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Canon Rebel XT and focussing

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Anonymous
September 23, 2005 1:10:59 PM

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

Hi all!

I notice that when I photograph close subjects such as a flower bed or even
a couple sitting at a table, one area might be in focus while the next is
not. Is there something I'm missing? Thanks, Marcel

More about : canon rebel focussing

Anonymous
September 23, 2005 1:11:00 PM

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

In article <4qSdndelDYB-Y67eRVn-sA@rogers.com>, Celcius
<cosmar@rogers.com> wrote:

> I notice that when I photograph close subjects such as a flower bed or even
> a couple sitting at a table, one area might be in focus while the next is
> not. Is there something I'm missing? Thanks, Marcel

First, take it out of "dummy" mode - then turn off all the AF points
except for one.
Anonymous
September 23, 2005 4:11:49 PM

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

"Randall Ainsworth" <rag@nospam.techline.com> wrote in message
news:230920050853150381%rag@nospam.techline.com...
> In article <4qSdndelDYB-Y67eRVn-sA@rogers.com>, Celcius
> <cosmar@rogers.com> wrote:
>
> > I notice that when I photograph close subjects such as a flower bed or
even
> > a couple sitting at a table, one area might be in focus while the next
is
> > not. Is there something I'm missing? Thanks, Marcel
>
> First, take it out of "dummy" mode - then turn off all the AF points
> except for one.

Ok for the AF points.
"Dummy mode"? is this P?
Marcel
Related resources
Anonymous
September 23, 2005 6:17:32 PM

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

Celcius wrote:
> Hi all!
>
> I notice that when I photograph close subjects such as a flower bed or even
> a couple sitting at a table, one area might be in focus while the next is
> not. Is there something I'm missing? Thanks, Marcel
>
>

What setting are you using? What is the aperature setting? Do you know
about Depth of Field?

--
John
Anonymous
September 23, 2005 6:17:33 PM

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

"John Reagan" <john.reagan@hp.com> wrote in message
news:08UYe.13128$Pv4.11629@news.cpqcorp.net...
> Celcius wrote:
> > Hi all!
> >
> > I notice that when I photograph close subjects such as a flower bed or
even
> > a couple sitting at a table, one area might be in focus while the next
is
> > not. Is there something I'm missing? Thanks, Marcel
>
>
>
> What setting are you using? What is the aperature setting? Do you know
> about Depth of Field?
>
Hi John!
Yes I know about the depth of field, but in this case, I was simply using
"P" (program AE). From what I can see, there are 7 points on AF mode. Does
it mean that if one point is on the main subject and another is not on the
other, then the 2nd one is blurred? The case in point:
http://celestart.com/images/publiques/019.jpg
He's in focus. She isn't, yet she's sitting next to him.
Marcel
Anonymous
September 23, 2005 6:17:34 PM

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

Celcius wrote:
> "John Reagan" <john.reagan@hp.com> wrote in message
> news:08UYe.13128$Pv4.11629@news.cpqcorp.net...
>> Celcius wrote:
>>> Hi all!
>>>
>>> I notice that when I photograph close subjects such as a flower
>>> bed
>>> or even a couple sitting at a table, one area might be in focus
>>> while the next is not. Is there something I'm missing? Thanks,
>>> Marcel
>>
>>
>>
>> What setting are you using? What is the aperature setting? Do you
>> know about Depth of Field?
>>
> Hi John!
> Yes I know about the depth of field, but in this case, I was simply
> using "P" (program AE). From what I can see, there are 7 points on
> AF
> mode. Does it mean that if one point is on the main subject and
> another is not on the other, then the 2nd one is blurred? The case
> in
> point: http://celestart.com/images/publiques/019.jpg
> He's in focus. She isn't, yet she's sitting next to him.
> Marcel

You have to take into account Personal Focusability. Some folks got
it, some don't. I understand that with training and practice one can
develop a sort of _Faux Focus_, but True Perceivers will always know
thhe difference.

