Tutorial Understanding Exposure, my take on it.

EdBray

EdBray

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EdBray submitted a new resource:

Understanding Exposure, my take on it. - Understanding Exposure, my take on it.

I have noticed that recently there has been a number of threads or questions posted about how to acheive correct exposure. As I have taught the basics of exposure control to many people over the years I thought I would try to put down on paper (or screen if you prefer) my take on the subject.

Hopefully some of you may find it useful.



Understanding exposure is not that difficult!

Camera Controls:
On the more advanced cameras with fully manual modes there are...
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Read more about this resource...
 
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Thank you EdBray - very informative, just what I need - thanks for sharing your knowledge
 
Thankyou for taking the time to put this together and deliver it in an easily understandable way:clap::clap:

I'm sure it will be very helpful to many people on here.
 
EdBray.

I haven't read the full article, mainly because I zoomed straight in on what you have to say about metering. Your description and examples are just about perfect. I hope you don't mind if I use your post/tutorial as a point of reference when I help others. I couldn't explain it any better myself, and metering is a much misunderstood component, which you have so eloquently described in an easily understandable way.

Many thanks for your efforts.
 
cheviot said:
EdBray.

I haven't read the full article, mainly because I zoomed straight in on what you have to say about metering. Your description and examples are just about perfect. I hope you don't mind if I use your post/tutorial as a point of reference when I help others. I couldn't explain it any better myself, and metering is a much misunderstood component, which you have so eloquently described in an easily understandable way.

Many thanks for your efforts.
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Thanks for your post (y) I do not mind you or anyone else using my description if they think it will be useful.
 
Many thanks. I don't intend cut and paste, but to link to your post. Its only right that the author gets full credit.
 
Thank you, excellent tutorial.
 
Removed - didn't read where it was properly!!
 
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note to read later to myself (as work computer can't see images)
 
Thanks for this Ed Bray, I'll be putting this in my favorites.
 
One of the best tools anyone can have is a grey card and/or light meter. Understanding HOW makes it easier than understanding why.
 
It's all beginning to make sense.........

Ed, I come back to this thread regularly. Thought it was about time to thank you.

Gary
 
Thanks for this straight forward explanation.

I will be reading it on a regular bassis.

G
 
Thanks Ed, Very useful info. Took some time to understand but getting there(y)
 
A big Thanks EdBray a big down fall of mine is the understanding of exposure and this has helped a lot..... :clap: :clap: (y)



John
 
Ed thanks for the heads up, all information received is appreciated.
Thanks
Paul.
 
To try this for yourself, take a picture of a white piece of paper with the cameras controls set to the reading obtained from metering from the paper.
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Apologies but I have read this on many ocassion trying to get my head around it..

Could you please tell me as if I have read & got it right -

I would find the reading obtained from the paper ... Would that be if I had taken a picture of the paper say in "matrix" and then read what numbers show up ie 1/160 @ f16 at ISO400?

Or have I totally mis-understood... I have a Nikon & not a Canon

Cheers
 
Ed very good. I had bought a tribalance a while ago and never really used it much and I sat the other night playing around and doing just what you did there :)

I certainly see the advantage in using for both exposure & colour balance.

I am however starting on the road to using full manual control and the use of a meter (Sekonik L358) for incident and flash readings.

Hopefully I'll get quicker as I go along :)!

Good work.
 
Trig's said:
Apologies but I have read this on many ocassion trying to get my head around it..

Could you please tell me as if I have read & got it right -

I would find the reading obtained from the paper ... Would that be if I had taken a picture of the paper say in "matrix" and then read what numbers show up ie 1/160 @ f16 at ISO400?

Or have I totally mis-understood... I have a Nikon & not a Canon

Cheers
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No you haven't misunderstood!

Yes, the meter automatically assumes that what you are pointing it at is grey, so if your meter bases it's exposure on a reading obtained from a white or brighter than grey object it will try to compensate thus causing underexposure as it tries to make the white/bright object grey.

We are talking tones here rather than colours.

So if you got 1/160th @ f16 @ ISO400 when the reading was taken from a white source with no detail then you really need to open up the exposure by 2.5 - 3.0 stops to get the tones correct when you take the picture.

To give a more accurate set of tones it is advised to take a reading either from the brightest tone in which you wish to retain detail or the darkest tone in which you wish to retain detail.

For digital files it is recommended that the brightest tone is used as this will offer some protection to the highlights, to then obtain the correct tones in the image you would have to increase the exposure by 4x (-2 stops) or in the case of the darkest tone in which you wish to retain detail decrease the exposure by 4x (+2 stops).

So again to clarify, if you got a reading of 1/160th @ f16 @ ISO400 from the brightest tone in which you wish to retain detail then you would have to adjust the exposure by x4 (-2 stops) to give the required end result, this could be done in a number of ways dependand on how you want the end result to look.

It could be any one of the following:

1/160th @ f8 @ ISO 400 (decrease in depth of field)
1/160th @ f11 @ ISO 800 (slight decrease in DOF, increase in noise)
1/160th @ f16 @ ISO 1600 (large increase in noise)
1/80th @ f11 @ ISO 400 (decrease in shutter speed with poss subject/camera movement and slight decrease in DOF)
1/80th @ f16 @ ISO 800 (decrease in SS poss subject/camera movement and slight increase in noise)
1/40th @ f16 @ ISO400 (further decrease in shutter speed with more possibility of subject/camera movement)

You have to decide what you want to lose to get the required end result.

Hope this helps?
 
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I think I've got the jist (will need reading thru again) & your prompt reply is much appreciated....

The other thing that gets me is that I have set up a WB pre 18% grey setting (as well as the others sunny/shade/flash etc) would this make any difference to the reading if I had the WB set on it or is that something completely different?

Apologies for the questions but it make's life easier as you cant ask questions to the manual/books on photography & get the answers.. (if you get my meaning)

Cheers
 
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Thought it was... Thanks again thou (y)
 
Trig's said:
I think I've got the jist (will need reading thru again) & your prompt reply is much appreciated....

The other thing that gets me is that I have set up a WB pre 18% grey setting (as well as the others sunny/shade/flash etc) would this make any difference to the reading if I had the WB set on it or is that something completely different?

Apologies for the questions but it make's life easier as you cant ask questions to the manual/books on photography & get the answers.. (if you get my meaning)

Cheers
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Different but use of the same materials. Shoot the grey card (or even a sheet of plain paper) and set that as your custom wb. Job done - then continue with the above - although you don't need to do that - Ed's process is the same.
 
Many thanks for a very informative well written tutorial .
 
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