Exposure Advise On Meter

Discussion in 'Lighting and Hardware' started by smoke665, Dec 13, 2019.

  1. smoke665

    smoke665 TPF Supporters Supporting Member

    Joined:
    Mar 29, 2016
    Messages:
    11,907
    Likes Received:
    5,835
    Can others edit my Photos:
    Photos NOT OK to edit
    It's seemed that lately my incident meter and my camera haven't always been on the same page, causing me to correct post. Tonight did a rather unscientific quick threesome, one as per the meter, then +1/3, and +2/3. If I'm reading these right, it looks like they are off. Light was adjusted for f/8 in all the shots, only the aperture was changed between shots. No adjustments other then crop post.

    #1 as per meter f/8 and the corresponding histogram

    exposure test.jpg f8.jpg

    #2 at f/7.1 and the corresponding histogram
    exposure test-2.jpg f7.1.jpg

    #3 at f/6.3 and corresponding histogram
    exposure test-3.jpg f6.3.jpg

    After looking at these I'm not so sure that I couldn't squeeze another 1/3 stop out, making the two read a full stop apart. Am I missing something here, or is it possible my meter could be that far off. This is an older model L308 which unfortunately doesn't have calibration adjustment but has been fairly close in the past. The battery seems to have lasted a long time, could it be a weak battery??? Or, do I need to be looking for a new meter?


     
    • Like Like x 1
  2. tirediron

    tirediron Watch the Birdy! Staff Member Supporting Member

    Joined:
    Jul 8, 2005
    Messages:
    45,748
    Likes Received:
    14,777
    Location:
    Victoria, BC
    Can others edit my Photos:
    Photos OK to edit
    Are you looking only at the histogram, or at the actual exposure? To me, the correct exposure appears to be somewhere in between #1 and #2. #3 is distinctly over-exposed. A lot of the 'far left' you're seeing in the histogram is a result of the dark background, black meter, and dark table-top. To me, a meter that's within or less than 1/3 stop from visually ideal is within spec.
     
  3. smoke665

    smoke665 TPF Supporters Supporting Member

    Joined:
    Mar 29, 2016
    Messages:
    11,907
    Likes Received:
    5,835
    Can others edit my Photos:
    Photos NOT OK to edit
    Both. Looking at the image, judging highlights, midtones, shadows, saturation, and overall brightness. Using the histogram to judge the amount data available. Can you explain why you see #3 as overexposed? Granted it's bumping the right, but whites are not blown? I appreciate another set of eyes and opinion on this.
     
  4. tirediron

    tirediron Watch the Birdy! Staff Member Supporting Member

    Joined:
    Jul 8, 2005
    Messages:
    45,748
    Likes Received:
    14,777
    Location:
    Victoria, BC
    Can others edit my Photos:
    Photos OK to edit
    Agree that nothing is blown, and the degree of over-exposure isn't significant, but the highlights just seem a bit hotter than I would opt for. This may also be due to differences in our monitors.
     
    • Like Like x 1
  5. dxqcanada

    dxqcanada Been spending a lot of time on here!

    Joined:
    Dec 4, 2008
    Messages:
    7,362
    Likes Received:
    1,438
    Location:
    Woodbridge, Ontario, Canada
    Can others edit my Photos:
    Photos OK to edit
    Stick a greycard there and use your camera's reflective metering off that ... then compare that to the incident meter reading.
     
    • Like Like x 1
  6. smoke665

    smoke665 TPF Supporters Supporting Member

    Joined:
    Mar 29, 2016
    Messages:
    11,907
    Likes Received:
    5,835
    Can others edit my Photos:
    Photos NOT OK to edit
    Incident is measuring flash. Camera reflective won't read incident/flash.
     
  7. smoke665

    smoke665 TPF Supporters Supporting Member

    Joined:
    Mar 29, 2016
    Messages:
    11,907
    Likes Received:
    5,835
    Can others edit my Photos:
    Photos NOT OK to edit
    I realize that when you're tweaking that last little bit it's a judgement call. Thanks for checking, having another opinion helps.
     
    • Like Like x 1
  8. dxqcanada

    dxqcanada Been spending a lot of time on here!

    Joined:
    Dec 4, 2008
    Messages:
    7,362
    Likes Received:
    1,438
    Location:
    Woodbridge, Ontario, Canada
    Can others edit my Photos:
    Photos OK to edit
    Ah, I missed the flash part ... thought it was ambient light.
     
