Ad
Ad
Ad
Pages: « 1 [2] 3 »   Bottom of Page
Print
Author Topic: HDR  (Read 6324 times)
ErikKaffehr
Sr. Member
****
Offline Offline

Posts: 7333


WWW
« Reply #20 on: December 04, 2012, 10:57:30 PM »
ReplyReply

Hi,

Just an idea. If you use LR 4.x you could try to open several images using "Merge to HDR Pro in Photoshop" but not doing tone mapping in photoshop but just saving the 32bit/channel image. As far as I recall you can open the image in LR and doing your tone mapping with LR-s controls which may be much better than the tools in photoshop.

Best regards
Erik

Trying to get a handle on HDR as I have little to no experience on this topic.

Given that an images max DR is restricted by pure black at one end and white at the opposite, am I correct that putting a "scene" (by way of multiple image exposed differently) through the HDR process only results in finer levels of tone? In other words, it doesn't make the ruler any longer, it just divides the ruler into finer increments? Presumably, this is impacted by the DR of the medium (i.e. monitor, print etc) as well.

Or, if a camera sensor is capable of say, twelve stops, can HDR actually result in an image that is, say, thirteen stops (so the ruler actually lengthens)? And if this is the case, what is the limit?

Have tried reading up on this subject, but so far it's a bit unclear.

Marv
Logged

dmerger
Sr. Member
****
Offline Offline

Posts: 686


« Reply #21 on: December 04, 2012, 11:07:40 PM »
ReplyReply

Uh … welcome to the forum, popnfresh.  Roll Eyes
Logged

Dean Erger
popnfresh
Guest
« Reply #22 on: December 04, 2012, 11:12:34 PM »
ReplyReply

Uh … welcome to the forum, popnfresh.  Roll Eyes

Thank you. Pleased to be here, mostly.

You may call me Doug.
Logged
Schewe
Sr. Member
****
Offline Offline

Posts: 5469


WWW
« Reply #23 on: December 05, 2012, 12:11:43 AM »
ReplyReply

You may call me Doug.

Ah, goodie, a name at last...(wasn't so hard, was it?)
Logged
popnfresh
Guest
« Reply #24 on: December 05, 2012, 12:13:54 AM »
ReplyReply

Ah, goodie, a name at last...(wasn't so hard, was it?)

What goes around, comes around.
Logged
michael
Administrator
Sr. Member
*****
Offline Offline

Posts: 4808



« Reply #25 on: December 05, 2012, 08:02:43 AM »
ReplyReply

Jeff, is right, we prefer real names here, not pseudonyms.

As to who Jeff is, yes, he is the police.  Smiley

Actually he's one of the world's recognized authorities on digital imaging, a consultant to Adobe, author of numerous books on the topic, and co-presenter of many of our LuLa training videos.

He's also a friend, a very large and agressive appearing guy (also a pussycat), drives a motocycle, and you'd rather have him on your side than against you.

Michael
Logged
RFPhotography
Guest
« Reply #26 on: December 05, 2012, 09:03:29 AM »
ReplyReply

Hi,

Just an idea. If you use LR 4.x you could try to open several images using "Merge to HDR Pro in Photoshop" but not doing tone mapping in photoshop but just saving the 32bit/channel image. As far as I recall you can open the image in LR and doing your tone mapping with LR-s controls which may be much better than the tools in photoshop.

Best regards
Erik


Not necessarily better, just different.  What is better for one may not be for another.  It's easier to get a more 'natural' result doing tonemapping with LR, although that can certainly be done in PS as well.

I think it was LR 4.1 that allowed editing of some 32 bit images.  Some means only 32 bit TIFF files.  LR still - with many people tapping their feet like Sonic the hedgehog waiting - can't catalogue or work with .exr or .hdr files.  The downside to TIFF is that the files are significantly larger than the other 32 bit file types.
Logged
popnfresh
Guest
« Reply #27 on: December 05, 2012, 10:20:40 AM »
ReplyReply

Jeff, is right, we prefer real names here, not pseudonyms.


