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Thread: EDUCATIONAL TOPIC #7- EXPOSURE COMPENSATION (comments/questions only)

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    Default EDUCATIONAL TOPIC #7- EXPOSURE COMPENSATION (comments/questions only)

    Comments and questions can be posted here. Please see the other "illustrated" thread for examples of exposure compensation at work Feel free to ask any question you like, its a tough concept to get your head around to begin with so don't feel silly

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    Okay, I'll kick off with a question

    I use partial metering, as I find I am usually good at putting the bird in the centre of the frame. So, taking the WWBT shot as an example (assuming no/minimal cropping to produce the image posted), would I need to actually use negative compensation. Cos wouldn't the camera try to over expose the black, and hence I would need to darken it?

    I think I'm going to swap to EV metering... All that I learnt about compensation was based on that setting, and it seems to me that spot/partial metering is much the opposite, when the bird is a different tone to the overall image?

    Cracking shots, by the way Paul, and thanks so much for the write up and illustrated examples
    Familiarity breeds contempt; don't neglect the common birds
    --\\
    ---\\_(j*)>.........Aus Life List: 534 (Northern Royal Albatross - 6/9/14)
    ----\___)................NSW List: 428 (Northern Royal Albatross - 6/9/14)
    ------\ \..............o..2014 List: 348 (Southern Giant Petrel - 6/9/14)

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    Partial metering covers about 8% of the frame right in the centre of the image so depending on what you metered you may get varying results. I'd be inclined to meter from the birds white shoulder if using spot or partial metering but you may still have issues.
    I added compensation to the image until the white shoulder patch was as bright as possible without being blown (actually, a very tiny bit was blown but thats not too bad and can be remedied in PP). As a lot of photographers advocate...get the whites right and the blacks will take care of themselves
    Hope that answers that, definitely a good move to start using EV or CW metering for your shots. If you are ever unsure, try setting AEB or auto exposure bracketing (for use with aperture priority mode). This will mean your camera will take 3 shots at a time. One below the metered exposure (faster shutter speed), one at the metered exposure and one over the metered exposure (slower shutter speed). I would suggest setting it so it brackets at 1/3 of a stop either way.
    This would mean that if you shot something at a metered speed of 1/800th of a second then the camera would also take one shot at 1/640th and one at 1/1000th of a second and then you could pick the best one.

  4. The following 2 users say thank you to Paul Randall for their reply:

    Ashy Drongo (02-10-2011), Keith Talbot (27-11-2014)

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    This would mean that if you shot something at a metered speed of 1/800th of a second then the camera would also take one shot at 1/640th and one at 1/1000th of a second and then you could pick the best one.
    I reckon this is a great idea and I have been using it for quite a while with my orchid shots.
    The voices in my head may not be real, but they come up with some great ideas..

    Cheers Rev.

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    Yes, bracketing can help a lot and when you have three images in front of you on the computer with differing exposures you soon learn which way (if at all) you need to compensate with a particular situation

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    Thanks Paul
    Bracketing is something I have meant to try out, and just never really taken the time to actually do it All three images will produce different histograms, won't they, so reviewing in the field is possible to, isn't it? Definitely something to check out next time I have time (in a month...)
    I will definitely switch to EV, and in time, will probably get onto CW. Using CW would take a fair bit of experience to start getting the compensation right, I would imagine, as understanding how much the camera weights the centre of the frame over the rest is not a definite amount that is easy to measure...

    Thanks again!
    Familiarity breeds contempt; don't neglect the common birds
    --\\
    ---\\_(j*)>.........Aus Life List: 534 (Northern Royal Albatross - 6/9/14)
    ----\___)................NSW List: 428 (Northern Royal Albatross - 6/9/14)
    ------\ \..............o..2014 List: 348 (Southern Giant Petrel - 6/9/14)

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    CW metering is super easy Ashy, it just gives a bit more emphasis to the middle of frame but is not that hard to get used to. I find I rarely have to compensate over/under by 1 stop in CW, with EV (because it gives more emphasis to the entire scene) I found I was often compensating by more than that so I switched to CW to keep it a bit simpler (and quicker). Does that make sense?

