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  • Exposure/noise/grain

    With the 5d I have been spoilt with lack of grain and file quality however now that I'm playing with much lesser cameras I find my digital knowledge about exposure/noise/grain needs upgrading.

    I have always exposure to the left as many call it. For those who don't understand it's referring to exposure compensation; left on the dial/gauge is underexposing and to the right is overexposing. However I often read on forums many expose to the right so they don't get any or not too much noise in the shadows of file

    My thought has been more on the line of preserving the highlights.

    So taking the these photos I would like to know how you would set the exposure.
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    All pretty rough but you get to idea
    Maybe time to set up auto bracketing for more experimenting/TRAINING

    I generally use centre weighted metering/AV/exposure comp. There are times I will move to spot metering

    Add anything you wish about how and what you do.
    Cheers for now, IanB.
    Photos by Ian Browne on Facebook

  • #2
    Apparently with film you exposed to the left (to do with the physical properties of that medium).

    Technically with digital sensors you are meant to expose to the right - I understand the technical reasons for this but don't always do it but I do tend to expose towards the right.

    NB: The technical reasons for wanting to expose to the right with digital are to do with how the image data is stored - half the total available image data space is used to store the rightmost stop on the histogram (the brightest parts of the image), then half of the remaining space (one quarter) is used to store the next stop down from the right, then half again (one eighth) is used to store the third stop down, half again (one sixteenth) is used to store the fourth stop down, 1/32th for the 5th stop, 1/64th for the 6th stop, 1/128th for the 7th stop, 1/256th for the 8th stop and so on.

    You can see here that if you shoot an image which is a couple stops underexposed then the actual raw image data is being stored in only a small proportion of the total available space and a vast proportion (possibly more than 75%) is not used.

    Where this becomes important is when you try to push those pixels in post processing - if you've got very little latitude of available tones to start with and you try to increase exposure you get banding and other artifacts. The expose to the right theory is that you purposely overexpose the image at capture so that it just touches the right of the histogram (whilst still preserving highlights) and then if the image is actually overall overexposed then you bring it down in post but you do so with the maximum amount of total data available AND in the capture file your shadows are stored up higher and have more data available for storage and thus have more available real detail and tonality available (even when you push the exposure down in post and/or try and recover shadow detail in post).

    So in practice what do I do... nothing much fancy really
    - I have highlight warning on so I tend to expose to preserve "important" highlights (nothing critical flashing on my LCD - with the knowledge that this is actually a JPEG preview histogram and that in reality my RAW file probably has another stop or more of highlight latitude)
    - If I see I've blown important highlights (lots of flashing on the LCD in places I don't want) I might dial in a little negative exposure compensation (generally only -0.3 or -0.7 or -1.0EV)
    - if however my histogram shows that the camera has grossly underexposed (I'm more than a stop from the right) then I'll dial in positive exposure compensation (or if I'm in manual play with slower shutter, higher ISO and/or wider aperture) to bring the exposure up (sometimes this can be a 1 to many stops worth)
    Last edited by Remorhaz; 09-04-2013, 06:11 PM.

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    • #3
      so all these lazy buggas who use multi metering points and full auto are on the money lol.Thanks for that Rodney, info I was not really aware of. My ways go back to my early days of digital when I used jpgs and I had dramas with clouds/white dresses. I often made several exposures and blended them in PS7. Every thing I read warned about over exposing the highlights.So that another thing to put away in old digital thoughts box.Your time to post a long reply is appreciate
      Cheers for now, IanB.
      Photos by Ian Browne on Facebook

      Comment


      • #4
        Hi Lost.
        Yes I have also had the similar problems, you read about over exposing highlights, which cannot be rescued because the pixels don't have any data there to rescue, and then the other side of the fence says expose to the right. All very confusing.

        But have you seen this web sight http://www.cambridgeincolour.com/tut...techniques.htm

        If you are not already familiar with this web site have a look there are some quite interesting articles on exposure and digital photography.
        Canon, 5D MK3 5D Mk11 300mm f2.8, 28-300 f3.5-5.6, 70-200 f2.8, 100 Macro.

        Gordon
        Excreta Tauri Astutos Frustrantor

        Comment


        • #5
          Originally posted by Remorhaz View Post
          Apparently with film you exposed to the left (to do with the physical properties of that medium).

