flash

American Speedlight Corporation (ASCOR)

We've come a long way, my friends

Many, many years ago I worked as a photo assistant in New York City. In 1979 I started at a catalog studio on West 23rd Street between 10th and 11th Avenues. Yes, that is where the New York High Line is now. Back then it was an abandoned elevated train track full of weeds and dead birds. In that studio we primarily used Mole Richardson hot lights to photograph things like ceiling fans and large room sets for Montgomery Ward and other similar retailers' catalogs.

Hot Lights!

These were 750- to 2000-watt hot lights. Within the first few days on the job you quickly learned to have a pair of leather gloves hanging from your belt along with some wooden clothespins to use when adjusting the lights. Ouch! And the lights were often mounted on large boom stands that had big maroon color counterweights on one end of the boom arm. Somehow, one of those counterweights, at about forehead level, often managed to find its way to a spot between the elevator and the light switch. Ouch! 

There was a fashion studio on one of the floors, though, that used electronic flash. Balcar was the brand. I don't recall if they were 1200 or 2400 watt second packs. But I do remember the small rectangular plugs that had a habit of arcing. One day the photographer I was working with, who was a bit ditzy, decided to change a head by himself. Unfortunately, I was standing next to him and he unplugged the light as I was yelling at him to turn the power off first. BANG! Lost my hearing for an hour or two. Luckily he didn't electrocute himself.

And that brings me to the subject of this post. My buddy Tony left this studio to go work as a photographer at another studio over on 7th Ave between 25th and 26th street. Shortly after that he brought me over there as a still life product photographer, too. This place was more modern and we used Speedotron 2400 watt-second packs and heads. (As an aside, I still have a Speedotron 2401A pack and one or two model 105 heads that still perform great. I even have a Dyna-lite D804II that is probably 40 years old and still going strong. See the photo below of these units alongside a modern Interfit strobe.) 

Speedotron 2401A and Dyna-lite D804ii pack & head systems, along side an Interfit S1 (self contained, including battery, no A/C power required, but optional).

Speedotron 2401A and Dyna-lite D804ii pack & head systems, along side an Interfit S1 (self contained, including battery, no A/C power required, but optional).

This studio also had a fashion studio, but it had these monster ASCOR Series 800 Sunlight strobes (which ASCOR called speedlights, noting in the instruction manual that strobe was a misnomer, as strobe implies repetitive flashing).

The ASCOR Sunlight

I have to assume that most of my readers might not have any idea what these Sunlight units were like. So, I will quote some things from the instruction manual for these monsters. Before that, I just want to add that almost everyone I talk to who was familiar with these speedlights mentions needing to keep a wooden broomstick nearby just in case they had to pry someone away from the unit in the case something went wrong.

So, from the user manual, dated around 1955...

"ASCOR has long stood for the best in electronic flash. The company (starting as Parker & Young and the trademark Fotolux in 1946, changing to American Speedlight Corporation in 1948) has, from the beginning, specialized in building the most advanced types of speedlights for exacting professionals."

"The tremendous number of speedlights in all shapes, sizes, and prices exhibited at recent photo shows leaves even the electronic flash engineer confused. With all the claims, counter-claims and partial information, it is no wonder that the dealer is wary...think of the poor customer...it is amazing that so many have the courage to buy. What is sorely needed are a few simple facts that can be used as a basis of comparison."

Not much has changed

Wow, not much has changed since the 40s and 50s. The manual then goes on to talk about guide numbers, and the "serious faults" in using guide numbers. 1. high guide numbers can be achieved by concentrating the available light in a narrow beam from the reflector, which results in uneven coverage or hot spots. 2. a guide number can honestly be chosen over a wide range, depending on how the film is developed, the latitude of the films, etc. 

They next talk about watt-seconds, "For too long most people have rated speedlights in watt-seconds. Just what is a watt-second? If you really know, you are one of the unusual photographers. Then again, what photographer really cares? Watt-seconds is not a rating of light output of speedlight equipment. The use of watt-seconds, microfarads, and other terms has so confused the photographer that many are thoroughly baffled about electronic flash."

