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Need help with some basics ...

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Anonymous
July 18, 2005 12:10:53 AM

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

Hi all,

Being new to DSLR photography I'd like to think that I'm slowly coming to
terms with the basics, but playing with my 350D tonight I've come across
something I don't understand.

Can someone help me out here? ...

If I set the camera to FULL AUTO and take a picture across the room the
flash pops up and the camera selects 1/60 Sec - F4.0 - ISO400 - no probs
there.

On PROGRAM Mode - same parameters.

On SHUTTER PRIORITY however, with 1/60 - ISO 400 set the Aperature indicator
is flashing to say "out of range" (it's only an F4.0 lens), and I have to
come down to 1/30 of a sec to keep it happy (flash is primed for all of
these tests by the way).

On APERATURE PRIORITY it again wants a shutter speed of 1/30 Sec for correct
exposure.

So ...

With ISO set to 400 for all tests and flash primed, WHY is the camera happy
with an 1/60 + F4.0 combo on AUTO or PROGRAM modes, but insisting on 1/30 +
F4.0 in Tv or Av modes?

I don't get it.

Any help apreciated.

Many thanks,

CC

More about : basics

July 18, 2005 12:10:54 AM

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

> On SHUTTER PRIORITY however, with 1/60 - ISO 400 set the Aperature
> indicator
> is flashing to say "out of range" (it's only an F4.0 lens), and I have to
> come down to 1/30 of a sec to keep it happy (flash is primed for all of
> these tests by the way).

It's warning you that you need more aperture, it obviously needs f2.8 which
isn't available on your lens.
basically it's metering without compensating for the flash and telling you
it's too dark.

> On APERATURE PRIORITY it again wants a shutter speed of 1/30 Sec for
> correct exposure.
>
As above

> So ...
>
> With ISO set to 400 for all tests and flash primed, WHY is the camera
> happy with an 1/60 + F4.0 combo on AUTO or PROGRAM modes, but insisting on
> 1/30 + F4.0 in Tv or Av modes?

Presumably in AUTO it knows it's going to use flash.
Sounds like the camera needs a bit more logic to tell it you are going to
use flash.
My 10D is identical.
Anonymous
July 18, 2005 12:10:54 AM

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

With the flash engaged, which it will do automatically in full auto or if
you manually engage it in P mode, the camera thinks that the flash will be
the main source of light and takes over setting the exposure. However, in
Tv, Av, or M mode the camera thinks the flash will be used only for fill and
takes its exposure settings from available light then adjusts the flash
duration for the amount of dialed-in fill.


"Cockpit Colin" <spam@nospam.com> wrote in message
news:hooCe.1165$PL5.152101@news.xtra.co.nz...
> Hi all,
>
> Being new to DSLR photography I'd like to think that I'm slowly coming to
> terms with the basics, but playing with my 350D tonight I've come across
> something I don't understand.
>
> Can someone help me out here? ...
>
> If I set the camera to FULL AUTO and take a picture across the room the
> flash pops up and the camera selects 1/60 Sec - F4.0 - ISO400 - no probs
> there.
>
> On PROGRAM Mode - same parameters.
>
> On SHUTTER PRIORITY however, with 1/60 - ISO 400 set the Aperature
> indicator is flashing to say "out of range" (it's only an F4.0 lens), and
> I have to come down to 1/30 of a sec to keep it happy (flash is primed for
> all of these tests by the way).
>
> On APERATURE PRIORITY it again wants a shutter speed of 1/30 Sec for
> correct exposure.
>
> So ...
>
> With ISO set to 400 for all tests and flash primed, WHY is the camera
> happy with an 1/60 + F4.0 combo on AUTO or PROGRAM modes, but insisting on
> 1/30 + F4.0 in Tv or Av modes?
>
> I don't get it.
>
> Any help apreciated.
>
> Many thanks,
>
> CC
>
>
Related resources
Anonymous
July 18, 2005 12:10:54 AM

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

David wrote:

>in Tv, Av, or M mode the camera thinks the flash will be used only for fill

and he and Justin are the only correct respondents!! I don't own a
Canon, but this is a pretty basic concept and I would be very surprised
if other DSLR's didn't act similarly. My prosumer does it too, and *so
it should*..
Anonymous
July 18, 2005 12:10:55 AM

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

This is indeed odd. I have tried this on my 350D at ISO 200 and with flash
raised (and registered in the viewfinder) in all cases:

In P mode: 1/60, f4

In Tv mode: 1/60 set, f4 flashing but taken anyway. Exposure on the result
identical to P mode.

In Av mode: f4 set, camera set and took at 1/6! Over exposure on the result.

I do not have an answer but at least we are all have the same issue.

Mike Bernstein

"dylan" <no@nowhere.com> wrote in message
news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
>
>> On SHUTTER PRIORITY however, with 1/60 - ISO 400 set the Aperature
>> indicator
>> is flashing to say "out of range" (it's only an F4.0 lens), and I have to
>> come down to 1/30 of a sec to keep it happy (flash is primed for all of
>> these tests by the way).
>
> It's warning you that you need more aperture, it obviously needs f2.8
> which isn't available on your lens.
> basically it's metering without compensating for the flash and telling you
> it's too dark.
>
>> On APERATURE PRIORITY it again wants a shutter speed of 1/30 Sec for
>> correct exposure.
>>
> As above
>
>> So ...
>>
>> With ISO set to 400 for all tests and flash primed, WHY is the camera
>> happy with an 1/60 + F4.0 combo on AUTO or PROGRAM modes, but insisting
>> on 1/30 + F4.0 in Tv or Av modes?
>
> Presumably in AUTO it knows it's going to use flash.
> Sounds like the camera needs a bit more logic to tell it you are going to
> use flash.
> My 10D is identical.
>
Anonymous
July 18, 2005 1:11:55 AM

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

"dylan" <no@nowhere.com> wrote in message
news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
> It's warning you that you need more aperture, it obviously needs f2.8
> which isn't available on your lens.
> basically it's metering without compensating for the flash and telling you
> it's too dark.

I doubt that it's not considering the flash because in addition to the flash
being primed, it's also showing the flash symbol in the view finder.

> Presumably in AUTO it knows it's going to use flash.

Not quite I don't think - in AUTO it'll raise and fire the flash as/when
required - in other modes it has to be manually deployed - but should still
be considered when it IS manually deployed.


With some further testing, I think the issue is to do with with AUTO
exposure - I did a series of tests - on AUTO it seems under-exposed, whereas
at 1/15 everything looks a lot brighter (and more correctly exposed).

Does anyone know of an issue where AUTO or PROGRAM modes under-expose?
July 18, 2005 1:11:56 AM

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

"Cockpit Colin" <spam@nospam.com> wrote in message
news:whpCe.1174$PL5.152100@news.xtra.co.nz...
>
> "dylan" <no@nowhere.com> wrote in message
> news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
>> It's warning you that you need more aperture, it obviously needs f2.8
>> which isn't available on your lens.
>> basically it's metering without compensating for the flash and telling
>> you it's too dark.
>
> I doubt that it's not considering the flash because in addition to the
> flash being primed, it's also showing the flash symbol in the view finder.

On my 10D deploying or not deploying the flash makes no difference to the
meter reading, apart form the flash symbol, so where's it considering it ?
Anonymous
July 18, 2005 1:11:56 AM

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

Cockpit Colin wrote:
> "dylan" <no@nowhere.com> wrote in message
> news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
>
>>It's warning you that you need more aperture, it obviously needs f2.8
>>which isn't available on your lens.
>>basically it's metering without compensating for the flash and telling you
>>it's too dark.
>
>
> I doubt that it's not considering the flash because in addition to the flash
> being primed, it's also showing the flash symbol in the view finder.
>
>
>>Presumably in AUTO it knows it's going to use flash.
>
>
> Not quite I don't think - in AUTO it'll raise and fire the flash as/when
> required - in other modes it has to be manually deployed - but should still
> be considered when it IS manually deployed.
>
>
> With some further testing, I think the issue is to do with with AUTO
> exposure - I did a series of tests - on AUTO it seems under-exposed, whereas
> at 1/15 everything looks a lot brighter (and more correctly exposed).
>
> Does anyone know of an issue where AUTO or PROGRAM modes under-expose?
>
>
>
Common problem with these cameras. Even some dedicated Speedlights will
underexpose. Take to camera back to Canon and ask them to adjust the
flash exposure. It's a warranty repair and fairly quick to do.

--
Message authored by Douglas Who has Zero Care Factor
about negative responses from anonymous posters.
Anonymous
July 18, 2005 1:11:56 AM

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

In message <whpCe.1174$PL5.152100@news.xtra.co.nz>,
"Cockpit Colin" <spam@nospam.com> wrote:

>"dylan" <no@nowhere.com> wrote in message
>news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
>> It's warning you that you need more aperture, it obviously needs f2.8
>> which isn't available on your lens.
>> basically it's metering without compensating for the flash and telling you
>> it's too dark.
>
>I doubt that it's not considering the flash because in addition to the flash
>being primed, it's also showing the flash symbol in the view finder.

That proves nothing. Both my 10D and 20D ignore the fact that the flash
is going to fire in Av and Tv modes, when choosing the floating
parameter.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
July 18, 2005 1:11:57 AM

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

I do not consider mine (350D) underexposed.

Mike Bernstein

"The Studio of Foto Ryadia" <nospam@ryadia.com> wrote in message
news:42da32eb$1@dnews.tpgi.com.au...
> Cockpit Colin wrote:
>> "dylan" <no@nowhere.com> wrote in message
>> news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
>>
>>>It's warning you that you need more aperture, it obviously needs f2.8
>>>which isn't available on your lens.
>>>basically it's metering without compensating for the flash and telling
>>>you it's too dark.
>>
>>
>> I doubt that it's not considering the flash because in addition to the
>> flash being primed, it's also showing the flash symbol in the view
>> finder.
>>
>>
>>>Presumably in AUTO it knows it's going to use flash.
>>
>>
>> Not quite I don't think - in AUTO it'll raise and fire the flash as/when
>> required - in other modes it has to be manually deployed - but should
>> still be considered when it IS manually deployed.
>>
>>
>> With some further testing, I think the issue is to do with with AUTO
>> exposure - I did a series of tests - on AUTO it seems under-exposed,
>> whereas at 1/15 everything looks a lot brighter (and more correctly
>> exposed).
>>
>> Does anyone know of an issue where AUTO or PROGRAM modes under-expose?
>>
>>
>>
> Common problem with these cameras. Even some dedicated Speedlights will
> underexpose. Take to camera back to Canon and ask them to adjust the flash
> exposure. It's a warranty repair and fairly quick to do.
>
> --
> Message authored by Douglas Who has Zero Care Factor
> about negative responses from anonymous posters.
Anonymous
July 18, 2005 2:45:05 AM

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

> On my 10D deploying or not deploying the flash makes no difference to the
> meter reading, apart form the flash symbol, so where's it considering it ?

Good point. I'm left with the feeling that this is either a major bug, or
I'm just not understanding how it's supposed to work.
Anonymous
July 18, 2005 4:34:50 PM

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

Thanks David,

I think you've hit the nail on the head.

Is there any resource that you can point me to that would give me more info
on this? (I couldn't immediately see the answers in the user manual)

Thanks,

CC


"David Hardin" <davedude46@sbcglobal.net> wrote in message
news:%xwCe.80$fx4.77@newssvr17.news.prodigy.com...
> With the flash engaged, which it will do automatically in full auto or if
> you manually engage it in P mode, the camera thinks that the flash will be
> the main source of light and takes over setting the exposure. However, in
> Tv, Av, or M mode the camera thinks the flash will be used only for fill
and
> takes its exposure settings from available light then adjusts the flash
> duration for the amount of dialed-in fill.
Anonymous
July 18, 2005 4:34:51 PM