    • Like Like x 1
  9. Derrel

    Derrel Mr. Rain Cloud

    Joined:
    Jul 23, 2009
    Messages:
    48,229
    Likes Received:
    18,841
    Location:
    USA
    Can others edit my Photos:
    Photos OK to edit
    Although we can see the histogram we need to know how much exposure correction has been applied to the jpeg images via the curves. Based upon your test scene I think you could brighten or darken these images quite easily so the tone curve would be more important to consider than just the histogram data. When looking at a JPEG image we have to consider how the raw file looked with a fairly flat or linear tone curve. It is possible that your default import curve is affecting our interpretation of the jpeg images?

    It is not that uncommon for a reflective light meter reading to be somewhat different from an incident Light reading. Because your camera cannot measure Flash with its built-in reflected light meter, it is quite difficult to compare.

    You have to be aware to that Nikon's 3D color aware Matrix metering gives you an exposure reading that is close to perfect based upon not only the reflecting light value but also upon the color that the meter has determined an object is. The Nikon 3D color Matrix metering can differentiate between white sand,grey sand, and brown sand because it is a color-aware metering device, whereas a light meter is a dumb,color-blind device which is designed to give you a reading which has to be interpreted somewhat. The modern Nikon is metering for color positive, RGB digital...
     
    Last edited: Dec 13, 2019
    • Informative Informative x 1
  10. smoke665

    smoke665 TPF Supporters Supporting Member

    Joined:
    Mar 29, 2016
    Messages:
    11,907
    Likes Received:
    5,835
    Can others edit my Photos:
    Photos NOT OK to edit
    Hey man, hoping you'd chime in. While the camera preview is always a guess as to what the "camera gods" in their infinite wisdom have applied, I was careful to make sure I had no presets applied including tone curves or camera profiles when I imported to Lr. Once there, the only adjustments made was to crop. I assumed that on export Adobe generated a JPEG that should have been devoid of any editing enhancements.

    You've confused me on reflective readings. The canera was on manual. The incident meter was used to adjust the flash (speedlight) to f/8. No camera metering was used. The light and shutter remained constant in the three shots, only the aperature was changed manually.

    My concern has been that I was originally opening up a 1/3 from the incident reading of the meter, but lately it seems that I've had to add increasingly more exposure compensation post. The test shots seem to indicate to me that the meter is in fact reading significantly under exposed.
     
  11. Derrel

    Derrel Mr. Rain Cloud

    Joined:
    Jul 23, 2009
    Messages:
    48,229
    Likes Received:
    18,841
    Location:
    USA
    Can others edit my Photos:
    Photos OK to edit
    Every jpeg image has some type of tone curve applied to it.

    If you need to add exposure then perhaps something in your system needs to be calibrated more exhaustively.

    One thing I can think of might be how you have the meter sitting in relation to your strobes. For example are you pointing the meter at the camera, or directly at the front face of the light modifier? You might see if there is much difference. Perhaps you prefer a more open Shadow. Incident light metering in my opinion is great for getting the Highlight tone value set, but that does not determine how about your shadows and midtones look.

    Most incident light meters will give you a good highlight tone when you are using a color positive system, such as color slide film, or modern digital.

    I think you should be aware that there are two schools of thought as far as where the dome is pointed when metering. One school of thought holds that the hemisphere should be pointed straight ahead,at the camera, while the other school of thought sees the photographer aiming the hemisphere directly at the main light.

    Secondarily let me say that your light meter uses what I call a "small hemisphere", whereas my Minolta uses a much larger and more gently rounded sphere. Perhaps this smaller hemisphere is more sensitive to aiming differences.

    Your your original post seemed to indicate that you were having a difference of opinion between your camera meter and your light meter and that is what I was talking about
     
    Last edited: Dec 13, 2019
    • Useful Useful x 1
  12. Derrel

    Derrel Mr. Rain Cloud

    Joined:
    Jul 23, 2009
    Messages:
    48,229
    Likes Received:
    18,841
    Location:
    USA
    Can others edit my Photos:
    Photos OK to edit


    Let me state it again:every jpeg image created from a raw file has had some type of tone curve applied. This is a very important part of how bright the image looks. Just open the image and go to the curves dialog and you will see exactly what the Adobe default curve is. This curve could greatly affect your interpretation of the exposure.
     

Share This Page