7i, a better way to lock focus, exposure and fill flash?

skane154190 · Jun 11, 2003

I wanted to take a picture of some people standing in open shade under a large canopy with a brightly lit landscape in the distance. I wanted both the landscape and the people properly exposed. To get enough light on the people I used the 7i's built-in flash.

The way I did it required a three step process and had to be redone for each photo. I wonder if there is a better way to do it. Here's what I did with the 7i set to Program mode:

1) Choose something to focus on, in this case the people, press and hold the shutter button halfway down.

2) With the built-in flash closed because the Spot-AE lock button doesn't work with the flash open, choose something to lock exposure on, the landscape in this case, press and hold the Spot-AE lock button.

3) Open the 7i's built-in flash.

4) Take the picture.

5) Repeat as needed.

Is there a better way to do this?
Is there a way to hold all the settings for subsequent shots?

Thanks.

Jawed49152 · Jun 11, 2003

You should immediately go full manual!

Because your camera shows you an exposure preview (with flash closed) it is very easy to balance the bright background.

So, first thing, focus and lock it by hitting the MF button. Now you no longer have to worry about focussing lag.

Now zoom into the landscape behind and determine the correct exposure, using the smallest aperture possible (you're aiming for f2.8). With the camera in P mode, you will get a reading, e.g. f6.7/180th.

Roll the wheel to get the max aperture, in this case roll the wheel so that it shows f3.5/750th.

Zoom out to compose the picture of the group.

Turn to M mode and dial in f3.5/750th or f2.8/1000th. Open the flash and take loads of pictures.

An alternative experiment to try is intriguing.

With the flash closed, in P mode, set exposure compensation so that the landscape looks correct. e.g. this might be -2.0 compensation. Now, open the flash, dial in FLASH compensation of +2.0 and take your pictures, focussing each time.

This trick underexposes the main picture, but overexposes the flash. The combination of the two compensations should produce perfect exposure of your subjects. It sounds silly, but when you try it you'll be most impressed!

Your only problem comes when -2.0 compensation isn't enough to make the landscape dark enough.

A third trick: If you have the camera set to AE Hold or AE Toggle (but not AF/AE Hold or AF/AE Toggle), then with the flash open, you can ask the camera to expose the picture as though the flash wasn't going to fire.

This approach unfortunately doesn't really tackle the problem you have, which is very bright backlighting which you want to "underexpose".

Jawed

Bob LaBarre · Nov 4, 2003

I was looking for some fill flash tips and came across this post. It brought up another issue. Once you focus and press the mf button you will often lose focus if you zoom out and in. You may want to experiment with this. Chose and object about 2 or 3 meters away. Zoom all the way in to 200 and focus. Now SLOWLY zoom wider..... all the way to 24. now back in to say 100. You will see an out of focus image in your viewfinder! The best policy is to always do your final focus AFTER you zoom. This could be especially true in larger apetures such as 2.8 and 3.5.

Jawed said:
You should immediately go full manual!

Because your camera shows you an exposure preview (with flash
closed) it is very easy to balance the bright background.

So, first thing, focus and lock it by hitting the MF button. Now
you no longer have to worry about focussing lag.

Now zoom into the landscape behind and determine the correct
exposure, using the smallest aperture possible (you're aiming for
f2.8). With the camera in P mode, you will get a reading, e.g.
f6.7/180th.

Roll the wheel to get the max aperture, in this case roll the wheel
so that it shows f3.5/750th.

Zoom out to compose the picture of the group.

Turn to M mode and dial in f3.5/750th or f2.8/1000th. Open the
flash and take loads of pictures.

An alternative experiment to try is intriguing.

With the flash closed, in P mode, set exposure compensation so that
the landscape looks correct. e.g. this might be -2.0 compensation.
Now, open the flash, dial in FLASH compensation of +2.0 and take
your pictures, focussing each time.

This trick underexposes the main picture, but overexposes the
flash. The combination of the two compensations should produce
perfect exposure of your subjects. It sounds silly, but when you
try it you'll be most impressed!

Your only problem comes when -2.0 compensation isn't enough to make
the landscape dark enough.

A third trick: If you have the camera set to AE Hold or AE Toggle
(but not AF/AE Hold or AF/AE Toggle), then with the flash open, you
can ask the camera to expose the picture as though the flash wasn't
going to fire.

This approach unfortunately doesn't really tackle the problem you
have, which is very bright backlighting which you want to
"underexpose".

Jawed

--
Who's that nut over there with the camera?

Jawed49152 · Nov 4, 2003

In two years of using my D7 I found that zooming out (e.g. 200mm to 50mm) the focus WAS ALWAYS ACCURATE.

Your mistake is to assume that zooming-in is accurate. When you zoom in to test the focus you have accidentally clobbered the focus.

