Results 1 to 17 of 17

Thread: This might be of interest

  1. #1
    JPS's Avatar
    Join Date
    Nov 2011
    Location
    Essex, UK
    Posts
    1,475
    Real Name
    John

    This might be of interest

    Hi a,
    I do not proclaim to be the author of the following tip, but thought it was worth sharing with my friends here at CiC.

    If for some reason you do not have your grey card with you, a bit of advanced preparation can give you the opportunity to salvage the situation. I know the cost of purchasing a “Grey” card is not that expensive and in fact bought mine brand new off ebay, for the princely sum of £4.29, all safely connected on a lanyard ready for easy use when needed.

    To use a grey card, hold it up in the light that is the same as the light hitting your subject, point your camera at it (preferably using spot metering mode for best results) and you now have a ‘perfect’ setting. This 18% grey card is what your camera assumes the world is; placing such a card in front of your camera now makes it able to meter the light with better accuracy giving you a great place to start.
    So then why do we all not use a grey card every time we take a picture? The number one reason is the card has been forgotten and not always with you.

    So what if you could have a grey card with you all the time?
    As long as you have two hands, a substitute grey card could always be with you.
    The technique is simple and the idea is that the colour and tone of the palm of your hand doesn’t change much. Certainly not as much as that back of your hand; this has more pigment and sees more sun. So why not use that?
    To use your hand as a grey card you will first need a grey card. In a nice even light, using spot metering and manual exposure mode, point your camera at the grey card. Set your ISO so it is not on Auto and maybe to 800, the number isn’t too important. Now adjust aperture and shutter speed until the camera metering is at zero, meaning it is not over or underexposed according to the camera. Next place your hand (Suggest your left hand) where the card was, with your fingers together. Ensure the centre metering spot is completely covered by your hand.
    What does the camera’s meter read now? If the setting you had for the grey card now shows 2/3rds of a stop too dark for your hand. It thinks these settings will make my hand too dark, but not so, because we set the camera’s settings using the grey card, which is accurate and matches the camera’s metering expectations. This means whenever I point the spot metering at your hand, and your hand is in the light hitting your subject, you just have to adjust the settings until your camera thinks the exposure is 2/3rds of a stop too dark and your set!

    I know if you are shooting RAW, you can adjust the white balance if needed, this is another option if you want to try and get things a bit more accurate in the field; not perfect I know, but maybe, just maybe someone might find this method useful, in an emergency.
    Last edited by JPS; 9th June 2012 at 11:24 PM.

  2. #2
    jjbacoomba's Avatar
    Join Date
    Mar 2011
    Location
    San Antonio,Texas
    Posts
    483
    Real Name
    Joe

    re: This might be of interest

    Thanks John. I will try that.

  3. #3
    herbert's Avatar
    Join Date
    Oct 2010
    Location
    Sussex, UK
    Posts
    471
    Real Name
    Alex

    re: This might be of interest

    This is a nice tip but it is not for setting the white balance. It is only for the exposure. In that case then you can use your hand or any other known tone within the scene to base your exposure such as green grass at +2/3, snow at +2, blue sky at +1 1/3, etc. However in the digital age I find it is better to use the camera histogram and a review of the camera LCD. As long as the essential highlights are not blown then things can always be brought back in post processing.

    To set the white balance is easy when using live view. Simply turn on live view and adjust the white balance and watch the image colours change. When they match what your eyes see for the scene then you are set. This works very nicely if you can adjust the kelvin scale, otherwise you just step through the presets and pick the best one.

    In the absence of live view you can do this process a bit slower by reviewing a test shot on the LCD after changing the white balance.

    Alex

  4. #4
    JPS's Avatar
    Join Date
    Nov 2011
    Location
    Essex, UK
    Posts
    1,475
    Real Name
    John

    re: This might be of interest

    Alex,
    you are of course correct, just testing if you noticed.

    My mistake everyone, I did say this was not my tip, but I did slightly mis-understand things; thanks to Alex for correcting things.

    I have adjusted the title of this tread to avoid any more confusion.

  5. #5
    William W's Avatar
    Join Date
    Jan 2009
    Location
    Sraylya
    Posts
    4,018
    Real Name
    William (call me Bill)

    re: This might be of interest

    When holding the Grey Card, or the palm of the hand, directly IN FRONT OF THE CAMERA, there are two matters which must be addressed.