If you allow people to register for this site using only pseudonyms, you should not hold it against them for going by them. Perhaps it's time to update your registration requirements.
« Last Edit: December 05, 2012, 10:23:15 AM by popnfresh » Logged
john beardsworth
Sr. Member
****
Online Online

Posts: 2759



WWW
« Reply #28 on: December 05, 2012, 11:34:04 AM »
ReplyReply

If you allow people to register for this site using only pseudonyms, you should not hold it against them for going by them. Perhaps it's time to update your registration requirements.
So true.
Logged

alanb
Newbie
*
Offline Offline

Posts: 17


« Reply #29 on: December 05, 2012, 12:05:27 PM »
ReplyReply

Let's remember that Schewe does have a hell of a sense of humor although he does seem a bit tough at times (he's really not).  It remains that it is probably better if he likes you since he probably has more knowledge of LR than anyone else here much of which he contrbutes free.  Unfortunately we must sometimes pay for it but his books are well worth the cost as they border on necessary.  Why not have fun  here?

Alan
Logged
dmerger
Sr. Member
****
Offline Offline

Posts: 686


« Reply #30 on: December 05, 2012, 12:50:17 PM »
ReplyReply

Doug, a lot of people use pseudonyms on this forum.  So, I wondered why Schewe singled you out to call stupid just for using a pseudonym.  Then I read Michael’s defense of Schewe’s rude behavior, and noted Michael’s strange reference to Schewe’s appearance.  I always thought that Schewe looked more like the Pillsbury Doughboy.   Then it hit me.  Doug, it’s your pseudonym  --  popnfresh --  that’s the Pillsbury Doughboy’s name!  Your unwitting use of popnfresh as your pseudonym evidently hit a raw nerve with Schewe.  Wink
Logged

Dean Erger
popnfresh
Guest
« Reply #31 on: December 05, 2012, 01:11:14 PM »
ReplyReply

Doug, a lot of people use pseudonyms on this forum.  So, I wondered why Schewe singled you out to call stupid just for using a pseudonym.  Then I read Michael’s defense of Schewe’s rude behavior, and noted Michael’s strange reference to Schewe’s appearance.  I always thought that Schewe looked more like the Pillsbury Doughboy.   Then it hit me.  Doug, it’s your pseudonym  --  popnfresh --  that’s the Pillsbury Doughboy’s name!  Your unwitting use of popnfresh as your pseudonym evidently hit a raw nerve with Schewe.  Wink

I like LuLa and I think Michael is one of the good guys. But I think if he expects people to use their real name rather than a pseudonym, he needs to make that clear when people sign up. Personally, if this were my site, I would probably insist that people register with their real names, even if only their pseudonym appears on their forum posts, just to have their real name on file. There's something to be said for insisting on real names to ensure that people are accountable for their conduct online. However, as someone who deals with internet security issues daily, I'm not going to dole out personal information to strangers if I don't have to, especially if everyone else on this site isn't required to.
Logged
hjulenissen
Sr. Member
****
Offline Offline

Posts: 1677


« Reply #32 on: December 05, 2012, 01:44:14 PM »
ReplyReply

Sometimes...yes. If you don't know who I am, I guess you don't really know much about LuLa, huh? You sure you wanna hang out here?
I dont care how much of an expert you are, this comment is not a good way to wish people welcome.

-h

-welcome to the internet, the place where men are men, women are women, and little girls are FBI agents.
« Last Edit: December 05, 2012, 01:50:59 PM by hjulenissen » Logged
Schewe
Sr. Member
****
Offline Offline

Posts: 5469


WWW
« Reply #33 on: December 05, 2012, 02:24:00 PM »
ReplyReply

Doug, it’s your pseudonym  --  popnfresh --  that’s the Pillsbury Doughboy’s name!  Your unwitting use of popnfresh as your pseudonym evidently hit a raw nerve with Schewe.

