Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies. Read More.
OK
Index  •   • New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Register to forums    Log in

 
FORUMS Photography Talk by Genre General Photography Talk
Thread started 23 Apr 2006 (Sunday) 23:38
Prev/next
sponsored links
(this ad will go away when you log in as registered member)

What is HDR?

 
cali
Senior Member
cali's Avatar
266 posts
Joined Jan 2006
Apr 23, 2006 23:38 |  #1

I see it mentioned around here but I haven't the faintest idea what it is?


20D, 17-85 kit lens, 70-200 F4, 50 1.4, Amvona AT CF 994 Tripod, Manrotto Monopod that I have never used and a 580EX Flash

LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as registered member)
Tsmith
Formerly known as Bluedog_XT
Tsmith's Avatar
10,427 posts
Joined Jul 2005
South_the 601
Apr 23, 2006 23:44 |  #2

In simple layman terms: High Dynamic Range. The ability to take a series of different exposures of the same scene and combining them in post processing so basically all the image is properly exposed.



Canon EOS 7D | Canon EF-S 10-22mm | Canon 17-40mm f/4L | Canon 24-105mm f/4L IS
Canon PowerShot S95
MY PBASE GALLERYexternal link

LOG IN TO REPLY
Duder
Goldmember
Duder's Avatar
1,201 posts
Joined Feb 2005
L.A. formerly N Ireland
Apr 24, 2006 01:46 as a reply to Tsmith's post |  #3

yeah, basically most camera's are not capable of recording the entire dynaimc range of light in that exists in the real world, capturing only about 5-7stops in good quality detail. HDR's are created my taking multiple LDR shots exposed for the highlights, mid-tones and shadows seperately and then merged into a single 32-bit image which has a dynamic range up to 14-15 stops.

Nearly all 32-bit images are impossible to view on a monitor or print out so you need to compress the tonal range down to 8 or 16bit by tone mapping.

HDR - High Dynamic Range, 32bit image produced by merging multiple images, then tone-mapping down to 8/16bit.

IDR - Increased Dynamic Range, produced by blending 2 or more images to extend DR

LDR - Low Dynamic Range, single shot images from any camera.


Pete
http://www.pbase.com/p​etejacksonexternal link

LOG IN TO REPLY
Jesper
Goldmember
Jesper's Avatar
2,742 posts
Joined Oct 2003
The Netherlands
Apr 24, 2006 03:56 |  #4

Have a look here: http://www.hdrsoft.com​/external link


Canon EOS 5D Mark III

LOG IN TO REPLY
SiberianSiren5
Hatchling
SiberianSiren5's Avatar
6 posts
Joined Nov 2009
Pilot Hill, California
Dec 28, 2009 12:18 |  #5

Is one RAW image enough to produce the 3 different exposures or should you actually shoot 3 separate exposures? Is that even possible with action photography?




LOG IN TO REPLY
i_am_hydrogen
Goldmember
i_am_hydrogen's Avatar
Joined Nov 2007
Chicago, IL
Dec 28, 2009 16:51 |  #6

^You can take a single exposure and make it into 3 exposures using Adobe Camera Raw.

2) Open the RAW file in PS and adjust the exposure to -1 or -2, depending on how much dynamic range you need to capture. Save as a tiff file.
3) Open the RAW file in PS again, adjust the exposure to +1 or +2, and save as a tiff.
4) Open the RAW file in PS a third time, adjust the exposure to 0, and save as a tiff.
5) Open all three tiffs in Photomatix.
6) Tonemap the files in Photomatix to suit your tastes.

That strategy is best if you don't have a tripod (or steady enough hands for hand-held HDR) and/or are photographing moving subjects. It's best to take three separate exposures, if possible.


flickrexternal link | Kevin

Canon 6D | Canon 5D II | Canon TS-E 17
L | Canon TS-E 24L | Canon TS-E 45 | Canon 135L | Canon 24-105 ISL

LOG IN TO REPLY
tzalman
Fatal attraction.
tzalman's Avatar
13,360 posts
Joined Apr 2005
Gesher Haziv, Israel
Dec 28, 2009 17:07 |  #7

Is one RAW image enough to produce the 3 different exposures or should you actually shoot 3 separate exposures?

HDR is by definition the extension of the dynamic range portrayed in the final image beyond what the camera can capture in one shot. The camera has a 11 stop range but your final image has detail from elements in the original scene that were 18 stops apart. One RAW from that camera will have 11 stops worth of data, no matter what you do to it. You are not God nor is your computer, you can't create new data from nothing. However, blending multiple conversions from a single RAW into what is called a "fake HDR" can be an excellent way to get the maximum milage out of the data you do have. Another way is to convert to a single 16 bit tif, to retain almost all the data, and work on it with something like PS's Highlight/Shadow tool. But the three conversion method does have a certain advantage in that you are pushing and pulling linear RAW data before it gets bent out of shape by the gamma correction of the conversion.


Elie / אלי

LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as registered member)

41,692 views & 0 likes for this thread
What is HDR?
FORUMS Photography Talk by Genre General Photography Talk


Not a member yet? Click here to register to the forums.
Registered members get all the features: search, following threads, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, settings, view hosted photos, own reviews and more...


AAA

Send feedback to staff    •   Jump to forum...    •   Rules    •   Index    •   New posts    •   RTAT    •   'Best of'    •   Gallery    •   Gear    •   Reviews    •   Polls

COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies. Privacy policy and cookie usage info.

POWERED BY AMASS 1.4version 1.4
made in Finland
by Pekka Saarinen
for photography-on-the.net
Spent 0.00143 for 4 database queries.
PAGE COMPLETED IN 0.02s
Latest registered member is Iljam
874 guests, 429 members online
Simultaneous users record so far is 6106, that happened on Jun 09, 2016