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Thread: HDR question

  1. #21
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    Default Re: HDR question

    Was the scene you shot has highdynamic range to begin with? Or is is a flatly lit room or shaded shed....what I mean is the scene must have high dynamic range before you can get HDRi...

    Another thing is, for CS2, when you convert from the 32bit to 8bit (normal JPG for viewing), there are some tweaking of parameters.....did you try playing with those parameters? I am not sure about Photomatix though.

    Quote Originally Posted by foxxkat View Post
    i've tried experimenting with photomatix and creating 3to5 different exposure files from One raw..

    but the results is no where near g-khoo's nor bigboy's piece of work

    is there more to it than just photomatix? it's really simple to use. but results look so different heheh.
    Last edited by lastboltnut; 5th September 2007 at 01:56 PM.

  2. #22
    Member/Tangshooter g-khoo's Avatar
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    Default Re: HDR question

    Quote Originally Posted by calebk View Post
    Are your exposures far apart enough in terms of dynamic range?
    You dont really need that a big difference in dynamic range to see the difference.

    Hmm can you post your original correctly exposed photo here for me to view?

    There are 2 possibilities as to why you cant get a HDR image.

    1.) The image has a low dynamic range - even when you under and overexpose it by one stop. Certain images where the lighting is flat and even, you wont see the difference even if you HDR it.

    2.) This is really simple. You forgot to do the tone mapping step.

  3. #23
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    Default Re: HDR question

    Quote Originally Posted by night86mare View Post
    No, but you got PM.
    Quote Originally Posted by lastboltnut View Post
    Hey night86mare, do you know where I can buy photomatix (not online, dun like to do online transaction) from store in CD/DVD form? Thanks.
    any idea? coz i want the photomatix too. and stores selling?
    mohd lukman
    photoblog | flickr | multiply

  4. #24
    Member log1t3ch's Avatar
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    Default Re: HDR question

    Quote Originally Posted by lukman View Post
    any idea? coz i want the photomatix too. and stores selling?
    u can get it from various sites for free if u know what i mean =P

  5. #25

    Default Re: HDR question

    Quote Originally Posted by g-khoo View Post
    You dont really need that a big difference in dynamic range to see the difference.

    Hmm can you post your original correctly exposed photo here for me to view?

    There are 2 possibilities as to why you cant get a HDR image.

    1.) The image has a low dynamic range - even when you under and overexpose it by one stop. Certain images where the lighting is flat and even, you wont see the difference even if you HDR it.

    2.) This is really simple. You forgot to do the tone mapping step.
    ok.. looks like i missed a few things:
    1. i don't understand low/high dynamic range. didn't realise this is important
    2. i didnt do tone-mapping
    3. not sure abt the pic i took.. here it is.


    pls advise if the pic has high dynamic range?
    thx

    exif:
    iso 200 f10 A-mode 1/320s

    above is original image.
    the below is HRD image using photomatix auto-mode. it call it the pseudo-hdr. generated from 1 raw file.

    Last edited by foxxkat; 6th September 2007 at 10:02 PM.
    D80 | 50 f1.4 | 85 f1.8

  6. #26

    Default Re: HDR question

    is this hdred
    or is this not

    if it is, the scene doesn't seem to require the hdr technique much
    if it isn't, then it still doesn't seem to require the hdr technique much

    but i could be wrong, were the flats backlit?

  7. #27

    Default Re: HDR question

    i...err.. not sure if it's backlit. i think not.
    added hdr image above.
    D80 | 50 f1.4 | 85 f1.8

  8. #28

    Default Re: HDR question

    oh, that was original
    in which case you don't really need to hdr it
    the dynamic range of the scene is pretty limited, most daytime scenes are, actually unless you have special case, like a particular portion in shadow, e.g. you take the picture of an archway with a city in the background and want the details of the parts in shadow below the archway. or in cases where the subject is backlit, i.e. sun isbehind perhaps, so the sky behind the hdb flats is much brighter than the hdb flats

    in this case a simple shadow/highlight tool manipulation along with contrast and exposure manipulation will get you similar results
    not exactly, of course, but similar

    like so



    this is a manipulation of the first image you have posted

  9. #29
    Member/Tangshooter g-khoo's Avatar
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    Default Re: HDR question

    Quote Originally Posted by foxxkat View Post
    ok.. looks like i missed a few things:
    1. i don't understand low/high dynamic range. didn't realise this is important
    2. i didnt do tone-mapping
    3. not sure abt the pic i took.. here it is.
    Ok first thing's first. Like what nightmare has said, the original picture has relatively flat lighting and very little variation in hues. So you wont see much difference even if you HDR it.

    What HDR does is it essentially expands the dynamic range(meanining the colour, hues, highlights, tones) of your photo by combining photos of different exposure levels and stacking them together.

    It is similar to what you can do with the shadow/highlights tool in photoshop except photomatrix does a better job of it.

    The HDR process is complete after you click generate and go to tone-mapping, where you can further adjust saturation levels, gamma light, black light, micro smoothing etc.

    Esentatially, the tone mapping brings up the level of detailin the photo and boosts the saturation of the picture to an almost surreal effect. Sometimes the problem caused by this is the noticable increase in noise level but i wont go into details about this just yet.

    I believe you just need practice and a good eye to spot pictures that are HDR-worthy.

    Start with sunrise/sunset pictures. They are simple to do.


    This is one of my early HDR pics. You can still further enhance the photos in PS by using the blend functions. Esp dodging and burning.
    Last edited by g-khoo; 7th September 2007 at 12:49 AM.

  10. #30
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    Default Re: HDR question

    you definitely need to nail the tone mapping feature to get anything close to worthy. additionally you should think like this :-

    -If the image is lit well e.g. Mid day shot you are going to have such alot of blowout at any exposure you will find that even tone mapping will leave you wondering. You could get arund this with ND filters to make sure your difference between exposures is enough to pick out the differences - but when there is not much to bring out e.g. shadows etc you will not get the WOW factor.

    - I agree that you should start to look for subjects where you will have a bigger difference between the stops. Try 3 exposures at -2 0 +2 and progress slowly.

    Finally - READ instruction manuals!! Photomatix has clear and well thought out manuals included.

  11. #31
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    Default Re: HDR question

    Quote Originally Posted by foxxkat View Post
    ok.. looks like i missed a few things:
    1. i don't understand low/high dynamic range. didn't realise this is important
    2. i didnt do tone-mapping
    3. not sure abt the pic i took.. here it is.
    more than technically trying to get every part of the picture to be visibly exposed, application of HDR is more about achieving a desired exposure (meaning you need to know what final product you want) not possible with the digital camera sensor.

    it's very dependent on your knowledge of and skill in post processing, meaning it takes practice. as you go about trying and improving, remember that a naturalness of gradation through the picture is extremely important, especially at edges where level of exposure changes steeply most HDR images commonly found on the internet fail on this count.
    Last edited by eikin; 7th September 2007 at 06:08 AM.

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