Technique: leaf Shutter and strobe

[Drew Bedo]

Got myself a little confused, perhaps over-thinking something.

So I want to do a strudio shot, table-top or portrait , and use strobes with my regular LF gear. Camera will be a Zone VI 4x5 and the lens/shutter will be a 210 Caltar in a Copal shutter.

I have a Minolta Autometer IVf that has worked well for me for years. Haven't done this sort of photograp;hy for yeqas too and I've forgotten just how to deal with the exposure. I can meter the light falling on the subject with the meter connected to the strobes by cable. I set the shutter speed and pop the strobes, then read an f-stop. OK . . the shutter will synch with the strobes at any speed, so what difference does it make? Will the metered subject be well exp;osed at any shutter speed? I do understand that at or the same aperture a higher shutter speed will underexpose the background. Anything else I need to consider?

[Duolab123]

Electronic flash is so fast with a leaf shutter speed doesn't matter.
The big old flash bulbs burned so long that shutter speed had a huge effect. .

[Duolab123]

I use that same meter. Love it works great for flash.

[Bob Salomon]

Shutter speed make a big difference with strobe. Shutter speed is how you balance ambient lighting to the strobe. Want a very dark background? Use a fast shutter speed. Want detail in the background? Use slower shutter speeds.

[BrianShaw]

What Bob wrote is very true, especially when background is deep and distinct from the strobe-lit subject. For tabletop, like you say is your current interest, when both subject and background is primarily lit by the strobe that consideration may be less possible.

[Drew Bedo]

Thanks everyone: As always, the pool of talanty and knowledge here is truly wide and deep.

All that info was there in my head, but I had to be reminded about how to sort it out.

[Bernice Loui]

Minolta flash/ambient meters have a flash sync socket on the bottom front of the light meter.

Flash exposure can be made using NC = No sync cord or C = with sync cord. Set the flash meter to the shutter speed to be used for exposure and proper film speed. Use either the No sync cord or With sync cord setting.

Setting the minolta meter to record the flash exposure can be done by pressing the set button on the side. firing the strobe should trigger the Minolta flash meter resulting in the f-stop for exposure at 18% gray. Sync cord triggering, set the Minolta meter to "cord". Then plug the sync cord into the sync socket on the front of the meter. Set shutter speed to be used, set-check film speed to be used. Pressing the side button should trigger the strobe and record the flash exposure for 18% gray on film.

Leaf shutters like Copal, Seiko, and other modern shutters have fixed X-sync for electronic flash. Older shutters like Ilex have optional flash bulb settings like M or a bulb burn speed dial on the side. If an electronic strobe flash is use with the shutter set for flash bulbs, the strobe light will not be recorded on film. Conversely, if flash bulbs are used with the shutter set for electronic strobe-flash, the strobe light recorded on film will not be accurate or congruent with the flash meter reading.

Setting the shutter speed to be used on shutter and flash meter is important as ambient light is part of the light recorded on film along with light from the strobe-flash unit. Unless the studio image is made in darkness, selecting and setting the proper shutter speed for combined ambient-strobe light is important. In the case of color film, mixed lighting often produces mixed color balance unless the ambient light has identical color temperature to the strobe light.

Do point the light meter dome towards the strobe light as that is the direction of light if a single light source is used. For multi lighting, take several light meter readings from several locations of the image, then consider what the overall exposure might be.

If more light is needed to achieve a required f-stop, multiple flashes from there strobe unit can be used. Set the Minolta flash meter to "Multi", with each additional flash from the strobe unit, it will effectively increase the amount of light recorded on film. The Minolta flash meter will add up the number of individual flashes to produce an effective f-stop number set on lens and for the exposure needed by the film. Again, the Minolta flash meter produces a meter reading for 18% gray on film at the set film speed.


Bernice

[BrianShaw]

Thanks everyone: As always, the pool of talanty and knowledge here is truly wide and deep.

All that info was there in my head, but I had to be reminded about how to sort it out.

Happens to all of us. :)

I keep reminding myself that, in general, aperture controls strobe exposure and shutter speed controls background exposure.