Yeah, that's pretty funny bud...not terribly accurate (I'm going more for the older Orson Welles look) but funny. I'll remember that one...
Logged
ErikKaffehr
Sr. Member
****
Offline Offline

Posts: 7333


WWW
« Reply #34 on: December 05, 2012, 02:43:41 PM »
ReplyReply

The original posting was about HDR by someone genuinely interested in HDR. If you need to discuss pseudonyms, anonymity or the forum terrier please start a new thread! It doesn't belong here!

Best regards
Erik

Yeah, that's pretty funny bud...not terribly accurate (I'm going more for the older Orson Welles look) but funny. I'll remember that one...
Logged

Peter_DL
Sr. Member
****
Offline Offline

Posts: 421


« Reply #35 on: December 05, 2012, 03:13:15 PM »
ReplyReply


HDR is really a two step process:

1) You combine several images into a HDR image

2) You "tone map" the image so it can be presented on a device with a normal dynamic range.

... I very seldom use HDR, because I generally feel that the DR of todays cameras is ample.

Many images as captured are indeed HDR relative to the designated output device,
and therefore call for HDR-typical tone mapping techniques (spatially non-uniform, as opposed to curves).

Some people prefer to use the term "HDR" only when two or more captures are combined,
although this niche is getting smaller with the advancing sensor technology and increasing camera DR - particularly in relation to a print.

Some further reading for the OP:
http://wwwimages.adobe.com/www.adobe.com/products/photoshop/family/prophotographer/pdfs/pscs3_renderprint.pdf

Peter

--
Logged
hjulenissen
Sr. Member
****
Offline Offline

Posts: 1677


« Reply #36 on: December 05, 2012, 03:21:58 PM »
ReplyReply

I do also believe that the concept of "tonemapping" will simply be swallowed by the increasingly sophisticated non-linear, space-variant, signal adaptive exposure/contrast/... settings of standard raw developers.

Then it is only a question of "do I need one or more exposures to capture this scene sufficiently?". Hopefully, future camera sensors will allow us to use a single exposure for most interesting scenes.

-h
Logged
ErikKaffehr
Sr. Member
****
Offline Offline

Posts: 7333


WWW
« Reply #37 on: December 05, 2012, 03:32:41 PM »
ReplyReply

Hi,

I agree, having written two small articles on the issue:

http://echophoto.dnsalias.net/ekr/index.php/photoarticles/61-hdr-tone-mapping-on-ordinary-image

http://echophoto.dnsalias.net/ekr/index.php/photoarticles/63-lot-of-info-in-a-digital-image

Best regards
Erik


Many images as captured are indeed HDR relative to the designated output device,
and therefore call for HDR-typical tone mapping techniques (spatially non-uniform, as opposed to curves).

Some people prefer to use the term "HDR" only when two or more captures are combined,
although this niche is getting smaller with the advancing sensor technology and increasing camera DR - particularly in relation to a print.

Some further reading for the OP:
http://wwwimages.adobe.com/www.adobe.com/products/photoshop/family/prophotographer/pdfs/pscs3_renderprint.pdf

Peter

--
Logged

LKaven
Sr. Member
****
Offline Offline

Posts: 798


« Reply #38 on: December 09, 2012, 06:00:09 AM »
ReplyReply

It's worth mentioning that the HDRI Handbook, Second Edition, by Christian Bloch, is hitting the shelves this month (12/22/12).  The revision is comprehensive and brings things very much up-to-date. 
Logged

kirkt
Full Member
***
Offline Offline

Posts: 172


« Reply #39 on: December 09, 2012, 11:09:36 AM »
ReplyReply

It's worth mentioning that the HDRI Handbook, Second Edition, by Christian Bloch, is hitting the shelves this month (12/22/12).  The revision is comprehensive and brings things very much up-to-date. 

FYI Here is the table of contents:

http://www.hdrlabs.com/book/toc.html

kirk

Logged
Pages: « 1 [2] 3 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad