Teacher: Kenji Tachibana Digital Photography I. Histogram (& EC) Exposure Graph & Bias 12 slides...

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Teacher: Kenji Tachibana Digital Digital Photography I Photography I . Histogram (& EC) Histogram (& EC) Exposure Graph & Bias Exposure Graph & Bias 12 slides 12 slides Copyright 2003 - 2009 Kenji Tachibana Copyright 2003 - 2009 Kenji Tachibana

Transcript of Teacher: Kenji Tachibana Digital Photography I. Histogram (& EC) Exposure Graph & Bias 12 slides...

Teacher: Kenji TachibanaDigital Photography IDigital Photography I.

Histogram (& EC)Histogram (& EC)Exposure Graph & BiasExposure Graph & Bias

12 slides12 slides

Copyright 2003 - 2009 Kenji TachibanaCopyright 2003 - 2009 Kenji Tachibana

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

HHistogram: Overview istogram: Overview

There are two (2) types. The better one is the There are two (2) types. The better one is the (1) (1) ActiveActive Histogram which shows the potential Histogram which shows the potential exposure as a graph. The more limited is the (2) exposure as a graph. The more limited is the (2) PassivePassive Histogram which only shows the Histogram which only shows the exposure graph after capturing the image.exposure graph after capturing the image.

In either case, Histogram can be a very useful In either case, Histogram can be a very useful tool if the graph makes sense to the user.tool if the graph makes sense to the user.

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

HHistogram: Avoid with passionistogram: Avoid with passion

Something to avoid is a ‘serious’ over-exposure Something to avoid is a ‘serious’ over-exposure because when that happens, some of the lighter because when that happens, some of the lighter parts of the image will become pure white areas parts of the image will become pure white areas without any image detail. And those areas are without any image detail. And those areas are referred to as ‘blown out’.referred to as ‘blown out’.

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

CCombat Blow Out: Turn on Zebra Stripingombat Blow Out: Turn on Zebra Striping

Most DSLR and many high end compacts have a Most DSLR and many high end compacts have a built-in feature called zebra striping which makes built-in feature called zebra striping which makes blown out areas of an image ‘flash’ when viewed blown out areas of an image ‘flash’ when viewed in conjunction with the Histogram. in conjunction with the Histogram.

That makes zebra striping a very useful feature or That makes zebra striping a very useful feature or it could be very annoying to users who do not it could be very annoying to users who do not understand its meaning…understand its meaning…

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

AAvoid: Serious over exposurevoid: Serious over exposure

When an image is seriously over-exposed, the When an image is seriously over-exposed, the lightest areas of the image gets washed-out to lightest areas of the image gets washed-out to more serious blown-out looking. more serious blown-out looking.

Some washed-out areas can be brought back Some washed-out areas can be brought back during the Photoshop basic processing phase. during the Photoshop basic processing phase. But blown-out areas can not be recovered But blown-out areas can not be recovered because there is no pixel information to reclaim.because there is no pixel information to reclaim.

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

HHistogram: Got one?istogram: Got one?

Do it now. Cycle through the Display choices until Do it now. Cycle through the Display choices until you see something that looks like this . It is you see something that looks like this . It is often found in the lower right quadrant of the LCD often found in the lower right quadrant of the LCD or viewfinder.or viewfinder.

It’s only drawback is its tiny size. Larger ones can It’s only drawback is its tiny size. Larger ones can be found on the DSLR cameras but, even then, be found on the DSLR cameras but, even then, they are still small.they are still small.

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

EExposure assessmentxposure assessment

UnderUnder Normal Normal ExposureExposure OverOver

Way Too DarkWay Too Dark Believable Believable Way Too LightWay Too Light

This assessment will only work properly whenThis assessment will only work properly whenyou follow assignment requirement such as:you follow assignment requirement such as:

1.1.Use broad-source (soft) Skylight.Use broad-source (soft) Skylight.2.2.Don’t have a light source in the background.Don’t have a light source in the background.3.3.Don’t shoot black, white, or shiny objects.Don’t shoot black, white, or shiny objects.

