Film speed correction in exposure?

Hello,
I made a very foolish blunder and forgot to reset the ASA setting on my
camera when I loaded my film, so all of my shutter timings should have
been for 100, but instead were taken at 400. I'm sure this will make
all my pictures too dark in developing them, but I was wondering, is
there a way the lab can correct for this, say exposing the film for
four times longer than they normally would? I know there are a lot of
mathematical relationships between the variables used in photography,
so if there's a chance I could sort of improve the quality of these
shots, that would be great. Thanks for the advice!

Ventudg@hotmail.com

Re: Film speed correction in exposure?

I disagree with this, Alan....He "pushed" the film by shooting it as if it
were two f-stops faster than it really was....He had iso 100 film in his
camera, but he told the camera that it was iso 400, so his pictures are two
stops underexposed, or the film was "pushed" two f-stops....Now the lab will
have to compensate for that by overdeveloping for some length of time that
depends on the film type.
See: http://www.photonaturalist.com/photoforum/Articles/Pushing.pdf
For an explanation of this terminology.....

William Graham

Re: Film speed correction in exposure?

Ask the lab to push it 2 stops. If they don't understand find another lab.
--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.

Alan Browne

Re: Film speed correction in exposure?

Color negative film over exposes nicely, but under exposes poorly. He
would be best to ask for a 2 stop push.
Most minilabs can push through time or temperature, time being the
preferred method. Of course the tech has to know what's up.
Cheers,
Alan
--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.

Alan Browne

Re: Film speed correction in exposure?

Actually he "pulled" (under exposed) so now needs a "push".
Cheers,
Alan
--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.

Alan Browne

Re: Film speed correction in exposure?

What Fuji means when they say Velvia 100F can only be pushed one stop, is
that a one stop push is the most they recommend for it still to behave more
or less 'normally'. One stop push on this film makes a it a bit more
contrasty, and increases the (already high) colour saturation. That doesn't
mean that a two stop push is impossible: just that 1) contrast and
saturation will be high enough that the results may not seem very 'normal'
any more and 2) that there is no standard Fuji recommended processing time
for a two stop push with this film published.
Regarding 1), you'll still get usable images, but you should expect that the
deeper shadow areas may have gone completely black - they'll be dramatic,
but you will still be able to make prints from them, and (in PS or similar
or via contrast masking with Ilfochrome or similar) make them look pretty
'normal' - except that detail that is lost in the shadows is lost for good,
and there's nothing you can do abaout that.
Regarding 2), I don't know if Fuji has given times to lab.s for a two stop
push, but not published them publicly, but it seems possible. In any case,
a good lab. will certainly have a processing time that they regard as
'right' for this, and will be able to do it for you. They may well charge
up to 50% extra per roll for the push.
I'd say it's definitely worth going for. Several photographers (myself
included) sometimes pushed the old Velvia one or in extremis two stops for
use in fading evening light or heavy overcast: the increased saturation
actually being quite welcome in this situation, and in the case of overcast
skies, the oncreased contrast was often not a problem either. I haven't
pushed 100F by two stops, but I have used a one stop push and it's fine.
Both Velvia 50 and Velvia 100 I have used two stop pushes with, and they
behaved as described above (ditto provia 100F, so the 'F' technology per se
doesn't suggest that things should be any different for Velvia 100F, if
anything prossibly a little better.)
Peter

Bandicoot

Re: Film speed correction in exposure?

ColinD <nospam@127.0.0.1> writes:
Worth asking, but it sounds like he's used to setting ASA manually, so
probably not. I didn't think of it, having owned only one DX-coded
body out of the, um, about a dozen 35mm film bodies (not counting film
P&S) I've owned over the years.
--
David Dyer-Bennet, <mailto:dd-b@dd-b.net>, <http://www.dd-b.net/dd-b/>
RKBA: <http://www.dd-b.net/carry/>
Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera/Steven Brust: <http://dragaera.info/>

David Dyer-Bennet

Re: Film speed correction in exposure?

"HeroOfSpielburg" <ventudg@hotmail.com> wrote in
I would go ahead for the two-stop push and see what you get. Slide
film doesn't handle well with underexposure, and you'd likely lose too much
color and shadow detail.
Expect contrast to become pretty high, however, with deep shadows.
- Al.
--
To reply, insert dash in address to match domain below
Online photo gallery at www.wading-in.net

Al Denelsbeck

Re: Film speed correction in exposure?

Yeah, I use a 1981 Canon A-1, so no support for that there. Thanks for
the suggestion though!

HeroOfSpielburg

Re: Film speed correction in exposure?

Does your camera not use the DX encoding on the cassette? I would check
this first, as your film may very well be properly exposed, unless you
actually overrode the DX settings.
Colin D.
--
Posted via a free Usenet account from http://www.teranews.com

ColinD

Re: Film speed correction in exposure?

If you were going to project these images, then I would ask the lab to do
whatever it can....Pushing them one f stop would be better than none. If you
were going to have prints made, or scan them into your computer and work on
them with Photoshop, then you have several other options. You can do amazing
things with Photoshop, and probably compensate for the bad initial exposure.
I would ask the lab what it can do for you, and take their advice.