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Getting no where with my image colours

Discussion in 'Beginner's Corner' started by Nikoboy, Jan 18, 2019.

  1. PeteRob

    PeteRob Well-Known Member

    Here is a castle.

    Correct (for me) exposure. Then + 0.5 stop then another +0.5 stop. You can see how the colour intensity fades out as the exposure increases.

    Correct

    [​IMG]DSCF3723-3.jpg by Pete, on Flickr

    +0.5 stop

    [​IMG]DSCF3723-2.jpg by Pete, on Flickr

    +1 stop

    [​IMG]DSCF3723.jpg by Pete, on Flickr
     
    Roger Hicks likes this.
  2. PeteRob

    PeteRob Well-Known Member

    A (clean) UV filter will not affect the image. Possibly shooting into the light it risks a bit more flare than a bare lens.

    A circular polarising filter will deepen the blue in the sky. The extent to which this works depends on the time of day and the position of the sun. It works best if the sun is to one side of you. The filter will have a little arrow on it. Move the arrow to point to the sun to have the most effect.

    My preference is to use Aperture Priority and set the aperture to determine depth of field (usually I keep it on F8 as a default for landscape) that I want. I keep an eye on the camera chosen exposure time. If it is too long - i.e. I risk camera shake - then I increase the ISO setting. If the scene is one I think needs less or more exposure then I use exposure compensation.
     
  3. Nikoboy

    Nikoboy Active Member

    Sorry, F4.8
     
  4. cliveva

    cliveva Well-Known Member

    Hi,
    I always shoot in aperture priority, so I can control depth of field. I also shoot in RAW, so I can tweet the exposure in post production as well as the levels, with option to readjust the image later if I not happy with a print.
    Best of luck
    Clive
     
  5. Nikoboy

    Nikoboy Active Member

    So if I used F8 as start point and use exposure -/+ to try and get the desired image.
    In Aperture mode the ISO cannot be set as Auto, I mostly use 100/200 unless the images are too dark then I increase the ISO accordingly or should I try the exposure setting more first.

    thanks
     
  6. GeoffR

    GeoffR Well-Known Member

    Looking at the first image, of the castle, the sky is blown (over exposed) which doesn't help the overall effect. I copied the image and played with it a bit. I darkened it slightly and increased the saturation of the water but I couldn't rescue the sky. Other than the sky it is fine, as previously under exposing by about 1/3 stop will help, but get the sky right, which will leave the foreground dark, but you can lighten that later, and you will have something closer to what you appear to be looking for. I won't post my version because the effect is subtle and, as I said earlier, the sky is the real problem.

    A polariser doesn't always help but it does always reduce the light reaching the sensor by around 1.3 stops so I would suggest using it only when you can actually see any difference. I rarely use one with digital but did with film, the effect can be less than subtle. Certainly in the woods I would rather have a 1.3 stop faster shutter speed. If you want a filter on the lens at all times a UV is the normal choice, but don't forget that a lens hood provides more protection against impact damage.
     
  7. RogerMac

    RogerMac Well-Known Member

    Sorry I have come late to this party - but the settings of the first image are
    exif.JPG
     
  8. PeteRob

    PeteRob Well-Known Member

    I just downloaded #5 and get the same information - only missing the software box.

    So it wasn't taken on Auto but shutter priority, it was using spot metering not the normal evaluative metering that auto would use and had +2/3 exposure compensation.

    If I take it down 2/3 of a stop it looks oversaturated to me so either it has had some editing/processing or the compression to reduce the file size has removed a lot of information. Certainly I think the compression hasn't helped the sky.
     
  9. PeteRob

    PeteRob Well-Known Member

    I downloaded #16 - that was taken on auto with evaluative metering and the flash activated, not that the flash would make any difference.

    The compression is quite extreme - the first would be about 9.6 MB uncompressed and the second 7.2 MB.
     
  10. RogerMac

    RogerMac Well-Known Member

    Personally I would also have stopped down a bit, even on a high grade lens working right up against the max apertures would be a bit tricky .

    also it might be sensible to experiment with down sizing algorithms if your editor allows, I normally use Lancos2 as it helps with keeping the result sharp but of course tastes may vary
     
    Roger Hicks likes this.
  11. PeteRob

    PeteRob Well-Known Member

    Hi, yes that is how I do it. I use exposure compensation more on the basis of experience as to how the camera behaves. You can get some idea using image review but rear LCDs are not very best at showing pictures.

    You need to check your settings. With the castle you were not on auto and you were using both spot metering and exposure compensation. To use spot metering you really need to know how the camera responds - the idea is to take the spot meter reading then adjust the exposure to reproduce the brightness of the object you metered off. The amount of adjustment depends on the choice of the "spot".

    It is best to use as low a value of ISO as possible. Depending on camera the image quality gets worse above, say 800, although more recent cameras are OK up to 1600 or even 3200.

    When posting pictures don't compress them to make them small. Use resize to change the number of pixels. The resizing program ( you seem to be using photoshop) will intelligently remove pixels. If you use compression then the algorithm will take information away, e.g if you have four pixels that are nearly the same it will eliminate the differences to save space. Then, when the picture is shown in a browser the browser will take pixels away to make it fit. Far better to resize to start with and avoid compression.
     
  12. RogerMac

    RogerMac Well-Known Member

    Unfortunately neither of my systems is Nikon but I presume that one can set the screen information to show the histograms? and that would show a lot of helpful information
     
  13. PeteRob

    PeteRob Well-Known Member

    Yes and no. The issue is getting the required saturation and while histograms can say something about avoiding clipping they are difficult to interpret in terms of overall colour information.

    This is one area that mirrorless cameras have an advantage. In good light you can see the effect of applying exposure compensation and, more importantly, get an immediate feeling of whether the camera metering is right or wrong. With a DSLR (unless I suppose you switch to liveview) all you can do is take the picture and review on the LCD. What you see there depends much on the external light as older LCDs especially are very hard to see in bright light and it is difficult to make fine assessments.
     
  14. Roger Hicks

    Roger Hicks Well-Known Member

    Dear Pete,

    As indeed will a linear polarizing filter.

    Cheers,

    R.
     
  15. PeteRob

    PeteRob Well-Known Member

    So true, but not suitable for use on that camera, which is why I added the qualification.
     
  16. Roger Hicks

    Roger Hicks Well-Known Member

    Dear Pete,

    Fair enough. Sorry.

    Cheers,

    R.
     
  17. GeoffR

    GeoffR Well-Known Member

    Any body ever tried a linear polariser on a DSLR? I know it is something to do with the semi-silvered mirror but when I used a linear polariser on an OM4 all it dis was to affect the finder, as far as I could tell.
     
  18. PeteRob

    PeteRob Well-Known Member

    It interferes with AF and advanced metering modes. With a manual focus camera and averaged metering it should be OK http://www.leefilters.com/index.php/camera/polariser
     
  19. Benchista

    Benchista Which Tyler

    It's all down to how the camera collects light for the metering system or AF system. If it uses beam splitter/semi-silvered mirror, then a linear polariser can upset the process regardless of the metering pattern.
     
  20. GeoffR

    GeoffR Well-Known Member

    Thank you gentlemen, doesn't really explain in any detail what effect it has on the camera and image but as I don't possess a linear polariser I can't experiment so I just wondered if anyone had tried. There is a serious reason for asking, it would be useful to be able to explain in some detail why a new user should buy circular polarisers, beyond "they don't work properly".
     
    Last edited: Jan 19, 2019

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