how to calculate exposure time?

You are either a troll and should go away or you are not qualified to teach
a large format photography class and should get someone who is knowledgeable
to teach it.

KB


<tracym.DeleteThis@askme.net> wrote in message
news:5tt8k0pipnhl0fifnm6bfti1lsj5n094ue@4ax.com...
 >
 >
 > hi all,
 >
 > I am starting a large format photg class, and I don't know what I'm
 > doing....
 >
 > I'm following the instructions on oeprating the camera step by step,
 > and have got past using the light meter to dertmine the f-stop,
 > based on the film speed. However, how do I use an exposure
 > calculator to determine the amount of time to expose the negative?
 >
 >
 > thanks,
 >
 > tracy<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

On Sun, 12 Sep 2004 17:01:52 GMT, "Ken Burns" <kenburns.DeleteThis@twave.net>
wrote:

 >You are either a troll and should go away or you are not qualified to teach
 >a large format photography class and should get someone who is knowledgeable
 >to teach it.
 >
 >KB

Now, if I was a teacher, why would I be trying to follow the
instructions on how to use the camera? Good Lord.

Thanks a whole lot for the attitude.


To everyone who helped, thanlk you very much.

tracy<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

Okay...giving anyone the benefit of the doubt...here is what I hope is a
concise answer.

A certain amount of light is falling on a given subject. This amount of light
is measured by a light meter...the light meter (depending on the model of
meter) will give you and exposure value ( a number ) or a direct reading in
terms of f stop and shutter speed (usually a digital meter will do this for
you). You set the light meter to the ASA speed of the film. When the meter
gives an exposure value, it usually has a dial of some sort where you point the
"little arrow" at the exposure value number and a scale on the meter gives you
a range of f stop/shutter speed combinations that would be appropriate. You
will notice that each shutter speed will generally be twice the duration of the
speed above it and half the duration of the speed below it...like: one second,
1/2 second, 1/4 second, 1/8 second....and so on. This relationship is
mathematically obvious...the relationship of f stops is about the same but the
notation system is not so obvious: one f stop lets in twice as much light as
the one above it and half the light of the one below it. The difference is
that the scale is something like : 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22...and so
on. Example: f 8 lets in twice the light of f11 but only half as much as
f5.6.

Thus you can get the same amount of light to fall on the film if the
combination is f8 at 1/60 of a second and f11 at 1/30 of a second. If you stop
down from f8 to f11, you let in half the light but then compensate for that by
changing the shutter speed so that it's open twice as long. So both of these
combinations have the same exposure value...just different variables (shutter
speed, f stop).

You might want to use a smaller (higher numbered) f stop to gain depth of
field...then you would go for the smaller f stop and slower shutter speed. You
may find that you don't need the depth of field but do need to stop action
(person walking, trees blowing in the breeze), so you go the other way: faster
shutter speed, open up the aperture (lower f stop numbers).

You will
 >> Stay informed about: how to calculate exposure time? 

In article <5tt8k0pipnhl0fifnm6bfti1lsj5n094ue.DeleteThis@4ax.com>,
tracym.DeleteThis@askme.net wrote:

 > hi all,
 >
 > I am starting a large format photg class, and I don't know what I'm
 > doing....
 >
 > I'm following the instructions on oeprating the camera step by step,
 > and have got past using the light meter to dertmine the f-stop,
 > based on the film speed. However, how do I use an exposure
 > calculator to determine the amount of time to expose the negative?

Most of the exposure calculators for bellows extension (which is what I
*think* you're talking about) involve putting a target in the same plane
as the object being photographed (all these situations would be for
closeups -- general metering would take care of most situations from 3
or 4 feet to infinity), then measuring its image on the ground glass
with a matched ruler. There is a site that has a PDF download that will
let you make your own target and gauge (don't have it bookmarked since
changing machines, but Googling for bellows extension factor would
probably have the right site show up).

I read what you wrote to mean taking the class, not teaching it.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

....and I continue thanks to a touchy "enter" button.