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    BTW, with bracketing, all three images would be there for you to review in the field and this will give you a good guide if you are unsure.

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    Quote Originally Posted by Paul Randall View Post
    CW metering is super easy Ashy, it just gives a bit more emphasis to the middle of frame but is not that hard to get used to. I find I rarely have to compensate over/under by 1 stop in CW, with EV (because it gives more emphasis to the entire scene) I found I was often compensating by more than that so I switched to CW to keep it a bit simpler (and quicker). Does that make sense?
    Sure does make sense I just wish I had time to get out and try this out in the field - the best way to get the hang of something
    Familiarity breeds contempt; don't neglect the common birds
    --\\
    ---\\_(j*)>.........Aus Life List: 534 (Northern Royal Albatross - 6/9/14)
    ----\___)................NSW List: 428 (Northern Royal Albatross - 6/9/14)
    ------\ \..............o..2014 List: 348 (Southern Giant Petrel - 6/9/14)

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    Just a question on compensating for white birds on partly cloudy days; by compensating upwards, wouldn't a white cloud in the shot get blown out, or is this not a concern as the focus is on the subject?

    BTW, discussion like this makes you marvel at the capabilities of the human eye and the way it can process a variety of complex conditions in an instant.

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    It has never been a concern for me Nigel, like you said, my focus would be on getting the subject right. Have a look at this link, the water is totally blown but the subject is pretty well exposed. Makes for an interesting effect in a lot of cases.
    http://www.feathersandphotos.com.au/...-Petrel)/page2

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    Nigel it all depends on what light the bird and subject are in and what you meter off. It's all easiest if the bird and subject are in the same light. If you are metering off something that to the CW or EV metering system is on average neutral, the blacks and whites fall into place and no compensation is needed.

    Really the best way to work it out is go and try it out. The histogram and blinking highlights are your friend in this case, if you are stalking a bird and slowly moving in you can take some more distant shots and judge everything off the histogram, that exposure will generally be fine from then on if whites/blacks were OK initially, what you do have to watch for then is the camera's metered exposure drifting if the light has not really changed.

    I've posted a shot of an inter egret in the images section(pretty horrible mid arvo light) to show what EV can do. It's with a 1D MkIIn with zero comp, as presented whites are not blown detail is lacking due to the angle of the light, not a great photo but shows two things, EV did a pretty good job (about as good as could be expected) and that whites in harsh light can be troublesome. Ideally I should have dialled in -1/3 stop, but the Raw file was totally recoverable. Though from what I understand the smaller 1.6x sensors are not as forgiving as the smaller pixels hold less light and have less dynamic range.

    Now if the egret started filling the frame, the whites would take up more and more of the scene and you would have to start adding light as the meter would start backing off because on average the scene would have shifted from near neutral towards white. You would pick that up because you would have been shooting at 1/1000 - 1/1250 and all of a sudden the shutter speed starts climbing up. but if you metered off something neutral (the overall scene is about 1/3 stop under neutral) and locked that in by switching to manual, you would be fine.
    Chris Ross
    Helensburgh NSW
    www.aus-natural.com
    Instagram: @ausnaturalimages

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    Paul, that's a pretty different effect having an all white background...almost surreal having the bird as the main subject. I guess my question was more directed to having say one or two sunlit cumulus clouds in the shot trying to steal the exposure limelight. I'll see if the clouds break tomorrow and experiment a bit to see what works best.

    Awesome, thanks Chris Now I just have to find the time away from work to try these things out!

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    On most occasions you should be OK. Even with dark birds (which need a lot of light added when being shot in flight in front of bright clouds) I have not had many cloud backgrounds that are totally blown. Like I said, even if it does blow out (but your subject is nicely exposed) you may end up with an interesting and unique effect

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    Sorry Chris, I think your example is a good one but the terms used (neutral exposure, daylight neutral) are a bit confusing for members trying to get their heads around this technique. All thats needed is to state what metering mode you've used, how much compensation you've added/subtracted and the reason why.

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