Calling All Smarty Pants :)

Skippy

Righto all you clever people out there

Lets talk F Stops and corresponding Speeds ....how does this work ??

I was reading in a book that for every F stop and correct exposure there is a speed to match right ?

Lets say F8 with a speed of 250 is a correct setting ......now if you then go to F10 which way to you go to match the speed ?
Do you go up or down :dunno

Can anyone provide a set of examples F stops/Speeds like this for instance........just pulling figures out of my head cause I don't have a clue....

F8 - 125
F12 - 100

I'd like to know if you choose to use a higher or Lower F Stop which way to you go to get the corresponding speed ?

Or have I got this all ASS UP :huh :scratch Skippy (Australia)

devbobo

Hey Skip,

You're talking about the rule of[font=Verdana,Tahoma,Arial,Helvetica] reciprocity, as the f-stop increases (f8-f12; less light), you need a longer exposure to get the same amount of light.
[/font]
Try this article...
http://www.apogeephoto.com/feb2003/Mkees2_2003.shtml

Hope this helps.

David

dragon300zx

WOW, reading that even confused me. Ok here it goes.

F/stops and Shutter speeds do match up thats correct. Here is an example.

f/8 at 1/60

say you drop down one full stop to f/5.6 that means you are letting in a full stop more light (twice as much light as at f/8. To keep the right exposure you have to up your shutter speed a full stop (I am working in full stops not half stops) to compensate or your image will recieve too much light. Your new combination would be:

f/5.6 at 1/125

Now say it wasn't your aperature that needed adjusting but you needed a faster or slower shutter speed to compensate for motion or hand holding of the camera. Same principle applies

f/8 at 1/60

60 is too slow and will cause blur on a moving object that you want to freeze. you need to up your speed to 125. Keep in mind that with fstops the smaller the number the light gets in. The opposite is for shutter speeds. The bigger the number the less light gets in. So to keep your exposure correct you need to drop your fstop one.

f/5.6 at 1/125

Now say you are messing with depth of field.

f/8 at 1/60

this will produce a some what shallow depth of field when doing a landscape. so you want a aperature or fstop of 32 to product the biggest depth of field you can. you have to adjust your shutter speed to let in more light because your aperature is letting in less light. I don't have my camera or a fstop/shutter speed chart in front of me and I can't remember all the numbers off the top of my head to do a proper conversion but this would be something like.

f/32 at 1/3

That shutter speed is wrong but you get the idea. I hope. There are lots of great books out there for this basic mechanics of photography type stuff. You might wanna check out a book that was mentioned here awhile ago called "photography" I forget who the author is because my copy is in another room right now. It is currently in it's 8th edition. If you do a search you should be able to find it or I'll post the author tomorrow.

Skippy

hehehe.......smarty pants
Excellent explanation.........I knew it wouldnt be long and I'd get a hit on this thread.......you folks over here are just too clever.
Thank you very much, your explanation has been written in such a way that I can actually understand it extra points to you for that
Thanks a lot .....Skippy (Australia)

dragon300zx wrote:

WOW, reading that even confused me. Ok here it goes.

F/stops and Shutter speeds do match up thats correct. Here is an example.

f/8 at 1/60

say you drop down one full stop to f/5.6 that means you are letting in a full stop more light (twice as much light as at f/8. To keep the right exposure you have to up your shutter speed a full stop (I am working in full stops not half stops) to compensate or your image will recieve too much light. Your new combination would be:

f/5.6 at 1/125

Now say it wasn't your aperature that needed adjusting but you needed a faster or slower shutter speed to compensate for motion or hand holding of the camera. Same principle applies

f/8 at 1/60

60 is too slow and will cause blur on a moving object that you want to freeze. you need to up your speed to 125. Keep in mind that with fstops the smaller the number the light gets in. The opposite is for shutter speeds. The bigger the number the less light gets in. So to keep your exposure correct you need to drop your fstop one.

f/5.6 at 1/125

Now say you are messing with depth of field.

f/8 at 1/60

this will produce a some what shallow depth of field when doing a landscape. so you want a aperature or fstop of 32 to product the biggest depth of field you can. you have to adjust your shutter speed to let in more light because your aperature is letting in less light. I don't have my camera or a fstop/shutter speed chart in front of me and I can't remember all the numbers off the top of my head to do a proper conversion but this would be something like.

f/32 at 1/3

That shutter speed is wrong but you get the idea. I hope. There are lots of great books out there for this basic mechanics of photography type stuff. You might wanna check out a book that was mentioned here awhile ago called "photography" I forget who the author is because my copy is in another room right now. It is currently in it's 8th edition. If you do a search you should be able to find it or I'll post the author tomorrow.

pathfinder

Skippy wrote:

Righto all you clever people out there

Lets talk F Stops and corresponding Speeds ....how does this work ??

