Is the changing BG affecting my exposure?

[Mark Young]

G'day everyone,

I hope this is the right place to post this question, my apologies if it isn't.

I was hoping someone could shed some light as to why the exposure on the bird changed as the wave in the background broke?

I took both images in Av mode with Evaluative metering. Both images were taken a split second of each other. There were no clouds in the sky at all, and it was about 2 hours prior to sunset.

Other exif info:

Canon 7D 300f4+1.4tc, ISO400, f7.1, -0.3ec, SS of the darker image was 1/2500 and the SS of the lighter image was 1/1250, HH

edit: No PP has been done, and these are jpeg's of the full frame images.

To stop this from happening, should I use Manual mode and/or a different method of metering? Or will this always happen with such a rapidly changing background?

First image.

[Mark Young]

And this is the second image a split second later.

[Roger Clark]

Mark,
Yes, the background is affecting the exposure in AV mode. This is a classic situation where manual mode would be best (in my opinion).

Roger

[Mark Young]

Thanks Roger. Would I also need to change my metering mode as well in this situation?

[Daniel Cadieux]

Manual mode, if light on the subject remains the same but the BG varies, is the way to go. The result you have is normal if you did not lock exposure...in AV (or TV) mode you can (and should) lock the exposure instead of constantly re-metering everytime - this would have worked perfectly in your case here. I photograph in Evaluative 100% of the time...metering mode does not matter if you understand how to use them, and compensate accordingly for each.

[Ákos Lumnitzer]

In your second shot it was the breaking wave (all that white) that made the image turn darker. Agreed with Daniel about understanding how the different modes work. I love my Av mode at all times too except night time photography or macro. :)

[Ian McHenry]

Hi Mark
Thanks for asking the question and getting the informative replies.
As I like to get BIF over or through the waves this is a good message to remember.
By the way like the angle of this neat wader in the second image.
Cheers: Ian Mc

[Charles Glatzer]

Mark,

Meter Patterns (Eval/Matrix, Spot, etc) are used to determine exposure, Priority Modes (Manual, Av, Tv) are used to alter and/or maintain the variables (shutter-speed, aperture), either manually or automatically.

If the light on the subject is not changing you should have no need to alter the exposure! By using Manual Priority you can maintain the aperture and shutter-speed you set in camera for initial subject exposure, regardless of the changing background tonality. Using Evaluative as above... the size of the subject is small relative to the pattern in use, thus the changing background had the greatest influence on exposure recommendation. This is even more true if your subject is of smaller size and different tonality than the background.

IMO Aperture Priority is not the way to go for beginning photographers.

If you want to move forward in your photography it is paramount that you learn the relationships between SHUTTER-SPEED, APERTURE and ISO. Understanding Metering Patterns and Priority Modes and how they can be used in conjunction to best advantage in a given situation will take years off your learning curve.

Warmest Regards,

Chas

[Mark Young]

Thanks everyone for the advice, it's very much appreciated.

@Daniel, I admit I don't really understand the differences in the metering modes all that well, and when to use one over the other. I set the metering to Evaluative because I've read that that is the preferred one for birds. I don't really understand why though, or if I should try other metering modes.

@ Akos, What metering modes do you use? You tend to take images out in the open and in areas with lots of shade, whereas 90% of all my photos are of Shorebirds or other aquatic birds in the open. Do you change your metering mode depending on where you are?

@ Ian, Thanks Ian.

@ Chas, Thanks for your informative input. I've been photographing birds for nearly 4 years now. I've been using a DLSR for 2 of them and have only recently upgraded to the 7D from my previous 400D. The learning curve for photography is HUGE! It's both a highly rewarding and enjoyable past time, as well as slightly frustrating when you try something you thought might work and it doesn't! :D

I've read the manual that comes with the 7D but it doesn't really give too much away about what situations are best for the different metering modes. This next question might sound a bit cheeky, but is there some sort of cheat sheet for birds that can provide some examples of what metering modes best suit which situation?

[Gerald Kelberg]

Hey Mark,

You will probably find Artie's manual on the 7D well worth the investment. I don't have a 7D myself but bought the manual for a friend and he really appreciated it.

Thought I should be quick and get that suggestion in before "himself". :)

G.

[Daniel Cadieux]

@Daniel, I admit I don't really understand the differences in the metering modes all that well, and when to use one over the other. I set the metering to Evaluative because I've read that that is the preferred one for birds. I don't really understand why though, or if I should try other metering modes.


Mark, I wouldn't worry about that too much. In 5 years of photography, I've used Evaluative for in the field work 100% of the time! I did experiment with spot just to understand it, but I put it on eval and have never switched to the others for "real" work. Ever. I know some people like to switch and use different ones for different situations (and that is also a good thing), but for me that is one less thing to worry about...and besides, neither I nor my images have so far suffered from not doing so:).

[Charles Glatzer]

Daniel,

All the Metering Patterns and methods work, some are simply easier to implement than others in certain circumstances.

