Some questions about metering and focusing

[caspertodd]

I have finished reading both Understanding Exposure (Bryan Peterson) and The Digital Photography Book (Scott Kelby). I have learned so much through these books, BUT I still have a couple basic questions on metering and focusing though.

Metering:
Do you mainly use spot metering, center weighted or matrix metering? Throughout both books, the authors never really explain this much (unless I just missed it). Mr. Peterson states that Matrix metering is great technology, but is that what you use all the time, or is there specific situations for each one? He also meters off of the sky quite a bit in the book, is that for only when the sky is going to be a part of the picture? If I were to do that, the picture would be severly underexposed. What I have been doing is spot metering off of the subject (unless I were trying to make a silhouette).

Focusing:
Do you use All Points focus, or Single Point focus when using auto focus? That is never explained in either book. When I am trying to pan with my dog running all out to catch a frisbee, it is tough to keep the little center focusing dot on him. Would you use All Points focus in this situation and let the camera do a little bit of the tracking work? Or if I am trying to take a picture of a vulture flying overhead, is it best to just switch to manual, single or all point focus?

I am trying to figure these out by trial and error, and I know they are basic, but I still do not understand. Can anyone shed some light on these, or point me in the right direction for some reading material that might would cover it? Thanks!

 

[Overread]

I can answer the focus points - for me center focus point is the one to use, especially when tracking a moving target. The problem with using all the tracking points is that there is always a chance that the camera will suddenly pick the wrong target and focus in on that (say a twig) and then you have lost all focus on the dog - a really fast focusing lens might let you get away with it, but personally I say go for the center one and keep practicing with tracking.
As for manual I think that depends both on you and your lens, some heavier lenses are more tricky to handhold (espcially if you are aiming up in the sky) and focus at the same time manually. For these I would certainly use autofocus as more times its going tobe faster than you. If, however, I were using support and shooting at birds on a pond say I might swap to manual because I don't have to support the greater weight of the lens/

 

[dEARlEADER]

I asked this question a couple weeks ago after reading understanding exposure..

The answer I got was to use Matrix metering.... which generally means half of the stuff in his book is outdated or only relevant if you a using the less superior center weighted metering...

I like his idea's referencing fstops to storytelling etc... but i don't think this should be a recommended book.. there surely must be something more updated that conveys the same ideas using modern technology...

why bother using center weighted to meter something green and backiup 2/3 stop if you can just use matrix and take the shot right to begin with??

 

[caspertodd]

Thanks Overread and dearleader.

I had been taking some pics in both all point and single point, but when looking at the pics I couldn't tell which was which. From what I remember though, the Canon viewer software lets you see what the focus points were. I need to go back and look at that again. So do you ever use the all points focus at all?

I was thinking that the matrix metering might be best, but just wasn't sure. I'm glad to know that I wasn't the only one that had that question after readin the book. To me, I loved the book, and I really felt that he did a good job repeating what he was doing so that it would sink in, its just that I felt there were important gaps that he left out.

Are there any more books that are highly recommended that should follow the ones that I have already read? From what Overread was saying in another thread was the two Langfords books: Basic Photography and Advanced photography. I also read that Light Science and Magic... was another good book.

 

[Overread]

hmm to be honest I mostly shoot wildlife so stick to the center focus point and the only time I use all of the focusing elements is when I do the very odd landscape, but I will admit to not being much of a landscape photographer (read not really read much about it).

That said the center focusing element is usually the best in the camera (fastest) and the other elements are often lesser in quality - though there are grades, but I cannot recall the order

 

[KOrmechea]

If you take the time to really compose a shot, you might as well choose the focus point too. It only makes sense.

 

[Jim H]

I'll be the voice of dissent and make it clear as mud for you. There is no "one size fits all" answer to the two questions you posed on metering and focusing. It all comes down to the subject you are capturing.

You will definitely use a different set of criteria from a wide open landscape to a portrait. Waterfall to wildlife and so on.

You really want to understand exposure? Go use your camera. If you don't think the exif data will be enough to jar your memory, take a voice recorder or make notes of what you are doing and how you are doing it. When you get the results you want for the subject type you are shooting, go do it again until it gets to be second nature to you. Practice, practice, practice.

I can also put it into perspective from my old film camera. Didn't have AF and the in-camera meter was something to be desired. Incident/reflective light meter, sunny 16 rule and a focus prism in the viewfinder is how we used to do it. (gawd do I feel old now)

From what I hear it's a great book - but you need to get some "hands-on" training to go along with it!