--
Frank ess
Anonymous
September 23, 2005 6:33:19 PM

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

----- Original Message -----
From: "Celcius" <cosmar@rogers.com>
Newsgroups: rec.photo.digital
Sent: Friday, September 23, 2005 3:07 PM
Subject: Re: Canon Rebel XT and focussing


> Hi John!
> Yes I know about the depth of field, but in this case, I was simply using
> "P" (program AE). From what I can see, there are 7 points on AF mode. Does
> it mean that if one point is on the main subject and another is not on the
> other, then the 2nd one is blurred? The case in point:
> http://celestart.com/images/publiques/019.jpg
> He's in focus. She isn't, yet she's sitting next to him.
> Marcel
>
>

"She" is NOT sitting next to "Him" in terms of distance from the camera, her
face is probably about 2 feet or 0.7 metres behind his face.

The camera has focussed on his face: at an aperture of f5.6, on a lens which
is focussing at 53 mm the "in focus depth of field" behind the subject (his
face) is probably less than one foot (30 cm).

Program mode cannot deal with all eventualities.

For similar photograph, suggest you use Aperture priority setting at say
f11, BUT also set the "custom function" (if there is one on the Rebel XT?)
to ensure that the minimum shutter speed in aperture priority mode is
1/200th. This will ensure the flash fires.

Alternatively use manual mode for setting both aperture and shutter speed
and the flash will adjust to compensate.

HtH
Anonymous
September 23, 2005 6:33:20 PM

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

"PHH699" <anonymous@NOTmail.com> wrote in message
news:D h13nf$gil$1@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com...
> For similar photograph, suggest you use Aperture priority setting at say
> f11, BUT also set the "custom function" (if there is one on the Rebel XT?)
> to ensure that the minimum shutter speed in aperture priority mode is
> 1/200th. This will ensure the flash fires.
>
> Alternatively use manual mode for setting both aperture and shutter speed
> and the flash will adjust to compensate.
>
> HtH
>
>
Thanks for the suggestion.
I will see if the Rebel XT has this custom function.
Marcel
September 23, 2005 7:43:44 PM

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

I have not had much luck with the A-DEP mode...in fact, some of the
points that the camera said were in focus (and I checked in the canon
image browser afterward) were only minimally in focus, and some weren't
in focus at all. This may be due to the circle of confusion size that
the camera uses for the calculation, but regardless, I don't feel like
it worked very well. Like in P mode, the camera goes for the largest
possible aperature to keep things in focus.

Anyway, I think there is a lot more control setting the aperature
myself.

It would be nice if the camera could use the manual settings and
calculate what points would be in focus based on the aperature and
focal length that was set, but anyway.

Brian

Bill wrote:
> PHH699 wrote:
>
> >> He's in focus. She isn't, yet she's sitting next to him.
> >
> >"She" is NOT sitting next to "Him" in terms of distance from the camera, her
> >face is probably about 2 feet or 0.7 metres behind his face.
> >
> >The camera has focussed on his face: at an aperture of f5.6, on a lens which
> >is focussing at 53 mm the "in focus depth of field" behind the subject (his
> >face) is probably less than one foot (30 cm).
>
> Exactly...and it's a common situation when people move from P&S cameras
> to DSLR's. The bigger sensor and lenses are able to get a much more
> shallow depth of field, so getting background blur can be a lot easier.
>
> >Program mode cannot deal with all eventualities.
> >
> >For similar photograph, suggest you use Aperture priority setting at say
> >f11, BUT also set the "custom function" (if there is one on the Rebel XT?)
> >to ensure that the minimum shutter speed in aperture priority mode is
> >1/200th. This will ensure the flash fires.
>
> Yup.
>
> This is exactly what happens in Program mode where the camera finds the
> subject, focuses on it, and sets the shutter speed and aperture for you,
> all automatically.
>
> The problem is "P" mode doesn't account for depth of field and by
> default the camera will use the largest aperture available unless it's a
> very subject, then it will stop the lense down. In "P" mode you can make
> adjustments, but the camera still does 99% of the work for you and often
> gets difficult situations wrong.
>
> Using the Av mode will let you reduce the aperture so you can increase
> the depth of field, getting all the subjects in focus. The manual covers
> how to use this mode, and it's one I use a lot.
>
> The Rebel XT also has a depth of field preview button which will stop
> the lense down to the current setting and let you see if the subjects
> are in focus. Note that stopping down the lense also reduces the amount
> of light getting through the lense, so the view will get darker the more
> you stop down the lense. This works best is well lit areas.
Anonymous
September 23, 2005 8:59:37 PM

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

Hi Marcel,
The 350D also has an A-DEP setting which, IIRC, tries to set the aperture to
ensure that all points registered by the autofocus (the red dots in the
viewfinder) are in focus. Never used it myself, though ....

