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Question about exposure???
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Oct 4, 2018 07:39:07   #
rpavich Loc: West Virginia
 
xamier wrote:
Good Morning,
I downloaded some images last night, portraits using hot lights. (I can't post, the model was underage and I don't have a release)

On the camera screen many of the photos seemed perfectly exposed. When I downloaded into light room on my laptop, I had to add at least one stop, sometimes more to get them light enough to see. I am using a Nikon 5300 and a Tamron 18-400 mm lens. I shoot in raw, the white balance was incandescent, picture control standard, color space adobe, ISO 500.

I am wondering if it is the adobe color space, my monitor, the hot lights......I have never run into this problem before and I would love to understand what is happening and any insight into the differences between what I see on the camera monitor and my computer.

Thank you .
Good Morning, br I downloaded some images last nig... (show quote)


How did you determine that your pictures where "perfectly exposed"? Just from looking at the brightness of the LCD?

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Oct 4, 2018 08:33:55   #
lamiaceae Loc: San Luis Obispo County, CA
 
xamier wrote:
Good Morning,
I downloaded some images last night, portraits using hot lights. (I can't post, the model was underage and I don't have a release)

On the camera screen many of the photos seemed perfectly exposed. When I downloaded into light room on my laptop, I had to add at least one stop, sometimes more to get them light enough to see. I am using a Nikon 5300 and a Tamron 18-400 mm lens. I shoot in raw, the white balance was incandescent, picture control standard, color space adobe, ISO 500.

I am wondering if it is the adobe color space, my monitor, the hot lights......I have never run into this problem before and I would love to understand what is happening and any insight into the differences between what I see on the camera monitor and my computer.

Thank you .
Good Morning, br I downloaded some images last nig... (show quote)


Minor! Should we call the authorities?

A few things,

If you are shooting Raw, Camera WB means nothing (but a starting point in the ACR displayed image). Unless your commercial printer wants or requests AdobeRGB, most Monitors and Home Printers work best with sRGB. The camera display is a tiny inaccurate JPEG even when you are shooting RAW. It is only a crude "ball park". The camera Histogram is slightly better, but you should open the image up in Photoshop ACR or Lightroom to really view and judge an image.

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Oct 4, 2018 08:58:16   #
Paul L_S Loc: Lithia Springs GA USA
 
Another idea, try changing the angle of the monitor screen on your laptop.

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Oct 4, 2018 09:03:36   #
camerapapi Loc: Miami, Fl.
 
What you see in the camera monitor is not necessarily an accurate representation of your image. To begin with no camera monitor is color calibrated.
Did you look at the histogram after the exposure? A color histogram is a pretty good representation of the final exposure. If the histogram displays pixels along the monitor without clipping the highlights your exposure has an excellent chance to be OK.
A color calibrated monitor at home is a must especially if you print your files.

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Oct 4, 2018 10:00:07   #
burkphoto Loc: High Point, NC
 
Tomfl101 wrote:
Please note right now I'm giving Burk the "I'm not worthy" bow but having also been in the school picture business and training hundreds of people without the ability to provide calibrated light meters to every photographer I came to use the following SIMPLE method with excellent results. Take a small (2-3 inch) piece of white paper, hold it directly in front of a test subject's face and purposely overexpose with the camera highlight indicator set to ON. Then reduce aperture or flash power in 1/3 stop increments. When the paper stops blinking, stop down an additional 1/3 stop. Once this is achieved you will have consistent Jpeg images without the need for post processing adjustment. This can be done in any fixed lighting situation in the studio or available light. The only variable is the color and density of the white paper. We were able to use a constant "camera card" which was part of the photographers paperwork. The back side of a Gray Card is a consistent white that can be used as well. Ratio lighting can be achieved by setting the camera aperture to the required light output and adjusting power independently with the white card in place.
Please note right now I'm giving Burk the "I'... (show quote)


We should trade “war stories,” Tom. I was at Delmar, 1979-96, Herff Jones Photography Division from 1996-2011, and Lifetouch from 2011-2012, all at the same business address in Charlotte.

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Oct 4, 2018 12:34:05   #
Tomfl101 Loc: Mount Airy, MD
 
I was at Lifetouch in Baltimore from 1985-2017. I really admire your technical expertise. We always appreciated the folks at the Charlotte lab. Consistently high quality products with fast turn around. Your legacy persists!

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Oct 4, 2018 13:51:40   #
dp75
 
rmalarz wrote:
A lot of this modern photography stuff requires the equipment to be synced. This could simply be a matter of your monitor not being calibrated. There are some great tools for this, Datacolor and Xrite both manufacture monitor calibration tools.