You will find that there will be a lot of variables involved in calculating the
exposure. When you are photographing a close up, you will run into "bellows
factor" which will necessitate more exposure. When the scene has extremes of
contrast some compensaton may be necessary as well. Hopefully you will learn
about these things later on...just getting an adequate negative is the first
step and you can build upon that. Best of luck.

I assume that you are a student in a class and not the instructor and that you
have come to this group with a legitimate question and are not a "troll", a
"goblin", a "boogey-man" or a "hob-goblin". I try to take this forum somewhat
seriously (not above an occaisional attempt at humour) and won't waste my time
trashing anyone who seems to be asking a legitimate question.

Please try finding a good source book for this kind of information before you
resort to the newsgroups for authoritative answers (I tell my children this as
well). Try the Ansel Adams books, one or another of the Ralph Hattersley books
or (heaven forefend I should reccomend it in THIS newsgroup) the Steve Simmons
book...there are a lot of others but these come to mind. Go to the library or
browse them at a Borders or B&N...or even BUY one if you have to.

best

argon
 >> Stay informed about: how to calculate exposure time? 

On 12 Sep 2004 17:41:10 GMT, argon3.RemoveThis@aol.com (Argon3) wrote:

 >...and I continue thanks to a touchy "enter" button.
 >
 >You will find that there will be a lot of variables involved in calculating the
 >exposure. When you are photographing a close up, you will run into "bellows
 >factor" which will necessitate more exposure. When the scene has extremes of
 >contrast some compensaton may be necessary as well. Hopefully you will learn
 >about these things later on...just getting an adequate negative is the first
 >step and you can build upon that. Best of luck.
 >
 >I assume that you are a student in a class and not the instructor and that you
 >have come to this group with a legitimate que


that's a good assupmtipon.

 >I try to take this forum somewhat
 >seriously (not above an occaisional attempt at humour) and won't waste my time
 >trashing anyone who seems to be asking a legitimate question.

that's a good policy.

 >
 >Please try finding a good source book for this kind of information before you
 >resort to the newsgroups for authoritative answers (I tell my children this as
 >well). Try the Ansel Adams books, one or another of the Ralph Hattersley books
 >or (heaven forefend I should reccomend it in THIS newsgroup) the Steve Simmons
 >book...there are a lot of others but these come to mind. Go to the library or
 >browse them at a Borders or B&N...or even BUY one if you have to.


You know, I believe I did mention I was waiting for a book to come,
didn't I? And I also mentioned that I had tried to find some info on
my own before coming here, and that I encountered some confusion
because I found that there are a lot of different formulas out there.

I am not waiting until the book comes because I have an assignment due
Thursday.

Thank you very much for your input. I will go read it.

Ya'll are almost as bad as the people on rec.video.production and the
way they pounce on anybody who asks about getting a job in video
editing (that wasn't me). sheesh.

tracy the "cranky now" newsgroup hazee<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

"Ken Burns" <kenburns RemoveThis @twave.net> wrote in message news:<4i%0d.15967$az6.12486@newsread2.news.atl.earthlink.net>...
 > You are either a troll and should go away or you are not qualified to teach
 > a large format photography class and should get someone who is knowledgeable
 > to teach it.

Why do you state he's teaching the class? It sounds to me as though
he's TAKING the class!


 >
 > KB
 >
 >
 > <tracym RemoveThis @askme.net> wrote in message
 > news:5tt8k0pipnhl0fifnm6bfti1lsj5n094ue@4ax.com...
  > >
  > >
  > > hi all,
  > >
  > > I am starting a large format photg class, and I don't know what I'm
  > > doing....
  > >
  > > I'm following the instructions on oeprating the camera step by step,
  > > and have got past using the light meter to dertmine the f-stop,
  > > based on the film speed. However, how do I use an exposure
  > > calculator to determine the amount of time to expose the negative?
  > >
  > >
  > > thanks,
  > >
  > > tracy<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

tracym.RemoveThis@akme.net wrote:

<snip>

It's usually not that bad here. We've had a rash of trolling on this group
lately and people are still a bit on edge.


: Ya'll are almost as bad as the people on rec.video.production and the
: way they pounce on anybody who asks about getting a job in video
: editing (that wasn't me). sheesh.