I believe to truly be a consistent photog you need to understand THE BENEFITS AND DETRIMENTS of each pattern and method. Knowing how the pattern or reference value determines the recommended exposure, be it Eval/Matrix, Spot, Incident, or Reference Values is paramount to this understanding.

What matters most is that a pattern or method affords the photographer a consistent means of determining exposure. My job is to provide students with a firm understanding of the fundamentals so that they can quickly make an informed decision, coming away with the envisioned image, regardless of the lighting circumstance. The ultimate goal is to put creative control back into the hands of the photographer instead of the camera. If a photographer cannot ascertain why an image exposure succeeded or failed he/she has not yet fully grasped the fundamentals.

Warmest Regards,

Chas

[Daniel Cadieux]

Chas, thanks for your input. Your expertise is valued and welcomed and there is tons to learn from your knowledge as always.

I agree (and understand) with what you say. I know they all work, and I know how they all work too...perhaps one day I'll alter my workflow and use the other methods, but I've made a personal decision to stick to one...and "I believe to be a truly been consistent photog" (IMO). If I need to use more or less EC by using just one metering mode all the time then I am still making that exposure decision, it is still my creative control.

I do agree it is best to learn the fundamentals and from there go with what works best individually.

Having said this, I think we can all agree that going Manual in Mark's situation would have been the best way to go...:cool:

[Charles Glatzer]

Daniel,

Thanks for the kind words.

I am glad you found a method that consistently works for you. The end justifies the means, it is the final image that matters most, not the method.

The key to all this lies in knowing how much to adjust/alter/deviate the variables from the exposure recommendation provided by the in-camera pattern, reference value, or hand-held meter to render tonal values in the image as desired. Not an easy task for most, especially for those just starting out.

Eval works well (Matrix is better) as long as the subject is not small in size and/or of very different tonal value relative to the background. Many aspiring photographers have problems discerning when and how much to add or subtract exposure from the Eval recommendation. Artie recognized the difficulty and produced a chart for visual reference to simplify the process, yet many remained perplexed. Spot metering can prove just as difficult for others to grasp.

As an educator I feel it is my obligation, as well as greatest desire, to provide the tools necessary for the student to make an informed decision. Hopefully, with a full "box of crayons" a better picture can be drawn.

Warmest Regards and Good Light to all,

Chas

[Daniel Cadieux]

Hopefully, with a full "box of crayons" a better picture can be drawn.


As someone who used to draw as a hobby before taking up photography I can relate to the above quote. Thanks Chas!:)

[Mark Young]

Thanks guys for the awesome input, it's all greatly appreciated.

Two nights ago I went back to the reef to try and photograph in manual mode. The situation was almost identical with the exception of the subject being totally black, (Sooty Oystercatchers). I shot in manual mode most of the time but found as the birds moved around that by the time I took an image, check it in the viewfinder and repointed the camera at the bird, that the bird had moved a half a metre or a metre to the side.
So I had to adjust my settings accordingly and repeat to see if my exposure was correct.
I found most of my time was spent adjusting my settings, checking and then re-adjusting my settings because the birds were constantly moving around. I didn't get the photo I was after unfortunately :o

[WIlliam Maroldo]

Hi Mark." with the exception of the subject being totally black" is about as big an exception I could think of, and proper exposure of a totally black bird is a challenge regardless of what metering mode. I almost always shoot manually, but when I've used aperture priority in such a case a full +3 EV is not out of the question. The fact that the bird moved a few meters to one side rarely has anything to do with exposure, and if you had the exposure correct in the first shot, why did you keep having to change it? Were you exposing for the bird only, and not the background? Was the light changing rapidly, like quickly moving clouds blocking the sun, then not? Although I prefer manual mode, sometimes I have to switch to Aperture priority under such conditions.

regards~Bill

[Mark Young]

Hi Mark." with the exception of the subject being totally black" is about as big an exception I could think of, and proper exposure of a totally black bird is a challenge regardless of what metering mode. I almost always shoot manually, but when I've used aperture priority in such a case a full +3 EV is not out of the question. The fact that the bird moved a few meters to one side rarely has anything to do with exposure, and if you had the exposure correct in the first shot, why did you keep having to change it? Were you exposing for the bird only, and not the background? Was the light changing rapidly, like quickly moving clouds blocking the sun, then not? Although I prefer manual mode, sometimes I have to switch to Aperture priority under such conditions.

regards~Bill

Thanks for the reply Bill.


The fact that the bird moved a few meters to one side rarely has anything to do with exposure, and if you had the exposure correct in the first shot, why did you keep having to change it?

I'll posts some images when I get home tonight, that might explain things a little better, but I found that in some of them the bird was really quite dark, and in others it was quite a lot lighter. I exposed for the bird as I wanted to get details in the blacks and I wasn't too concerned with the bg or environment at all. You'll notice in some of the images that the bill is overexposed. This didn't show up in the camera though, even though I had it set to show any overexposed areas.


