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11-01-2020, 12:47 PM   #1
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Lighting & Contrast help

Not sure if anyone has run into this problem.

I sell old paper and us a K-50 now, previously a Nikon d3300 with prime lens to shoot illustrations, engravings, ads, etc for ebay. I have a home made lighting setup using LED daylight side lighting. I use preset white balance, manual exposure, etc. and use the Bright in the K-50 or the Standard previously using the D3300. Same problem on both cameras.


Without adjusting the custom settings, boosting the low key and raising the contrast or post processing (too much time to do that) I get washed out images with low contrast. I have the same problem with 3d items using incandescent on my second lighting setup. Is this normal? Is it the lighting? I tried removing the uv filter without seeing any difference. See some samples below.


The first image is using the default custom image settings, washed out and low contrast.


Second image is -3 low key and +3 contrast and then the image becomes acceptable and looks accurate.

Why are such drastic setting adjustments necessary?






11-01-2020, 01:02 PM - 1 Like   #2
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Probably because the meter sees the paper as mainly white, and adjusts the exposure accordingly. Meters are set up to expose for an 18% grey subject. Have you tried photographing the back of your hand, then using that exposure as a basis for manual exposure control ?
11-01-2020, 01:07 PM   #3
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To the naked eye, which of the two images is closest to the original ?
11-01-2020, 01:08 PM   #4
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QuoteOriginally posted by FlyingEagle Quote
Without adjusting the custom settings, boosting the low key and raising the contrast or post processing (too much time to do that) I get washed out images with low contrast. I have the same problem with 3d items using incandescent on my second lighting setup. Is this normal? Is it the lighting? I tried removing the uv filter without seeing any difference. See some samples below.
QuoteOriginally posted by FlyingEagle Quote
Why are such drastic setting adjustments necessary?
Because the original exposure was inadequate (not enough light to the sensor to support the desired tonal range).

The custom image feature is sort of evil, though it did allow you to get something approaching black while boosting the whites by leveraging its limits.

My suggestion is to use manual exposure with daylight WB and shoot in RAW, placing exposure to an are you want to render as bright white (use spot metering with histogram chimping to place the high value peak to the right). This should only need to be done, at most, once per magazine. Let your camera capture as much information as is in the frame and adjust as needed in post. That last might be most easily done with profiles appropriate to the most common types of documents you see. Most software allows batch application of profiles.

Back to the custom settings; even with parameter adjustments they are too unpredictable in that the effect varies by subject and are a processing effect only (do not result in changes to exposure). They also apply to JPEG only, resulting in more difficult PP. FWIW, High/Low Key adjust results in a decrease in contrast. Also note that "Bright" or "Radiant" (Bright's more impressive brother) does not mean brighter per se. It means differential increase to color values may result in perception of higher contrast without changing the actual gray-tone value range in the frame.

Good luck!


Steve


Last edited by stevebrot; 11-01-2020 at 05:06 PM. Reason: clarity and completeness
11-02-2020, 06:30 AM - 1 Like   #5
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QuoteOriginally posted by 35mmfilmfan Quote
Probably because the meter sees the paper as mainly white, and adjusts the exposure accordingly. Meters are set up to expose for an 18% grey subject. Have you tried photographing the back of your hand, then using that exposure as a basis for manual exposure control ?
If the camera saw all white and tried to convert the image to 18% grey, then I'm guessing the picture would be under exposed. The problem here looks like the picture was over exposed by a couple of stops.
11-02-2020, 07:06 AM - 1 Like   #6
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Have you tried raw processing the files? The additional control and potentially useful presets could make things easier.
11-02-2020, 07:42 AM   #7
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Focus appears to be considerably off in the first image as well.

11-02-2020, 08:06 AM   #8
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QuoteOriginally posted by 35mmfilmfan Quote
Probably because the meter sees the paper as mainly white, and adjusts the exposure accordingly. Meters are set up to expose for an 18% grey subject. Have you tried photographing the back of your hand, then using that exposure as a basis for manual exposure control ?
Agree with 35mmfilmfan. Try a gray card too.
11-02-2020, 10:48 AM   #9
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QuoteOriginally posted by hjoseph7 Quote
If the camera saw all white and tried to convert the image to 18% grey, then I'm guessing the picture would be under exposed. The problem here looks like the picture was over exposed by a couple of stops.
I take your point, but as the OP was using some kind of auto mode (apparently), this may have caused over-compensation in the camera. I've not used the K-50, so this is just off the top of my head.
11-02-2020, 05:08 PM   #10
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QuoteOriginally posted by stevebrot Quote
Because the original exposure was inadequate (not enough light to the sensor to support the desired tonal range).

The custom image feature is sort of evil, though it did allow you to get something approaching black while boosting the whites by leveraging its limits.

My suggestion is to use manual exposure with daylight WB and shoot in RAW, placing exposure to an are you want to render as bright white (use spot metering with histogram chimping to place the high value peak to the right). This should only need to be done, at most, once per magazine. Let your camera capture as much information as is in the frame and adjust as needed in post. That last might be most easily done with profiles appropriate to the most common types of documents you see. Most software allows batch application of profiles.

Back to the custom settings; even with parameter adjustments they are too unpredictable in that the effect varies by subject and are a processing effect only (do not result in changes to exposure). They also apply to JPEG only, resulting in more difficult PP. FWIW, High/Low Key adjust results in a decrease in contrast. Also note that "Bright" or "Radiant" (Bright's more impressive brother) does not mean brighter per se. It means differential increase to color values may result in perception of higher contrast without changing the actual gray-tone value range in the frame.

Good luck!


Steve
Thanks for everyone's comments. Stevebrot had some insightful information regarding the in camera rendering a jpg. Now I understand.


I do manual White Balance and I use a gray card for exposure then save everything into U1. So I will just stick with the additional tweaks to the custom image settings that give me the best results like second image I posted, which looks just like the real thing. I normally shoot RAW+, but when I have to churn out fifty images in an hour for ebay, I don't have time to post process anything. The image needs to look like what I am selling and show some detail as much as possible, considering time constraints. It does not need to be perfect, rather just not look crappy.
11-02-2020, 05:24 PM   #11
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QuoteOriginally posted by FlyingEagle Quote
Thanks for everyone's comments. Stevebrot had some insightful information regarding the in camera rendering a jpg. Now I understand.


I do manual White Balance and I use a gray card for exposure then save everything into U1. So I will just stick with the additional tweaks to the custom image settings that give me the best results like second image I posted, which looks just like the real thing. I normally shoot RAW+, but when I have to churn out fifty images in an hour for ebay, I don't have time to post process anything. The image needs to look like what I am selling and show some detail as much as possible, considering time constraints. It does not need to be perfect, rather just not look crappy.
That makes sense.
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