: tracy the "cranky now" newsgroup hazee







:

--




Keep working millions on welfare depend on you
-------------------
fwp.RemoveThis@deepthought.com
 >> Stay informed about: how to calculate exposure time? 

In article <h4f9k0d8g37sp4jqamq7v3h4g9gsgeg5nh.TakeThisOut@4ax.com>,
tracym.TakeThisOut@akme.net wrote:

 > To everyone who helped, thanlk you very much.

I'm curious as to what precisely you were trying to figure out --
bellows factor or reading speed and f-stop settings off a light meter?<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

On Sun, 12 Sep 2004 21:36:11 GMT, Rebecca Ore
<spamtrapforore.RemoveThis@NOHarvestverizon.net> wrote:

 >In article <h4f9k0d8g37sp4jqamq7v3h4g9gsgeg5nh.RemoveThis@4ax.com>,
 > tracym.RemoveThis@akme.net wrote:
 >
  >> To everyone who helped, thanlk you very much.
 >
 >I'm curious as to what precisely you were trying to figure out --
 >bellows factor or reading speed and f-stop settings off a light meter?

I am just trying to figure out how long to expose the negative.

I already know how to use the light meter to get the f-stop, at least
I hope so.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

tracym.RemoveThis@akme.net wrote:
 > On Sun, 12 Sep 2004 21:36:11 GMT, Rebecca Ore
 > <spamtrapforore.RemoveThis@NOHarvestverizon.net> wrote:
 >
  >>In article <h4f9k0d8g37sp4jqamq7v3h4g9gsgeg5nh.RemoveThis@4ax.com>,
  >> tracym.RemoveThis@akme.net wrote:
  >>
   >>> To everyone who helped, thanlk you very much.
  >>
  >>I'm curious as to what precisely you were trying to figure out --
  >>bellows factor or reading speed and f-stop settings off a light meter?
 >
 > I am just trying to figure out how long to expose the negative.
 >
 > I already know how to use the light meter to get the f-stop, at least
 > I hope so.


If the light meter is giving you an F/stop it should be giving you a time.
The two are a matched set. No use having a F/stop without the shutter speed.

Nick<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

In article <d1h9k055ago18f0ji35471ce1k9ahacmg7 DeleteThis @4ax.com>,
tracym DeleteThis @akme.net wrote:

 > On Sun, 12 Sep 2004 21:36:11 GMT, Rebecca Ore
 > <spamtrapforore DeleteThis @NOHarvestverizon.net> wrote:
 >
  > >In article <h4f9k0d8g37sp4jqamq7v3h4g9gsgeg5nh DeleteThis @4ax.com>,
  > > tracym DeleteThis @akme.net wrote:
  > >
   > >> To everyone who helped, thanlk you very much.
  > >
  > >I'm curious as to what precisely you were trying to figure out --
  > >bellows factor or reading speed and f-stop settings off a light meter?
 >
 > I am just trying to figure out how long to expose the negative.
 >
 > I already know how to use the light meter to get the f-stop, at least
 > I hope so.
 >

What kind of light meter are you using? Basically, if you aren't making
a close up, you set the film speed on the meter (where and how to do
this varies depending on the meter), decide on the shutter speed based
on what the subject is (slower if it's landscape or a still life, a bit
faster if it's a portrait of an adult, faster yet if you've got dogs or
children in the shot). The f stop will affect depth of field and you
probably want to shoot at f/16 if you want less of the background in
focus or closer to f/45 if you want more in focus.

If you can, shoot one shot with a faster shutter speed and smaller f
stop (lens more open) and another of the same subject with a slower
shutter speed and larger f stop (lens more stopped down).

Digital meters make finding out which f stop goes with which shutter
speed given your film and light conditions easier, but a non-digital
meter can be faster once you understand what you're looking at.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time? 

<tracym.RemoveThis@askme.net> wrote in message
news:5tt8k0pipnhl0fifnm6bfti1lsj5n094ue@4ax.com...
 >
 >
 > hi all,
 >
 > I am starting a large format photg class, and I don't know what I'm
 > doing....

Wait for Lesson Two. It's all there.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: how to calculate exposure time?