Digital BW, The Print

On Sun, Sep 2, 2012 at 2:25 PM, russmeadseattle <russmead@...>wrote:

> Thanks Pete. So let me call this back to see if I understand what has
> worked for you. I set my meter at asa 200 for tmax 400 film. Then I don't
> use my normal practice of looking for a medium grey zone to use my spot
> meter, I look for shadows.


Yes. Rather than finding a medium gray zone (i.e., V), I find it easier to
identify something I want to be a shadow with detail (per zone system -
around III), meter it and adjust the exposure to make sure I get the detail
on film. Remember, there may be some density in the negative, but if there
isn't enough exposure to show differences between slightly different
brightness values you'll just have gray mush (in the technical jargon, this
is called getting it off the "toe" of the film-exposure-development (aka
"characteristic" curve). Don't get alarmed by the jargon on this page, but
it's helpful to have a mental image of the curve in mind: see
http://en.wikipedia.org/wiki/Sensitometry .


> So lets say my shadow reads f8 at 1/250. Then I set the camera for f4 at
> 1/250.


Nope, you want two stops less exposure than your meter tells you to use
(whatever the ISO rating you finally decide to set on the meter). So make
it f8 @ 1/1000 second.

By the way, it wouldn't be necessary to adjust this exposure if the
straight line response of the film to exposure extended a long way. It
doesn't, so we're trying to make sure everything that's important to us in
the scene is recorded well. By adjusting the exposure to get the shadow
detail exposure good enough, we're trying to make sure that the highlight
exposure+development doesn't go past the "shoulder" of that
film-exposure-development curve I mentioned before. As the complement to
the shadow exposure, if there is too much exposure (and as I recall, you
said you're not planning to adjust development), you'll have density on the
film for these highlights, but you won't have a recording of the
differences between slightly different brightness values - you'll have (a
different) gray mush.

The entire goal is to get the exposure for as much of the scene you want on
the film so that you can do great things with it later. By the way, you
might dedicate a few moments to some "finger exercises". Set up your camera
and meter a few substantially different lighting scenes: bright daylight
with and without shadows, full shade without highlights. You'll often find
10-15 or more stops of brightness differences between shadows and bright
sunlit areas; given that your plan is to scan the negatives, your film
probably can record 6-10 with good detail and have loss of detail in the
rest ranging from some loss to total mush. Fully shaded scenes might have
2-3 stops of brightness difference. In the film world, altering development
can help with this, but it's a lot more convenient with digital tools such
as channel curves. Channels won't do anything to extract detail out of gray
mush, however.

Now, the pedantic reference in my earlier message was that I wouldn't want
to see someone adopt a general rule of underexposing everything by
inflating the film ISO value. You may actually find that with your
equipment (meter, camera shutter and lens) and your photo developer shop,
the appropriate ISO rating to use is 500; frankly it doesn't matter what
the number is once you've established a baseline for getting your negatives
the way you want them.