( oh .. and don't forget to come back and tell/show us how you did. )

 

[BoblyBill]

I use spot metering and primarily use the center focus spot. This is where manual comes in handy I think I meter the part I want to be in focus change me shutter and aperature, then focus on that spot hit my focus lock button and recompose. After some practice this doesn't take very long (maybe ten seconds). Besides... I have to think more carefully about the shot while I'm setting it up.

 

[dEARlEADER]

I use spot metering and primarily use the center focus spot. This is where manual comes in handy I think I meter the part I want to be in focus change me shutter and aperature, then focus on that spot hit my focus lock button and recompose. After some practice this doesn't take very long (maybe ten seconds). Besides... I have to think more carefully about the shot while I'm setting it up.

Well I do this sometimes too... this is generally the method that peterson describes....

but if you spot meter the trunk of a tree you will blow out the sky.... if meter the sky you will underexpose the tree.... if you use matrix the camera will meter the sky and the tree to give you the most balance exposure possible...

I don't see how shooting manual makes a difference... I shoot manual with matrix metering all the time..... except with matrix I can meter the whole scene instead of metering a part of the scene...

Please correct me if i'm wrong..

 

[BoblyBill]

I see what you are saying.
But if you meter the tree, then isn't that main focus of the shot? I only meter the part of the picture that is my main focus. I have to except the dynamic range of the camera. After awhile you start getting a feel of what the picture will look like and you can compansate for that in the shot. If I was shooting a shot that I metered the sky and the tree and one or other would be not exposed right I would average the two and probably then favor the exposure towards my main focus point. That make sense?
Let's take this picture for example.

I metered the house because that was what me focus was and knew that trees would be dark and the sky blown out.

 

[Stillsky]

Matrix metering has always given me less than desirable results.

You can meter an entire scene with spot metering, it's just a few seconds extra work. There's really no right or wrong meter though. Everyone has their preference. It's just a matter of getting out there and seeing what works best for you.

 

[Socrates]

I usually use matrix metering but I'll use spot metering under some circumstances. In either case, automatic bracketing helps a lot although it's useless in some situations.

I always use the center focus point. It's about the only way that I can keep track of what the camera is doing.

 

[dEARlEADER]

I see what you are saying.
But if you meter the tree, then isn't that main focus of the shot? I only meter the part of the picture that is my main focus. I have to except the dynamic range of the camera. After awhile you start getting a feel of what the picture will look like and you can compansate for that in the shot. If I was shooting a shot that I metered the sky and the tree and one or other would be not exposed right I would average the two and probably then favor the exposure towards my main focus point. That make sense?
Let's take this picture for example.

I metered the house because that was what me focus was and knew that trees would be dark and the sky blown out.

Sure... makes total sense... for some situations (like above) if your focal point is the house than spot metering may be the way to go... I would be curious to have seen how matrix would have exposed this picture.. It most likely would have failed as this type of shot would be an uncommon algorithm.. but technically the spot metering wasn't perfect either because of lost lowlights and blown highlights... i guess it boils down to artistic intention...

 

[dEARlEADER]

Matrix metering has always given me less than desirable results.

You can meter an entire scene with spot metering, it's just a few seconds extra work. There's really no right or wrong meter though. Everyone has their preference. It's just a matter of getting out there and seeing what works best for you.

If your matrix metering has always given you less than desirable results than your camera's meter is defective or you shoot very uncommon subjects that exceed the matrix programming...

I don't understand what you mean by spot metering an entire scene.... spot metering is gathering data from the spot your camera is pointing to.... you adjust your aperture/shutter to your meter reading.... using the same example as discussed in the thread there might be a 4 stop difference between the tree and the sky.... to me it's seems silly to take randomly placed exposure samples using spot metering to calculate your aperture/shutter settings.... this is the idea behind matrix...

but I'm a noob so perhaps you could share the technique...

 

[Stillsky]

If your matrix metering has always given you less than desirable results than your camera's meter is defective or you shoot very uncommon subjects that exceed the matrix programming...

I don't understand what you mean by spot metering an entire scene.... spot metering is gathering data from the spot your camera is pointing to.... you adjust your aperture/shutter to your meter reading.... using the same example as discussed in the thread there might be a 4 stop difference between the tree and the sky.... to me it's seems silly to take randomly placed exposure samples using spot metering to calculate your aperture/shutter settings.... this is the idea behind matrix...

but I'm a noob so perhaps you could share the technique...

The spot metering in a camera is almost the same as a using a reflected light meter. Main difference being that the reflected light meter is generally more accurate as it has a narrower field of view. You compose your shot, then aim your camera at different areas within the scene to get your different exposure values, mull that information over to come to an aperture and shutter speed setting, recompose the shot, fire away.