I was reading in a book that for every F stop and correct exposure there is a speed to match right ?

Lets say F8 with a speed of 250 is a correct setting ......now if you then go to F10 which way to you go to match the speed ?
Do you go up or down

Can anyone provide a set of examples F stops/Speeds like this for instance........just pulling figures out of my head cause I don't have a clue....

F8 - 125
F12 - 100

I'd like to know if you choose to use a higher or Lower F Stop which way to you go to get the corresponding speed ?

Or have I got this all ASS UP Skippy (Australia)

I posted this table a while back, Skippy. Feel free to copy it or print it out.
The relationship of F stop to shutter speed is apparent in the table.
:

gtc

it was a lot harder in the days before histograms
if your camera has a histogram it will make correct exposure easier-move shutter speed ,aperture and film speed around until you get what you want-so then histogram shows exposure as being correct but you need a faster shutter speed,say to stop motion etc,then you will need to either open the aperture to let in more light to enable faster shutter speed or increase 'film' speed or maybe use a flash or reflector to increase the light falling on the subject.

we have it so easy in the digital world-with TTL exposure metering and TTL flash-the old timers have to be admired when one considers all the calculations required to get correct exposure,particularly with flash,and no instant view to tell whether they got it right or not

gus

Skip i just leave the camera on AV mode & let it choose maximun shutter for that particular F/stop ...this leaves me to decide in DOF with the F/stop in each shot.

Gus

Skippy

Hi Pathfinder

pathfinder wrote:

I posted this table a while back, Skippy. Feel free to copy it or print it out.
The relationship of F stop to shutter speed is apparent in the table.
:

Thank you very much for posting this table.......I emailed it to myself at work and printed it off there........then tonight I went straight to my travel documents and put it with my important papers
Wow you sure know what your talking about too don't ya
Yup .....you guys are just wayyyyyyy toooo clever, and that's a good thing for us dumbies I tell ya thank you again....... Skippy (Australia)

Skippy

Hi gtc

gtc wrote:

if your camera has a histogram it will make correct exposure easier-move shutter speed ,aperture and film speed around until you get what you want-so then histogram shows exposure as being correct but you need a faster shutter speed,say to stop motion etc,then you will need to either open the aperture to let in more light to enable faster shutter speed or increase 'film' speed or maybe use a flash or reflector to increase the light falling on the subject.

we have it so easy in the digital world-with TTL exposure metering and TTL flash-the old timers have to be admired when one considers all the calculations required to get correct exposure,particularly with flash,and no instant view to tell whether they got it right or not

Yep things have changed in leaps and bounds, I am really excited about the way the Digital World is moving, and moving fast too.....I'm still using Aperture Mode, but one of these days, I'm gonna go Manual
Skippy (Australia)

Skippy

Hi Ya Gus

Humungus wrote:

Skip i just leave the camera on AV mode & let it choose maximun shutter for that particular F/stop ...this leaves me to decide in DOF with the F/stop in each shot.

Gus

Hi Gus my friend......... I use AV Mode too, but I want to go Manual for the Fireworks, and I might try it out on a few other things too, just need to know in which direction I need to be adjusting

I better know what I'm doing because I will not be in a position to review my images except in the back of the camera for a large part of my trip to USA.

I have that book UNDERSTANDING EXPOSURE, but I didn't quite get this point, but I do now ohhhhhhh geez mate I'm just scareing meself bigtime with the things I think I am understanding lately :lol4 :lol

Hey the new X-Drive arrived today........boy is it sleek compared to the other one .......smaller and very compact indeed, no surfaces stick up, the unit is very smooth indeed, and that blue light man does that glow....this will make it a lot easier to download in bad lighting for sure....comes with a really cool pouch too that can be used with a belt......I'm charging up the battery now as I write, had to put the 100 gig hard drive in meself.....and to my surprise it worked when I turned it on :lol4 take care Skippy (Australia)

4labs

So Skippy all this time you have taken these amazings photos without understanding exposure? Holy Crap now that you really know what you are doing I can't wait to see what you come up with.

Skippy

Ohhhhhhhhh Ummmmmm

4labs wrote:

So Skippy all this time you have taken these amazings photos without understanding exposure? Holy Crap now that you really know what you are doing I can't wait to see what you come up with.

I gotta confess........technical things just go straight over my head, comes with being a school drop out in my early days I guess reading was something I never did........so that makes me a "DO-ER" I have to do things to understand, usually sinks in really well if I can actually do what someone is trying to explain to me.

Shooting in RAW really helps cause you can cover up your stuff ups afterwards yup......... RAW I like .....well we will see if I really really comprehend what you wonderful folks share in knowledge if not, I'm no worse off hu Skippy (Australia)

spockling

Hey Skip, try a quick peek at this page. There are two charts in there that you can print off and use together.