[Pieter]

Ambient light will only affect the exposure if it is very bright. As an example, take a reading without the strobe(s) or modeling light, then another with the strobes. If there is 4 or more stops difference, ambient won't be an issue unless there are certain reflections such as glass or polished metal. Also, do not point the meter at the strobe(s) as suggested in post #7. Point the dome at the camera from the subject position.

[Jac@stafford.net]

If an electronic strobe flash is use with the shutter set for flash bulbs, the strobe light will not be recorded on film. Conversely, if flash bulbs are used with the shutter set for electronic strobe-flash, the strobe light recorded on film will not be accurate or congruent with the flash meter reading.

Correct, and to add: Concerning the flash meter with flashbulbs. It is my understanding that if one uses cord mode with correct set shutter speed (or longer) in meter, then a correct flashbulb reading will be made. The cord by-passes sensing of the initiation of flash because bulbs have a long, gentle rise-time which w/o cord mode cannot reliably trigger the meter.

Thank you for any correction you may offer, Bernice.

I am suddenly tempted to try cord-mode with my 1.7 second duration bulbs.

[Bernice Loui]

This works depending on the intensity of the ambient light -vs- power of the flash bulb. If one were to use one of those "nuke" Edison base flash bulbs at short distance (10 ft_ish), ambient light intensity is not likely going to be a problem .... Ever. Do this same measurement with a Kodak Flash cube, ambient light -vs- shutter time and built light intensity will be a problem at ... 10ft.

Really a question of bulb burn up time -vs- film speed -vs- shutter open time. Possible to make an ambient light measurement for a given film speed and shutter speed, then figure in this exposure to the amount of light that would be added by the flash bulb.



Bernice



Correct, and to add: Concerning the flash meter with flashbulbs. It is my understanding that if one uses cord mode with correct set shutter speed (or longer) in meter, then a correct flashbulb reading will be made. The cord by-passes sensing of the initiation of flash because bulbs have a long, gentle rise-time which w/o cord mode cannot reliably trigger the meter.

Thank you for any correction you may offer, Bernice.

I am suddenly tempted to try cord-mode with my 1.7 second duration bulbs.

[Bernice Loui]

OK..... why, explain?


Bernice




Also, do not point the meter at the strobe(s) as suggested in post #7. Point the dome at the camera from the subject position.

[Peter De Smidt]

Because the final reading needs to take into account the key light and the fill light, i.e. the fill light will likely add some light to the areas already illuminate by the key light.

[Jac@stafford.net]

This works depending on the intensity of the ambient light -vs- power of the flash bulb.

With bulbs in cord mode, the meter does not depend upon the flash to initiate metering. Ambient light is just added to the measure for the duration of the meter's setting of shutter speed.

[Bob Salomon]

Because the final reading needs to take into account the key light and the fill light, i.e. the fill light will likely add some light to the areas already illuminate by the key light.

Are you talking about classic Rembrandt Portrait Lighting or something else?

Remember, expose for the shadows, the fill light is what the exposure is based on, the key light determines the ratio, which is normally 3:1.

That means you base your exposure solely on the fill light. Then you turn your fill light off and measure the key light so it is 2 stops more then the fill light.

[Leigh]

That means you base your exposure solely on the fill light. Then you turn your fill light off and measure the key light so it is 2 stops more then the fill light.Hi Bob,

Does that work regardless of whether or not the key and fill overlap?

- Leigh

[Bob Salomon]

Hi Bob,

Does that work regardless of whether or not the key and fill overlap?

- Leigh

You are exposing for the shadow so the key light is not on while metering the fill. When the key light is on it won’t make a difference in the exposure as long as the key is not replacing the fill light on the subject.

[Duolab123]

Shutter speed make a big difference with strobe. Shutter speed is how you balance ambient lighting to the strobe. Want a very dark background? Use a fast shutter speed. Want detail in the background? Use slower shutter speeds.

Sure for balancing ambient and strobe. So does color temperature, and reciprocity failure with traditional films. I was thinking we were talking studio lights etc. Thought we were talking how much light from flash, getting to the film, varied with changes in leaf shutter speeds.

If the OP wants to know about fill flash that's a topic onto itself.