     Firstly, it is important to have the palm (or the Grey Card) in exactly the position where the Subject will be. and directly facing the Camera Viewpoint. That usually means the PHOTOGRAPHER has to MOVE closer to that postion (unless it is possible to ensure that at the Camera Viewpoint Position the light is close enough to EXACTLY the same as it is falling upon the SUBJECT).

     Secondly, (especially for the Palm Reading), it is better to use a Metering Mode which sees the Whole Viewfinder and not to use Spot Metering: the reason is the Palm of the hand is NOT flat and if a SPOT METER mode is used it is in some circumstances possible to make the meter read differently as it moves across the undulations of the palm which will have differing areas of light and shadow.

    In this example below, the Grey Card is being used to make a Light Reading in the Shadow Area of the Patio, which is where the Subject will be standing – and as is obvious, the Background will be blown out because the Direct Sunlight is illuminating the Background.

    The point of this exercise was to MAKE the Photographer to MOVE to the position just in front of where the Subject will be positioned and to make the Meter Reading on the Grey Card, at that position, even though the Photographer will be taking the shoot from quite a distance away.

    This might be of interest

    WW
    Last edited by William W; 10th June 2012 at 01:42 AM.

  6. #6
    JPS's Avatar
    Join Date
    Nov 2011
    Location
    Essex, UK
    Posts
    1,475
    Real Name
    John

    re: This might be of interest

    Thanks Bill,
    Both points noted and I appreciate the feedback.

    In my opinion, I think understanding how to use these basic tools is an important part of our ‘Art / hobby’.

    As you can see I’m still on the first few “Runs of the ladder” in terms of learning; so all help is greatly received.
    Kind regards

  7. #7
    William W's Avatar
    Join Date
    Jan 2009
    Location
    Sraylya
    Posts
    4,018
    Real Name
    William (call me Bill)

    re: This might be of interest

    You’re welcome.
    You might like to add to the list of ‘basic tools and tricks of the trade’:

    Nature’s ‘Lush Green’ is about the same as ‘Photographic 18% Grey’.
    So if you are in a situation where a lush green bush is illuminated in the same manner as the Subject – the bush will serve as your grey card: so too lush green grass.

    WW

  8. #8

    Join Date
    Apr 2011
    Location
    Ontario (mostly)
    Posts
    6,632
    Real Name
    Bobo

    Re: This might be of interest

    No expert at this and get it wrong more often the right but I will use a grey pavement or bush as needed.
    Last edited by Dave Humphries; 10th June 2012 at 02:03 AM.

  9. #9

    Join Date
    Feb 2012
    Posts
    43
    Real Name
    Ana

    Re: This might be of interest

    First of all, this is the day of tips :P and understanding.

    Thank you JPS for opening this topic. For me is very important. Thank you Herbert(nice and perhaps A GOLDEN TIP) and Bill for developing the subject.

    There are some parts that i don't see them very clear.

    What are the issues we are talking about here? I guess(but i'm not sure) we are talking about THE GREY CARD(which i don't understand it, but i'll try).

    1.The grey card is used to determine a CORRECT exposure.
    2.The grey card is used to determine the CORRECT WB.

    @Bill.
    Exactly, i have a subject and a grey card. How is this helping me determining the correct exposure? Practicaly, step-by-step. a.I put the grey card on the place where the subject will be.
    b.Move the camera to Av(or manual, etc).
    c.Set the metering mode to Spot.
    d.Meter the center of the grey card(filling the viewfinder with it)
    e.Let's say i'm in manual mode. I have a f/4 with 1/250. Rotate the shutter wheel/aperture until the indicator arrives to zero? When at zero that means that i have the correct exposure? (let's say the indicator was set to zero at f/4 with 1/15)...?
    f. Put my subject in the same place where my grey card was and start shooting at f/4 & 1/5.? This way i know that my exposure is correct(we are not taking in discution the artistic problem,etc.), not regarding the color of his clothes white/black/yellow/etc.? This method could be a TEMPLATE in determining the correct EXPOSURE?

    After i determined the LUMINANCE of my scene(the correct exposure) do i have to adjust the WB anymore?
    a. Set custom WB and indicate the image took with the grey card(f/4 and 1/15)?
    b. Set "K" as custom WB and rotating the wheel of Kelvin Scale until i find the most appropiate reality-imageonscreen equality?