How do you compare lights?

So, what are the points of comparison between various studio strobes? "Speedlight is just light." Photographic effectiveness comes down to...

  1. Strength of the light

  2. Color of the light

  3. Coverage of the reflector

  4. Speed of the flash or exposure

  5. Recharge or recycling time of the equipment

"The ASCOR Speedlight (ASCORLIGHT) is an electronic device for converting electrical energy from a relatively small power source into a high-speed, high intensity flash of light. Essentially, the energy is drawn slowly from the power line or battery, converted into hight voltage, and stored in a capacitor (an electrical storage tank). Then at the moment the flash of light is desired, the energy is dumped instantaneously out of the capacitors through the flashtube (watt-seconds) which converts the electrical energy into light."

Enough of the boring stuff. What I really wanted to point out was the size of the units and the simplicity of operation. The manual then lists 23 important features of the ASCORLIGHT SERIES 800. Things such as "from 800 to 40,000 watt-Seconds" and "Economical (average power drawn is less than drawn by a 200-watt light bulb." But the one that really stands out to me is #22: "Designed for One Man Operation and Portability." Keep the word portability in mind as it then lists the specifications.

Portability!?!?

ASCOR A801 power supply with 4 800w-s conders

There were two power supplies available. The power supply is the control unit and does nothing on its own until you add condenser (capacitor) units to it. The Sunlight Maste Power Supply A801 weighed 85 lbs. The Super Master Model A805 weighed in at a svelte 355 lbs! The A801 dimensions were 9-38"H x 12-1/8"W x 21-3/8"L. The A805 was 42"H x 22"W x 17"D. Remember, designed to be "portable." And this is just the power supply.

In addition to the power supply, you need condensers. Each condenser stores 800 watt-seconds of power and each weighs in at 60lbs. These are metal boxes filled with oil as the dielectric element. Slightly smaller than the A801 power supply, each condenser was 9-3/8"H x 8-5/8"W x 21-3/8"L. Remember, "portable." And we still haven't added a flash head and the required cables. The manual doesn't list the weight of the heads, but they were pretty substantial. If I remember correctly, the flash tube was around 9" long. The standard head reflector was 14" across and other reflectors were available from 9" to 24" across. And we still haven't added the light stands, which could range from 10 to over 100 lbs each. The model 503 flash head could handle up to 3200 watt-seconds of energy. The model 623 head used a model FT623 flash tube, and could handle up to 45,000 watt-seconds and could be attached to forty-eight (48!!) condenser units. 48 metal boxes, weighing 60 lbs each. That is almost 1-1/2 tons of lighting gear for one flash head!

Guessing that there are about 20 condensers ganged up here for 16,000 watt-seconds of power. Each condenser is oil-filled and weighs 60 lbs.

You are advised to "Stack the model A802 condenser units on the Type 3200 Dolly (M251) which is designed to hold six condenser units. Place the Platform Adapter M261 on top of the condenser units, this Platform Adapter will fit down over two condenser units placed side by side. If the model A801 Power Supply is to be used, it is placed on the Platform Adapter." At least the dolly has wheels (portable!). Then you took these very thick 3-foot and 6-foot cables and plugged them in between the power supply and condenser and then between each additional condenser and then plug the 25-foot cable to the flash head into the end of the chain. Then use dummy plugs to seal any condenser or power supply connectors not being used.

"Next, connect the Power Cord AC, D102, to the power supply outlet and plug it directly into any 117 volt 60 cycle AC source, "NOTE: MAKE A SOLID CONNECTION OF AC CORD: If a flimsy connection of the AC cord is made this condition can cause trouble. A momentary interruption of the power will cause the discharge relays to make contact. If the power is then applied before the capacitors are allowed to discharge, and arc can be started, which can damage the relays and the discharge resistors. The third wired should be attached to a ground." In total, there are 15 steps (each a paragraph) involved in turning on the unit. Step 15 is to plug your camera sync cord into the end of the sync cord which is connected to the power supply. Flash the unit by tripping your camera." Whew! Portable and fast operation. 

