same exposure is achieved by doubling the aperture area to f/2 and halving the exposure time to 1/250 s, or by halving the aperture area to f/4 and doubling the exposure time to 1/60 s.

^^^^^^

E=IxT

I can't remember how many times I wrote that when studying commercial photography all those years ago..

sued5320 wrote in post #10271346
Full stops are all about halving and doubling the amount of light. Closing down one stop lets half as much light. decreasing the shutter speed a full stop lets twice as much light. Increasing the ISO one stop means the sensor "absorbs" twice as much light. (And vice versa)

So...f5.6 to f8.0 means -1 stop. 1/125 to 1/60 shutter speed is +1 stop. Add them together you get 0 stops - so there's no change in the amount of light hitting the sensor.

(Thought I'd add this even though 400dabuser figured this out two weeks ago.)

Not a problem You lot are making me understand more, thanks you lot