[Newcomer] How should I measure exposure for nighttime portraits?

[marguerite]

...

[xkaes]

Welcome to the FORUM. You'll get a lot of advice/suggestions, and it will be difficult to decide which to take. And please don't take any of it personally.

My first point is, if you take a reading of a shadow at midnight, it won't be anywhere close to 1/500 of a sec. On most meters you won't get a reading at all.

Where did you get this advice?

[Willie]

If you are doing portraits why not a meter reading of the facial skin and expose for Zone VI - or a bit less for darker skin - then let the rest fall where they may.

Do a few tests before you get going so you can hone in on exposure and don't fumble around with clients in front of your lens.

[jim_jm]

For low-light photography, especially portraits, I would take the meter readings of the subject's face if you want that to appear well-exposed. Shadows will be too dark to serve any useful metering purpose. For nighttime and low-light situations, you can't use many of the metering "best-practices" that you would during the daytime. You want to meter off of your primary subject and work from there.
You're likely going to have to shoot at slow speeds (a challenge for portraits unless you add some light to the subject) so be sure to compensate for reciprocity. Download the reciprocity chart for Portra.

[Tin Can]

Be reasonable

Perhaps approach by shooting in ever lessening light

and find your dream empirically

practice as I do with DIGI

then I shoot REAL film portraits

few have Polaroid/Fuji to test with, like days of old




Thanks so much for the swift replies!

1. Noted that I should meter off of the subject's face. Looking at the Zone System, I see that Zone VI corresponds to "average caucasion skin value in sunlight." Given that I'm not shooting in sunlight, should I rather go for Zone V? If so, I don't need to adjust my exposure - right?

2. Could you please also give me ballpark aperture and shutter speed figures?

3. I might consider adding some light as you suggested Jim, although I'm trying to go for a natural look.

4. Finally, do I have to factor for bellows extension when taking portraits up-close? I haven't fully grasped the concept yet.

Can't wait to go out "in the field" and take my first LF shots. I'm doing a mock shoot with a friend tonight to try and nail this. Either way, it's a personal project so if I mess up that's fine as long as I'm learning :)

[nitroplait]

I think there is a good deal of overthinking in your approach.
It is great to have a vision but you have decided on a very difficult and costly first project.

My approach would be to get familiar with LF portraiture under more normal lighting conditions, perhaps with a cheaper emulsion, if you develop yourself, maybe B&W?
Perhaps even dropping the idea of portraiture until you have the concept of exposure measurement reasonably under your skin.
When you have a good grasp of portraiture in normal light under control, it is not that hard to extrapolate your knowledge to the more challenging night scenario.

Just my thoughts.

[BrianShaw]

Use a flash!

[jnantz]

Be reasonable

Perhaps approach by shooting in ever lessening light

and find your dream empirically

practice as I do with DIGI

then I shoot REAL film portraits

few have Polaroid/Fuji to test with, like days of old

fantastic advice!

FYI
when I was photographing on median strips and in parking lots that had 50 foot tall Sodium Vapor Lamps I used ISO 400 film. Even with 2-3 lights over head my exposures were 45 seconds f22.

[Bernice Loui]

Helmar Lerski,
https://www.moma.org/artists/3493

Portraits are much more a lighting and sitter pose question than a exposure question with camera being the lowest on the list priorities..

Example of this Lerski portrait.
230137

Hints of how the lighting was done are found in the eye catch lights. Look carefully at the eye catch lights notes the two hot lights and light stands are visible. Lighting position renders the bright "hot" lighted areas and where the shadows are falling on this face portrait.
230138

If this is the kind of portraiture your goals are, get a few hot lights, light stands, a head model (like for whigg...s), table to set that head model on, back drop paper, spot light meter and a digital camera with a short telephoto lens for head shots. Then experiment with lighting, pose and discover the exposure compensation on that digital camera which will become your "friend" to figure out what exposures and much more might be. This is much about technique development and learning before trying any of this using any film camera. Highly recommend using a roll film camera first to learn the quirks, needs and ways of film before moving to a sheet film camera.. which is a steeper progression from using a roll film camera.