They then talk about strobing or repetitive flashing. That is done by "firing several speedlights successively with the ASCOR Strober, each unit powering its own set of lights. The operator can vary the speed of flashing and ONE POWER UNIT IS REQUIRE FOR EACH IMAGE DESIRED ON THE FILM." Emphasis mine. You want 10 images of the swing of a tennis racket? That means 10 power supplies and at least 10 condenser units. At least you could attach two lights to each condenser unit. A spider box was available if you wanted to use three heads. 

Many of you might have heard of sync voltage of older flash equipment and the damage it could do to digital cameras as the current goes through the shutter contacts. Well, ASCOR took care of that way back when. "ASCORLIGHT units use an electronic tube in the triggering circuit or sync circuit which directs the current through the flash tube--not into the shutter contacts. NOTE: Here we have incorporated ANOTHER SAFETY FEATURE to prevent electrical damage to the shutter contacts and to personnel."

For my friends such as Tony Corbell and Matthew Jordan Smith who live by the light meter, I should mention flash meters here. Take a look at this page from the ASCOR manual that pictures the M333 General Radio Light Meter in use. Might be why Joel Grimes says he doesn't want to know what a flash meter is. It is bigger than my cameras.

So, how much light did these monsters put out? The manual claims that using one condenser (800 watt-seconds) at 6-feet using the standard reflector would give you F/22. They don't list an ASA or ISO number, but earlier refer to daylight Ektachrome. I don't know the ASA rating for 1950s Ektachrome. However, they do provide a nomograph that says at ASA (ISO) 100 the guide number for one condenser would be about 400. So that is F/40 at 10 feet. 

The Interfit S1 has 500 watt-seconds of power and weighs in at a little over 6 lbs.

A modern flash, like the Interfit S1 that is 500 watt-seconds gives me f/18 at 10 feet with the standard 7" reflector. That is 2-1/3 stops more light with the ASCOR (which was rated at 800 w-s), and which has a brighter, more focused reflector. It is also with the ASCOR weighing in at close to 160 lbs plus a heavy-duty light stand, while the S1 weighs in at 6.3 lbs and is battery operated. We have a very different view of "portability" now. 

I am sorry, but I don't know who to credit the photos of the ASCOR equipment to. If these are your photos, may I please ask for permission to keep them in this blog post?

If you used these ASCOR lights and have any stories about them please share them in the comments here. We've come a long way since these units from the 40s. Let's keep some memory of them alive.

Thanks!
John

 

 

 

More shutter speed and speed lights

Speed lights

Thanks for all the feedback on yesterday's shutter speed post here and on social media. Some folks wondered about the action stopping capabilities of the speed light. I only have one speed light to test with, a Canon 430 EXii. So here are some more photos of the fan.

First, I will start out with this series of photos taken with no flash. Here only the shutter speed of the camera is affecting the amount of motion blur in the fan blades. Shutter speeds range from 1/8 second to 1/1000 second using window light.

No flash, just window light at the indicated shutter speeds

No flash, just window light at the indicated shutter speeds

The next series was taken with the flash on Manual power control and the camera shutter set to 1/15th second. The first image is without flash to show the ambient light at 1/15 second at f/8. The images then progress from 1/64 power to full power. The f/stop was adjusted for each frame to give the same exposure.

flash-15th-second

This next series is the same as the above, except that the shutter speed was increased to 1/125 second. I want you to notice that most of the images look exactly the same, despite the three step difference in shutter speed. Where you will see a difference is in the low powered shots where the aperture had to be opened up to compensate for the low power flash, causing more ambient light to be recorded at 1/15th than at 1/125th. But the edges of the blades are still about the same, despite the ghosting.

flash-125-second

Here are close-ups of the fan blades at 1/4 power on the flash. On the left is 1/15 second at f/11 and on the right is 1/125 second at f/11. The motion blur is the same. The flash duration is the effective shutter speed in the studio. The flash doesn't care how long the shutter is open, and the flash isn't affected by how long the shutter is open (as long as the shutter speed is at or below the sync speed). If the room was completely dark the camera shutter could be set to 30 seconds or more and the exposure would still be the same as at 1/125. The only light hitting the fan is the brief flash from the speed light.

