Adorama Retro Speedlight - How It Works, and When It Won't

Photo Source: Click here.

It's unusual for me to write about something that I don't already own, haven't already used, or never actually touched. However, this new Godox Lux Senior Retro Camera Flash, a.k.a. Flashpoint FlashBack Senior Retro Camera Flash (they are one and the same) is a different story. While I await the arrive of my new flash, I thought it time to put it in perspective, considering the long-neglected technologies that have be re-purposed for the growing interest in film photography. This new flash looks like it will be a winner, considering it can function in both digital and film venues.

This new flash and its old technology bypasses the problem posed by proprietary flash exposure technology called TTL (Through The Lens) metering. TTL proved to be an incredible boon to photographers, one that developed in parallel with the rise of the SLR (Single Lens Reflex) camera to its dominance in the advanced amateur-professional photography market. Photographers 

were now confident that what they composed in their viewfinders would be what the filem would see when the shutter curtains opened during exposure. The development of TTL exposure metering allowed the camera to measure the light as it passed through the lens itself, greatly improving the probability of a "perfect" exposure. 

The technology would eventually expand to include TTL flash exposure control, introduced by Nikon in 1980. I have used the current Nikon TTL system extensively, and feel totally comfortable with it. It suffices to say that the control interface is proprietary, and expensive, which essentially puts a lock on keep both your flash and your camera body "in the family".  This got to be an expensive proposition until relatively recently, when more and more manufacturers had offerings that could work with the proprietary flash-to-body interface, perhaps because the original patents have expired.

How Flash Exposure Works: To extend the Retro Speedlight's versatility, the manufactures went to an earlier, non-TTL exposure system. To explain how this works, we need to accept the following:

• Light can be represented as a cloud of paint droplets coming from a spray can,
• "Proper exposure" will be obtained when the droplets of paint are dense enough to completely cover the surface being painted, and
• The greater the distance, the longer you'll need to spray to insure an even coating of paint.

If we adapt this model and substitute units of light called "photons" for paint droplets, we can begin to understand how flash exposure works. In the photo at the right, the white arrow points to the forward-facing sensor at the base of the flash. It regulates the length of the photo "spray" based on the density of the photons hitting the surface. When the surface is completely covered, the sensor shuts off the flow. Obviously there will be some point where the surface is too distant to be completely covered. This would represent the limits of the flash output. 

If you convert the paint to droplets of light, you now understand the basics of pre-TTL, 1960s flash exposure technology. While revolutionary at the time, the system has its shortcomings. First, the on-flash sensor can under or overexpose your subject is not centered in the frame. Second, it not particularly sensitive. Lastly, and perhaps most important, the flash decides the output, and you must adjust your camera's ISO and aperture to obtain your optimal exposure. This is critical, since the Lux flash has only one automatic exposure setting, so far as I can tell, which is a F 2.8 at ISO 100.

In Use: Based on the promotional videos, the "default" setting, which I take to mean the "only" setting, is F 2.8 at ISO 100, maximum distance unspecified. From a marketing perspective, it makes sense because this extends the usable range of the flash to the max. This is where the versatility starts to crumble. If for some reason you wanted/needed to shoot at F 4.0, the limits of the flash would require you to increase your ISO setting to 200. If you needed a shooting aperture of F 5.6, you'd have to boost the ISO to 400. At first blush, this is workable if you confine yourself to subjects that don't require much depth of field. Shucks, even the ancient Vivitar 283 allowed you to select 4 settings. Even though I can still use the Retro flash manually, I still feel like I've been shortchanged.

Possible Work Around: When the flash is released (September 30, 2022) I am going to tape a thin sheet of 2X Neutral Density Gel over the sensor. Hopefully this will trick the flash into doubling the output, allowing me to work at F 4.0. It that works, a second layer of NDG will drop this to 5.6, a reasonable working aperture for a leaf-shutter camera like the Fuji X100, the Nikon Cool Pix A, and most fixed lens rangefinder film cameras. Luckily, I can see the results of this experimentation a few moments after the photo is made. On paper this should work. I obviously won't know for sure until the flash arrives in October. In the mean time, I tried it on an SB-800 using a Rosco Cine Gel (2x ND filter) and it seem to have worked. Right now, the biggest hurdle is finding a way to attached the gel in such a way as to not prevent closing the flash.

It seems strange to spend as much time thinking about a flash that has yet to arrive. Alas, the September 30 release date is a long way off, and I plan on using this flash a great deal. I just hope the ND gel cover works reasonably well. I just need to be sure that there aren't any glare issues to complicate things.

 Photo Source: Click here.

I was taken by this promotional image of the flash paired up with the classic Rollei twin lens reflex. My own back story includes a Mamiya Flex twin lens reflex camera, multiple rolls of 12-exposure 120 roll film, and a side mounted flash gun. I remember that the camera bag held mostly flashbulbs. Notice that the flash is mounted on the camera's left side so the photographer could freely operate the controls on the right side.

The Retro Look: There can be two interpretations. First, the opened fan reflector suggest the side-mounted flashguns mounted on Speed Graphic cameras from the 1920s and 30s. To the right, we see that classic round reflector, in miniature, mounted on a 1960s era roll film camera. In both cases, the flash was placed at some distance from the lens axis, providing slightly better modeling when you subject was relatively close. Second, it made "red eye" a non-problem. Lastly, the flash's elevated position directly above the lens axis (see that vintage Nikon SLR photo) throws the subject's shadow behind them, often giving better separation between the subject and background. 

"Their First Murder” (1941).Photograph by Weegee

Arthur Fellig (1889-1968), whose nom de guerre was  Weegee the Famous, was responsible for more "gritty street photographs" than any other photographer. Shown at the right with a Speed Graphic camera, you can see that the flash reflector is high and to his right, which explains the offset shadows on the two closest subjects in this sample photo. The placement on the camera's right side was to give the photographer easy access to the sheet film holders that were exchanged using the left hand.

Depth Of Field: Legend has it that Weegie said that the secret to his success was summed up in one phrase: "F 8.0 and be there*". It you look at the photo closely you'll see that the two closest subjects are out of focus. This was due to an inescapable rule of optics: The longer the focal length of the lens, the shallower the depth of field. The normal lens for a 4 X 5 Speed Graphic was typically 127mm, which would be considered a telephoto lens by modern 35mm standards. This required midrange to small aperture settings just to achieve a nominal depth of field. I don't doubt that Weegie followed his own advice when he made this photo, so blurry foregrounds are to be expected.

I have a lot to look forward to. I'll just bide my time until the new flash arrives and I can test my theories. Maybe I'll select a monochrome film simulation, look for a fedora, and start smoking stogies. 

* A more logical variations on the phrase is "F16 and be there", as the smaller aperture would give greater depth of field.