Basic Exposure Question

Discussion in 'General Technical Discussion' started by Mike Z, Oct 30, 2005.

  1. Mike Z

    Mike Z

    May 30, 2005
    Northbrook, IL
    Perhaps someone can answer this for me. The leaked info regarding the D200 mentions that it has a 1005 point advanced metering system. That's really wonderful, but doesn't it all still boil down to the aperture and shutter speed that the entire sensor is exposed to, all at once? How many realistic variations can there be f8-1/60 and f8-1/100, that would make any difference.

    It would seem to me that the metering system should be applied to the raw image to get the final image, but isn't that what curves, either in the camera or in the software, does? And if it's in the camera, its just limited to only 4 or 5 choices.

    I must be wrong because such a big thing is made of the metering system, but can someone explain how?

    Thanks,

    Mike
     
  2. MontyDog

    MontyDog

    Jan 30, 2005
    #1064 - You have an error in your SQL syntax;
     
  3. Mike Z

    Mike Z

    May 30, 2005
    Northbrook, IL
    Paul,
    Thanks for the answer, but I'm not sure what you're saying. Are you saying that the term "3D Colour Matrix Metering II" has nothing to do with metering but is just descriptive of the CCD, or are you saying that the individual pixels are in fact affected by the metering, or are you saying it's still a matter of one aperture and shutter speed accross the whole CCD?
    Mike
     
  4. Baywing

    Baywing

    Feb 22, 2005
    CT USA
    Maybe this will help. Think of the 1005 pixel light meter as 1005 tiny little light meters, each metering the portion of the scene that it sees. You now have 1005 exposure values, ranging from the lightest in the scene to the darkest and everything in between. All that info is passed to a computer which, in a simple way, averages the values together, and "suggests" a shutter speed/aperture setting. It takes into consideration the locations of all the 1005 values and compares the mosaic to patterns in it's memory. The earlier versions of these meters actually "learned" based on each photo taken, adding the info to the databank for a wider selection for the next shot.
     
  5. MontyDog

    MontyDog

    Jan 30, 2005
    #1064 - You have an error in your SQL syntax;
     
  6. Mike Z

    Mike Z

    May 30, 2005
    Northbrook, IL
    Paul and Baywing,
    Thanks for sticking with me. I think I understand both your answers, and, if so, corresponds with my understanding. It all turns into a single aperture and shutter speed setting.

    If that's correct, isn't all this "1000 etc." just marketing hype. How much change would be apparent in the final image with a setting of 1/100 as compared to 1/102?

    I'm not bashing, because I'm going to get a D200 as fast as I can. It's just that I seem to adjust exposure in ACR or NC by moving my slider to the right or left anyway, and I would be doing that even if my old Nikkormat had magically turned into a digital camera capable of shooting RAW.

    Mike
     
  7. Baywing

    Baywing

    Feb 22, 2005
    CT USA
    The purpose is to analyze the components in the scene and come up with an exposure that is the best all-around. You can do the same thing manually with a spot meter, if you are shooting slide film, you want to hold the highlights to keep them from blowing out and let the shadows fall where they will. You meter the highlights, make your adjustments and shoot. This does basically that, it just does it in a micro-second. You won't get 1/102 sec, it only computes to the nearest 1/3 stop. Under most conditions, I find Nikon's matrix metering very good. The trick is to know when it isn't going to get you what you want, then you have to start thinking again.
     
  8. Mike Z

    Mike Z

    May 30, 2005
    Northbrook, IL
    Baywing,
    thanks for the explanation. I understand all that you're saying. It's almost as if you take 1000 readings with your spot meter and use your knowledge to decide how to "average" them. The camera with its meter and its algorithms does that in almost an instant. Pretty impressive.

    Mike
     
  9. Baywing

    Baywing

    Feb 22, 2005
    CT USA
    That's it, in simplistic terms!
     
  10. Henry Goh

    Henry Goh

    301
    Mar 17, 2005
    Singapore
    Exposure and metering

    All these modern gizmos make things more automated and supposedly easier for photographers. However, for someone like myself, who is not very computer savvy and not too clever with electronics, I still think of my spotmeter and using that to find the highlight, midtone and shadows. Then I decide where to place my exposure and the highlight is either 1 2/3 or max 2 stops above whatever the exposure EV I happen to use.

    Maybe that is why I set my camera to M and metering to SPOT all the time.

    Henry
     
  11. MontyDog

    MontyDog

    Jan 30, 2005
    #1064 - You have an error in your SQL syntax;
     
Loading...
Similar Threads Forum Date
Noise and exposure. General Technical Discussion Aug 16, 2014
Need some basic shooting technique help General Technical Discussion Sep 15, 2012
basic camera software General Technical Discussion Jul 18, 2012
Photomatix Basic Wanted General Technical Discussion Aug 6, 2010
Basic questions about fast lenses, bokah, settings, and noise..? General Technical Discussion Apr 17, 2010