15-vs-125.jpg

One more series of photo and then I hope we're done with the fan and can get back to more creative endeavors. This time the flash is in eTTL mode at a range of shutter speeds. The aperture is the same (f/5.6) in the 6 flash lit shots, the output of the speed light is controlled by the eTTL circuitry. The seventh image is the fan at 1/2000 second with no flash for comparison.

ettl-flash

One of the things to notice in this series is that at 1/15 and 1/125 (the first two images) the flash is in normal mode and the speed of the flash freezes the blades. Above 1/200 second the flash is in high-speed sync mode where the flash fires a series of flashes (too quick in succession for the eye to see) as the shutter curtains move across the sensor. Because of the rapid movement of the fan blades, they are in different positions for each of the flashes and the fan blades show more motion at the faster shutter speeds (1/250, 1/500, 1/1000 second). At 1/2000 second the shutter speed alone stops the blades, as you can see by comparing the last two images, both taken at 1/2000 second. One is with the and one is without the flash.

As pointed out by Paul in the comments on yesterday's post, most subjects probably won't be moving as fast as the fan is, so you might not get a lot of subject motion blur using high-speed sync. I am exaggerating the effect here to make the point that high-speed sync is a tool used to help balance outdoor exposures between flash and sunlight while maintaining large apertures for shallow depth of field. It isn't meant to help stop subject motion, and, as can be seen here, may actually show more motion in extreme conditions.

Shutter Speed with Flash or Strobes

Avoiding Motion Blur

In response to some questions in the comments section about power settings and freezing motion with a speed light I added a new post to the blog today.

Yesterday I got a question from a friend on Facebook asking how to get their flash to sync with their camera at a shutter speed higher than 1/125 so they could freeze the motion of their subject (children in this case). This question also comes up in almost every CreativeLive strobe lighting class that I've worked on. I hope that this post can help clear up the big misconceptions about shutter speed and flash photography.

Instead of using children, I decided on something that moves even faster--a box fan.

In the first series of images below we see 6 images of the fan. The first one (1) was  taken without a flash. The rest were taken with different brands and models of studio strobes. And the most important thing to recognize here is that all 6 images were taken at 1/15 of a second, and the fan was running at the same speed in all the images. What I hope to show you here is that in the studio with strobes the shutter speed is pretty much irrelevant as long as it isn't so slow that ambient light infiltrates the exposure or isn't too fast that the camera's shutter cannot synchronize with the flash, which will leave a black band across one side of the image (see my previous post on sync speed for more information on that).

shutter-speed-strobe-motion

As noted above, photo 1 was taken at 1/15th second with no flash
#2 was with a Speedotron 805 pack and a model 102 head (1/670 second flash duration)
#3 was with the same Speedotron 805 pack, but with a model 202 head (1/900 second flash duration)
#4 was taken with an SPS Systems Excalibur 1600 monolight (unknown flash duration)
#5 was taken with a Speedotron Force 5 monolight (1/1500 second flash duration)
#6 was taken with a Paul C. Buff Einstein monolight in Action mode (1/4826 second flash duration, and yes, the fan was spinning)

studio-shutter-speed-strobe

In the above series of images, the shutter speeds in both rows go from 1/15 to 1/30 to 1/60, and finally 1/125 (all at f/7.1). In the top row the studio strobe was not turned on, so you can see the base exposure. There is a slight rendering of the subject in the 1/15 and even the 1/30 second shots, but not enough to affect the exposure when the strobe is turned on (second row). At 1/60 and 1/125 there is no ambient light at all in the exposure. All of the images in the bottom row show the same exposure, controlled by the ISO, flash power, and aperture. The shutter speed is inconsequential to the overall exposure in a reasonably dark studio setting.

