Linked Questions

0
votes
1answer
162 views

Guide number and exposure [duplicate]

I am having a bit of a difficulty calculating this. Guide#= 32 feet at ISO 100 X sync speed= 1/250 Min ISO= 100 Max ISO= 800 What exposure values to expose to capture subject that's far away? What ...
68
votes
4answers
152k views

What does f-stop mean?

What does f-stop mean? Is it the same thing when people say "2 stops" for example?
28
votes
10answers
83k views

What is an easy way to remember the full stop scale?

If you were teaching someone new to photography the full stop scales, is there a better way then flat out memorizing these values? Does anyone have an easy way that they remember the scale? Would it ...
6
votes
3answers
2k views

Why are f-stops not linear?

Why don't we use a linear scale for f-stops, rather than one based on square roots? A linear scale will be easy to remember (in fact, there will be nothing to remember) and to calculate how much ...
16
votes
2answers
2k views

What is the inverse-square law, and how does it apply to lighting for photography?

I hear photographers talk about the inverse-square law, particularly with reference to lighting. What is this law about, and most importantly, how is it applied to lighting for photography?
6
votes
5answers
4k views

Does adding additional strobes cumulatively add to the flash power?

I've been reading articles that talk about using multiple strobes next to each other, all pointing in the same direction: as a means to add more light over what one flash can do. Does the addition of ...
8
votes
2answers
6k views

How do I set exposure with a manual flash?

I recently got an old Canon AE-1 film camera back in working order. I'd like to use my modern 430EXII Speedlight flash with it, however since there is no TTL metering, I have no idea how much the ...
7
votes
2answers
2k views

Pentax P-TTL: Why and when does underexposure occur and what can I do?

Pentax's P-TTL flash metering system tends to be unreliable and may underexpose at times. When and why does the system underexpose and what can I do? I want to know the situations that cause flash ...
2
votes
1answer
1k views

What is the relationship between Guide Number and flash power level?

From this post, I understand that the flash guide number (GN) is given by the following formula: Guide Number = Shooting Distance × f-number ÷ ISO factor I'm assuming that the GN calculated via the ...
1
vote
3answers
479 views

Is the Flash GN calculation or formula explained with bare strobe or softbox?

I just re-read the title of "What is the quantitative relation between flash guide number and ISO?" and was wondering: Is the GN formula stated referring to bare light or with softbox?
3
votes
2answers
426 views

What flash guide number do I need to underexpose a “sunny” background?

I'm familiar with the maths behind flash usage (guide numbers, etc.). Here's a more practical question that doesn't yet seem to have an answer on photo.se: Consider a subject, outdoors, on a regular "...