Why do some portraits have "hot"/clipping highlight and some dont? Started 6 min ago | Discussions

Example of hot highlights: click!
Example of even light (skin retains full detail, desired): click!

I often undesirably get the blown out look in my portraits. Without relying on the LCD on the back of my digital camera (I also want to use film for some shots), how can I ensure with my lights+modifiers, flash meter and exposure settings that I retain detail in the light side of the face ? Is it simply a matter of metering towards the light source, or do I have to underexpose that reading?

moodlover wrote in post #17464238
Example of hot highlights: click!
Example of even light (skin retains full detail, desired): click!

I often undesirably get the blown out look in my portraits. Without relying on the LCD on the back of my digital camera (I also want to use film for some shots), how can I ensure with my lights+modifiers, flash meter and exposure settings that I retain detail in the light side of the face ? Is it simply a matter of metering towards the light source, or do I have to underexpose that reading?

As this question is a bit 'what if', the answer is 'do it properly'.
If you'd linked to your own work, we would ask about your method and could pinpoint the problem.

The answer is to meter properly, and you should have no problems. Do you use a meter?

Are you checking your lighting ratios? You could be getting hotspots because one light is turned up too high, relative to the other(s).

Without knowing what you are doing though, setting up your lights, how you are metering etc., it is hard to tell you what you are doing wrong. As PhilV says, if you meter properly and check your ratios then there shouldn't be any problems.

Ratios and metering.
Northern European caucasian skin is just about 18% grey.
When I was a young photographer, I used the back of my hand with a reflected meter the same way I'd use an 18% grey card.

It was close enough for a starting point.

Here is another trick, take a piece of corrugate from a box. The normal yellowish color that most of us consider untreated kraft paper. Bend it to about 90 degrees and place it in subject position. Edge toward camera so that main is hitting mostly one side and fill is hitting both or the shadow side, depending on how you arrange your lights.

If your lights have modeling lights that track, use them to set the ratio that looks right. Then make an exposure and look at the LDC. Adjust power and camera settings to get what you want. The corrugate is about the same reflectance as caucasian skin.

If you have a flash meter, then its even easier. Meter main with dome facing light. Adjust power to get the exposure you want. Then turn off main. Turn on fill and set it to the ratio you want. If main and fill lights read the same and fill is hitting the same area as main as well as shadow area then ratio is 1:2. If fill light is reading one stop less the ration is 1:3 etc.

The ratios and getting proper exposure are independent of modifier. The modifier determines how gradually the highlights transition to shadow. The ratio determines how deep the shadows are compared to highlights. Exposure determines how bright the highlights are on the tone curve.

Phil V wrote in post #17464244
As this question is a bit 'what if', the answer is 'do it properly'.
If you'd linked to your own work, we would ask about your method and could pinpoint the problem.

The answer is to meter properly, and you should have no problems. Do you use a meter?

My work looks exactly like the first undesired example, overexposed on the light side and shadow detail is gone. I was using a 3x4 softbox to the side with no fill which was probably causing way too much contrast. I did acquire a flash meter recently and am enjoying how reliable it is, so I was wondering how do I use it to set my power or exposure to ensure it won't be blown out. I'm guessing the idea is to meter straight at the key light and use that as my main exposure, then add fill light to taste.

sandpiper wrote in post #17464352
Are you checking your lighting ratios? You could be getting hotspots because one light is turned up too high, relative to the other(s).

Without knowing what you are doing though, setting up your lights, how you are metering etc., it is hard to tell you what you are doing wrong. As PhilV says, if you meter properly and check your ratios then there shouldn't be any problems.

Well previously I didn't have a meter so no I wasn't checking ratios, I was using the LCD on the back of the camera but as you know its unreliable, and for film it's not available. I was using a 1-light setup to the side of the subject (split-lighting) with 0 fill, so I guess a 1:0 ratio which is what creates the muddy over-contrasted look. Is the ratio in the desired example 3:1?

dmward wrote in post #17464778
Ratios and metering.
Northern European caucasian skin is just about 18% grey.
When I was a young photographer, I used the back of my hand with a reflected meter the same way I'd use an 18% grey card.

It was close enough for a starting point.

Here is another trick, take a piece of corrugate from a box. The normal yellowish color that most of us consider untreated kraft paper. Bend it to about 90 degrees and place it in subject position. Edge toward camera so that main is hitting mostly one side and fill is hitting both or the shadow side, depending on how you arrange your lights.

If your lights have modeling lights that track, use them to set the ratio that looks right. Then make an exposure and look at the LDC. Adjust power and camera settings to get what you want. The corrugate is about the same reflectance as caucasian skin.

If you have a flash meter, then its even easier. Meter main with dome facing light. Adjust power to get the exposure you want. Then turn off main. Turn on fill and set it to the ratio you want. If main and fill lights read the same and fill is hitting the same area as main as well as shadow area then ratio is 1:2. If fill light is reading one stop less the ration is 1:3 etc.

The ratios and getting proper exposure are independent of modifier. The modifier determines how gradually the highlights transition to shadow. The ratio determines how deep the shadows are compared to highlights. Exposure determines how bright the highlights are on the tone curve.

So if the key power is reading f/8 and the fill power is reading f/5.6 the lighting ratio is 3:1 ratio like in the examples? For the camera setting, do I use the reading when the dome is pointing at the light or when the dome is pointed at the camera? Thanks for the very helpful post.

dmward wrote in post #17464778
Ratios and metering.
Northern European caucasian skin is just about 18% grey.
When I was a young photographer, I used the back of my hand with a reflected meter the same way I'd use an 18% grey card.

Due to variances in skin tone during the seasons due to sun exposure (summer tans, or even skiing tans) as well as to eliminate ethnic skin differences, the wisdom says to meter the PALM and compensate the reading which is about +1EV brighter than 18% tonality.

moodlover wrote in post #17465428
I did acquire a flash meter recently and am enjoying how reliable it is, so I was wondering how do I use it to set my power or exposure to ensure it won't be blown out. I'm guessing the idea is to meter straight at the key light and use that as my main exposure, then add fill light to taste.

Not correct procedure. Do this...

1. Meter only the Fill with a flat disk (or shield the hemisphere from reading any light from Main)
   
2. Meter only the Main with a flat disk (or shield the hemisphere from reading any light from Fill)
   
3. The ratio of light source intensity is #2:#1
   
4. Point hemisphere of meter at the lens and meter with both Main and Fill striking the hemisphere
   ...the reading in #4 is your exposure.
   

Wilt wrote in post #17465450
Not correct procedure. Do this...

1. Meter only the Fill with a flat disk (or shield the hemisphere from reading any light from Main)
   
2. Meter only the Main with a flat disk (or shield the hemisphere from reading any light from Fill)
   
3. The ratio of light source intensity is #2:#1
   
4. Point hemisphere of meter at the lens and meter with both Main and Fill striking the hemisphere
   ...the reading in #4 is your exposure.
   

The assumption is that Fill and Main overlap in some areas of the subject, and since light is additive, the proper measurement is to measure the SUM -- what the lens sees! -- , not the Main-only illumination for overall exposure setting on the camera.

Simple and understandable instructions. Thanks Wilt! So meter the fill, meter the main, then use those two readings to determine ratio. Am I correct when saying that the reading from the lens with boths lights firing would actually give a darker exposure than just pointing the meter at the key light?

Right.
Assuming Main meters f/5.6, and Fill meters f/4, our light source ratio is 2:1, and the exposure measures something more than f/5.6 because the fill adds to the main illumination where the two overlap.