What about speedlights? What about high-speed sync and speed lights? Let's look at another set of images. As above, #1 is the same reference image as used above at 1/15 second with no flash.

flash-sync-speedlight-shutter-speed-blur

#2 was taken with a Canon 430EXii flash at 1/15 second
#3 was taken with a Canon 430EXii flash in high-speed sync mode at 1/500 second

Here you can see that engaging high-speed sync does not help stop subject motion. It actually led to more subject motion, even though the shutter speed was at 1/500 second. Additionally, high-speed sync robs the flash of power, leading to an underexposed image. This is because high-speed sync works by pulsing the flash multiple times at a lower power during the exposure. This makes the speed light less bright, helps burn through batteries, and does not help stop motion blur.

I hope that this helps clarify why shutter speed is usually not an important factor in determining exposure or in stopping motion when working in a studio with speedlights or strobes. The important factor here is the flash duration of your strobes or speed lights.


Taking it outside

Shutter speed with flash does play an important role in outdoor flash photography with a lot of ambient light. There your ISO and aperture control the exposure on the flash-lit subject and the shutter speed affects the brightness of the background. By slowing down your shutter speed in this situation you will make the background brighter. By speeding it up, you darken the background.

This situation (outdoor flash photography) is where high-speed sync (HSS) comes into play. Without HSS you are limited to shutter speeds at or below the camera's sync speed. Depending on the camera, this could typically be anywhere from 1/60 to 1/250. You will need to consult the owner's manual for your particular camera to find the sync speed.

The usual situation here is that you want to take a flash photo outdoors on a sunny day and want to use a large aperture (maybe 2.8 or faster) to blur out the background. The base exposure, without flash in this situation might be something like 1/5000 second at f/2.0. If you add a flash that doesn't have HSS your shutter speed is limited to, in this example, 1/160 second. This means that you cannot shoot at f/2.0, you need to stop down to f/11. But this gives you too much depth of field (the background objects are too in focus and distracting). By engaging HSS on your speed light you can now sync the camera at 1/2000, but your flash will need to be in close to your subject because of the reduction in output power that enables HSS.

fill-flash-no-high-speed-sync

The image on the left above is at 1/160 second at f/11 with no flash
The middle image is 1/160 at f/11 with flash
In both images, the background is too distracting. To fix that, we want to shoot at f/2.0
The image on the right is 1/5000 at f/2.0 with no flash to give shallow depth of field. But the eyes are in shadow. We would like to use a flash to fill in the shadows.

fill-flash-high-speed-sync

Here we start with the last image from the last series. 1/5000 at f/2.0 with no flash
In the middle image I turned on the flash without high-speed sync which dropped the shutter speed to 1/200 second (maximum sync speed on the Canon 5D mkIII). Because I am at f/2.0 for the background, the image is way overexposed.

On the right I turned on high-speed sync which let the camera and speedlight sync at 1/5000 second at f/2.0. Now there is some light in the eyes, shadows are opened up a bit, and the background is nicely blurred to help make the subject stand out.

Controlling the ambient exposure

Earlier I mentioned controlling the ambient exposure via shutter speed. Let's take a look at that. Here I have combined high speed sync, manual exposure, and manual flash settings.

The base setting for the sky exposure is 1/2000 at f/4. My on-camera flash is set to full power so that it has enough reach for high-speed sync. The images above are shot at 1/640, 1/1000, 1/2000, and 1/4000 with flash. Notice that the background is lighter in the first two images, normal in the third, and darker in the last image. The last image, at 1/4000 shows a darker subject because the flash didn't have enough power to handle high-speed sync even at full power at this distance and at such a high shutter speed.

Questions? Comments? Thanks for following along!

 

Shutter Speed and Flash

How Shutter Speed affects studio flash

What are your settings?

That's the question that disheartens so many photography instructors. The settings are particular to the situation. I know that many photo magazines list settings along with the photos. But until the digital age with that information in the EXIF data, I'm willing to guess that 50% or more of the "settings" listed with a photo were a guess. I was there. I never took detailed notes on my photos while making them. If someone asked me about the settings used on an image from a week/month/year ago I would have had to guess. I think most others would have too.

