My 'next step' photography questions...

[jai]

Hello all,

Right, I've had my 400D (XTi) for a few months and I'm starting to get the hang of the very basics (the smaller the aperture #, the more light, and the longer the shutter speed to capture movement and all that...) Yes, I know it's the very basics.

Now, I'm reading Bryan Peterson's 'Understanding Exposure', that was recommended on here.
He's talking about metering and that in M mode, that the camera detects what aperture and/or shutter speed to select, after having evaluated the light...(I think).
How do I do this on my camera? Is it when I press the shutter button half-way, a red dot flashes (indicating the in-focus part of the frame, I think)?
What do I do if the wrong part is indicated in focus?
However, the aperture and shutter speed values don't change (which is probably logical in M mode).

Also, can someone explain the (light?) metering to me? I currently have it set to 'Evaluative metering' but don't really get the difference between the three options and when to choose them?

Also, what's the exposure indicator for, and why does it move when I focus on different subjects...

So basically, how do you choose the correct aperture/shutter speed?

Thanks,

[Nickcanada]

There is quite a bit to cover in your post so I'll start with metering.

In M mode you select the Aperature and the SS, the camera is not in control, you are.

Try shooting in Av mode, you choose the aperature value and the camera will select the proper SS based on the avaliable light and your chosen ISO.

The exposure indecator is there to tell you if you have achived proper exposure with your settings. If you choose Av or Tv, insdead of the exposure bar moving the camera will set the proper SS or aperature. I use Av most of the time.


I suck at explaining things like this so please ask specific questions if I'm being unclear.


"What do I do if the wrong part is indicated in focus?"

Release the shutter button and refocus on your desired subject. Are you having trouble achiving focus in specific situations?

[RebelRat]

Hello all,

Right, I've had my 400D (XTi) for a few months and I'm starting to get the hang of the very basics (the smaller the aperture #, the more light, and the longer the shutter speed to capture movement and all that...) Yes, I know it's the very basics.

Now, I'm reading Bryan Peterson's 'Understanding Exposure', that was recommended on here.
He's talking about metering and that in M mode, that the camera detects what aperture and/or shutter speed to select, after having evaluated the light...(I think).
How do I do this on my camera? Is it when I press the shutter button half-way, a red dot flashes (indicating the in-focus part of the frame, I think)?
What do I do if the wrong part is indicated in focus?
However, the aperture and shutter speed values don't change (which is probably logical in M mode).

I always have my focus point on the center point. Unless I choose to change the focus point for a specific composition.

Also, can someone explain the (light?) metering to me? I currently have it set to 'Evaluative metering' but don't really get the difference between the three options and when to choose them?

I've attached a picture from the XT's manual. The metering modes are the same as the XTi's

Also, what's the exposure indicator for, and why does it move when I focus on different subjects...

Do you mean the red focus points? (I'm guessing here) That shows you where the camera has decided to focus. (basically the closes object to your camera in the focusing range.

So basically, how do you choose the correct aperture/shutter speed?

That depends on the subject ( quick moving subjects will need fast shutter speed to freeze the action) and the look you are trying to accomplish (depth of field).
Thanks,

Hope this helps a little.

[jai]

Thanks.

I've worked out the "press the shutter button again to get another point in focus".

The book kind of says that M mode is the best way to go. The thing is, I can't just look at something and say: "I need this aperture and this shutter speed". Basically, as long as there's focus, does it really matter?

Also, I guess that I'm better off just leaving the exposure on evaluative for the time being, right?

Yes, I was talking about the red focus points.

I guess I need to practice more!

[cwphoto]

Thanks.

I've worked out the "press the shutter button again to get another point in focus".

The book kind of says that M mode is the best way to go. The thing is, I can't just look at something and say: "I need this aperture and this shutter speed". Basically, as long as there's focus, does it really matter?

Also, I guess that I'm better off just leaving the exposure on evaluative for the time being, right?

Yes, I was talking about the red focus points.

I guess I need to practice more!

Firstly, focus and exposure are two totally unrelated (but equally important) functions on your camera.

While obviously being the tools which control exposure, aperture and shutter speed also serve a very useful creative process (control of Depth of Field and movement).

M mode is unique to all other exposure settings on the camera (P, Av, Tv and all the others) in that M is the only one where the camera does not select the exposure for you - you have to input both values before you shoot. I would argue that M mode is not necessarily the best mode for all occasions though.