Was the light changing rapidly, like quickly moving clouds blocking the sun, then not? Although I prefer manual mode, sometimes I have to switch to Aperture priority under such conditions.

regards~Bill

The light was quite consistent. It was about 90 minutes before sunset. There was only a thin wisp of cloud about, but not much. I did go back and shoot in AV mode as I found it was the only way I could get the photo I wanted.

[Charles Glatzer]

Hi Mark." with the exception of the subject being totally black" is about as big an exception I could think of, and proper exposure of a totally black bird is a challenge regardless of what metering mode. I almost always shoot manually, but when I've used aperture priority in such a case a full +3 EV is not out of the question. The fact that the bird moved a few meters to one side rarely has anything to do with exposure, and if you had the exposure correct in the first shot, why did you keep having to change it? Were you exposing for the bird only, and not the background? Was the light changing rapidly, like quickly moving clouds blocking the sun, then not? Although I prefer manual mode, sometimes I have to switch to Aperture priority under such conditions.

regards~Bill

Bill,

Why is it more difficult to correctly expose a black bird than any other?

Chas

[Roger Clark]

Thanks guys for the awesome input, it's all greatly appreciated.

Two nights ago I went back to the reef to try and photograph in manual mode. The situation was almost identical with the exception of the subject being totally black, (Sooty Oystercatchers). I shot in manual mode most of the time but found as the birds moved around that by the time I took an image, check it in the viewfinder and repointed the camera at the bird, that the bird had moved a half a metre or a metre to the side.
So I had to adjust my settings accordingly and repeat to see if my exposure was correct.
I found most of my time was spent adjusting my settings, checking and then re-adjusting my settings because the birds were constantly moving around. I didn't get the photo I was after unfortunately :o

Mark,
If conditions were like before, the light on the bird should have been constant, so one exposure, no matter where the bird moved should have worked. No need to adjust exposure.

I would have metered on any white surf I did not want saturated, and set the exposure to max the signal without saturating in manual, then imaged away without checking the exposure for a while. If you wanted the white surf saturated, it would have been no different--set exposure and leave it there for a while.

So I'm confused why you felt the need to check exposure after every shot.

Roger

[WIlliam Maroldo]

Hi Charles, I came up with a number of reasons black birds are more difficult to photograph (actually 4 paragraphs with sample images). I've been wrong before. If you think it is not the case, I really would like to know why not.
I included an image of a "black bird" (a grackle) I took yesterday.
Sony A850~Sony70-400G @400mm~ISO 3200~1/640sec~F5.6~manual exposure~HH~12-7-2010~overcast~CS5/ no NR /Sorry, I clipped the tail.
If it was as easy to take images of black birds as any other, how do explain the need to use ISO 3200?


regards~Bill

[Charles Glatzer]

Bill,

If your initial exposure is based upon the quantity of light falling on the subject/scene all tones will be rendered accordingly. You need only place one tonal value accurately on a histogram and all others will fall into place. Thereafter, it is a matter of salt and peppering to taste to render the subject as desired, shifting to the right to show more detail in a dark subject, shifting left to render more detail in a white subject. Of course shifting the exposure effects all tonal values in the image, most times at the sacrifice of highlight or shadow detail on either end. Typically, with new cameras having a wider dynamic range the shift need not be as great as with film.

The high ISO you used is a function of the quantity of light illuminating the subject and having to open up approx 2/3-1EV from a correct mid-tone exposure to show more detail in the dark subject.

How you determine the base mid-tone exposure for the light illuminating the scene/subject is key.

I prefer the Spot Pattern as there is never a deviation in the method, no second guessing what built in-camera algorithms are doing, subject size to background is irrelevant, etc. The Spot pattern does one thing, it renders whatever is in the pattern as a mid-tone value, and it does it accurately and consistently. I know exactly how the pattern works and what it does every time I depress the shutter.

In my 28 years at this I would venture to say 80 plus percent of photog's I (initially, wink, wink) come across do not fully comprehend how Metering Patterns, Incident and Reference Values really work. Most photog's that simply make an image lighter or darker than initially taken are missing a world of opportunity.

Warmest Regards,

Chas

[Mark Young]

Mark,
If conditions were like before, the light on the bird should have been constant, so one exposure, no matter where the bird moved should have worked. No need to adjust exposure.

I would have metered on any white surf I did not want saturated, and set the exposure to max the signal without saturating in manual, then imaged away without checking the exposure for a while. If you wanted the white surf saturated, it would have been no different--set exposure and leave it there for a while.

So I'm confused why you felt the need to check exposure after every shot.

Roger

I had a look at my images when I got home last night, and I couldn't find any that I was talking about that I had taken in manual.
So I think I've made a huge error here. I sometimes find that I accidentily move the dial from Av mode to other modes, so I think that I must've done that when having a look in the viewfinder. Sorry about the confusion.

[Daniel Cadieux]

He he, been there done that:p...now it is second nature that I check that dial as I find it gets accidentally switched easily on my 40D too.