But enough of that rant. The question is still going to be asked. So, lets talk about one of those settings. Shutter Speed when using flash in a studio situation. When doing a workshop I often get to hand over the flash trigger to a student and give them some settings to get started. The important ones are ISO (how sensitive the film/sensor is) and Aperture (how much light the lens lets through).

Then there is shutter speed.

A difficult concept for some is that within a range, the shutter speed doesn't much matter in the studio when using flash. You have the ISO, the Aperture, and the power of the flash. There's your Exposure Triangle for the studio. You can usually set your shutter speed somewhere between 1/30 and 1/125 of a second and be good to go.

But what about blur? Won't my image be blurry from camera shake or subject motion if I shoot at 1/30 of a second? In most cases the answer is No. A studio setting is usually dark enough that even at 1/30 nothing will be recorded. The duration of the flash becomes your "shutter speed." While the shutter is physically open for 1/30 of a second, the flash duration may be 1/500 of a second or faster (depending on the particular flash you are using). Yes, in a bright studio or if you are working at a high ISO and at a wide open aperture you might experience some motion blur. You can do a quick test to see what's up. Set the ISO and Aperture for the flash exposure and take a shot WITHOUT firing the flash. In most cases the image will be black. That's good. That's what we expect. If there is something recorded, you can go to 1/60 or 1/125 of a second.

But my camera manual says it syncs at 1/250 of a second. Well, yes. It will do that with a dedicated speedlight/lite. The flash duration on those little things can be really fast and work at 1/250. But when you go to studio strobes you have to give a bit on the shutter speed. For example, the Canon 5D MkIII (used for these tests) specs say that its X-Sync shutter speed is 1/200 of a second. But on page 104 of the manual you will find some additional information:

Using Non-Canon Flash Units
Sync Speed
The camera can synchronize with non-Canon compact flash units at 1/200 sec. and slower shutter speeds. With large studio flash units, since the flash duration is longer, set the sync speed within 1/60 sec. to 1/30 sec. Be sure to test the flash synchronization before shooting.

That's good advice. Test for yourself. That's what I did this afternoon and here are the visual results. Next to each image is the Shutter Speed (SS) used (80=1/80 sec.) and the info reading for the spot on the shoulder identified in the first photo. You will see that at 1/80 to 1/125 sec. the image is pretty clean/similar. But at 1/160 and 1/200 sec. the bottom of the image starts getting darker. At 1/250 sec. there is a clear black band across the bottom of the image.

cornicello_photography_sync_speed.jpg

It might be easier to see the comparison side-by-side. Here are the images that were taken at 1/125, 1/160, 1/200, and 1/250 sec. to more easily see the shadow of the shutter curtain starting to impinge on the bottom of the photo. The image at 1/200 sec. is also starting to be darker overall.

cornicello_photography_sync_speed_2.jpg

In many situations you might not notice the darkness on the bottom of the image (or on the side if holding the camera in vertical orientation) at these faster shutter speeds. But it is there. And it may be troublesome if you have taken the time and energy to create an even background light on the scene and then find one side of the image is darker when you get the file into your computer for editing.

If you are using a wireless flash triggering system with your Canon or other compact flash gun you may also be limited to slower shutter speeds. I don't have such a system to test with. If you do, please let us know your test results in the comments section below.

What happens if you go slower than 1/30 sec? A few things might happen. If there is enough ambient light in the studio you might pick up some color variation and a bit more exposure as the ambient light will then be adding to the overall exposure. Here you can see images taken at 1/60 sec. and 1/8 sec. at the same ISO, Aperture, and flash power level. The image at 1/8 is slightly brighter and a little more yellow from the tungsten modeling lamp in the flash.

cornicello_photography_sync_speed_3.jpg

So, when in a controlled studio setting using studio strobe units you should heed the warning in the camera manual and work at around 1/60 sec. to sync the camera and strobes.

When outside doing syncro-sun flash the shutter speed becomes more important. But that's for another article.