How you come up with those values is up to you, but remember that you still have to satisfy correct expsoure in the parts of the image that are important to you. The camera's light meter may still be useful (you will notice a marker will move up and down the exposure scale as you adjust the aperture or shutter), or you can use an external light meter, or you can take an educated guess.

[jai]

But what exactly is the light meter and how do I regulate it?
Is it the -2 -> +2 meter that you see in the viewfinder?
What do those numbers relate to, and why do they change?

Thanks,

[aparmley]

But what exactly is the light meter and how do I regulate it?
Is it the -2 -> +2 meter that you see in the viewfinder?
What do those numbers relate to, and why do they change?

Thanks,

Yes - the meter's visible through the viewfinder. . . as you stated it goes from -2...-1...0...1...2. The green bar that moves along that line is the meter showing you where your exposure will be given the current subject and meter mode. In M, they change as the amount of light changes. You increase shutter speed you reduce the amount of light that will hit the sensor (negative amount). You decrease the shutter speed you increase the amount of light that hits the sensor (positive value). You increase aperture and you decrease the amount of light that hits the sensor (negative value). You decrease aperture and you increase the amount of light that hits the sensor(positive value). You increase ISO to increase the amount of light the sensor records (positive) value. You decrease ISO to decrease the amount of light the sensor records.

OR

and more likely . . .

You'll use a combination of ISO, SS, and aperture to vary the amount of light you record. The meter is a guide; nothing more. Sometimes it has no clue what you really want to meter - hence underexposure or overexposure - you must learn the meter and its mode of metering to master exposure. You'll learn it will over expose greens, under expose whites . . . etc etc so you can use your meter as a guide. Say you are shooting the snow, well its going to tell you that you will over expose by about 1-2 +EC if you're shooting in manual to get a proper exposure. I was fairly sure that "Understanding Exposure" was pretty clear on all of this, the reason I say that is I don't think I can write it out any more clear, hopefully a different writing style will help you ??? :confused: good luck

[cwphoto]

But what exactly is the light meter and how do I regulate it?
Is it the -2 -> +2 meter that you see in the viewfinder?
What do those numbers relate to, and why do they change?

Thanks,

The light meter in your camera is normally activated by pressing the shutter-release button.

the -2 to +2 to which you refer are variances to what the camera's meter thinks is correct exposure (middle) and the actual exposure set based on your aperture/shutter. Normally in any mode other than M, the 'marker' will be in the middle (unless an Exposure Compensation (EC) is set).

For example; -1 means the set exposure is one Exposure Value (EV) or "stop" under what the camera's meter thinks is correct.

The number's change because the lighting changes. In bright light the camera needs to reduce the amount of light coming in (because it's so intense), in dull light the camera needs to do the opposite.

[jamison55]

And to simplify Andy and Christian's explanations even more, the goal (at least to begin with) in M mode is to use the aperture and SS to put the meter inticator at the 0 position. +1 is overexposed, -1 is underexposed.

SO

If the meter is at -1, slow your shutter speed or decrease your f stop (i.e. choose a smaller number) or increase your ISO.

If the meter is at +1, increase your shutter speed or increase your f stop(i.e. choose a bigger number) or decrease your ISO.

It's that easy!

[boog]

Well done Andy, CW, and Jamie. Can't just beat plain ol experience!!!

[jai]

Thanks guys, I'm starting to understand it a little better.

Now, let's see if I get this right:

The light meter (the -2 -> +2 meter) indicates when the camera *thinks* that the picture may be overexposed (too much light) or underexposed (not enough light). The meter is right in most cases and the aim is to adjust the aperture, shutter speed and ISO settings to get the meter on '0'.

Is that correct?

Now, is my work flow correct:

1. Find something to photograph.
2. Set the shutter speed first if I want my photograph to be "frozen" or "in motion".
3. Depending on what I've chosen as shutter speed, regulate the aperture so that the light meter is on '0'.
5. Set ISO if shutter speed is too fast to capture light.
4. Take picture.

Now, how do I know if like 1/4000 or 1/2000 is the correct shutter speed for a scene, as I can't really relate to the difference.
Same as how do I know if , for example, f/8 or f/11 is the right aperture?

I really need to practice some more! :o

[cwphoto]

Thanks guys, I'm starting to understand it a little better.