Pete


> This would be 3 stops over exposed, but would be perfect in your
> experience to get the best scan for latter printing. Is this correct? (one
> stop for the asa change on the meter, and two stops for adjusting the
> aperture from the meter.) Is this correct? And thanks again for sharing
> your expertise.
>
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Pete Bergstrom
> <petebergstrom@...> wrote:
> >
> > Hi Russ,
> >
> > Don't take the following as pedantic, but you shouldn't be underexposing
> > the film as there is a point at which you'll lose information that you
> > might actually want for your prints.
> >
> > If I understand what you wrote about underexposing your film (rating it
> at
> > 500), I think you have it backwards. I personally wouldn't set the film
> ISO
> > rating at a higher value than the manufacturer unless your processing lab
> > recommends it and their results bear out the practice. I haven't used
> T-Max
> > film in quite a while, but I always found it effective to derate the ISO
> by
> > about half (100 to 50, 400 to 200-320), again, to make sure the shadows
> got
> > enough exposure to register on the film.
> >
> > Whatever the ISO number you finally opt to use for your meter, choose an
> > exposure that will preserve the parts of the scene you most want to keep.
> > For negative film, especially B&W, make sure your shadows get enough
> > exposure on the film (for example, I like to meter dark shadows and then
> > give it 2 stops less exposure just to make sure there's something there
> on
> > the film - underexposing might mean something like 4-5 stops less
> exposure
> > than the meter indicates which might result in blank film areas). Since
> > you're having the film processed at a "normal" rating, your highlights
> will
> > fall "where they may" - sometimes they'll be perfect for the desired
> image
> > contrast and sometimes they'll be too flat or too harsh. You can do a lot
> > with digital processing to tame this, of course, as long as you have
> enough
> > local contrast in the negative to support your intent.
> >
> > With this film, you'll probably have little trouble scanning negatives
> that
> > have gotten pretty dense in the highlights, although in extreme cases you
> > may be forced to have multiple scans performed and then assemble a
> > composite yourself (think HDR techniques).
> >
> > Bear in mind that this set of guidelines works opposite to what you'd
> want
> > to do with color transparency film, which has a whole different set of
> > challenges and rewards.
> >
> > Pete
> >
> > On Sun, Sep 2, 2012 at 12:27 AM, russmeadseattle <russmead@...>wrote:
> >
> > > Ii am pulling out old film cameras to shoot black and white film to
> scan,
> > > then to digitally print. I will primarily be shooting medium format. I
> live
> > > in then land of no sun,Seattle Wa  so use tmax 400 rather than a 100
> Asa
> > > film. I will be using a good lab to develop the film withou any push or
> > > pull. They provide a low level scan with developing for a reasonable
> price.
> > > I will have them do a high Rez drum scan when I have a print made. My
> golal
> > > is to have 20 by 20 prints. Ok, my question... In reading this site it
> > > seems like I need to under expose the film. Is this correct? And if so
> by
> > > how much? And just to make sure I get this right I would set the light
> > > meter for say 500 Asa for tmax 400 (not set the meter for Asa 300)
> > >
> > > Thanks!
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Please visit the Group Homepage to check the Files, and other
> resources as
> > > they are often being updated.
> > >
> > > http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
> > >
> > > If you wish to receive no emails or just a daily digest, or you wish to
> > > unsubscribe, please edit your Membership preferences by visiting this
> same
> > > page.
> > >
> > > Please follow these basic guidelines:
> > > - As threads develop, trim off excess portions of earlier messages to
> keep
> > > them short.
> > > - Good manners are required at all time. No personal attacks or flames.
> > > Hostile, aggressive or argumentative users may be removed from the
> > > membership without notice.
> > > - Keep your posts and threads related to the group topic of digital B&W
> > > printing. Users who persistently make off-topic posts may be removed
> from
> > > the membership.
> > > - By posting on this forum you agree to abide by the group rules and
> > > guidelines, and to abide by the actions and decisions of the group
> Owner
> > > and Moderators. See "Group Topic, Rules and Guidelines" in the Files
> > > section:
> > > http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/
> > >
> > > BY PARTICIPATING IN AND/OR POSTING MESSAGES TO THE DIGITAL BW, THE
> PRINT
> > > YAHOO! GROUP YOU EXPRESSLY UNDERSTAND AND AGREE THAT THE "OWNER" AND
> > > "MODERATORS" OF DIGITAL BW, THE PRINT YAHOO GROUP SHALL NOT BE LIABLE
> TO
> > > YOU FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL OR
> > > EXEMPLARY DAMAGES, INCLUDING BUT NOT LIMITED TO, DAMAGES FOR LOSS OF
> > > PROFITS, GOODWILL, USE, DATA OR OTHER INTANGIBLE LOSSES (EVEN IF THE
> > >  "OWNER" AND "MODERATORS" OF DIGITAL BW, THE PRINT YAHOO GROUP HAVE
> BEEN
> > > ADVISED OF THE POSSIBILITY OF SUCH DAMAGES), RESULTING FROM: (i) THE
> USE OR
> > > THE INABILITY TO USE THE DIGITAL BW, THE PRINT YAHOO GROUP; (ii)
> > > UNAUTHORIZED ACCESS TO OR ALTERATION OF YOUR TRANSMISSIONS OR DATA;
> (iii)
> > > STATEMENTS OR CONDUCT OF ANY THIRD PARTY ON THE DIGITAL BW, THE PRINT
> YAHOO
> > > GROUP; OR (iv) ANY OTHER MATTER RELATING TO THE DIGITAL BW, THE PRINT
> YAHOO
> > > GROUP.
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
> ------------------------------------
>
> Please visit the Group Homepage to check the Files, and other resources as
> they are often being updated.
>
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
>
> If you wish to receive no emails or just a daily digest, or you wish to
> unsubscribe, please edit your Membership preferences by visiting this same
> page.
>
> Please follow these basic guidelines:
> - As threads develop, trim off excess portions of earlier messages to keep
> them short.
> - Good manners are required at all time. No personal attacks or flames.
> Hostile, aggressive or argumentative users may be removed from the
> membership without notice.
> - Keep your posts and threads related to the group topic of digital B&W
> printing. Users who persistently make off-topic posts may be removed from
> the membership.
> - By posting on this forum you agree to abide by the group rules and
> guidelines, and to abide by the actions and decisions of the group Owner
> and Moderators. See �Group Topic, Rules and Guidelines� in the Files
> section:
> http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/
>
> BY PARTICIPATING IN AND/OR POSTING MESSAGES TO THE DIGITAL BW, THE PRINT
> YAHOO! GROUP YOU EXPRESSLY UNDERSTAND AND AGREE THAT THE �OWNER� AND
> �MODERATORS� OF DIGITAL BW, THE PRINT YAHOO GROUP SHALL NOT BE LIABLE TO
> YOU FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL OR
> EXEMPLARY DAMAGES, INCLUDING BUT NOT LIMITED TO, DAMAGES FOR LOSS OF
> PROFITS, GOODWILL, USE, DATA OR OTHER INTANGIBLE LOSSES (EVEN IF THE
>  �OWNER� AND �MODERATORS� OF DIGITAL BW, THE PRINT YAHOO GROUP HAVE BEEN
> ADVISED OF THE POSSIBILITY OF SUCH DAMAGES), RESULTING FROM: (i) THE USE OR
> THE INABILITY TO USE THE DIGITAL BW, THE PRINT YAHOO GROUP; (ii)
> UNAUTHORIZED ACCESS TO OR ALTERATION OF YOUR TRANSMISSIONS OR DATA; (iii)
> STATEMENTS OR CONDUCT OF ANY THIRD PARTY ON THE DIGITAL BW, THE PRINT YAHOO
> GROUP; OR (iv) ANY OTHER MATTER RELATING TO THE DIGITAL BW, THE PRINT YAHOO
> GROUP.
> Yahoo! Groups Links
>
>
>
>


[Non-text portions of this message have been removed]