The only three things you need to know about DSRL

The Only Three things you Need to know about DSLR

A practical guide to exposure

Guilherme Zühlke O’Connortwitter.com/guioconnor

facebook.com/guioconnorPhoto

Once upon a time…

Once upon a time…… there was SLR

SLR – Single Lens Reflex

SLR – Single Lens Reflex

• A camera with a single lens

SLR – Single Lens Reflex

• A camera with a single lens

• Use of reflection to send the image to the viewfinder

SLR – Single Lens Reflex

• A camera with a single lens

• Use of reflection to send the image to the viewfinder

Back in the old times…

Back in the old times…

• The body of the camera was responsible for the exposure time

Back in the old times…

• The body of the camera was responsible for the exposure time

• The lens was responsible for the aperture

Back in the old times…

• The body of the camera was responsible for the exposure time

• The lens was responsible for the aperture• The film was responsible to hold the projected

image for eternity (or a sub-period of it)

The camera body

Tipically, a camera body would be set to expose the film for a period of time ranging from 30

seconds to 1/2000 of a second (but your mileage may vary)

http://www.flickr.com/photos/buou/4884738437/

The Lens

• Has a diafragm that controls the area of the aperture through which the light enters the camera

• The amount of light is proportional to the area of the aperture

(*) See previous presentation on aperture athttp://www.slideshare.net/guioconnor/aperture-in-photography-or-how-boheh-happens

http://www.flickr.com/photos/cycleologist/1454436980/

The Film

• The film has an emulsion containing silver salts that react to the presence of light

• The more light it receives, the more grains of salt will react

• The coarser the grains of salt the less light you need but the lower the definition of the resulting image(*)

http://www.flickr.com/photos/remediatethis/4353934129/

(*) That’s the ISO setting for ya

The correct exposure needs a certain amount of light.

The correct exposure needs a certain amount of light.

If you want a faster shot, you need a wider aperture. And vice versa.

Alright, alright. What about DSRLs, then?

Alright, alright. What about DSRLs, then?

Same thing but with a sensor in place of the film.

Manual Mode

• Most DSLRs have a manual mode setting

Manual Mode

• Most DSLRs have a manual mode setting• You set the exposure time

Manual Mode

• Most DSLRs have a manual mode setting• You set the exposure time• You set the aperture

Manual Mode

• Most DSLRs have a manual mode setting• You set the exposure time• You set the aperture• Settings are based on the photometer

indication

Aperture priority mode

• Most DSLRs have an Aperture Priority Mode

Aperture priority mode

• Most DSLRs have an Aperture Priority Mode• You set the aperture you want to take the

picture on

Aperture priority mode

• Most DSLRs have an Aperture Priority Mode• You set the aperture you want to take the

picture on• The camera works out how fast (or slow) it

needs to be

Aperture priority mode

• Most DSLRs have an Aperture Priority Mode• You set the aperture you want to take the

picture on• The camera works out how fast (or slow) it

needs to be• Ideal to control the depth of field

f/32

f/4.8

Shutter Priority Mode

• Most DSLRs have a Shutter Priority Mode

Shutter Priority Mode

• Most DSLRs have a Shutter Priority Mode• You set the exposure time of the shot

Shutter Priority Mode

• Most DSLRs have a Shutter Priority Mode• You set the exposure time of the shot• The camera works out the aperture

Shutter Priority Mode

• Most DSLRs have a Shutter Priority Mode• You set the exposure time of the shot• The camera works out the aperture• Ideal to control motion blur

1/90 s

1/500 s

But also for extreme light conditions

Exposure time 104s, barely visible with the naked eye. Shot with ISO 50.See more at http://www.facebook.com/media/set/?set=a.224883254190744.71882.119779558034448

The ISO setting

• Just as in film

The ISO setting

• Just as in film• The higher the ISO the less light you need

The ISO setting

• Just as in film• The higher the ISO the less light you need• The higher the ISO the more noise you have

The ISO setting

• Just as in film• The higher the ISO the less light you need• The higher the ISO the more noise you have• Different sensors have different qualities for a

given ISO value

The ISO setting

• Just as in film• The higher the ISO the less light you need• The higher the ISO the more noise you have• Different sensors have different qualities for a

given ISO value• ISO is based on the amount of light needed,

not the amount of grain/noise produced

ISO 200

ISO 1600

All fancy exposure settings on your DSLR are based on these three

basic principles.

?Questions

Further reading• http://www.z-oc.com/blog/2007/08/understanding-cameras-and-photography/• http://www.slideshare.net/guioconnor/aperture-in-photography-or-how-boheh-happens