--
Paul ============}
o o

// Live fast, die old //
PaulsPages are at http://homepage.ntlworld.com/pcbradley/
Anonymous
September 23, 2005 8:59:38 PM

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

"PcB" <pcbradley@no_spam_lineone.net> wrote in message
news:ZvWYe.1733$3q4.853@newsfe5-gui.ntli.net...
> Hi Marcel,
> The 350D also has an A-DEP setting which, IIRC, tries to set the aperture
to
> ensure that all points registered by the autofocus (the red dots in the
> viewfinder) are in focus. Never used it myself, though ....
>
> --
> Paul ============}
> o o
>
> // Live fast, die old //
> PaulsPages are at http://homepage.ntlworld.com/pcbradley/
>
>
Paul,
I saw it and read it, but somehow I didn't understand how it works. More
homework, I guess ;-)
Thanks,
Marcel
September 23, 2005 10:19:40 PM

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

PHH699 wrote:

>> He's in focus. She isn't, yet she's sitting next to him.
>
>"She" is NOT sitting next to "Him" in terms of distance from the camera, her
>face is probably about 2 feet or 0.7 metres behind his face.
>
>The camera has focussed on his face: at an aperture of f5.6, on a lens which
>is focussing at 53 mm the "in focus depth of field" behind the subject (his
>face) is probably less than one foot (30 cm).

Exactly...and it's a common situation when people move from P&S cameras
to DSLR's. The bigger sensor and lenses are able to get a much more
shallow depth of field, so getting background blur can be a lot easier.

>Program mode cannot deal with all eventualities.
>
>For similar photograph, suggest you use Aperture priority setting at say
>f11, BUT also set the "custom function" (if there is one on the Rebel XT?)
>to ensure that the minimum shutter speed in aperture priority mode is
>1/200th. This will ensure the flash fires.

Yup.

This is exactly what happens in Program mode where the camera finds the
subject, focuses on it, and sets the shutter speed and aperture for you,
all automatically.

The problem is "P" mode doesn't account for depth of field and by
default the camera will use the largest aperture available unless it's a
very subject, then it will stop the lense down. In "P" mode you can make
adjustments, but the camera still does 99% of the work for you and often
gets difficult situations wrong.

Using the Av mode will let you reduce the aperture so you can increase
the depth of field, getting all the subjects in focus. The manual covers
how to use this mode, and it's one I use a lot.

The Rebel XT also has a depth of field preview button which will stop
the lense down to the current setting and let you see if the subjects
are in focus. Note that stopping down the lense also reduces the amount
of light getting through the lense, so the view will get darker the more
you stop down the lense. This works best is well lit areas.
Anonymous
September 23, 2005 11:38:08 PM

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

"Bill" <bill@c.a> wrote in message news:WpadnY36wrjh4qneRVn-ig@golden.net...
> PHH699 wrote:
>

> The problem is "P" mode doesn't account for depth of field and by
> default the camera will use the largest aperture available unless it's a
> very subject, then it will stop the lense down. In "P" mode you can make
> adjustments, but the camera still does 99% of the work for you and often
> gets difficult situations wrong.
>
>
>
I found the P mode handy when taking "snapshots", where I only have to
adjust the WB or maybe the ISO or even flash...

> Using the Av mode will let you reduce the aperture so you can increase
> the depth of field, getting all the subjects in focus. The manual covers
> how to use this mode, and it's one I use a lot.
>
>
No problem on this one. But please in what other situation(s) would you want
to use Av?

> The Rebel XT also has a depth of field preview button which will stop
> the lense down to the current setting and let you see if the subjects
> are in focus. Note that stopping down the lense also reduces the amount
> of light getting through the lense, so the view will get darker the more
> you stop down the lense. This works best is well lit areas.

