Canon Digital Rebel metering in low-light

Archived from groups: rec.photo.digital.slr-systems, rec.photo.digital (More info?)

Hi,

Take a look at these shots
http://gallery129375.fotopic.net/c395008.html
(WARNING: The originals are 2+MB each)

When I was setting the camera for these shots, the indicator on the EV
scale had gone below -2EV and so was blinking. I would say the
exposures were -3EV to -4EV from the camera recommended "0" EV.

Everyone in my office who looked at the photos liked them so I am
assuming the exposure is right. The question is that if the exposure is
right then how come the camera meter was WAY off?
Canon 300D
Canon EF-S 18-55mm f/3.5-5.6

- Siddhartha

Archived from groups: rec.photo.digital.slr-systems,rec.photo.digital (More info?)

"Siddhartha Jain" <losttoy2000@yahoo.co.uk> writes:

> Hi,
>
> Take a look at these shots
> http://gallery129375.fotopic.net/c395008.html
> (WARNING: The originals are 2+MB each)
>
> When I was setting the camera for these shots, the indicator on the EV
> scale had gone below -2EV and so was blinking. I would say the
> exposures were -3EV to -4EV from the camera recommended "0" EV.
>
> Everyone in my office who looked at the photos liked them so I am
> assuming the exposure is right. The question is that if the exposure is
> right then how come the camera meter was WAY off?
> Canon 300D
> Canon EF-S 18-55mm f/3.5-5.6

Camera meters aren't all that smart. They evaluate a scene, and more
or less want the result to be middle gray, and in digital perhaps
they're doing math to minimize the number of pure white (all 1's)
pixels. If you shoot a black cat in a coal mine, a proper exposure
will be a few stops below middle gray. If you shot a white cat in a
snow storm, your exposure will have to be a few stops over middle gray
to look accurate.

Your shots are a nighttime scene, and are very dark--and I'd agree
with your camer that they are several stops below middle gray.
Techincally, they are somewhat lacking in contrast and could stand to
punched up a bit, and I think they might benefit from having been
exposed longer. I don't see any areas that are at risk of becoming
overexposed anytime soon.

Also with long exposures, there's this bit about reciprocity failure
that comes into play as I recall. I don't know enough about the
subject to expound upon it at great length though, but what I remember
of it tells me to not expect any metering to be terribly accurate when
you get into 15 and 30 second exposures. "Bracket like hell--those
buildings aren't moving away anytime soon" is the advice I tend to
follow to get a good one.

I'd be curious if your photos would look punchier if they were exposed
even longer, or at higher ISO's.

Best Regards,
--
Todd H.
http://www.toddh.net/

Archived from groups: rec.photo.digital.slr-systems,rec.photo.digital (More info?)

Todd H. wrote:

> Also with long exposures, there's this bit about reciprocity failure
> that comes into play as I recall.

"Reciprocity failure" is the tendency of color films to shift color over
long exposures; the real problem with it is that it's inconsistant and
largely unpredictable and varies from one brand and formulation of film
to the next. It DOES NOT affect digital photos (see
http://www.pbase.com/bret/image/34152731 and note the exposure settings).

Archived from groups: rec.photo.digital.slr-systems,rec.photo.digital (More info?)

In article <1105376744.514468.46680@f14g2000cwb.googlegroups.com>,
Siddhartha Jain <losttoy2000@yahoo.co.uk> wrote:
>
>Everyone in my office who looked at the photos liked them so I am
>assuming the exposure is right. The question is that if the exposure is
>right then how come the camera meter was WAY off?

They're night shots, dominated by dark skies. Assuming you were using
evaluative metering, it never really stood a chance. Try partial on the
buildings, with maybe -1 EV for this sort of thing, and experiment around
there. You should find you get better results.