As for exposure, it's still pretty simple. The basic f-stop is equal to 1/ISO. The shutter speed is equal to 1/foot-candles to place the measured subject in Zone V.
--Bob


Can you please explain "the basic f-stop" and "the shutter speed" in an easy way? Thank you.

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Oct 4, 2018 14:32:01   #
Ron Dial Loc: Cuenca, Ecuador
 
Check the brightness of your camera viewer. If the viewer is too bright (sometimes you do this so you can see it in sunlight), and you adjust the exposure in the camera so it looks OK in the viewer, then the downloaded image will be off.

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Oct 4, 2018 18:38:39   #
burkphoto Loc: High Point, NC
 
dp75 wrote:
Can you please explain "the basic f-stop" and "the shutter speed" in an easy way? Thank you.


Order Bryan Peterson’s book, *Understanding Exposure* and read it.

‘f/stop’ is the focal length of the lens divided by the number of times the diameter of the aperture will fit into it.

f/4 (for example) theoretically lets in the same amount of light on any lens. The aperture diameter must change as the focal length changes. f/4 on a 100mm lens makes the diaphragm aperture 25mm wide. On a 50mm lens, it’s 12.5mm wide.

Of course, only a lens designer cares about the diameter of the aperture. We just need to know that each full f/stop change equals double or half the light, depending on which way you move the control. f/2 is wider than f/2.8, and lets in twice the light. The scale is a rounded progression of the square root of two (f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8...)

Shutter speed is time — how long the light that gets through the lens hits the film. Most of the time, we deal in fractions of a second (1/2 to 1/16,000 second).

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Oct 4, 2018 18:53:27   #
dp75
 
Thank you again.

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Oct 5, 2018 09:05:31   #
xamier Loc: Citronelle, Alabama
 
Thanks every one, fortunately my laptop has a very good UHD monitor with a wide viewing angle. I was eyeballing the exposure on the camera screen, I didn't realise there was such a difference. I am saving up for another monitor and light meter and I am continuing to work on the manual settings.
Betty

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Oct 7, 2018 12:37:08   #
xamier Loc: Citronelle, Alabama
 
burkphoto wrote:

Image adjustment by a person with accurate color vision (Take the Munsell Hue Test at http://www.colormunki.com/game/huetest_kiosk.)
Proper choice of output parameters (bit depth, file type, compression, resolution, color space required for the end use)
.


:) I just took the test and my score was 0. Thanks for posting the link. :)

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Oct 7, 2018 13:02:34   #
BebuLamar
 
dp75 wrote:
Can you please explain "the basic f-stop" and "the shutter speed" in an easy way? Thank you.


Using that formula you will have to do 2 things. You will have to meter in Candela/m² and you have to know how to find the square root of a number. By the way Bob may make a mistake. The basic f stop is the square root of the ISO, the shutter speed is 1/the reading in Cd/m².

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Oct 7, 2018 13:43:06   #
User ID
 
burkphoto wrote:

... you have to be careful .... if you're photographing
low key or high key subject matter.

A correct exposure of a low key subject will have a
histogram skewed far to the left, because only a few
tones define the subject. ...........

If you decrease exposure of a high key subject much
below that of a normally exposed gray card, you may
dull the background that you spent so much time
lighting evenly to render it just barely white.

A histogram does not indicate correct exposure. It
just tells you the *relative* distribution of tones in
the image.

............
br ... you have to be careful .... if you're phot... (show quote)


The above is excellent advice clearly stated. Yet the
obvious ... and easy ... approach to getting USEFUL
in-camera histograms is not mentioned.

Since the situation in question is a well controlled
studio session, approach the subject so to fill the
frame with only significant portions of the overall
scene ... small hints of any very dark or very bright
backgrounds, mostly skin tones plus the subject's
garments, etc. Frame really tight, and then back
up to not so tight. Reading the histograms of these
test frames will be VERY usefully informative, with
most, or all, misleading tones eliminated. Acoarst
don't be a robot ... apply some judgement !


---------------------------------------------------


Ancient advice from the film era:
"Use your meter creatively, not slavishly".

Following thru to the digital era:
"Used creatively, a digital camera is the
best, most informative, light meter ever
put in a photographer's hands".



`

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Oct 7, 2018 14:07:45   #
BebuLamar
 
BebuLamar wrote:
Using that formula you will have to do 2 things. You will have to meter in Candela/m² and you have to know how to find the square root of a number. By the way Bob may make a mistake. The basic f stop is the square root of the ISO, the shutter speed is 1/the reading in Cd/m².


I made a mistake. The unit is Candela/ft² and not Candela/m².

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