That's one thing (depth of field preview button ) I haven't understood. I
read it and re-read it but somehow, I don't catch. Say I choose f16 (because
at that aperture my shutter will be 125, I press halfway, then on the depth
of field preview button, the viewfinder darkens. It says I can "check the
depth of field range"... Where? How? What do I look for?
Thanks for your patience, Marcel
Anonymous
September 23, 2005 11:46:01 PM

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

"Brian" <ripcurl187@yahoo.com> wrote in message
news:1127515424.322650.288730@o13g2000cwo.googlegroups.com...
> I have not had much luck with the A-DEP mode...in fact, some of the
> points that the camera said were in focus (and I checked in the canon
> image browser afterward) were only minimally in focus, and some weren't
> in focus at all. This may be due to the circle of confusion size that
> the camera uses for the calculation, but regardless, I don't feel like
> it worked very well. Like in P mode, the camera goes for the largest
> possible aperature to keep things in focus.
>
> Anyway, I think there is a lot more control setting the aperature
> myself.
>
> It would be nice if the camera could use the manual settings and
> calculate what points would be in focus based on the aperature and
> focal length that was set, but anyway.
>
> Brian

Brian, I guess my problem is linked to the fact that AF points seem to have
2 purposes (unless I haven't understood): 1- to evaluate the light 2- to
focus. I suppose that If I photograph a landscape and nothing such as a tree
is "in the way", everything is in focus, even using the 7 AF points. If I
use only the center AF point, all the scene would be in focus... however,
the lighting condition that prevailed at the time would be "translated" in
terms of that AF point and not the average of 7 such points (or three,
depending). I suppose that if I use Av as suggested by Bill, part of my
problem would be resolved. IM left with understanding the famed 7 AF
points... Marcel
Anonymous
September 24, 2005 1:01:35 AM

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

"Bill" <bill@c.a> wrote in message news:WpadnY36wrjh4qneRVn-ig@golden.net...
> PHH699 wrote:
>
>>> He's in focus. She isn't, yet she's sitting next to him.
>>

>
> This is exactly what happens in Program mode where the camera finds the
> subject, focuses on it, and sets the shutter speed and aperture for you,
> all automatically.
>
> The problem is "P" mode doesn't account for depth of field and by
> default the camera will use the largest aperture available unless it's a
> very subject, then it will stop the lense down. In "P" mode you can make
> adjustments, but the camera still does 99% of the work for you and often
> gets difficult situations wrong.

You can use "Program Shift," which allows you to change either the aperture
or shutter speed to match your requirements. This isn't available in the
"Automatic" or "green square" mode, however, only in "Program."
>
> Using the Av mode will let you reduce the aperture so you can increase
> the depth of field, getting all the subjects in focus. The manual covers
> how to use this mode, and it's one I use a lot.

Also available in the above mentioned "Program Shift."
>
--
Skip Middleton
http://www.shadowcatcherimagery.com
September 24, 2005 2:47:34 AM

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

Celcius wrote:

>> Using the Av mode will let you reduce the aperture so you can increase
>> the depth of field, getting all the subjects in focus. The manual covers
>> how to use this mode, and it's one I use a lot.
>>
>No problem on this one. But please in what other situation(s) would you want
>to use Av?

Any situation that warrants altering the depth of field, be it shallow
or deep. Using Av mode to ensure you get a shallow depth of field and a
good background blur like portraits.

Any time you want to stop down a bit to improve image sharpness with a
less than ideal lense.

Any time you want a keep the lense wide open for certain effects.

And I'm sure there are other scenarios I can't think of right now
because I'm tired.

:) 

>> The Rebel XT also has a depth of field preview button which will stop
>> the lense down to the current setting and let you see if the subjects
>> are in focus. Note that stopping down the lense also reduces the amount
>> of light getting through the lense, so the view will get darker the more
>> you stop down the lense. This works best is well lit areas.
>
>That's one thing (depth of field preview button ) I haven't understood. I
>read it and re-read it but somehow, I don't catch. Say I choose f16 (because
>at that aperture my shutter will be 125, I press halfway, then on the depth
>of field preview button, the viewfinder darkens. It says I can "check the
>depth of field range"... Where? How? What do I look for?

