A digital photography questionary

[massa2908]

1. What is the difference in stops between f.8 and f.16 aperture?
2. Whatis the difference in stops between 125 of sec and 500 sec shutter speed?
3. What is the difference in exposure between these camera settings 125-sec at f.5.6 and 250-sec at f.4?
4. Which photographic negative will receive less exposure: a negative exposed at 60 sec at f.2.8 or a negative at 60 sec at f.16?
5. Which of the following lens 24m, 110mm, or 800mm are most appropriate for portrait photography and why? ( I know that nswer is 110 mm, but why??? )

 

[analog.universe]

Exposure is measured in stops, with each stop being a doubling of the amount of light.

#2 is the most straight forward application, the length of time the shutter is open directly correlates to the amount of light reaching the sensor/film. So 1/500 * 2 * 2 = 1/125, thus they are 2 stops apart.
#1 is slightly more complicated because aperture is a measurement of diameter. f/8 indicates that the aperture is 1/8 * the focal length of the lens in diameter. The amount of light passing through it is determined by it's area however, the area of a circle, which is pi*r^2. If you solve this formula for r, it's apparent that the area of the circle doubles (one stop), when the diameter (or radius) is multiplied by the square root of 2, not 2 itself. So, f/8 / sqrt(2) / sqrt(2) = f/16, 2 stops.
#3 is both of these principles together. 1/125 to 1/250 sec is half as much light, but f/5.6 to f/4 is twice as much, so these will expose the same.
#4 the time remains constant, so since the aperture f/2.8 is larger than f/16, it will yield more exposure.
#5 24mm is a wide angle, so in order to fill the frame with the subject, you'd have to be extremely close, resulting in perspective distortion. 800mm is a super telephoto, so you'd need to be extremely far away. 110mm is long is enough that you can get a shallow depth of field to blur the background, while also giving a pleasant perspective, since you are a reasonable distance from your subject.

If you do end up needing to put any of this into practice, I strongly suggest picking up the book I linked to. There aren't too many concepts at play on a fundamental level, so if you can get your head around all of them, you'll be prepared for any photographic situation. If you have an electronics background the math should be second nature, that's usually where most people glaze over. (and there are far better explanations of it than the cursory one I've provided)

Good luck!

 

[Trever1t]

Is this what this forum has come to? Now were doing elememtary homework. I say get off your butt and do the reseach rather than have others do it for you.

 

[Tony S]

damn, some people are difficult, just trying to complicate things for others where they can

... to this I say "damn, some people are pretty lazy".

Folks posting here don't mind helping out, but when you come right out and say you aren't interested in learning that all you want are answers then we get a little testy. We don't mind helping out, but we do mind doing work you should be doing.

 

[massa2908]

Thank you analog universe!!!
and as if for you trevor, don't copy comments of others, they have already said what they think, just merge into the group

 

[Trever1t]

I didn't copy anybody's comments, I got off my butt and made my own.

 

[massa2908]

sorry if i got you "little testy". the deal is that i have very little time remaining, one billion things to do, and i dont have too much nerves now. sorry again, and again, thanks everyone for the help!

 

[2WheelPhoto]

sorry if i got you "little testy". the deal is that i have very little time remaining, one billion things to do, and i dont have too much nerves now. sorry again, and again, thanks everyone for the help!

 

[Patrice]

Quick answers:

1. Depth of field
2. Interpretation of motion
3. Perspective and field of view
4. Double or half
5. 2 stops
6. 2 stops
7. None
8. 60 seconds a f/16
9. Blend of foreground and background exposure
10. 110 mm, more pleasing perspective
11. ASA: American Standards Association
ISO: International Organization for Standards
12. Size, 120 film is about 60 mm wide, 135 film is about 24 mm wide.


That took 90 seconds.

 

[KmH]

Hi people, this is how things are: I need to answer these 12 questions till 12.september . I don't know the answers on all questions, just few, so i will post all questions here, and hope that you will be so kind to help me, beacuse i really need to solve this. Thanks in advance!

1. What effect does aperture control have on the image other than exposure? Yes

1. What effect does shutter control has on the image other than exposure? No

1. How does focal lenght affect on image? For example the difference between a 28 mm lens and a 150 mm lens. 150 mm - 28 mm = 122 mm

1. What does the word A Stop mean in photographic terms? more or less

1. What is the difference in stops between f.8 and f.16 aperture? $2000

1. What is the difference in stops between 125 of sec and 500 sec shutter speed? 47 - because a motorcycle does not have doors.

1. What is the difference in exposure between these camera settings 125-sec at f.5.6 and 250-sec at f.4? No. ISO.

1. Which photographic negative will receive less exposure: a negative exposed at 60 sec at f.2.8 or a negative at 60 sec at f.16? Density

1. What effect does using a slow shutter speed with flash have on the final image? What advantage is there in this technique? 2 stops. Airy disk.

1. Which of the following lens 24m, 110mm, or 800mm are most appropriate for portrait photography and why? Rembrandt

1. What do acronyms A.S.A. and I.S.O. stand for? Another Senseless Amateur - Internet Seach Organization (based at CERN)

1. What is the difference between 120 or 135mm format film? 47 - because a motorcycle does not have doors.

Thank you!

You're welcome! Why are they all 1.?

Did I pass?

 

[2WheelPhoto]

Hi people, this is how things are: I need to answer these 12 questions till 12.september . I don't know the answers on all questions, just few, so i will post all questions here, and hope that you will be so kind to help me, beacuse i really need to solve this. Thanks in advance!

1. What effect does aperture control have on the image other than exposure? Yes

1. What effect does shutter control has on the image other than exposure? No

1. How does focal lenght affect on image? For example the difference between a 28 mm lens and a 150 mm lens. 150 mm - 28 mm = 122 mm

1. What does the word A Stop mean in photographic terms? more or less

1. What is the difference in stops between f.8 and f.16 aperture? $2000

1. What is the difference in stops between 125 of sec and 500 sec shutter speed? 47 - because a motorcycle does not have doors.

1. What is the difference in exposure between these camera settings 125-sec at f.5.6 and 250-sec at f.4? No. ISO.

1. Which photographic negative will receive less exposure: a negative exposed at 60 sec at f.2.8 or a negative at 60 sec at f.16? Density

1. What effect does using a slow shutter speed with flash have on the final image? What advantage is there in this technique? 2 stops. Airy disk.

1. Which of the following lens 24m, 110mm, or 800mm are most appropriate for portrait photography and why? Rembrandt

1. What do acronyms A.S.A. and I.S.O. stand for? Another Senseless Amateur - Internet Seach Organization (based at CERN)

1. What is the difference between 120 or 135mm format film? 47 - because a motorcycle does not have doors.

Thank you!

You're welcome! Why are they all 1.?

Did I pass?

I disagree. Please cite your source for question #1 (addressing motorcycle doors)

(pic credit: "Panther Motorcycle & Sidecar by Christopher Hester")

 

[Trever1t]

that hack would go well with the car from the "Munsters", awesome!

 

[massa2908]

thanks to people who helped me, patrice and analog universe, and the rest of you, especially trever, kmh and 2wheelphoto, thanks guys for reminding me what kind of man i'am never going to be. If you can be such an asshole that you cant share your knowledge with someone who needs it that moment, just beacuse you're so stuck up, now that's sad. 90 seconds says patrice. 90 seconds. Big photo experts. i should've known, wheres wheat, there's chaff.

 

[Trever1t]

ahahahaa!! you got me pegged! Now you go get that A you don't deserve!

 

[2WheelPhoto]

Got me pegged too, except the photo expert part. I'm a student too. I just learned how to use google and youtube long ago