          Technically with digital sensors you are meant to expose to the right - I understand the technical reasons for this but don't always do it but I do tend to expose towards the right.

          NB: The technical reasons for wanting to expose to the right with digital are to do with how the image data is stored - half the total available image data space is used to store the rightmost stop on the histogram (the brightest parts of the image), then half of the remaining space (one quarter) is used to store the next stop down from the right, then half again (one eighth) is used to store the third stop down, half again (one sixteenth) is used to store the fourth stop down, 1/32th for the 5th stop, 1/64th for the 6th stop, 1/128th for the 7th stop, 1/256th for the 8th stop and so on.

          You can see here that if you shoot an image which is a couple stops underexposed then the actual raw image data is being stored in only a small proportion of the total available space and a vast proportion (possibly more than 75%) is not used.

          Where this becomes important is when you try to push those pixels in post processing - if you've got very little latitude of available tones to start with and you try to increase exposure you get banding and other artifacts. The expose to the right theory is that you purposely overexpose the image at capture so that it just touches the right of the histogram (whilst still preserving highlights) and then if the image is actually overall overexposed then you bring it down in post but you do so with the maximum amount of total data available AND in the capture file your shadows are stored up higher and have more data available for storage and thus have more available real detail and tonality available (even when you push the exposure down in post and/or try and recover shadow detail in post).

          So in practice what do I do... nothing much fancy really
          - I have highlight warning on so I tend to expose to preserve "important" highlights (nothing critical flashing on my LCD - with the knowledge that this is actually a JPEG preview histogram and that in reality my RAW file probably has another stop or more of highlight latitude)
          - If I see I've blown important highlights (lots of flashing on the LCD in places I don't want) I might dial in a little negative exposure compensation (generally only -0.3 or -0.7 or -1.0EV)
          - if however my histogram shows that the camera has grossly underexposed (I'm more than a stop from the right) then I'll dial in positive exposure compensation (or if I'm in manual play with slower shutter, higher ISO and/or wider aperture) to bring the exposure up (sometimes this can be a 1 to many stops worth)
          Hello Rodney this was really quiet interesting bit of information to read I am going to print it out so I can read it away from my comp and other things that are going on around me. when you say flashing on the screen is that the flickering you see I will see that if I blow out the sky I don't blow the sky out as much any more but on flat over cast cloudy days the more white there is I will blow it out so is that what you mean by flashing ( flickering ) as I call it.

          Thanks Ian for making this post and thanks Rodney for your reply with this helpful information
          All Experts at anything were once beginners





          MWAH Sandy

          Comment


          • #6
            Here's a revolutionary concept - How about just expose in the middle?

            Generally speaking, most camera's AE performance is excellent, and it's not that often that you need to change the exposure-compensation* (especially if shooting RAW).

            I normally just use the AE during the day, then switch to manual or bulb mode for long exposures with filters or night photography.

            If you want to debate the technicalities - effectively exposing to the right (without blowing out the highlights) will retain the most 'useable' data in a file due to how the tonal graduations are stepped out over the 0-255 brightness scale, which prevents data having to be extrapolated out from under or overexposed areas of the scene (which creates noise - particularly in blocked or blown out areas of 0,0,0 pure black or 255,255,255 pure white).

            Ian, if the noise is a problem for you, remember ACR (and I assume therefore also Lightroom) has Noise Reduction settings than can be tweaked in editing - but remember you will lose sharpness when doing this.

            *(more than 1/3rd or 2/3rd, which can generally easily be recovered from a RAW file with minimal impact on noise properties of an image...)
            Last edited by beeb; 09-04-2013, 09:11 PM.
            -Tim.

            Comment


            • #7
              a lot of nature photogs I know expose to the right.
              capturing as much details in the shadows and reducing noise.
              if required you can pull exposure back a bit in post.
              I personally expose for the whites and shooting in good light mostly means the blacks are ok too.
              as digital cameras get better with noise performance and dynamic range it becomes less of a problem imho.
              Stephen Davey. Nikon Shooter

              Comment


              • #8
                Originally posted by Lost View Post
                so all these lazy buggas who use multi metering points and full auto are on the money lol.Thanks for that Rodney, info I was not really aware of. Every thing I read warned about over exposing the highlights
                Originally posted by Gordon View Post
                you read about over exposing highlights, which cannot be rescued because the pixels don't have any data there to rescue, and then the other side of the fence says expose to the right. All very confusing.
                Ian/Gordon - You can do both at the same time - i.e. I do still mean to protect the "important" highlights - but the expose to the right theory is to ensure there isn't a gap in the histogram on the right - i.e. the right side of the histogram meets the far right but doesn't have a spike along the right edge.