    Once again i appreciate you all

  10. #10
    William W's Avatar
    Join Date
    Jan 2009
    Location
    Sraylya
    Posts
    4,018
    Real Name
    William (call me Bill)

    Re: This might be of interest

    Quote Originally Posted by anita View Post
    i have a subject and a grey card. How is this helping me determining the correct exposure? Practicaly, step-by-step. a.I put the grey card on the place where the subject will be.
    b.Move the camera to Av(or manual, etc).
    c.Set the metering mode to Spot.
    d.Meter the center of the grey card(filling the viewfinder with it)
    e.Let's say i'm in manual mode. I have a f/4 with 1/250. Rotate the shutter wheel/aperture until the indicator arrives to zero? When at zero that means that i have the correct exposure? (let's say the indicator was set to zero at f/4 with 1/15)...?
    f. Put my subject in the same place where my grey card was and start shooting at f/4 & 1/15.? This way i know that my exposure is correct(we are not taking in discution the artistic problem,etc.), not regarding the color of his clothes white/black/yellow/etc.? This method could be a TEMPLATE in determining the correct EXPOSURE?
    YES.
    For all practical purposes, the above is correct, except for two points:
    the typo – the shutter speed is 1/15 and not 1/5. (underlined and corrected in the extracted quote)

    I would use EVALUATIVE metering if using a Canon DSLR or I would use MATRIX metering if using a Nikon.
    I would NOT use SPOT METERING (or Centre Weighted Average).

    ***

    Detailed Explanation:

    Please refer to Post #5 – please note that the precise words used were:

    When holding the Grey Card, or the palm of the hand, directly IN FRONT OF THE CAMERA, there are two matters which must be addressed. . . Secondly . . . it is better to use a Metering Mode which sees the Whole Viewfinder and not to use Spot Metering.

    In Post #5, a detailed reason was given for not using SPOT METERING when using the Palm of the Hand, but no reason was given why SPOT METERING should not be used when using a Photographic Grey Card.

    If Evaluative (Canon) or Matrix (Nikon) Metering Mode is used, the result will be an image with an sRGB value of around 118:118:118 when a Grey Card is metered and then Photographed. That result is about 18% Grey.

    If CWA or Spot Metering is used and a Grey Card is metered the resultant sRGB values will be about 100:100:100. That is about 13% Grey.

    So therefore, if an 18% Photographic Grey Card is used as the Reference and the metering Modes CWA or Spot Metering are used - then the resultant exposure will about ½ Stop UNDER.


    There is a lot of discussion about this point.

    It appears to me that there is often confusion, as various debates seem to rage about whether an 18% Grey Card is accurate or inaccurate as an exposure reference for Digital Cameras and it is often it is stated that one must ALWAYS allow for that approximate ½ Stop difference . . . BUT the issue about which METERING MODE is being used, is often totally missed and not ever mentioned.

    This subtle exposure difference in reading a Grey Card, by the different METERING MODES seems reasonably consistent within the Canon and Nikon DLSR range of Cameras I have used – but I would be interested to know if others’ test results differ: and if their results do differ, specifically with which Cameras.

    WW
    Last edited by William W; 13th June 2012 at 09:58 PM.

  11. #11
    Glenn NK's Avatar
    Join Date
    Sep 2010
    Location
    Victoria BC
    Posts
    1,510

    Re: This might be of interest

    Quote Originally Posted by herbert View Post
    To set the white balance is easy when using live view. Simply turn on live view and adjust the white balance and watch the image colours change. When they match what your eyes see for the scene then you are set. This works very nicely if you can adjust the kelvin scale, otherwise you just step through the presets and pick the best one.

    Alex
    Many photographers using various brands have complained that their LCD screen wasn't colour accurate, so I would suspect that it's usually safer to not judge any colours by what the LCD shows.

    It's a frequent topic on photo forums - and the usual advice is to not judge the colour of an image by the LCD.

    For WB, I would suggest that a card is far more accurate.

    Glenn

  12. #12
    William W's Avatar
    Join Date
    Jan 2009
    Location
    Sraylya
    Posts
    4,018
    Real Name
    William (call me Bill)

    Re: This might be of interest

    Quote Originally Posted by anita View Post
    After i determined the LUMINANCE of my scene (the correct exposure) do i have to adjust the WB anymore?
    a. Set custom WB and indicate the image took with the grey card(f/4 and 1/15)?
    b. Set "K" as custom WB and rotating the wheel of Kelvin Scale until i find the most appropiate reality-imageonscreen equality?
    Not sure if this was also specifically directed to myself – but my answer is as follows:

    Quote Originally Posted by anita View Post
    After i determined the LUMINANCE of my scene (the correct exposure) do i have to adjust the WB anymore?
    I am not sure of the meaning of the phrase underlined – so there are these two answers:

    1. By setting an exposure using the Grey Card, there has NOT been any White Balance Setting achieved at all.

    2. If the question is asking: “After i determined the LUMINANCE of my scene (the correct exposure) do I still need to set a White Balance?”: then the answer is - you can set a Manual White Balance if you want to, or you can adjust the WB, later in post production. If you choose to adjust the WB later in post production, then it is advisable to shoot ‘raw’.