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

Don't know if it's still active but try --

http://teladesign.com/photo/eos-flash/





"Cockpit Colin" <spam@nospam.com> wrote in message
news:CKCCe.1307$PL5.165276@news.xtra.co.nz...
> Thanks David,
>
> I think you've hit the nail on the head.
>
> Is there any resource that you can point me to that would give me more
> info
> on this? (I couldn't immediately see the answers in the user manual)
>
> Thanks,
>
> CC
>
>
> "David Hardin" <davedude46@sbcglobal.net> wrote in message
> news:%xwCe.80$fx4.77@newssvr17.news.prodigy.com...
>> With the flash engaged, which it will do automatically in full auto or if
>> you manually engage it in P mode, the camera thinks that the flash will
>> be
>> the main source of light and takes over setting the exposure. However,
>> in
>> Tv, Av, or M mode the camera thinks the flash will be used only for fill
> and
>> takes its exposure settings from available light then adjusts the flash
>> duration for the amount of dialed-in fill.
>
>
Anonymous
July 18, 2005 9:18:05 PM

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

>I stand a suitably humbled man - on the upside,
>that's about 3 things I've learned from the group already :) 

I wasn't intending to humble you, but I was a little surprised at some
of the replies!

So to summarise - as soon as you step into A and S modes, the camera
should (and obviously did) go into 'you're the boss' mode, along with
'meter the scene only' mode.

In P and Auto modes, it pretty much assumes you're a dummy, and you
just want the camera to give you a well-lit exposure. So if it thinks
the scene is too dim for a hand-held shot, it decides to do the whole
lighting thing itself with the flash as the light source.

In A and S (or Av and Tv) modes, it just meters the scene and assumes
you know what you are doing - and if the flash is up/on, the camera
logic will dial it down to just *fill* the exposure.

Which is all probably *exactly* what you want..!
Anonymous
July 18, 2005 10:39:46 PM

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

I stand a suitably humbled man - on the upside, that's about 3 things I've
learned from the group already :) 

.... at least I've heard of the term "fill in flash"!



"Chrlz" <chrlz@go.com> wrote in message
news:1121647418.335326.78270@o13g2000cwo.googlegroups.com...
> David wrote:
>
> >in Tv, Av, or M mode the camera thinks the flash will be used only for
fill
>
> and he and Justin are the only correct respondents!! I don't own a
> Canon, but this is a pretty basic concept and I would be very surprised
> if other DSLR's didn't act similarly. My prosumer does it too, and *so
> it should*..
>
Anonymous
July 18, 2005 11:27:34 PM

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

It's working a treat - thanks for that - I think it's going to cover
EVERYTHING I need to know for now (and some time to come!)

Cheers,

CC

"David Hardin" <davedude46@sbcglobal.net> wrote in message
news:D WFCe.215$Ok6.115@newssvr29.news.prodigy.net...
> Don't know if it's still active but try --
>
> http://teladesign.com/photo/eos-flash/
>
>
>
>
>
> "Cockpit Colin" <spam@nospam.com> wrote in message
> news:CKCCe.1307$PL5.165276@news.xtra.co.nz...
> > Thanks David,
> >
> > I think you've hit the nail on the head.
> >
> > Is there any resource that you can point me to that would give me more
> > info
> > on this? (I couldn't immediately see the answers in the user manual)
> >
> > Thanks,
> >
> > CC
> >
> >
> > "David Hardin" <davedude46@sbcglobal.net> wrote in message
> > news:%xwCe.80$fx4.77@newssvr17.news.prodigy.com...
> >> With the flash engaged, which it will do automatically in full auto or
if
> >> you manually engage it in P mode, the camera thinks that the flash will
> >> be
> >> the main source of light and takes over setting the exposure. However,
> >> in
> >> Tv, Av, or M mode the camera thinks the flash will be used only for
fill
> > and
> >> takes its exposure settings from available light then adjusts the flash
> >> duration for the amount of dialed-in fill.
> >
> >
>
>
July 18, 2005 11:43:36 PM

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

In article <dbd58g$t89$1@newsg4.svr.pol.co.uk>, dylan <no@nowhere.com> wrote:

>basically it's metering without compensating for the flash and telling you
>it's too dark.