As for the 4x5 camera and lens current, head shots like these should be done with a longer than normal focal length lens _ typical about 240mm to 300mm. Typical field folder camera will not have enough bellows and camera extension to focus a head shot like these. Alternative to work with this camera limitation is to used a telephoto design view camera lens.. or make the camera choice driven by and based on the needs of the image goals (in this case tight head shot) and the lens required to achieve this. Difficulty with a 150mm lens on 4x5 for head shots like this, subject to lens/camera will be short. This makes lighting difficult to not possible... and having camera/lens that close to the portrait sitter can make the sitter uncomfortable... which alters_affects the expression captured from the portrait sitter. Adding to this problem with a 150mm lens, the field folder camera might not have enough camera/bellows extension to focus this close to the portrait sitter. Full length portrait, very likely no problem.



Bernice

[Tin Can]

This my 2 friends, I use them often for models

I am the guy

Studio lights, Instant Film 4X5 Fuji

Need new plan for this year

https://live.staticflickr.com/65535/52224686275_2206e7dc86_z.jpg (https://www.flickr.com/gp/tincancollege/6f4N1yM0Sq)2021 Halloween (https://www.flickr.com/gp/tincancollege/6f4N1yM0Sq) by TIN CAN COLLEGE (https://www.flickr.com/photos/tincancollege/), on Flickr

[jim_jm]

1. I usually meter average caucasian skin tones at Zone V or VI. It shouldn't be much different regardless of the light source, it's the amount of exposure that the film receives that is important.
2. It's not possible to predict what shutter and aperture settings to expect, given that the intensity of artificial lights and distance from the subject will vary greatly. If your main light source is the setting sun, streetlights, lamps, candles or otherwise, that will be the main determinant of your exposure settings, along with your film speed. The rule of "Sunny-16" for daylight exposures is only possible given that the luminance of the sun at certain latitudes and times of day is a known factor. Correct exposure becomes very difficult to predict with artificial light sources and at night, until you start taking meter readings of your subject.
3. You can add light to the subject without having it look too artificial or resorting to strobe flash. This may let you use shorter shutter speeds and/or smaller apertures. It's a big can of worms and there's lots of options available.
4. Exposure compensation for bellows extension is always a factor to consider. As you focus on a closer subject, you need to extend the bellows to get a sharp image. This means the lens is further from the film and the intensity of the light hitting the film is fainter. This is where a tape measure comes in handy. First set up your camera in daytime and focus on a distant object more than a few hundred feet away. Measure the distance from the lens board to your film plane and this will be your infinity focus distance for this lens. It should be approximately equal to the focal length of the lens, say 180mm (or 7"). To focus on objects that are closer, you'll need to extend the bellows. A general rule I use is to add one stop exposure for every 50% of bellows extension. So if my 180mm lens has been focused on a close subject and it measures 270mm from the film (an extra 50% or 90mm), I would add an additional stop of exposure (either slower shutter speed or larger aperture). If the subject was not so close and the bellows measured 225mm (an extra 25% or 45mm) then add only 1/2 stop exposure.

Low-light exposures with large format can be tricky. You're generally using slower shutter speeds and most lenses are not very fast. Your shutter speeds may be very slow so your subject will need to hold still. Mistakes will be more expensive per shot also. Personally, I'd try this with 35mm or medium format as the lenses are faster and the cost per shot is much less.

Here's an example of a shot I took in low light and while not really a people portrait, the metering situation was similar to what you are describing.
- Interior shot, both carousel horses illuminated by spotlights from above.
- The shadows were very dark so I spot metered off the horses' heads only. With the black one I was careful to avoid the silver headpiece (will influence the meter), and put it at about Zone III. With the lighter background horse I metered at about Zone VI.
- This was taken on 35mm, handheld but braced against a chair, and I think the exposure was about 1/8 sec at F:2 on ISO 400 film. The negative looks underexposed, but it printed very easily in the darkroom.

230142

[BrianShaw]

I’m surprised that the old-timers haven’t mentioned this… perhaps they forgot or never used this technique.

The white side of the gray card had a use for exposure determination in the days before it became primarily used for white balance on digital cameras! This usage doesn’t seem to have been mentioned for decades. See the section on exposure determination in dim light:

https://www.scantips.com/lights/kodakgraycard.pdf

[Tin Can]

"...For this reason, it is generally
easier to make an extra negative with the card at the center of interest. ...