    ***

    Explanations:

    My four main reasons to consider setting a Manual White Balance in the Camera are:

    1. If I am shooting a series of shots under the same lighting conditions and especially if I want to present a Proof Run (or Proof Sheet) to the Client – because of PP speed and turnaround time.

    2. If I am shooting Available Light at Low EV, especially under Household Incandescent Lights - because in most DLSRs there is leverage in using the lowest °K and maybe even a Colour Correction Filter.

    3. If I am shooting under a WHITE lighting grid with Three Phase Power and especially if I am using a Shutter Speed faster than the Electricity Cycle Rate – to keep continuity, because three phase can confuse AWB when using high Shutter Speeds.

    4. If I plan to use the JPEG especially Straight Out of the Camera – because it is obvious why.



    Quote Originally Posted by anita View Post
    b. Set "K" as custom WB and rotating the wheel of Kelvin Scale until i find the most appropiate reality-imageonscreen equality?
    If this means using the LCD display as a reference: then I would not do that.

    In this regard I concur 100% with the advice given in by Glenn in Post #11 – “[do] not judge the colour of an image by the LCD.”

    WW

  13. #13

    Join Date
    Feb 2012
    Posts
    43
    Real Name
    Ana

    Re: This might be of interest

    Thanks a lot Bill for detailed explanation, in conclusion Grey Card to determine correct exposure and use that image to set the Manual WB, if i'm right.

    Yet, another question arrises. The Grey Card measurment can be done on subjects that are close to manipulate(portrait not so far, posing for you) or still subjects. But:
    a. What about a subject at 30m away?
    b. What about a subject that's a landscape?(night/day).

    PS: I will try to use Evaluative Measurment(as adviced).

    Thanks, Ana.

  14. #14
    Glenn NK's Avatar
    Join Date
    Sep 2010
    Location
    Victoria BC
    Posts
    1,510

    Re: This might be of interest

    Quote Originally Posted by anita View Post
    But:
    a. What about a subject at 30m away?
    b. What about a subject that's a landscape?(night/day).

    Thanks, Ana.
    I suggest:

    Use the RGB histogram to set/adjust exposure.

    Take an extra shot with the WB card in the image to get an accurate reading of white balance.

    Shoot RAW, and adjust the WB in PP.

    And I might add:
    c. What about the different colour temperatures that exist in one image?

    Landscape scenes can have different colour temperatures in one scene (light in the shade is a different colour than light in open sunlight, and this will affect the colours in the image).

    Another difficult situation is artificial lighting that uses different type of lighting in the same room.

    So, very often, there will be no perfect solution - only compromises.


    Interesting videos (actually there are eight of them - the first two):

    http://www.whibalhost.com/_Tutorials/WhiBal/01/

    This second one gets into the meat of the subject:

    http://www.whibalhost.com/_Tutorials.../02/index.html

    Glenn

  15. #15
    William W's Avatar
    Join Date
    Jan 2009
    Location
    Sraylya
    Posts
    4,018
    Real Name
    William (call me Bill)

    Re: This might be of interest

    Quote Originally Posted by anita View Post
    in conclusion Grey Card to determine correct exposure and use that image to set the Manual WB, if i'm right.
    Yes.
    If one chooses to use a Grey Card for Exposure, then that correctly exposed Image of the Grey Card, can be used to set an Manual White Balance and the White Balance will be accurate.

    ***

    Quote Originally Posted by anita View Post
    The Grey Card measurment can be done on subjects that are close to manipulate(portrait not so far, posing for you) or still subjects. But:
    a. What about a subject at 30m away?
    b. What about a subject that's a landscape?(night/day).
    Response to (a).
    For a Subject 30mtrs away a Grey Card might be able to be used, please see Post #5, the underlined portion here:

    "it is important to have the palm (or the Grey Card) in exactly the position where the Subject will be. and directly facing the Camera Viewpoint. That usually means the PHOTOGRAPHER has to MOVE closer to that position (unless it is possible to ensure that at the Camera Viewpoint Position the light is close enough to EXACTLY the same as it is falling upon the SUBJECT").

