Exposure Adjusting

[Josh]

Yes appature is referd to as f-stop. But what I learnd in my internship is to think of it as a meter of light, and thinking about it that way has helped tramendusly, over the years, with hitting exat lighting ratios.

I won't say that if someone says "stop down" I don't know they mean appature. All that I am saing is that you can call the diferance between 200 asa and 100 asa a stop. Because that is the diferance. So when I say:

to keep from getting confused, f-stops go by dubbling and film speeds tend to fallow.


50, 100, 200, 400, 800, 1600, 3200

count the stops and shoot like mad baby!

I am comfident that ppl know what I mean.

 

[ksmattfish]

Where people get confused, and I've seen this in the "Intro to Photography" classes I teach, is that while doubling/halfing shutter speed and ISO is one stop, doubling or halfing f/#s is not 1 stop, but 2 stops: f/2 is 2 stops more than f/4, f/4 is 2 stops more than f/8, f/8 is 2 stops more than f/16, etc...

I understand that you know this, but I felt that your initial statement was confusing to newbies.

I still stand by my statement that the term "f/stop" refers only to aperture, while the term "stop" refers to any doubling or halfing of the exposure. See the definitions I posted at http://www.thephotoforum.com/forum/viewtopic.php?t=3362 ; these aren't my definitions, they are from the books of Ansel Adams, Henry Horenstein, Michael Langeford, John Hedgecoe, etc...

f/stop = focal length divided by diameter of aperture

I was taught that the "f" in "f/stop" originally came from musical notation, but then again I know nothing about music. On the other hand I'm confident that I understand the basics of photography.

 

[Josh]

Yes you are right that the way I said that would be confusing.

I don't think about #'rs for any exposer control method (ISO, apature, shutter speed). But I think of them all as dobbuling or halfing the amount of light, not there number. Witch is what they do. Just because f-8 is not, numericly, twice as much as f-5.6 dosn't mean that it isn't dubling the amount of light. I know you know this =)

I sometimes forget that the rest of the world dosn't use the same thought prosses I do.