It's kind of hard to explain without a lot of writing...you have to see
it for yourself to understand it's effects. So try an experiment like
this:

Go out tomorrow when it's bright outside and setup two shots looking
down a long street using Av mode and focus on a sign or something down
the street about 10 feet away. Use the largest aperture value (like
f/4.0) and notice how the signs in the distance become blurred and out
of focus. Now setup another one with a small aperture (like f/11) and
still focus on the sign 10 feet away.

Now while you're getting ready to take the second shot, hold the depth
of field preview button and the image will darken. While it's darkened,
look at the focus of the distant objects. Even though the image will be
darker, keep looking for several seconds so your eye gets adjusted to
the dimmed view and you'll see how depth of field affects focus. Release
the DOF preview button and you'll see distant objects blur out again.

Play with it a bit and you'll soon learn how to use it effectively to
ensure you're getting the depth of the image you wish to capture. Try it
at f/4, f/8, f/11, f/16, and you'll see the depth increase each time.
September 24, 2005 3:42:00 AM

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

"Celcius" <cosmar@rogers.com> wrote in message
news:4qSdndelDYB-Y67eRVn-sA@rogers.com...
> Hi all!
>
> I notice that when I photograph close subjects such as a flower bed or
> even
> a couple sitting at a table, one area might be in focus while the next is
> not. Is there something I'm missing? Thanks, Marcel
>
>
Hi there.

No-one seems to have made it clear that no matter how many focussing points
are in use, the lens will only be in focus for one distance. If you have
two subjects with one of them further away than the other, and have a
focussing point on each, then the camera might focus on either one of them,
(usually the nearest), or somewhere in between them.

There have seen some references to "Dummy" modes.

Having all focussing points active at the same time is normally fairly dumb.
Select just one point for the main subject.

"P" is not a "Dummy" mode, since it is easy to vary the shutter speed and
aperture, by rotating the Command Dial, (or whatever Canon call it), to get
the combination you want.

Roy G
Anonymous
September 24, 2005 3:42:01 AM

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

"Roy" <royphoty@iona-guesthouse.co.uk> wrote in message
news:cp0Ze.14095$zw1.1268@newsfe2-gui.ntli.net...
>
> "Celcius" <cosmar@rogers.com> wrote in message
> news:4qSdndelDYB-Y67eRVn-sA@rogers.com...
> > Hi all!
> >
> > I notice that when I photograph close subjects such as a flower bed or
> > even
> > a couple sitting at a table, one area might be in focus while the next
is
> > not. Is there something I'm missing? Thanks, Marcel
> >
> >
> Hi there.
>
> No-one seems to have made it clear that no matter how many focussing
points
> are in use, the lens will only be in focus for one distance. If you have
> two subjects with one of them further away than the other, and have a
> focussing point on each, then the camera might focus on either one of
them,
> (usually the nearest), or somewhere in between them.
>
> There have seen some references to "Dummy" modes.
>
> Having all focussing points active at the same time is normally fairly
dumb.
> Select just one point for the main subject.
>

Now that you say so, and I stopped to think about it, re-read that part of
the manual and it states: "By selecting a suitable AF point, you can shoot
with autfocus while framing the subject..." I don't know why I let it on
auto.... Thanks. I think 50% of my present problem is solved.

Marcel
>
> "P" is not a "Dummy" mode, since it is easy to vary the shutter speed and
> aperture, by rotating the Command Dial, (or whatever Canon call it), to
get
> the combination you want.
>
> Roy G
>
>
September 24, 2005 10:14:51 AM

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

Skip M wrote:

>> The problem is "P" mode doesn't account for depth of field and by
>> default the camera will use the largest aperture available unless it's a
>> very subject, then it will stop the lense down. In "P" mode you can make
>> adjustments, but the camera still does 99% of the work for you and often
>> gets difficult situations wrong.
>
>You can use "Program Shift," which allows you to change either the aperture
>or shutter speed to match your requirements. This isn't available in the
>"Automatic" or "green square" mode, however, only in "Program."