    For example, Shooting in a reasonably evenly lit Auditorium.



    Response to (b).
    For a Landscape a Grey Card could also be used - IF the light at the Camera is reasonable indicative of the light on the scene.

    Note that commentary about HOW a Grey Card might be used - does not imply that using a Grey Card is the best or easiest option.

    ***

    Quote Originally Posted by Glenn NK View Post
    And I might add:
    c. What about the different colour temperatures that exist in one image?

    Landscape scenes can have different colour temperatures in one scene (light in the shade is a different colour than light in open sunlight, and this will affect the colours in the image).
    Yes, this was made as a workshop example.
    There several different Artificial Lights illuminating this scene. It shot just before Sunrise and the Different Colour Casts of those lights are quite evident:
    This might be of interest
    506632v01 The Many Colours of Mixed Lighting

    ***

    Quote Originally Posted by Glenn NK View Post
    Another difficult situation is artificial lighting that uses different type of lighting in the same room.
    An example when shooting in Available Light.
    In this large room there is a window letting in sunlight (Camera Right) and in this Portrait the Sunlight is used as a Rim Light – BUT the down lights have a strong Yellow Cast – as is very evident in the Background.
    The Subject is NOT directly under one of those down lights and the PHOTOGRAPHER has a WHITE BOUNCE CARD used to bouncing some of the strong window light onto the face of the Subject and that appears to have had some effect to reduce any jaundice looking skin.

    This might be of interest
    143 Candid Portrait – Available Light

    *

    An example when using Flash as Fill and the Flash is NOT the same Colour Temperature as the (dying) Ambient Sunlight.
    Note how the Stone Decking changes colour to a Blue Cast in the background and the White curtains on the windows in the House in the Background are Blue:

    This might be of interest
    Flash Fill at Dusk – rapidly changing Ambient Light.


    WW

  16. #16

    Join Date
    Feb 2012
    Posts
    43
    Real Name
    Ana

    Re: This might be of interest

    Ok, Bill.

    I'll try to rephrase it. I'm not understanding the big picture with this GREY card. When i'm looking at the scene as a beginner i'm seeing mountains, people. This kind of stuff. I do not have an experimented EYE. What i was saying was:

    If i can plan the shooting i can set the WB, measure the Wb in the position of the subject, etc. I was asking what if i saw a subject at 30m away that i can't disturb. I can't go there to measure WB. If the subject is a LION , or a candid shot.

    I'm struggling to see the technical details in everything, to understand all peaces and in the end put them together to form the BIG PICTURE.

    My mind is blocked. It's still absorbing information, stocks it somewhere, refuse to process it. At some moments reading something i'm understanding a part .

    In the beginning when i was looking at a scene, i was seeing mountains. After a while, the rule of thirds. Dynamic Range, exposure, color of the light. These are all peaces of the big picture. In the end it's only a PUSH BUTTON and a setting(or 2). To obtain these it's a little bit difficult.
    When you see explanations of WB, they give you a simple example OF a white shirt/black shirt etc and seems clear. But when taking photos, it's different, there are much more details, combined, white shirts, red, all kind of colors, different source light. The more you discover things the more you realize that behind a photo it's a WHOLE UNIVERSE of DECISIONS.

    I don't know. Should i buy a color passport? Should i invest in one? Should i calibrate my camera(i don't know what that means, i've heard the term.). I want when i'm starting to shoot to have all instruments known and take photos as PROs. . I dream of it.

    Thank you for effort.
    Last edited by anita; 16th June 2012 at 09:51 AM.

  17. #17
    William W's Avatar
    Join Date
    Jan 2009
    Location
    Sraylya
    Posts
    4,018
    Real Name
    William (call me Bill)

    Re: This might be of interest

    Quote Originally Posted by anita View Post
    I'm struggling to see the technical details in everything, to understand all peaces and in the end put them together to form the BIG PICTURE.
    One very good way to learn a PRACTICAL CRAFT such as PHOTOGRAPHY is to join a Photography Club and participate in the regular events i.e. making Photographs – and then C&C the Images WITH a GROUP from the club.

    Posting Images for critique here would be similar, but the C&C obviously will be via the written rather than the spoken word.

    Both of these methods are arguably far better ways to understand and improve a PRACTICAL CRAFT, rather than seeking out only the answers to hypothetical and technical questions.

    WW

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •