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Thread: How to preserve most of Dynamic range in a single exposure.

  1. #1

    Default How to preserve most of Dynamic range in a single exposure.

    hi everyone,
    Anybody have tips on how to preserve the maximum dynamic range in a single exposure?

    I understand there could be clipping on either ends on a single exposure however any tips?

  2. #2
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    Default Re: How to preserve most of Dynamic range in a single exposure.

    bracketing then merge it into hdr

  3. #3

    Default Re: How to preserve most of Dynamic range in a single exposure.

    That works.. But what i meant was in a single exposure, as i need to shoot 2 frames for HDR merging.

  4. #4
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    Default Re: How to preserve most of Dynamic range in a single exposure.

    Quote Originally Posted by blurry80 View Post
    hi everyone,
    Anybody have tips on how to preserve the maximum dynamic range in a single exposure?

    I understand there could be clipping on either ends on a single exposure however any tips?
    I assume this is for electronic sensors? In this case:

    Use maximum exposure that doesn't result in clipping of any channels. Furthermore, one could use colour filters to equalize different colour channels (in situations where one channel would clip much earlier than the others).

    Obviously, any lossy compression techniques are out for this.

  5. #5
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    Default Re: How to preserve most of Dynamic range in a single exposure.

    Also, shoot in RAW format, which cover more Dynamic Range than jpg format.
    Sony Alpha 700 hobbyist

  6. #6

    Default Re: How to preserve most of Dynamic range in a single exposure.

    I suppose you mean to desaturate the colours before being captured on the sensor through use of filters? Interesting. Do you have any website reference for this technique or could you briefly explain how can it be done? Do we compensate for the colours during post process?

    i usually shoot in raw just exploring some other ways to have better dynamic range as i find my Canon 400D is really lacking in this aspect.
    Last edited by blurry80; 12th December 2007 at 05:55 PM.

  7. #7

    Default Re: How to preserve most of Dynamic range in a single exposure.

    Quote Originally Posted by blurry80 View Post
    I suppose you mean to desaturate the colours before being captured on the sensor through use of filters? Interesting. Do you have any website reference for this technique or could you briefly explain how can it be done? Do we compensate for the colours during post process?

    i usually shoot in raw just exploring some other ways to have better dynamic range as i find my Canon 400D is really lacking in this aspect.
    Use a different curve. Maybe try the Neutral picture settings instead of the Standard? (I'm not a EOS person so pardon me if I get it wrong. )

  8. #8
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    Default Re: How to preserve most of Dynamic range in a single exposure.

    Quote Originally Posted by blurry80 View Post
    I suppose you mean to desaturate the colours before being captured on the sensor through use of filters?
    You cannot "desaturate" colours by optical filters. What will give you the best possible signal/noise ratio is the optimum exposure for EACH colour channel. Usually, you're limited to the exposure that prevents clipping on ANY colour channel. Let's say you have RGB channels, and you have optimum exposure without causing clipping. Then, e.g. the "red" channel may be optimal, but the "green" and "blue" channels could still do with more exposure.

    What gives optimum results is the situation where all channels are equally "bright". This can be achieved using colour filters, by selectively attenuating the most intense colours.

    Do we compensate for the colours during post process?
    Yes, one would need to do this. (One needs to do this anyway, just the coefficients will be different.)

    However, let me point one thing out: I answered your question on "how to preserve most ...". What I'm suggesting is technically sound, but may not be very practical, depending on your style of photography. If I would be mostly photographing e.g. red tomatoes on green leafs, and absolutely would HAVE to get the best possible quality, I might use a filter. But I don't.

  9. #9

    Default Re: How to preserve most of Dynamic range in a single exposure.

    I just read from canon website that setting the Picture style to neutral, Contrast and saturation settings to low values will help in preserving more details. Not sure if this is refering to dynamic range. Anyone can tell me if this is correct?

    http://web.canon.jp/imaging/pictures...e/neutral.html

  10. #10
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    Default Re: How to preserve most of Dynamic range in a single exposure.

    Quote Originally Posted by blurry80 View Post
    I just read from canon website that setting the Picture style to neutral, Contrast and saturation settings to low values will help in preserving more details. Not sure if this is refering to dynamic range. Anyone can tell me if this is correct?
    Picture style, contrast, and saturation only apply to processed files. Fiddling with the settings can help to mitigate limitations of the file format used to store the processed images (i.e. JPEG). But you don't get something for nothing - you may e.g. preserve more shadow detail, but will lose other detail instead. You will never get the same amount of detail as with raw sensor data.

    The basic problem is that a vanilla JPEG file can only hold a fraction of the image information recorded by the sensor, so you have to compromise on something. With the in-camera picture parameters you have some (but very limited) control over how the compromise is made. If you record raw files and process them on the computer, you have much better control.

  11. #11

    Default Re: How to preserve most of Dynamic range in a single exposure.

    Use lower ISO.

    I read somewhere that lower ISOs have a greater dynamic range.

  12. #12

    Default Re: How to preserve most of Dynamic range in a single exposure.

    not so much lower ISO but rather the native ISO of the imaging chip, which may not be the lowest ISO...

  13. #13

    Default Re: How to preserve most of Dynamic range in a single exposure.

    yeah, lower ISOs tend to have better range. frankly, the best way that i can see to preserve DR is to ensure you got you're exposure right. leaving it up to the camera's matrix meter just isnt enough. dont be lazy and spot meter a couple areas and find some a setting that will best expose the scene. if not, choose something artistic, like a silhouette.

  14. #14

    Default Re: How to preserve most of Dynamic range in a single exposure.

    I'm thinking you're asking how to increase the dynamic range of your camera? Having the correct ISO would help a little but I doubt it will be significant. Only real way to do this is with a ND filters... and even then, this seriously limits you to shooting landscape photos

    best is to just choose if you want to sacrifice your highlights or your shadows. Although I think I remember reading somewhere that highlights can be recovered (to a certain degree) more easily than shadows in PP.

  15. #15

    Default Re: How to preserve most of Dynamic range in a single exposure.

    ND filters allow a camera to increase exposure time, possibly to prevent images that are very bright from being blown out... don't see how it can increase dynamic range...

    highlights are more recoverable if talking about film, and shadows less so... but in digital, its the other way round...

    to make the most of dynamic range is to have proper exposure, to choose the ISO value closest to the camera's native value, and possibly to bracket shots and either use the best exposed shot, enhancing the RAW data (which of course means shooting in RAW) if required, or combining the bracketed shots in a high dynamic range image if need be...

  16. #16

    Default Re: How to preserve most of Dynamic range in a single exposure.

    oh, i was talking about nd filters with graduations or splits or whatever....i just group them all under nd filters

  17. #17

    Default Re: How to preserve most of Dynamic range in a single exposure.

    edit:nevermind

  18. #18

    Default Re: How to preserve most of Dynamic range in a single exposure.

    Quote Originally Posted by dw2chan View Post
    oh, i was talking about nd filters with graduations or splits or whatever....i just group them all under nd filters
    oh, ok... but it is not so much increasing the dynamic range capturing capability of the camera as to reduce the dynamic range of the image to be captured...

  19. #19

    Default Re: How to preserve most of Dynamic range in a single exposure.

    haha...yup that is correct

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