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Photography F.A.Q (Last Updated: 2024 Nov 26 6:56 am)
Subject: HDR
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Hi short_ribs,
In first time i want to explain the HDRI :
HDRI means High Dynamics Range Image. The dynamic range of an image has to do with the resistance between darkest the most shining regions and. In most of the images, the dynamic range exists between values 0 and 255. This is ideal leg most of the uses of the photographies. Your printer cannot print values superior or inferior to the rank between 0 and 255, as your monitor cannot either show superior values. The problem is in which this range is not enough to create specular brightness like in the reality.
Images HDR are those in which we can see the light source directly, as for example the filtered beams of solar light through a window in a dark and full room of dust. The key in these images is in which its dynamic range is but ample that in the normal images. On the contrary, the typical images (we will call images of low dynamic range: LDR) have their maximum in 255, whereas the HDR have values of luminosity of a million or but.
Images HDR are indicated normally with extension HDR. To obtain an image of this type is not as easy as to increase the resistance of an ordinary image, since images HDR contain more information than a standard photography. Anyway, you can create your own images HDR using HDR manipulated Shop because it facilitates the processing and of image of high dynamic range. This tool developed by students of the university of the south of California, allows to give to the photos necessary the additional information without no aid.
What has all this to do with 3D? Some applications 3D are prepared to extend these ranks. In particular the reflection channels are able to go beyond the values of standard light. In the real world the specular brightness is been from very subtle reflections. Most of renders it is only able to coarsely simulate the specular reflections of the real world.
In the recent versions but of C4D the use of archives HDR is gotten up. These are used in surfaces that are reflected as well in other surfaces. As example an object sky would be perfect for an image an image HDR. Any object of the scene that it has activated the reflection channel will be able to take advantage of the additional rank image HDR, giving like result brightness reflected with real aspect. The key is in the creation of suitable of materials. It activates all the materials except the one of luminance in the material that is going to make use of the archives HDR (he himself that is going to be applied to the object sky). Instead of the channel luminance, it places an image HDR in the texture.
It deactivates the specular channel in all the materials that are going to radiate specular brightness (it sounds stranger, but it works). Asegúrate that the reflection channel is activated so that you obtain the reflected lights to straighten.
In order to work with images HDR you must experiment. For some of renders more spectacular radiosidad has been used, because these images also can be used to define the illumination of a scene. Again to obtain results, you will have to be making adjustments and tests. Sometimes the added rank can affect all the colors of the scene. Dale an opportunity.
Links interesting : http://www.cybergrain.com/tech/hdr/ and http://www.lightworks-user.com/hdri.htm and http://www.sachform.de/ and http://gl.ict.usc.edu/HDRShop/
I hope this links can help you 
hehe valou - spoken like a true multi-lingual:
"Asegúrate that the reflection channel is activated so that you obtain the reflected lights to straighten."
Madrugaste? 
Very useful information tho, i'm sure kai will appreciate the time and thought put into the post
"In every colour, there's the light.
In every stone sleeps a crystal.
Remember the Shaman, when he used to say:
Man is the dream of the Dolphin"
Rich Meadows Photography
For the technical explanation see Valou's posting above 
I've not done much with this only messed about a few times experimenting. But I'll offer my opinion anyway 
First time I had heard of Photomatrix - if it is a PS plug in how can it be doing anything that can't be done in PS given a little time and patience? Is the cost of it worth the time saving in learning how to do it with what you have for yourself ?
If you have CS2 the HDR does work and works well. First thing to identify is a type of shot that would benefit from HDR. OK I'll give you an easy example to experiment with if you want to. The example is taking a shot from right where you are now ! See told you it was easy ! Shoot toward a window from inside a room. If you have ever done this you will know what will happen. Either the room will be dark and the view out the window will look great or the room will look great and the window will look like there's been a nuclear explosion outside.
So set your camera on a tripod and take the same shot again, this time though take at least 6 shots without moving the camera. Each shot you take you alter the shutter speed one stop at a time. What you want is shots from the room being very light and the window blown to the room looking black and the view out the window dark. Over do it ! - from very light in the room to very dark in the window. You must alter the exposure by altering the shutter speed only !!! The aperture has to stay the same on each shot of your DOF will vary.
OK got your shots !
Now blend them together using CS2 HDR .
It takes practise as valou said and a little experimenting. What you will end up with is a shot like you see in the house adverts. A beautiful room where you can see everything inside, but also a fantastic view out the window where you can see everything outside too.