                Originally posted by Nikkie View Post
                when you say flashing on the screen is that the flickering you see I will see that if I blow out the sky I don't blow the sky out as much any more but on flat over cast cloudy days the more white there is I will blow it out so is that what you mean by flashing ( flickering ) as I call it
                Sandy - when I say flashing - if you go into your camera's playback/image review menus and enable the highlight warning screen (and view the images with highlight warning turned on) then parts of the image which are overexposed (i.e. the histogram for that image has parts which are off the right edge of the histogram and appear as a spike line along the far right of the histogram) will flash on the LCD display in image review. This is simply an indication to you that there are parts of the image which "might" be overexposed that you might want to further consider.

                Note also when they/I say to protect the "important" highlights - it doesn't mean you should never have flashing parts on the highlight display (irrecoverably overexposed areas) - it means you don't want to have them where you want to have detail but you don't mind having them where it's not important or where it is to be expected - for example if you take a photo of the sun or of a chrome or mirrored surface you expect to have blown specular highlights in those areas.

                Lastly Tim is entirely correct - nowadays the metering in modern D-SLR's is so good you should just use auto metering (matrix metering) almost all the time and it does a fabulous job almost always in exposing to the right and most of the time in protecting highlights. My comment above about the simple extra things I do is only for the very few occasions it gets it wrong - and it's simple to see on the LCD - look at the highlight warning (and if stuff I care about is flashing dial in minus EV) or if the image looks dark check the histogram to see if it's more than a stop from the right edge (and if it is dial in plus EV).

                Comment


                • #9
                  went for a walk along the river to put into practise my education. Big difference!

                  Yeah; the only dumb question is the one we don't ask.
                  For a while now I have not been overly happy with too many of my snaps; I just thought something was missing.

                  Cameras cannot work out picture compositions but it's pretty dam good at working out exposures and white balance so I will leave that the camera and do the composition side of it.

                  Letting the camera do it. There was overexposure in the top LHS
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                  Under the wharf
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                  one stop left to fix the over exposure
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                  under the wharf. I'm rather shocked at the difference!
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                  If I was planning to post these like this I would have done another one stop to right. May do that tomorrow.

                  I have often said we make digital photography harder than it has to be by have too much gear available. Now that's another mistake I have been making by taking the three cameras in the car. Today i just took my mate Lumi, and learnt more about that camera and what it can and cannot do.

                  And thanks for your thought Charles.

                  and newbies, I can see and hear you scratching your heads about a lot of this info. Don't be shy and ask questions. I did and just look at the help I received and I have been fiddling with cameras for around 40 years. The photos I took today are just sooooooo much better than in recent times. Yep; I have LOTS of photos to bore you with lol!!
                  Cheers for now, IanB.
                  Photos by Ian Browne on Facebook

                  Comment


                  • #10
                    Some interesting information. Thanks for all the input. Luckily I read something when I first bought my D3100 and usually have my highlight clipping preview on. Was a bit paranoid about it at first and tried to eliminate all flashing highlights, now I'm more comfortable in ignoring unimportant ones. I did find the D3100 tends to underexpose more than my D7000 does with the exposure set to the middle and it took me ages to get my head around exposure compensation.

                    Comment


                    • #11
                      Originally posted by P Plates View Post
                      Some interesting information. Thanks for all the input. Luckily I read something when I first bought my D3100 and usually have my highlight clipping preview on. Was a bit paranoid about it at first and tried to eliminate all flashing highlights, now I'm more comfortable in ignoring unimportant ones. I did find the D3100 tends to underexpose more than my D7000 does with the exposure set to the middle and it took me ages to get my head around exposure compensation.
                      My Nikon 100 and 200 both underexposed and in some way that might have had something to do me having bull the by Bs instead of the horns.
                      Cheers for now, IanB.
                      Photos by Ian Browne on Facebook

                      Comment


                      • #12
                        lol I felt a little posting this thread but it has been worth while for me, and many silent others also I suspect. It's amazing the bad habits we collect and the info we don't understand fully.