Yes that's what I meant when I said "you can make adjustments". But the
Av and Tv modes allow you to start at a specific point without having to
"shift" the camera settings.
Anonymous
September 24, 2005 10:14:52 AM

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

"Bill" <bill@c.a> wrote in message news:kcKdnQRAS8mGuqjeRVn-3g@golden.net...
> Skip M wrote:
>
>>> The problem is "P" mode doesn't account for depth of field and by
>>> default the camera will use the largest aperture available unless it's a
>>> very subject, then it will stop the lense down. In "P" mode you can make
>>> adjustments, but the camera still does 99% of the work for you and often
>>> gets difficult situations wrong.
>>
>>You can use "Program Shift," which allows you to change either the
>>aperture
>>or shutter speed to match your requirements. This isn't available in the
>>"Automatic" or "green square" mode, however, only in "Program."
>
> Yes that's what I meant when I said "you can make adjustments". But the
> Av and Tv modes allow you to start at a specific point without having to
> "shift" the camera settings.

The one thing about program shift on Canons that annoys me is that you have
to reset it after every shot. And I do usually use AV, but some newer users
are not even aware of program shift.
The good thing about program shift is that you don't have to fiddle with EV
like you would in manual.

--
Skip Middleton
http://www.shadowcatcherimagery.com
Anonymous
September 24, 2005 12:10:07 PM

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

Thank you very much. All your help is appreciated. I now recognise that I
hadn't understood some of the basics in the XT manual. I bought a few books
in the past few years, such as The Joy of Digital Photography by Jeff
Wignall. Is there a few others that would help, please?
Thanks for your patience.
Marcel


"Celcius" <cosmar@rogers.com> wrote in message
news:4qSdndelDYB-Y67eRVn-sA@rogers.com...
> Hi all!
>
> I notice that when I photograph close subjects such as a flower bed or
even
> a couple sitting at a table, one area might be in focus while the next is
> not. Is there something I'm missing? Thanks, Marcel
>
>
September 25, 2005 11:45:40 AM

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

Marcel,

Glad you posted, I have found this too on my 350D. I was getting a bit
worried the other day when I noticed this having just bought the camera. I
took some photos of some flowers and the petals in one place were in focus
but everywhere else, where out of focus

I also found that using a tripod helps remove this by keeping steady.

Interesting to hear about the 'default' nature of P mode, will have to keep
a eye on that.

Alex

"Celcius" <cosmar@rogers.com> wrote in message
news:g7KdnfPooJ6C36jeRVn-vQ@rogers.com...
> Thank you very much. All your help is appreciated. I now recognise that I
> hadn't understood some of the basics in the XT manual. I bought a few
books
> in the past few years, such as The Joy of Digital Photography by Jeff
> Wignall. Is there a few others that would help, please?
> Thanks for your patience.
> Marcel
>
>
> "Celcius" <cosmar@rogers.com> wrote in message
> news:4qSdndelDYB-Y67eRVn-sA@rogers.com...
> > Hi all!
> >
> > I notice that when I photograph close subjects such as a flower bed or
> even
> > a couple sitting at a table, one area might be in focus while the next
is
> > not. Is there something I'm missing? Thanks, Marcel
> >
> >
>
>
Anonymous
September 25, 2005 12:53:56 PM

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

Alex,

I learned a lot on this post. The first thing was that I don't read
properly. I read my manual twice and yet, there are things I still don't
inderstand, and worse, there are thing that _I thought_ I understood.

What I retain is that the AF points can be changed so that the camera
doesn't have to move, yet you can focus on an object on the right, below or
any other of the 7 AF points.

While I knew about DOF, I wasn't using it (I hardly had any problem with my
G1 and later my Pro 1). I will now use more extensively the Av feature.

Although one may use an SLR for "point and shoot", it's not a very good
idea.

On my past film cameras, including the Canon Eos, since I was using film, I
was more attentive not to shoot hastily. Digitals are so practical that I
have the tendency to shoot many photos, but not differently.

I am now re-reading my book :-)

Have a great day!