Now, let's see if I get this right:

The light meter (the -2 -> +2 meter) indicates when the camera *thinks* that the picture may be overexposed (too much light) or underexposed (not enough light). The meter is right in most cases and the aim is to adjust the aperture, shutter speed and ISO settings to get the meter on '0'.

Is that correct?

Now, is my work flow correct:

1. Find something to photograph.
2. Set the shutter speed first if I want my photograph to be "frozen" or "in motion".
3. Depending on what I've chosen as shutter speed, regulate the aperture so that the light meter is on '0'.
5. Set ISO if shutter speed is too fast to capture light.
4. Take picture.

That's pretty much it. Keep in mind that the camera won't always calculate exposure correctly as we want it.

[cwphoto]

Now, how do I know if like 1/4000 or 1/2000 is the correct shutter speed for a scene, as I can't really relate to the difference.
Same as how do I know if , for example, f/8 or f/11 is the right aperture?

Experience. Trial and error. ;)

[forno]

I find the hardest thing to nail down is getting the right + or - value on the exposure to get the camera to see what I see rather than it trying to get the light values to conform to its idea of what it shoould look like

[jai]

Well, it's not an easy hobby, is it!?

At least I'm learning from the book and on here...

I'm sure I'll have more questions tomorrow!

Thanks,

[GaryS]

Well, it's not an easy hobby, is it!?

Bang. You just hit the nail on the head!

Everybody takes pictures, and everybody sometimes gets a real winner.... But its hard to consistently get winners, and that is what makes this hobby so frustrating (and so rewarding too)! Practice and taking notes are what I find helps... Oh, and some more practice!

[99allturbo]

jai, thanks for starting a thread with these questions. I recieved my 400D last night and I was asking my self the same exact questions you had.

Thanks to all for answering the questions. I look fwd to putting this info to use.

Christian, I've been following your pic threads as well, and I appreciate you providing the settings on each picture. I plan on using them as a guide. Thanks.

[TenD]

I find the hardest thing to nail down is getting the right + or - value on the exposure to get the camera to see what I see rather than it trying to get the light values to conform to its idea of what it shoould look like
This is where the histogram and flashing highlights help the most. I have a 10D and an S2, with the S2 missing the live histogram and that is the feature I miss the most on it.
Here are two articles that go a long way toward understanding histograms:

http://www.luminous-landscape.com/tutorials/understanding-series/understanding-histograms.shtml

http://www.luminous-landscape.com/tutorials/expose-right.shtml

[RichNY]

Now, how do I know if like 1/4000 or 1/2000 is the correct shutter speed for a scene, as I can't really relate to the difference.
Same as how do I know if , for example, f/8 or f/11 is the right aperture?


Using the scenario you have presented, freezing an object in motion, there may very well be various shutter speeds you can choose. Once you've set a shutter speed fast enough to stop motion (lets say 1/250 for example), think of the differences (1/250, 1/500, 1/1000, etc.) in terms of what f/stop they will allow you to use to control depth of field.

Your fastest shutter option will require the largest aperture openning to properly expose your image- a larger aperture openning will give you a smaller depth of field. Conversely the slowest shutter option will require a smaller openning which will give you a larger depth of field.

[tiger1438]

I've read "Understanding Exposure" and one thing that has me a little lost is how to compose the way he talks about it. He frequently suggests getting a meter reading off of a different object than what you're shooting then recomposing on the object. How do you keep the exposure if you're shooting Av or Tv?

[cwphoto]

I've read "Understanding Exposure" and one thing that has me a little lost is how to compose the way he talks about it. He frequently suggests getting a meter reading off of a different object than what you're shooting then recomposing on the object. How do you keep the exposure if you're shooting Av or Tv?

AE lock - little button (labelled: *) near your thumb.

[tiger1438]

Thanks. I'm sure I should have gotten that before, but I appreciate the help.

[Honest Gaza]

....or note the Aperture and Shutter Speed settings, switch to "M" mode and use these same settings (I hope).

[jai]

jai, thanks for starting a thread with these questions. I recieved my 400D last night and I was asking my self the same exact questions you had.


No problem 99, glad I could help.

Also, thanks for the * tip Christian, I had no idea it did that. But why would one want to get a reading off something other than what is intended to be photographed?

[GaryS]

Also, thanks for the * tip Christian, I had no idea it did that. But why would one want to get a reading off something other than what is intended to be photographed?