This indicates blown out This indicates blown out highlights. Lost detail highlights. Lost detail can’t be retrieved. Avoid can’t be retrieved. Avoid this at all cost! this at all cost!

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

EExposure Adjustment: ECxposure Adjustment: EC

The digital camera exposure can be adjusted to The digital camera exposure can be adjusted to lighter or darker using exposure compensation (EC) lighter or darker using exposure compensation (EC) feature of your camera. The EC has an adjustment feature of your camera. The EC has an adjustment range from range from --2 to 2 to ++2 f/stops as shown below:2 f/stops as shown below:

|| | | || || || || || || || || || | | || --2.02.0 - -1.71.7 - -1.31.3 --1.01.0 - -0.7 0.7 - -0.30.3 0000 + +0.3 0.3 + +0.70.7 ++1.01.0 + +1.31.3 +1.7 +1.7 ++2.02.0

Your camera may have a scale that looks like this…Your camera may have a scale that looks like this… || | | | | || || || || || || || || | | | | -2.0-2.0 -1.0-1.0 0 0 ++1.01.0 ++2.02.0

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

AAdjustment: Bias changesdjustment: Bias changes

Exposure can be lightened or darkened in 1/3 Exposure can be lightened or darkened in 1/3 f/stop increments. Usually the adjustment change f/stop increments. Usually the adjustment change can be seen in the camera display. Corrective can be seen in the camera display. Corrective actions shown below:actions shown below:

If UnderIf Under Normal ExposureNormal Exposure If OverIf Over

Add Add “+”“+” No changeNo changeSubtract Subtract “-”“-”

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

TTry It Now:ry It Now:

The EC button is usually in the back ofThe EC button is usually in the back ofthe camera on the Cursor multi-button.the camera on the Cursor multi-button.Press on it once to get the scale withPress on it once to get the scale withthe center bar highlighted as a defaultthe center bar highlighted as a defaultBias ‘0’ setting. Bias ‘0’ setting. || | | | | | | || | | || || || || || | | | | -2.0-2.0 -1.0-1.0 0 0 ++1.01.0 ++2.02.0

The highlight bar is moved using theThe highlight bar is moved using thecursor left or right buttons. Try it now…cursor left or right buttons. Try it now…Press the SET button to accept the new bias. Press the SET button to accept the new bias.

If you press the EC the second time. It will adjust If you press the EC the second time. It will adjust the EC for the Flash. Try it now…the EC for the Flash. Try it now…

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

LCD LCD Display:Display:

Histogram can be turned on or off as one of the Histogram can be turned on or off as one of the Display options. When the EC is activated, Display options. When the EC is activated, sometimes the Histogram is also turned on.sometimes the Histogram is also turned on.

|| | | | | | | || || || || || || || | | | | -2.0-2.0 -1.0-1.0 0 0 ++1.01.0 ++2.02.0

EC: - 0.7 EC: - 0.7

There may also be a highlighted area with the There may also be a highlighted area with the exact bias written out as shown above. The exact bias written out as shown above. The example above shows that the next exposure will example above shows that the next exposure will be ‘darkened’ by 2/3 f/stop. be ‘darkened’ by 2/3 f/stop.

Teacher: Kenji TachibanaDigital Photography IDigital Photography IHistogram & EC: Exposure graph & biasHistogram & EC: Exposure graph & bias

SSummary:ummary:

Knowing how your camera sees the photographic Knowing how your camera sees the photographic seen is very important to getting the exposure right. seen is very important to getting the exposure right. Being able to custom adjust the image brightness Being able to custom adjust the image brightness using EC and being able to interpret the Histogram using EC and being able to interpret the Histogram are both necessary part of your job as the image are both necessary part of your job as the image maker.maker.

Another Another light source reminder light source reminder – – use Skylightuse Skylight which is which is mostly blue (cyan). And the cyan is mostly mostly blue (cyan). And the cyan is mostly neutralized by the WB on Auto.neutralized by the WB on Auto.

Teacher: Kenji TachibanaDigital Photography IDigital Photography I

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