So what's to be done about it? I can't imagine that putting a Canon
flash on a Canon camera takes us back to the days of manual exposure.
Anonymous
July 19, 2005 3:08:10 AM

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

Cockpit Colin wrote:
>
> "dylan" <no@nowhere.com> wrote in message
> news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
> > It's warning you that you need more aperture, it obviously needs f2.8
> > which isn't available on your lens.
> > basically it's metering without compensating for the flash and telling you
> > it's too dark.
>
> I doubt that it's not considering the flash because in addition to the flash
> being primed, it's also showing the flash symbol in the view finder.
>
> > Presumably in AUTO it knows it's going to use flash.
>
> Not quite I don't think - in AUTO it'll raise and fire the flash as/when
> required - in other modes it has to be manually deployed - but should still
> be considered when it IS manually deployed.
>
> With some further testing, I think the issue is to do with with AUTO
> exposure - I did a series of tests - on AUTO it seems under-exposed, whereas
> at 1/15 everything looks a lot brighter (and more correctly exposed).
>
> Does anyone know of an issue where AUTO or PROGRAM modes under-expose?

In Av or Tv mode, the camera will attempt to expose for the ambient
light, whereas in auto or P mode it only exposes for the flash. The
typical use for Av or Tv is outdoor exposures in dull light or at night
where you want to capture some of the background. The manual should go
into this for you.
Colin
Anonymous
July 19, 2005 3:08:11 AM

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

Herewith the section from the 350D manual. I do not personally think the
manual deals with this quite as described in this group, although the last
paragraph may have something to do with it.

"P:
For fully automatic flash photography. The shutter speed (1/60 sec. - 1/200
sec.) and aperture value are set automatically, just as in <1> (Full Auto)
mode.

Tv:
Enables you to set the desired shutter speed (30 sec. - 1/200 sec.). The
camera then automatically sets the flash aperture value to obtain the proper
exposure at the shutter speed you have set.

Av:
Enables you to set the desired aperture value. The camera then automatically
sets the shutter speed (30 sec. - 1/200 sec.) to obtain the proper exposure
at the aperture you have set.
Against dark backgrounds such as the night scenes, slow-sync shooting will
be set so that both the subject and background are exposed correctly. The
main subject is exposed with the flash, and the background is exposured with
a slow shutter speed. Because automatic slow-sync shooting uses a slow
shutter speed, always use a tripod. If you do not want a slow shutter speed
to be set, set C.Fn-3 [Flash sync. speed in Av mode] to [1: 1/200sec.
(fixed)]."

Mike Bernstein

"Colin D" <ColinD@killspam.127.0.0.1> wrote in message
news:42DB8D9A.50743954@killspam.127.0.0.1...
>
>
> Cockpit Colin wrote:
>>
>> "dylan" <no@nowhere.com> wrote in message
>> news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
>> > It's warning you that you need more aperture, it obviously needs f2.8
>> > which isn't available on your lens.
>> > basically it's metering without compensating for the flash and telling
>> > you
>> > it's too dark.
>>
>> I doubt that it's not considering the flash because in addition to the
>> flash
>> being primed, it's also showing the flash symbol in the view finder.
>>
>> > Presumably in AUTO it knows it's going to use flash.
>>
>> Not quite I don't think - in AUTO it'll raise and fire the flash as/when
>> required - in other modes it has to be manually deployed - but should
>> still
>> be considered when it IS manually deployed.
>>
>> With some further testing, I think the issue is to do with with AUTO
>> exposure - I did a series of tests - on AUTO it seems under-exposed,
>> whereas
>> at 1/15 everything looks a lot brighter (and more correctly exposed).
>>
>> Does anyone know of an issue where AUTO or PROGRAM modes under-expose?
>
> In Av or Tv mode, the camera will attempt to expose for the ambient
> light, whereas in auto or P mode it only exposes for the flash. The
> typical use for Av or Tv is outdoor exposures in dull light or at night
> where you want to capture some of the background. The manual should go
> into this for you.
> Colin
Anonymous
July 19, 2005 3:08:52 AM

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

Cockpit Colin wrote:
>
> > On my 10D deploying or not deploying the flash makes no difference to the
> > meter reading, apart form the flash symbol, so where's it considering it ?
>
> Good point. I'm left with the feeling that this is either a major bug, or
> I'm just not understanding how it's supposed to work.

No bug. Read the book.

Colin
Anonymous
July 19, 2005 4:20:08 PM

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

> No bug. Read the book.

I did - it didn't help.

I think that you need a certain basic level of knowledge before a lot of
things in the book make sense - I'm not at that point just yet, although I'm
learning quickly.
Anonymous
July 19, 2005 4:22:07 PM

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

My point exactly - to me it only implies what it does - the reader has to
draw a conclusion (which was beyond me at that point in time).