[Duolab123]

Correct, and to add: Concerning the flash meter with flashbulbs. It is my understanding that if one uses cord mode with correct set shutter speed (or longer) in meter, then a correct flashbulb reading will be made. The cord by-passes sensing of the initiation of flash because bulbs have a long, gentle rise-time which w/o cord mode cannot reliably trigger the meter.

Thank you for any correction you may offer, Bernice.

I am suddenly tempted to try cord-mode with my 1.7 second duration bulbs.

I had a garden shed with a huge stockpile of flashbulbs, Edison socket, #25 etc. I got rid of them, I was afraid I would have an accident some night and think the Russians had nuked us . At that time we were in the country. If that shed had got hit by lightning, between the propane, gasoline, flashbulbs and old ammunition it would have been picked up by the "Space Command" :-)

[Pieter]

Incident light meters are designed to measure the light hitting the subject as seen from the camera position, taking in all the lights, fill cards and reflectors. I often used a strong, raking backlight or feather the strobe, the subject just catching the edge of the light and that would give me bad readings if the meter were pointed directly at the source.

OK..... why, explain?


Bernice

[Bernice Loui]

No, Incident light meters measure source of light to the subject. Minolta had two different diffusors for their incident light meters, one is a done the other is flat.

If your belief of incident light meter is specifically designed to measure light as the lens-camera-film would capture it, why the two different diffusors (dome and flat) for Minolta incident light meters?

Have you looked at and fully understood what is written in the Minolta incident light meter instruction manual and understood why the light meter head rotates?
http://pdf.textfiles.com/manuals/CAMERAS/VINTAGE/minolta_autometer_iv_f.pdf

191977

If you're sure of how this works, check this out... unless you're picking to "play" again.. which there is zero interest. Spreading mis-information is not tolerable.


Bernice



Incident light meters are designed to measure the light hitting the subject as seen from the camera position, taking in all the lights, fill cards and reflectors. I often used a strong, raking backlight or feather the strobe, the subject just catching the edge of the light and that would give me bad readings if the meter were pointed directly at the source.

[Peter De Smidt]

Setting exposure and setting lighting ratios are two different things. As per the Minolta manual:

https://www.dropbox.com/s/1n3txt9e6zlajst/incident.JPG?raw=1

https://www.dropbox.com/s/kh9m5etwzf2bou3/incident_b.JPG?raw=1

[Bernice Loui]

Size and type and number of light source(s)?

-Does that make a difference in incident light meter head position?


Bernice

[Pieter]

I worked as an art director for over 40 years, attending photo shoots with top professional photographers and cinematographers whose livelihoods depend on delivering artistic and technically excellent images. Unless they (or their assistants) were measuring light ratios, they all used the incident meter the way I have described: from the subject's position, dome facing the camera.

[Duolab123]

I worked as an art director for over 40 years, attending photo shoots with top professional photographers and cinematographers whose livelihoods depend on delivering artistic and technically excellent images. Unless they (or their assistants) were measuring light ratios, they all used the incident meter the way I have described: from the subject's position, dome facing the camera.

I'm no pro by any means. I've been using these meters with Photogenic flash and nice old stands for decades. I have the flat diffuser, I very rarely use it for flash exposure. If I am doing a black and white portrait and want some dramatic ratio, I will use the flat disc.
I remember the first time I used a old Wein plastic box flash meter in high school (1973). I was taking a friend's family portraits . I had borrowed a couple flashes. I'm pretty sure I had one of the subjects hold the magic box. It worked perfectly.
I found a like new Wein meter a couple years back bought it for 10 bucks. It's set at 1 ASA with the little dome and the toggle switch. :-) life was simpler then.

[Sasquatchian]

In addition to the metering information here, there are many times where, even though your leaf shutter *will* sync at any shutter speed, it will give you inaccurate in camera exposures when the flash duration is longer than the shutter speed. Most low powered flashes that people are using these days are not a problem but anyone using the old Speedo Black Line have to be aware that the flash duration at full power was 1/200th of a second. Shoot at 1/500th with one of those and you have an underexposure problem no matter what you meter is telling you. I shot decades of flash sync'd to Copal shutters on 4x5 and to the RZ leaf shutters - up to 1/500th and 1/400th respectively with no issues ever, but the strobes I was using then and still, have a 1/400th duration at full power. And back then we shot a lot at full power, and all too often multiple pops on product shots.