                        I experimented yesterday with auto bracketing and then looked more closely at the shadows in the files. Files underexposed by a 1.66 stops has very little grain in the shadows, although the highlight areas are pretty well lost so it does defeat the propose in some ways. My camera will by set mostly at about 1/2 underexposed for most of the photos I do these today. I will rephotograph some of my lonely trees (with clouds) to see what difference there is.


                        You would think camera designers would have in camera auto bracketing done with one click. It's amazing how far a duck moves in the time the camera takes three photos lol


                        Thanks to all those who have added info/thoughts into the thread. As I move more towards the smaller cameras I will need to take more care with what I do.
                        Cheers for now, IanB.
                        Photos by Ian Browne on Facebook

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                        • #13
                          may as well post the 1.66 stop overexposed (according to the camera) photo.
                          Attached Files
                          Cheers for now, IanB.
                          Photos by Ian Browne on Facebook

                          Comment


                          • #14
                            Rodney (Remorhaz) posted the BEST explanation to why it is that one should shoot to the right. (love the light painting stuff you do Rodney BTW!)

                            I knew this for a long time, just could not explain it in these detailed terms at the two camera club talks I did as guest speaker this week. Damn! Lucky, I had my real examples showing on the projector screen testing the shoot to the right principle showing the attendees why it is so important to understand the histogram and use it to minimize the noise in dark tones. I hear so many people complain about how noisy their cameras are, but many don't understand the basic priniciple that digital exposure is NOT like film was. You must use the histogram, enable highlight warnings (blinkies), know that a little blink is OK and accept the fact that no matter how hard you try, sometimes you just don't have the capability of taking in the dynamic range of a scene like the human eye can. That's where HDR comes in. So if I shoot a dark bird against a really bright (eg cloudy white) sky, I often overexpose even by three (3) stops and get detail in the bird but blow out the sky. That's how it is sadly.

                            Personally, I always use one metering mode, that is matrix/evaluative. That's it. I don't need any other mode, because I have learned how this metering mode interprets tonalities and can get my exposures pretty good most of the time, with some minor chimping and histogram reviews. However, with my kind of photography (birds) it is sometimes hard to adjust after I take a shot so there is always a slight risk of getting it wrong. This is where manual mode comes in handy, but again, there is the need to slightly adjust exposure based on the tonalities of the subject - which I can do once I pick that up in the VF. There is no real wizardry in digital photography.

                            Shooting to the right is exactly why people don't get as much noise in their images for starters, when they understand AND use this basic principle. Feel free to read this blogpost I wrote last year. I used a Canon EOS 1DMkIIn, but any DSLR would surely work with this exposure principle.

                            http://www.amatteroflight.com/wordpress/?p=417


                            Trying to bracket for moving subjects is not a good idea as the tonalities change very quickly due to subject moving!

                            I agree that cameras do get better (Steve/Avkomp), but do you still not shoot to the right? Although you are with Nikon, but the principle should still be the same no?

                            Comment


                            • #15
                              Originally posted by White Falcon View Post
                              This is where manual mode comes in handy, but again, there is the need to slightly adjust exposure based on the tonalities of the subject - which I can do once I pick that up in the VF. There is no real wizardry in digital photography.
                              Thanks for your input WF. Is there a reason you don't use exposure compensation to "slightly adjust exposure"
                              Cheers for now, IanB.
                              Photos by Ian Browne on Facebook

                              Comment


                              • #16
                                Hi
                                You still adjust exposure by changing the shutter speed or aperture when in manual mode.
                                I will change the exposure if I think a bird I am about to photograph warrants me changing it. Eg. Shooting a dark bird against the sky I may use + 1 2/3 EC (when looking at the light meter in the VF). If I suddenly get a white bird against the sky, I will probably pull it back a stop at least, so I would increase shutter speed by one stop to compensate or close the aperture down by one stop to do the same. Does that make sense?

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                                • #17
                                  Originally posted by White Falcon View Post
                                  Does that make sense?
                                  sure does. I seldom use Tv so I don't think about shutter speed a lot apart from camera shake dramas
                                  Cheers for now, IanB.
                                  Photos by Ian Browne on Facebook

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