And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies
live;
Their heads are green, and their hands are blue, And they went to
sea in a Sieve.
Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html
Attached Link: http://gl.ict.usc.edu/HDRShop/
Here's a link for HDR Shop which is the premiere program for working with and exploring HDR images. I find it an invaluable tool as I have been working with one of their plugins [light gen] to do renders in Imagine3D which does not support HDRI as such.
Once
in a while I look around,
I see
a sound
and
try to write it down
Sometimes
they come out very soft
Tinkling light sound
The Sun comes up again
Bravo Valou that about covers it! Yeah as has been aid CS2 has got it included I have been eperimenting myself and it is nice effect with the right images.. There has also been some great images posted here in our galleries...
Danny O'Byrne http://www.digitalartzone.co.uk/
"All the technique in the world doesn't compensate for the inability to notice" Eliott Erwitt
As onslow stated taking multiple shots and blending them together in photomatics is one way of doing it. Another way to do this is to take the image in raw. I use a program called Raw Shooter Essentials 2006. In this program you can open your raw image then save the image with the original settings to a jpeg file. Next you can go back to the raw file and adjust your exposure compensation up to +3, save it then adjust it down to -3. Now you can take these 3 images and make your hdri
"seeing HDR shop costs $400"
Not true, ver. 1 is free, check the Download V.1 right next to Purchace V 2. Not as full featured but still a fantastic way to come to grips with HDR images
Once
in a while I look around,
I see
a sound
and
try to write it down
Sometimes
they come out very soft
Tinkling light sound
The Sun comes up again
Thanks for all the help on this.... Hmm I've played with the hdr feature in photoshop and yeah I do find it pretty tricky (yet to do one in photoshop worth saving :crying: ) but have also been playing with the same shots in photomatix demo I mentioned and yeah it's 1. easy and 2. fairly quick to do :thumbupboth: so now really considering it. Oh and Valou, if you have a look at the photomatix one it comes as a stand-alone program so you can use it, and do the last touchups in the editing software of your choice ;) AND on top of all that it doesn't cost $400 :woot: So here I present to you a quick one i did in the back garden... sure it's not very good in any was but there could be 2 reasons for that... 1. I'm still learning what I'm doing with that program and 2. they were pretty much snapshots! ;) Once again thanks for all the help people!
Oh and anyone feel free to post your attempts or stunning hdr pics here :biggrin: and if you really want ya can tell us what you used to do it LOL :tt2:
I payed to get myself into an institution :m_tear: Check out my temporary site: APACHA
Attached Link: http://www.renderosity.com/mod/gallery/index.php?image_id=1269837
For digital photography, HDR is a lot of fun, and there is no reason to be intimidated by 3D stuff. Think of it as a way to combine several shots taken at different exposures. This enables a lot more detail in the bright highlights and deep shadows than is normally available. Results can vary from "realistic" to quite strange, almost like a painting.I'd suggest using a utility like Photomatix rather than Photoshop, as it is easier to use and provides more interesting tone mapping variations. A trial version (with a watermark) can be downloaded for testing. [I've not used the other application mentioned; it may be fine also.]
This was one of my first attempts: http://www.renderosity.com/mod/gallery/index.php?image_id=1269837
Well done Kai - that looks a fine job on that image 
And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies
live;
Their heads are green, and their hands are blue, And they went to
sea in a Sieve.
Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html
I have done a few as experiments in PS. I think from limited experience that the prog works just fine. Still, much has to do with the image subject. Does the subject have a high dynamic range? Some lighting does not have that much range while some scenes are "picture perfect" for hdr. Will the image be static or still enough for at least 5 shots?
Then again, you will see improvements but not the full potential of this in 16 bit or on the monitor.
I have only experimented and have not had a really inspiring scene to shoot. Still, it is certainly worth playing with. Unless you get it into print with the improved dynamic range I am not certain at this time much has been gained. Then again, what do I know..corrections to my thoughts are appreciated since I am working from a limited knowledge base. LOL :) Tom.
The curve allowed the bright leaves to be slightly better in render. Oh my, enough fooling around on a Sunday afternoon. Tom
@ gradient....well I got curious because, as I'm not really a photog as much as a 3D guy, I've not had any truck with .raw so had never had to open or save one. It seems from the menus that you can both import raw data files, and save as .raw out of V.1[free]....so those interested, but lacking the $400.00, here's your chance to play a bit.
