HDR?
I have been
banging on for a while now so I thought I should add something here..
I know some
HDR pics are a bit overdone and can be a bit harsh on the eyes. This
is a easy mistake to make as when you first start playing the the
software you tend to push it to its limits just to see what it can do
(and forget to reset it afterwards) . I must confess that I have done
this myself in the past.
The main
reason for using it is to reduce the excessive Highlights and Shadows
that can be found in some pictures. To give a colour boost to a
“Flat” picture I find that can be done with one frame.
Some people
also say that it reduces noise in dark areas of a picture..
An example
of this may be a church interior. Normally the camera will attempt to
meter for the average light and in a church this may give very dark
interiors with correct light from windows or correct light of the
interior with 'Blown Out'* windows.
HDR uses a
series of 3/5/7 frames which are the Reference frame with other
frames darker or lighter. Personally I use three frames :- Normal, +
2stops under exposed & 2 stops over exposed
Go to
Aperture priority mode (You need a fixed focal length. The shutter
speed will vary.)
1 Take a
normal picture
2 Set the
exposure adjustment to -2 stops and take a pic
3 Set the
exposure adjustment to +2 stops and take a pic
If you check the pics on your LCD you should have something like the
following :-
Normal
Underexposed by -2 stops
Over
exposed by two stops.
Perhaps the
easiest way of processing the HDR pics is lightroom.. All you have to
do is highlight the three pictures and press CTL H (CMD H on a mac
I believe) or “Photo”, “Photomerge”, “HDR”
This will go
to the HDR preview screen. On the side of the screen are a couple of
tick boxes.
Make sure
the auto align box is ticked as this will attempt to correct for
movements of the camera.
The other
option is for ghosting – this is for anything that might move in
the picture (between the 3 frames). I would recommend setting to
either “None” or “low” - This should reduce the processing time
required. If there is a large amount of pink areas on the preview set
the ghosting higher.
Once you
have done this press “Merge” and it will take a short time to
process the picture depending on your pc. Once complete it will
return to the normal Lightroom screen..
The
processed frame might not be visible right away as the you are
looking at imported files. You will have to go to your normal
“Library” view of the folder
Initial Result of HDR process
At first
glance the picture does not look greatly different from your
reference image but you now have a greater dynamic range of colours
and controls available to you..
By reducing
the Highlights & White sliders you should be able to fix that
“Blown Out” window and the Shadow & Dark sliders should
improve the darker areas of the picture.
The vibrance
and saturation sliders will allow you to control the colour (along
with the other colour controls)
Also
remember these controls can be applied locally by the filters and
correction brush as well!
After processing
Photoshop
I believe
there are two ways of processing HDR files in Photoshop. As I am not
a PS expert I will give the most straightforward.
Open P.S.
“Files”
“Automate”
“Merge to
HDR PRO”
You will be
prompted to open your pictures and then a 'Processing Dialogue' will
open on the screen.
Photomatix
is a HDR processing program that can act as a stand-alone or a
Lightroom plug-in
You can
download a trial version to play with but this will put a watermark
on any pictures it creates. These can be removed by purchasing a
license.
HDRefex
Pro is part of Google's free (NIK collection) designed to act
as a plug-in to LR or PS.
With a
little playing around it is possible to run this as a stand-alone
program (run the exec file from within the program files folder).
Ken
*Blown out -An area where the image appears bright white and the camera hasn't stored detail that may have been available to the naked eye.