I always recommend that best manual focus be obtained at full zoom, if possible, and then you can safely zoom out to the required composition.

Jawed

Bob LaBarre said:
I was looking for some fill flash tips and came across this post.
It brought up another issue. Once you focus and press the mf button
you will often lose focus if you zoom out and in. You may want to
experiment with this. Chose and object about 2 or 3 meters away.
Zoom all the way in to 200 and focus. Now SLOWLY zoom wider.....
all the way to 24. now back in to say 100. You will see an out of
focus image in your viewfinder! The best policy is to always do
your final focus AFTER you zoom. This could be especially true in
larger apetures such as 2.8 and 3.5.

Sandy · Nov 4, 2003

Jawed said:
Your mistake is to assume that zooming-in is accurate. When you
zoom in to test the focus you have accidentally clobbered the focus.

I always recommend that best manual focus be obtained at full zoom,
if possible, and then you can safely zoom out to the required
composition.

Jawed

Bob LaBarre wrote:
Once you focus and press the mf button

Jawed49152 said:

you will often lose focus if you zoom out and in. The best policy is to always do
your final focus AFTER you zoom. This could be especially true in
larger apetures such as 2.8 and 3.5.

Click to expand...

The GT lens will alter its focus as you zoom, just as Bob says. However, there will be good depth of focus at wider angle. This increased depth of focus will allow one to focus at 200 mm and move to (say) 40 mm and have good focus. It will probably not be spot on but in the real world it will be plenty good enough - as Jawed has found in practice.
--
Sandy

Bob LaBarre · Nov 4, 2003

I know you are an accomplished photographer and that you know your camera well. I would like to point out however, that in the sequence you suggest, you zoom in after focus and back out. Does this initial zoom in "clobber" the focus"? Perhaps I misunderstood. I have been known to do that .....lol.

Jawed said:
Your mistake is to assume that zooming-in is accurate. When you
zoom in to test the focus you have accidentally clobbered the focus.

I always recommend that best manual focus be obtained at full zoom,
if possible, and then you can safely zoom out to the required
composition.

Jawed

Bob LaBarre said:

I was looking for some fill flash tips and came across this post.
It brought up another issue. Once you focus and press the mf button
you will often lose focus if you zoom out and in. You may want to
experiment with this. Chose and object about 2 or 3 meters away.
Zoom all the way in to 200 and focus. Now SLOWLY zoom wider.....
all the way to 24. now back in to say 100. You will see an out of
focus image in your viewfinder! The best policy is to always do
your final focus AFTER you zoom. This could be especially true in
larger apetures such as 2.8 and 3.5.

Click to expand...

--
Who's that nut over there with the camera?

Matthew Geier · Nov 4, 2003

Bob LaBarre said:
Jawed said:

In two years of using my D7 I found that zooming out (e.g. 200mm to
50mm) the focus WAS ALWAYS ACCURATE.

Your mistake is to assume that zooming-in is accurate. When you
zoom in to test the focus you have accidentally clobbered the focus.

Click to expand...

I've seen the comment more than once that the GT lens isn't really a zoom lens by the exact definition of the term, but a variable focal lenght lens. The camera's computer moves the lens focusing elements as you 'zoom' the lens to simulate the behavour people expect from zoom lenses.

Probably why every one else has motorized zooms, if you are in fact sending a command to the CPU to move the lens, it can caculate and move the focus elements in sync. Minolta camera users just twist the zoom in or out at speed, and the CPU in the camera has to read this movement and recaculate the focus element positions and move them as fast as you move the barrel.

Jawed49152 · Nov 4, 2003

Ah I understand you're talking about my original instructions on setting focus and exposure.

Yes that is a mistake. It would definitely be better to set exposure first in the sequence I described.

My mistake,
Jawed

Bob LaBarre said:
Jawed said:

Your mistake is to assume that zooming-in is accurate. When you
zoom in to test the focus you have accidentally clobbered the focus.

I always recommend that best manual focus be obtained at full zoom,
if possible, and then you can safely zoom out to the required
composition.

Jawed

Bob LaBarre said:

I was looking for some fill flash tips and came across this post.
It brought up another issue. Once you focus and press the mf button
you will often lose focus if you zoom out and in. You may want to
experiment with this. Chose and object about 2 or 3 meters away.
Zoom all the way in to 200 and focus. Now SLOWLY zoom wider.....
all the way to 24. now back in to say 100. You will see an out of
focus image in your viewfinder! The best policy is to always do
your final focus AFTER you zoom. This could be especially true in
larger apetures such as 2.8 and 3.5.

Click to expand...

Click to expand...

--
Who's that nut over there with the camera?

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7i, a better way to lock focus, exposure and fill flash?

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