Once
in a while I look around,
I see
a sound
and
try to write it down
Sometimes
they come out very soft
Tinkling light sound
The Sun comes up again
My pleasure friend...maybe you could post a lil tute on it's[HDR Shop] use re: .raw files for those of us reading here who are totally clueless like me about using .raw files. I see my digital camera[Sony cybershot DSC60] will out put them so if they have advantages I'd be willing and anxious to investigate the format.
Once
in a while I look around,
I see
a sound
and
try to write it down
Sometimes
they come out very soft
Tinkling light sound
The Sun comes up again
Maybe we need a thread on raw. Not a bad idea. Huh folks??????
I suppose some of the non-DSLR digitals will do raw?
For anyone interested, here is a decent explanation of what is and how to HDR:
Hey guys, instead of trying to do all the bracket shots on the tripod you can take one image in raw. Open your raw file with "Rawshooter Essentials 2006".Get this program ...its free, 100% free and fully funtional with no time limit. There is a premium version for purchase with more whistles and bells but this one works great. After you open your raw file you can go in and change your exposure compesation as easily as moving a slider. Other ajustments can be made also. This program is so easy. After you get your different exposures for your image you can play with them in your HDR program. Goto this site for the free download.
http://www.pixmantec.com/products/rawshooter_essentials.asp
Heres a link to an image I uploaded on Renderosity.
http://www.renderosity.com/mod/gallery/index.php?image_id=1318058
Having been acquired by Adobe(Lightroom beta product) the Pixmatic program may be available only for a short time. If you want it, I suggest you go for it now! I have the full version and love it...great program. The freebie does not lack much of the full version, yes, some functions, but is fully functional and will do a credible job on raw processing. Just a note. TomDart.
@jimken61....yes, that is one way of doing it....and you don't even need RSE for it...it can be accomplished with the RAW software that comes with your cam. It works well for shots that don't have an excessively high range.
Visually, the results are somewhat more satisfactory but it does not however give you the latitude that the bracketing method (as explained by Onslow) does. Furthermore, be aware that not all RAW files are equal...some use a slight compression in their format...what this means is that the camera manufacturer has slightly reduced the bit depth when storing that sensor data to the RAW file.
Additionally, from the Photomatix site;
"Can't I just create the exposures from one RAW file?
Not really. Your RAW file contains data captured by the sensors for only one exposure. The total dynamic range you can reconstruct from one photo converted with different exposure settings can never be more than the dynamic range captured by your camera, and this is rather limited (see above).
When you are using only one exposure to capture the scene, your RAW file is already your HDR image.
Converting the RAW file to images with different exposure levels is a bit like slicing the dynamic range of the RAW into several parts. Combining back the parts into an HDR image will at best re-produce the dynamic range of the initial RAW file. "
Working from a single RAW file will often give you a result that is more visually appealing...but really it does no more than selective curve adjustment and masking.
In youth, we learn....with age, we understand.
Gradient, I knew there was some reason and I thank you for bringing that to light. Obviously, one raw cannot capture the range of + or - 6 EV total exposure.
In my meger experiments, I will take one off hand shot with what I consider a decent exposure. From that, I consider that the "center shot" then use shutter to vary EV up and down from that shot. I am sure the original starting point has a lot to do with the final result. For example, my first image in previous posts could have been one stop higher to start. Then again, I had to delete one shot from the HDR since highlights were too bright! Go figure.
I am only learning this stuff and unfortunately do not see a decent way of presenting the final image as it should be seen except in print...and that capable of much higher dynamic range than we are used to in general prints of photos. The print business is an entirely different ballfield...one on which I have not played enough to be more than a helper on the sidelines.
Tom
@Tom...yes the way you are doing it is correct.
Depending on the range of your image though,and the number of exposures taken....for your "center" shot, you may want to bias your metering slightly to the shadows because it will lessen the likelihood of noise in these areas in your final image.
In youth, we learn....with age, we understand.
Back to business now.... I've kinda got the hang of the photomatix hdr now but that's cause there isn't much to learn really :tongue1: still playing with photoshop thought and keep getting stuck when I try convert then 32 bit file into a 16 or 8 bit... how do I go about using that "toning curve and histogram" 
thingy hmm anyway here are more quick pics I've done just around the house they aren't the best quality but there could be about 3 reasons for that. 1) it's very wind here at the moment 2) The tripod I'm using isn't very stable and 3) I guess I'm not taking much time shooting them :ohmy:**
**
I payed to get myself into an institution :m_tear: Check out my temporary site: APACHA
@Kai...looks like you've got it nailed down quite nicely. My only critique is on the top right and lower left image...that is the "glow" that tends to show around what were once the darker objects. I don't think it is anything that you are doing wrong....I think it is symptomatic of the HDR programs. Although very time consuming, it is in these cases where manual HDR blending has its advantage.