Marcel



"Alex" <alex.cruse@btinternet.com> wrote in message
news:D h5kj4$pj6$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
> Marcel,
>
> Glad you posted, I have found this too on my 350D. I was getting a bit
> worried the other day when I noticed this having just bought the camera.
I
> took some photos of some flowers and the petals in one place were in focus
> but everywhere else, where out of focus
>
> I also found that using a tripod helps remove this by keeping steady.
>
> Interesting to hear about the 'default' nature of P mode, will have to
keep
> a eye on that.
>
> Alex
>
> "Celcius" <cosmar@rogers.com> wrote in message
> news:g7KdnfPooJ6C36jeRVn-vQ@rogers.com...
> > Thank you very much. All your help is appreciated. I now recognise that
I
> > hadn't understood some of the basics in the XT manual. I bought a few
> books
> > in the past few years, such as The Joy of Digital Photography by Jeff
> > Wignall. Is there a few others that would help, please?
> > Thanks for your patience.
> > Marcel
> >
> >
> > "Celcius" <cosmar@rogers.com> wrote in message
> > news:4qSdndelDYB-Y67eRVn-sA@rogers.com...
> > > Hi all!
> > >
> > > I notice that when I photograph close subjects such as a flower bed or
> > even
> > > a couple sitting at a table, one area might be in focus while the next
> is
> > > not. Is there something I'm missing? Thanks, Marcel
> > >
> > >
> >
> >
>
>
September 25, 2005 2:15:29 PM

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

I've been doing some research, so here's an update on A-DEP mode.

A-DEP is just a dumbed down version of DEP mode which used to appear on
some of Canons cameras (I don't know the history). DEP mode basically
let you choose the closest and farthest subjects you wanted in focus
and the camera would recommend an aperature and focus at the hyperfocal
distance to keep those subjects in focus. You could choose those
points by using one of the AF points but the whole procedure required
several half-clicks.

A-DEP attempts to do this automatically using all the AF points -
choosing the closest and farthest subjects based on the parts of the
image that are covered by the AF points. The general consensus of what
I've read is that it is mediocre in general but if you have the time to
do some work arounds you can get it to work well. The basic procedure
that some others have outlined is:

1. Twist and turn the camera around to cover the nearest and farthest
subjects that should be in focus with the AF points. Re-focus a few
times because the camera selects different Av/Tv values each time.
When the lights flash on the nearest and farthest subjects (technically
at this point all the lights should flash if you're using the nearest
and farthest subjects in the image) note the aperature value suggested
by the camera,
2. Switch to MF (so the camera won't refocus)
3. Switch from A-DEP to Av mode selecting the aperature you noted in
step 1. It is best stop down a couple more stops to make sure you get
the detail and sharpness you want (this has to do with circle of
confusion size and that the AF focus points are larger than what you
see in the viewfinder).
4. Take the picture.

I tried this technique yesterday and it seemed to work reasonably well.
I only had a couple problems where I thought the AF point had focused
on the subject I wanted it to but it actually chose something nearby
with more contrast at a different distance from the camera - which of
course caused an incorrect focus setting.

I certainly won't rely on this mode, but I think it can be helpful in
some situations.