"Mike Bernstein" <mike.bernstein@REMOVECAPSchemlaw.co.uk> wrote in message
news:42dbc311$0$31021$db0fefd9@news.zen.co.uk...
> Herewith the section from the 350D manual. I do not personally think the
> manual deals with this quite as described in this group, although the last
> paragraph may have something to do with it.
>
> "P:
> For fully automatic flash photography. The shutter speed (1/60 sec. -
1/200
> sec.) and aperture value are set automatically, just as in <1> (Full Auto)
> mode.
>
> Tv:
> Enables you to set the desired shutter speed (30 sec. - 1/200 sec.). The
> camera then automatically sets the flash aperture value to obtain the
proper
> exposure at the shutter speed you have set.
>
> Av:
> Enables you to set the desired aperture value. The camera then
automatically
> sets the shutter speed (30 sec. - 1/200 sec.) to obtain the proper
exposure
> at the aperture you have set.
> Against dark backgrounds such as the night scenes, slow-sync shooting will
> be set so that both the subject and background are exposed correctly. The
> main subject is exposed with the flash, and the background is exposured
with
> a slow shutter speed. Because automatic slow-sync shooting uses a slow
> shutter speed, always use a tripod. If you do not want a slow shutter
speed
> to be set, set C.Fn-3 [Flash sync. speed in Av mode] to [1: 1/200sec.
> (fixed)]."
>
> Mike Bernstein
>
> "Colin D" <ColinD@killspam.127.0.0.1> wrote in message
> news:42DB8D9A.50743954@killspam.127.0.0.1...
> >
> >
> > Cockpit Colin wrote:
> >>
> >> "dylan" <no@nowhere.com> wrote in message
> >> news:D bd58g$t89$1@newsg4.svr.pol.co.uk...
> >> > It's warning you that you need more aperture, it obviously needs f2.8
> >> > which isn't available on your lens.
> >> > basically it's metering without compensating for the flash and
telling
> >> > you
> >> > it's too dark.
> >>
> >> I doubt that it's not considering the flash because in addition to the
> >> flash
> >> being primed, it's also showing the flash symbol in the view finder.
> >>
> >> > Presumably in AUTO it knows it's going to use flash.
> >>
> >> Not quite I don't think - in AUTO it'll raise and fire the flash
as/when
> >> required - in other modes it has to be manually deployed - but should
> >> still
> >> be considered when it IS manually deployed.
> >>
> >> With some further testing, I think the issue is to do with with AUTO
> >> exposure - I did a series of tests - on AUTO it seems under-exposed,
> >> whereas
> >> at 1/15 everything looks a lot brighter (and more correctly exposed).
> >>
> >> Does anyone know of an issue where AUTO or PROGRAM modes under-expose?
> >
> > In Av or Tv mode, the camera will attempt to expose for the ambient
> > light, whereas in auto or P mode it only exposes for the flash. The
> > typical use for Av or Tv is outdoor exposures in dull light or at night
> > where you want to capture some of the background. The manual should go
> > into this for you.
> > Colin
>
>
Anonymous
July 20, 2005 2:01:49 AM

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

Chrlz wrote:
>
<snip>
>
> In P and Auto modes, it pretty much assumes you're a dummy, and you
> just want the camera to give you a well-lit exposure. So if it thinks
> the scene is too dim for a hand-held shot, it decides to do the whole
> lighting thing itself with the flash as the light source.

Not quite right, there. In 'P' mode, the camera will attempt to
calculate the correct exposure, and if the light is too dull, the camera
will set the aperture or shutter readout in the VF flashing to indicate
that there is insufficient light. In 'P' mode - or indeed any of the
'creative' modes - the flash will not automatically pop up as it does in
the auto modes. If you want it, you have to press the button to elevate
the flash to activate it.
>
> In A and S (or Av and Tv) modes, it just meters the scene and assumes
> you know what you are doing - and if the flash is up/on, the camera
> logic will dial it down to just *fill* the exposure.
>
>Yep. Catches some people by surprise when they try to choose a smaller aperture with Av, whereupon the camera gives a loooong exposure.

Colin
!