The biggest reason is the sun. Lets say you are taking a picture of a kid, and the sun is just over their shoulder and you can see it in the frame. The sun will be very bright, and all the light will cause your camera to darken the whole picture, which results in the kid being very dark. If you move the camera so that the sun is not in the frame, and then lock the exposure, the kid would be properly exposed.

There are lots of situations where the camera's meter gets fooled, and through experience you learn when it is happening, and what to do to fix it. "Understanding Exposure" goes through the times when the camera gets it wrong, and tells you what you can do to correct it. But to be honest, I found I had to practice, and then come back to the book to start to 'get it'. On first read, there is just too much there when starting out!

Sorry to jump in Christian...

[99allturbo]

The biggest reason is the sun. Lets say you are taking a picture of a kid, and the sun is just over their shoulder and you can see it in the frame. The sun will be very bright, and all the light will cause your camera to darken the whole picture, which results in the kid being very dark. If you move the camera so that the sun is not in the frame, and then lock the exposure, the kid would be properly exposed.

There are lots of situations where the camera's meter gets fooled, and through experience you learn when it is happening, and what to do to fix it. "Understanding Exposure" goes through the times when the camera gets it wrong, and tells you what you can do to correct it. But to be honest, I found I had to practice, and then come back to the book to start to 'get it'. On first read, there is just too much there when starting out!

Sorry to jump in Christian...


I understand better now. Thanks for the explanation. I've had issues like that (sun related) with my p&s where the pic comes out dark because of the sun. Especially an instance when a person was standing by a window on the inside of a home. The person would come out dark because the sun was was shining through the window. The solution on the SLR would be point the camera on a different subject (away from the window), lock it, then point back to person, and they will be properly exposed, correct?

[cwphoto]

The biggest reason is the sun. Lets say you are taking a picture of a kid, and the sun is just over their shoulder and you can see it in the frame. The sun will be very bright, and all the light will cause your camera to darken the whole picture, which results in the kid being very dark. If you move the camera so that the sun is not in the frame, and then lock the exposure, the kid would be properly exposed.

There are lots of situations where the camera's meter gets fooled, and through experience you learn when it is happening, and what to do to fix it. "Understanding Exposure" goes through the times when the camera gets it wrong, and tells you what you can do to correct it. But to be honest, I found I had to practice, and then come back to the book to start to 'get it'. On first read, there is just too much there when starting out!

Sorry to jump in Christian...

No problems Dusty.

Another reason is when your subject's reflectance isn't average (say a Bride in her wedding dress). Under this situation you can meter off something in the same light which is of average reflectance (say grass, a hand, whatever) and apply that meter reading to your original picture. :)

[jai]

Thanks Dusty & Christian.

I'm getting it a bit as well.

But wouldn't 'metering off something else' kind of falsify the light, in that it wouldn't be true to the scene, if you get what I mean.

Thanks,

[DonSchap]

You could always toss your subject an "18% gray-card" to get the lighting right ... then have them toss it back, before you shoot.

They're about $40 on a good day, but certainly assist for those tricky lighting shots.

[cwphoto]

Thanks Dusty & Christian.

I'm getting it a bit as well.

But wouldn't 'metering off something else' kind of falsify the light, in that it wouldn't be true to the scene, if you get what I mean.

Thanks,

No. Your light meter isn't a magic wand. It only measures the intensity, as long as your sample is of average reflectance and is under the same lighting conditions (ie; not in shade) as your subject then it is perfectly reliable.

[99allturbo]

Experience. Trial and error. ;)

You got that right.

I ran into the issue of knowing what aperture value/ss to use to get a sharp picture.

I was taking pictures of my car yesterda. I was nice sunny day. I was using aperture priority. I started at F/16 and went as high as F/18, later decided to go down to F/11. I used both the kit lens and an a 75-200 zoom lens. After viewing the pitures on the pc, I saw that the only time the pictures got sharp was at F/11. The reason I used those high aperature values was because I thought I was going to blur the backround more with a higher value (which is what I wanted), but I later realized that in Av mode, that higher aperature will give me a slower ss, causing a blurry picture (I did not use a tripod).

Later in the evening (during sunset) I figured that per my experience above, the lower the Aperture value, the sharper the image got. So, I went as low as F/5.6 and the picture was sharper.

This is going to take lots of practice.

[cwphoto]

And the great thing is that you have a lifetime of enjoyment in front of you with this hobby. You have all the time in the world. :)

[99allturbo]

Yes and I am having lots of fun doing it. :D