In youth, we learn....with age, we understand.
@gradient :tt2: (or anyone else) that "glow" is it just photomatix or do most/all the HDR programs do that? :unsure: Dont feel like getting it to be told "Oh btw that program you bought is bad... see that glow... that's a big no no." LOL hmm Ok and how would I go about doing manual HDR blending? :blink: Thanks for all the help btw people ;)
I payed to get myself into an institution :m_tear: Check out my temporary site: APACHA
Attached Link: Manual HDR
@Kai...can't say whether it is this prog or that prog that causes it. I don't use any of them!I can say that many images I have seen that were obviously HDR'd had a similar glow around the darker objects....
To go about manual HDR....take all your shots, layer them in your image editing program...then mask each one so that you only get the part you want to show through. Yeah, I know...it's time consuming...but I think it's worth it.
The link is one of mine that I manually HDR'd
In youth, we learn....with age, we understand.
Thanks buddy! I guess if I go about it maualy I'd want to take the shots at finer increments so instead of juts 1 stop between each shot I'd be better to do them at 1/3 of a stop between each shot? OR would I just be creating heaps more work for no reason? :unsure:
I payed to get myself into an institution :m_tear: Check out my temporary site: APACHA
I guess it would depend on the scene...but yeah...the more layers...the greater the pain!
Just a thought, but what you could do is this....use photomatix ( or whatever )....then if you do end up with the "glow"...layer one of your darker exposures over it and blend/mask to get rid of the glow area. It would probably save tons of time....because it's obvious that the "glow" does not happen in every scene ( the other two are fine) ....so, you'd just have to use this method when it occurs.
In youth, we learn....with age, we understand.
Sounds like a great plan buddy! I'll have to look into that! thanks for the tip!
I payed to get myself into an institution :m_tear: Check out my temporary site: APACHA
This link give a bit more info on Photoshop HDR with screen shots of the "toning curve".
http://www.earthboundlight.com/phototips/photoshop-cs2-hdr-32bit.html
Well, time to go to work... good thread, folks. Tom.
Attached Link: HDR link
Nice thread Kai, with great participation. Digimon posted an informative gallery entry that discussed HDR, and I included a link in it. Take a peek if you want.Kort Kramer - Kramer Kreations
Yes, but it is not as in your face as many as I've encountered. :) That Luminous Landscapes sunset was another example of what I would consider a successful HDR photo. But again, that is just me.
Kort Kramer - Kramer Kreations
I have done an HDR using PS.
It is in my gallery - http://www.renderosity.com/mod/gallery/index.php?image_id=1319041
Made out of 6 shots and merged.
And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies
live;
Their heads are green, and their hands are blue, And they went to
sea in a Sieve.
Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html
Thx bobby .
It is not something I have done much of the trick seems to be in selecting the right starting material. I took 16 RAW images to start with ranging from 20secs exposure all the way through to 1/60th sec. I found that by altering which ones I used I was able to get a result with detail in all areas. The final image is using 6 exposures.
I would have liked to have gotten a better composition, but the camera seems to have slipped in the tripod slightly on one showing the full arch so that sequence of shots is ruined.
And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies
live;
Their heads are green, and their hands are blue, And they went to
sea in a Sieve.
Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html
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Hi all,
I haven't been to active here in the forums but hope to change that now....
I bring to you a question about HDRI (High Definition Range Imageing) programs. Well I see one can use Photoshop CS2 to do this but I have also noticed others like Photomatix that seem pretty good.
Well to tell the truth I'm not sure what's better where and how it all should be done, but would like to give it a go. I'm very keen to start playing...... SO.... Any advice on what I should do is very welcome! I've downloaded the demo of Photomatix and gotta say the ease of use and results do seem pretty awesome... the photoshop way... well that only know's how to confuse me! :rolleyes: anyone got any advice at all if you got a special program or know a way to do it please help me! I'm tempted to fork out the little cash I have to get the Photomatix one but want to see what is said here first before I go waisting money one something I might not need :biggrin:
I payed to get myself into an institution :m_tear: Check out my temporary site: APACHA