Returning to the photographic world

justiceischeap · Dec 26, 2012

Heya, I'm Justice and I'm returning to the photographic world with an absence so long, I've forgotten everything I ever learned in high school photography class.

In real life, I'm a web designer/developer, so I have some understanding of composition (but have a difficult time correlating that to photography). F stops confuse me because they're backwards (it's not logical).

Anyway, before Thanksgiving, I finally stopped comparison shopping (had been doing so for about 5 years) and took the plunge. I purchased a Nikon D5100 'cause I have all Nikon film camera's so I figure I'd already invested in that brand with the lenses I could reuse. Unfortunately, I've not been able to get out much with the DSLR (been sick) but shoot daily with my iPhone--figure shooting is better than not shooting.

I love the stories photography can tell. I like contrasty, sometimes over-processed looks (but not a fan of HDR), I love B&W, I love good street and urban landscape photography and startling portraiture. And that's pretty much me in a nutshell.

KmH · Dec 26, 2012

:thumbup: Welcome to TPF! :camera:

F-stops are logical if you understand that what they describe is the size of the lens opening (aperture) relative to the lens focal length.
The first thing to realize is that f/4 is a fraction. so, F/4 is a bigger number than f/8 is.

The little f is a variable number - the focal length of the lens.

A 100 mm lens set to f/4 has a 25 mm lens aperture diameter (100 mm divided by 4 = 25 mm). A 50 mm lens set to f/4 has a 12.5 mm diameter lens aperture (50 mm divided by 4 = 12.5 mm)

Here is where most people get lost. A 'stop' is a doubling or a halving, but doubling or halving the lens aperture diameter does not let in 2x or 1/2x as much light.
To double or halve the amount of light the area of the lens opening has to be doubled or halved. To do that we have to use the square root of 2 (1.4142) to determine the aperture needed to make a 1 stop change in tha amount of light the lens lest in or blocks.

f/1 times 1.14142 = f/1.4. F/1 to F/1.4 is 1 stop and f/1.4 is a smaller aperture than f/1 is.

So, the whole stop steps of aperture are f/1 - f/1.4 - f/2 - f/2.8 - f/4 - f/5.6 - f/8 - f/11 - f/16 - etc - each being 1.41412 (square root of 2) times apart.

justiceischeap · Dec 26, 2012

Thanks Keith! Unfortunately, you lost me at "fraction." Math was never my forte, so maybe that's why this has been a difficulty for me. I think I'm going to have to learn that "this f stop corresponds with this amount of light" without the knowing the math behind it, if that's at all possible.

BTW, I read your post like 5 times and didn't get it at all but thank you so much for taking the time to write it out. Maybe if I keep reading it, I'll "get" it.

mishele · Dec 26, 2012

Welcome to the forum!!
Maybe these links will help you out. Don't get discouraged, have fun!!
Introduction to Aperture in Digital Photography
Photography 101.4 – Exposure and Stops
Photography 101.5 Aperture

terri · Dec 26, 2012

Welcome to the forum, Justice! The more you shoot, the more natural it becomes. Respect for Keith's post aside, you don't need to carry that in your head at all times, as it becomes a more instinctive process. You are simply trying to control the amount of light in any given situation. Read the links Mishele posted, too, and practice with your camera. Even holding it and watching the aperture move in response to you playing with the settings can be informative and help it "sink in".

You'll get there!