Film Pre-Exposure?

Is anybody using pre-exposure when takeing pictures? I know it
requires multiple exposure capability but can be done, at least
for one frame, in advance of the actual picture takeing.

I've been lazy up till now but think the added shadow density and
gain of a stop or two in EI might be worth the extra effort.

What about technique? Will a plastic bag over the lens and a three
or four stops down exposure do the job? Dan

In article ,
(Dan Quinn) wrote:

Is anybody using pre-exposure when takeing pictures? I know it
requires multiple exposure capability but can be done, at least
for one frame, in advance of the actual picture takeing.

I've been lazy up till now but think the added shadow density and
gain of a stop or two in EI might be worth the extra effort.

What about technique? Will a plastic bag over the lens and a three
or four stops down exposure do the job? Dan

The idea was for sheet film where you are processing each sheet
seperately. Never the less you could shoot the whole roll through the
camera,...there's really no reason you can't. If I was doing it I would
make a round disk out of white opaque plexiglass, mounted into a
stepping ring the thread size of the lens. Or you could cut a square
4x4 piece and use a slip in filter holder.
--
LF website http://members.bellatlantic.net/~gblank

For best results expand this window at least 6" at 1152 x 768 resolution

(Dan Quinn) wrote in message . com...
Is anybody using pre-exposure when takeing pictures? I know it
requires multiple exposure capability but can be done, at least
for one frame, in advance of the actual picture takeing.

I've been lazy up till now but think the added shadow density and
gain of a stop or two in EI might be worth the extra effort.

Generally this is not a good idea. It lowers contrast in the shadows,
just where you need it. Lens designers have been striving for decades
to reduce flare....so why the hell do you want to add it?


What about technique? Will a plastic bag over the lens and a three
or four stops down exposure do the job? Dan

Put the plastic bag over your head...

Press photographers used to "shoot the sky" to effect this. Exposure should
be around 4-5 stops less than middle gray (obviously you need to test this
procedure).

I also have plans somewhere for a camera mod using grain of wheat lamps to
preflash film in roll cameras, one of the cameras modified was a M-3.

Gives a real 1-2 stop boost in shadow detail. Threshold effect. Get
enough photons in those really dark areas to print. It looks better than
inky black shadows or half-baked dodging.

One can also post flash film by hanging it in a dark (real dark not near
dark) darkroom and use a #3 safelite to expose the film.


--
darkroommike

----------
"Dan Quinn" wrote in message
om...
Is anybody using pre-exposure when takeing pictures? I know it
requires multiple exposure capability but can be done, at least
for one frame, in advance of the actual picture takeing.

I've been lazy up till now but think the added shadow density and
gain of a stop or two in EI might be worth the extra effort.

What about technique? Will a plastic bag over the lens and a three
or four stops down exposure do the job? Dan

(Michael Scarpitti) wrote in message
Put the plastic bag over your head...

Follow your own advice, Scarcrappi.

As for the question, yes it can be done, and there are many reasons to
do so, but what are yours? What are you trying to achieve by doing
so?

Alexis

www.alexisneel.com

"Dan Quinn" wrote in message
om...
Is anybody using pre-exposure when takeing pictures? I know it
requires multiple exposure capability but can be done, at least
for one frame, in advance of the actual picture takeing.

I've been lazy up till now but think the added shadow density and
gain of a stop or two in EI might be worth the extra effort.

What about technique? Will a plastic bag over the lens and a three
or four stops down exposure do the job? Dan

Dan:

The technique works well in some circumstances when the shadow values are
really off the scale and your visualization indicates they would enhance the
final print. Such a scenario as a beach scene where the subject has greatly
shadowed areas compared to the brightly lit "other" side(s). I have metered
a little gray card I carry around in the ol' bag but almost any printed
medium can be used as middle gray. Rack the focus out and make the exposure
as you suggest (3 or 4 stops down) then expose the subject. Develop
"normally". I have used this on roll film where it is difficult to alter
development per frame.I do have a couple of prints made from negatives
produced with this technique and will send you one email (650x650) for
brevity if you wish.

Truly, dr bob.

Michael Scarpitti wrote:

(Dan Quinn) wrote in message . com...


Is anybody using pre-exposure when takeing pictures? I know it
requires multiple exposure capability but can be done, at least
for one frame, in advance of the actual picture takeing.

I've been lazy up till now but think the added shadow density and
gain of a stop or two in EI might be worth the extra effort.



Generally this is not a good idea. It lowers contrast in the shadows,
just where you need it. Lens designers have been striving for decades
to reduce flare....so why the hell do you want to add it?



Wrong. The technique, implemented by shooting the sky at 4-5 stops
below meter reading, is often used to add detail in the shadow areas
without affecting the highlights. A uniform increase of 1 unit of
exposure value in Zone 1 yields 2 or Zone 2. Zone 2 becomes 2 1/2.
Zone 3 becomes 4 1/4. By the time you are at Zone 8, the affect is only
1/128th additional light, not noticeable to the human eye. Flare, on
the other hand, is a lens affect, not an exposure affect.



What about technique? Will a plastic bag over the lens and a three
or four stops down exposure do the job? Dan



Put the plastic bag over your head...


Michael, such passive-aggresive or anti-social behavior is not helpful.
Nor is it funny.


Francis A. Miniter

On 5/11/2004 8:14 AM Francis A. Miniter spake thus:

Michael Scarpitti wrote:

(Dan Quinn) wrote in message
. com...

What about technique? Will a plastic bag over the lens and a three or
four stops down exposure do the job?

Put the plastic bag over your head...

Michael, such passive-aggresive or anti-social behavior is not helpful. Nor
is it funny.

Quite the contrary: it is both. Helpful in reminding all of his true nature,
and funny as only a fool self-destructing can be.


--
I was quickly apprised that an "RSS feed" was not, as I had naively
imagined, some new and unspeakable form of sexual debauchery practised
by young persons of dubious morality, but a way of providing news
articles to the cybernetic publishing moguls of the World Wide Wait so
they can fill the airwaves with even more useless drivel.

- Cynical shop talk from comp.publish.prepress

(Alexis Neel) wrote in message . com...
(Michael Scarpitti) wrote in message
Put the plastic bag over your head...

Follow your own advice, Scarcrappi.

As for the question, yes it can be done, and there are many reasons to
do so, but what are yours? What are you trying to achieve by doing
so?

Alexis

www.alexisneel.com

This is folly. Nothing to be gained except ruined shadow contrast.
There are better ways, such as compemsating devlopment, that will
accomplish your goal better.

Quit listening to morons.

Michael Scarpitti wrote:
(Alexis Neel) wrote in message . com...

(Michael Scarpitti) wrote in message

Put the plastic bag over your head...

Follow your own advice, Scarcrappi.

As for the question, yes it can be done, and there are many reasons to
do so, but what are yours? What are you trying to achieve by doing
so?

Alexis

www.alexisneel.com


This is folly. Nothing to be gained except ruined shadow contrast.
There are better ways, such as compemsating devlopment, that will
accomplish your goal better.

Quit listening to morons.


Michael, if the detail was not recorded in the shadows to begin with, no
amount of compensating development can put it there. That is why a
pre-exposure can be extremely useful.


Francis A. Miniter