Brian


Celcius wrote:
> Alex,
>
> I learned a lot on this post. The first thing was that I don't read
> properly. I read my manual twice and yet, there are things I still don't
> inderstand, and worse, there are thing that _I thought_ I understood.
>
> What I retain is that the AF points can be changed so that the camera
> doesn't have to move, yet you can focus on an object on the right, below or
> any other of the 7 AF points.
>
> While I knew about DOF, I wasn't using it (I hardly had any problem with my
> G1 and later my Pro 1). I will now use more extensively the Av feature.
>
> Although one may use an SLR for "point and shoot", it's not a very good
> idea.
>
> On my past film cameras, including the Canon Eos, since I was using film, I
> was more attentive not to shoot hastily. Digitals are so practical that I
> have the tendency to shoot many photos, but not differently.
>
> I am now re-reading my book :-)
>
> Have a great day!
>
> Marcel
>
>
>
> "Alex" <alex.cruse@btinternet.com> wrote in message
> news:D h5kj4$pj6$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
> > Marcel,
> >
> > Glad you posted, I have found this too on my 350D. I was getting a bit
> > worried the other day when I noticed this having just bought the camera.
> I
> > took some photos of some flowers and the petals in one place were in focus
> > but everywhere else, where out of focus
> >
> > I also found that using a tripod helps remove this by keeping steady.
> >
> > Interesting to hear about the 'default' nature of P mode, will have to
> keep
> > a eye on that.
> >
> > Alex
> >
> > "Celcius" <cosmar@rogers.com> wrote in message
> > news:g7KdnfPooJ6C36jeRVn-vQ@rogers.com...
> > > Thank you very much. All your help is appreciated. I now recognise that
> I
> > > hadn't understood some of the basics in the XT manual. I bought a few
> > books
> > > in the past few years, such as The Joy of Digital Photography by Jeff
> > > Wignall. Is there a few others that would help, please?
> > > Thanks for your patience.
> > > Marcel
> > >
> > >
> > > "Celcius" <cosmar@rogers.com> wrote in message
> > > news:4qSdndelDYB-Y67eRVn-sA@rogers.com...
> > > > Hi all!
> > > >
> > > > I notice that when I photograph close subjects such as a flower bed or
> > > even
> > > > a couple sitting at a table, one area might be in focus while the next
> > is
> > > > not. Is there something I'm missing? Thanks, Marcel
> > > >
> > > >
> > >
> > >
> >
> >
September 26, 2005 3:51:01 AM

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

Brian wrote:

>1. Twist and turn the camera around to cover the nearest and farthest
>subjects that should be in focus with the AF points. Re-focus a few
>times because the camera selects different Av/Tv values each time.
>When the lights flash on the nearest and farthest subjects (technically
>at this point all the lights should flash if you're using the nearest
>and farthest subjects in the image) note the aperature value suggested
>by the camera,
>2. Switch to MF (so the camera won't refocus)
>3. Switch from A-DEP to Av mode selecting the aperature you noted in
>step 1. It is best stop down a couple more stops to make sure you get
>the detail and sharpness you want (this has to do with circle of
>confusion size and that the AF focus points are larger than what you
>see in the viewfinder).
>4. Take the picture.

Oh boy...what a long convoluted way to get depth of field.

As long as the subjects are bright enough, I just hit the DOF preview
button to confirm my best guess and adjust aperture as needed to get the
depth I want, and I'm done.
September 26, 2005 4:11:46 AM

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

I completely agree..."as long as the subjects are bright enough"!!
Brian
Anonymous
September 26, 2005 8:05:24 AM

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

PHH699 wrote:

> ----- Original Message -----
> From: "Celcius" <cosmar@rogers.com>
> Newsgroups: rec.photo.digital
> Sent: Friday, September 23, 2005 3:07 PM
> Subject: Re: Canon Rebel XT and focussing
>
>
>
>>Hi John!
>>Yes I know about the depth of field, but in this case, I was simply using
>>"P" (program AE). From what I can see, there are 7 points on AF mode. Does
>>it mean that if one point is on the main subject and another is not on the
>>other, then the 2nd one is blurred? The case in point:
>>http://celestart.com/images/publiques/019.jpg
>>He's in focus. She isn't, yet she's sitting next to him.
>>Marcel
>>
>>
>
>
> "She" is NOT sitting next to "Him" in terms of distance from the camera, her
> face is probably about 2 feet or 0.7 metres behind his face.
>
> The camera has focussed on his face: at an aperture of f5.6, on a lens which
> is focussing at 53 mm the "in focus depth of field" behind the subject (his
> face) is probably less than one foot (30 cm).
>
> Program mode cannot deal with all eventualities.
>
> For similar photograph, suggest you use Aperture priority setting at say
> f11, BUT also set the "custom function" (if there is one on the Rebel XT?)
> to ensure that the minimum shutter speed in aperture priority mode is
> 1/200th. This will ensure the flash fires.
>
> Alternatively use manual mode for setting both aperture and shutter speed
> and the flash will adjust to compensate.

If the XT is the same as other Rebel models, it should have an "A-DEP"
function that will find the focus for any subjects on the focus points,
and then set the aperture to obtain the necessary DOF.


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