Canon - Exposure Compensation

Archived from groups: rec.photo.digital (More info?)

How EC works depends on the mode and the lens. If there isn't any
aperture left (if it can't open up any further), it bumps your shutter
speed down (longer).

You can shift the selected exposure values with the front wheel --
again, provided there's any room to move with your aperture.

Your other choice would be to use shutter priority, in which case EC
will set the aperture based on shutter speed +/- whatever EC you've set.
Again, if there's no wider aperture available, the only thing EC will
accomplish is make the underexposure warning (blinking aperture value)
occur earlier/later.

EC will not mess with ISO, at least on the D60.

advid wrote:
> ... can someone on here point me to a simple web page explanation of
> Exposure Compensation....
>
> Example - If i'm in AP mode on my Canon d30/d60 - I can increase EC
> (to make my dark picture brighter) by rotating the wheel on the back
> of the camera clockwise... BUT in doing so this slows down my shutter
> speed...what if I want to use that particular shutter speed ?
> I would presume that EC should keep the same shutter speed but work
> as Photoshop Levels to mask the image brighter...??

Archived from groups: rec.photo.digital (More info?)

Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
news:0dhu72-f9e.ln1@narcissus.dyndns.org:
> It sounds like what you want is a totally manual exposure, where you
> set the shutter speed and aperture, and then have the camera boost the
> signal to accomodate. That is accomplished by changing the ISO
> setting, which you'll have to do manually. An "exposure priority"
> mode, that automatically adjusts the ISO to give correct exposure, is
> an obvious feature for a digital SLR, but one that the manufacturers
> don't seem to have thought of yet.

Many digicams do this automatically - my Canon Ixus v3 does, my Minolta
DiMAGE 7 did (and presumably still does for its new owner) and at least one
DSLR does this, the Pentax *ist D. There is a setting on the *ist D to stop
it doing it, which is mostly how I use it, and by default it is limited to
ranging ISO200-1600: again, you can set it so that it will range all the
way up to ISO3200.

--Sophie

Archived from groups: rec.photo.digital (More info?)

Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
news:rolu72-3fe.ln1@narcissus.dyndns.org:

> In article <Xns95B1A970D4429sophiewilson@130.133.1.4>,
> Sophie Wilson <sophie.wilson@bigfoot.com> wrote:
>>Chris Brown <cpbrown@ntlworld.no_uce_please.com> wrote in
>>news:0dhu72-f9e.ln1@narcissus.dyndns.org:
>>> It sounds like what you want is a totally manual exposure, where you
>>> set the shutter speed and aperture, and then have the camera boost
>>> the signal to accomodate. That is accomplished by changing the ISO
>>> setting, which you'll have to do manually. An "exposure priority"
>>> mode, that automatically adjusts the ISO to give correct exposure,
>>> is an obvious feature for a digital SLR, but one that the
>>> manufacturers don't seem to have thought of yet.
>>
>>Many digicams do this automatically - my Canon Ixus v3 does, my
>>Minolta DiMAGE 7 did (and presumably still does for its new owner) and
>>at least one DSLR does this, the Pentax *ist D.
>
> ..specifically I mean a mode where *you* set the Av and Tv manually,
> and the camera sets the ISO for you. I've seen cameras with "auto"
> modes, where it picks all three. Is the one on the *ist just a "full
> auto" type mode (in which case, the Canons and presumably others have
> this too), or the former, where the exposure is set manually and the
> sensor gain adjusts to get the correct exposure? If so, then kudos to
> Pentax.

It won't do it in full manual mode, it will do it Av and P (and auto)
modes. In all modes, you can get the metering result fed in to start with
if you wish. So, in manual mode, it will use the currently set ISO no
matter what, but you can press the button and get the initial shutter
time and aperture set (and then change them with the front and back
wheels - one each). In Av or Tv mode, you can press the button and get
the initial exposure settings and then change the aperture or speed and
it will also change the ISO as you do it for Av to keep the shutter speed
up (logically, I suppose it could have changed ISO in Tv mode to keep the
aperture towards the sweet spot, but it doesn't seem to). In P mode it
(obviously) feeds in the metering decision, but you can still over ride
it with the front and back wheels and it will still dynamically change
the ISO. In full auto mode, you're leaving it all up to the *ist D! In
all of this, the exposure line and thus ISO can be set to one of four
modes - HiSpeed (always get the highest speed you can), Best MTF, Best
Depth of Field, or auto blended between these [erm... perhaps my setting
of this is stopping Tv mode doing something it could have done - any
Pentax firmware engineer watching, feel free to butt in!]

Some serious camera users designed this thing!

--Sophie