F-Stops

[nikond50man]

Hi, Ive been asked to do a shoot, im not entirely sure what the difference between iso and f.stops are, is their suck thing as a calendar/map of the time to tell you when to use such advanced controlls? its going to be christmas lights..

Thanks

Lawrie

www.cornish-photography.co.uk

 

[rabaroo]

well i am no expert as many on this forum will agree.... however, from what I know

A "stop" is a generic term used to describe aperture, shutter speed and iso, so basically the manipulation of any of those controls to let more or less light in is widely regarded as "a stop"

with regards to ISO and F-stops, I am presuming that you mean f-stop in terms of aperture? as changing from ISO100 to ISO200 could be described as a stop.... as too is moving from F2.8 to F4...

its based on reciprocals so as you adjust one, you make an equal adjustment of the other, e.g. at ISO100 and F2.8, moving to ISO200 means you could run at F4 (equivalent changes with shutter speed too)

so thats the basics, as for controls to tell you what to use - thats a bit advanced for me...... so cant help with that one

 

[vmlopes]

I suggest that you get a good book, Understanding Exposure by Bryan Peterson will give you some good reading on this subject.

But essentially f-stops control depth of field, depending on your lens this can be a low number f/2.8 for example for a very shallow depth of field and a larger number say f/16 will give you a much greater depth of field i.e more will be in focus from front to back.

Get reading, before you do your shoot, you have a website selling photos and you asking about this stuff??? dont make sense to me

Victor

 

[Chappers]

ISO was and is a measure of how sensitive film is to light. The higher the ISO number the more sensitive the film is. This has now been imported into the digital arena, and relates to how senstive the camera ( chip) is to light. Point to bear in mind you don't get something for nothing. The higher the ISO with film then the more grain you see on the final result. The same goes for digital except you don't get grain you get noise. The digital version of grain. So the lower the ISO the finer the grain/lower noise.

Stop or F stop relates to the amount of light the aperture control of a lens will let through. Now the larger the number the less light that gets through. So a stop ( or aperture ) of F8 lets through LESS light than F 5.6 ( in fact half as much. ).

As a side effect, which I wont go into know, by changing the aperture ( F stop) you can vary the depth of field .

If you are new to this aspect of photography I do suggest you try and get hold of the book already mentioned. The subject of exposure is not complicated, you just have to understand whats happening