X-24 Fill Flash question

greenspun.com : LUSENET : Konica 35mm SLRs : One Thread


I am seeking an explanation of operating my X-24 flash for daylight fill flash use. How do you do it?

Let me preference this with the following. When I use flash, either inside or out, I just set my lens on AE/EE and let the camera (FT1) pick the aperature. Of course I set the shutter speed for 1/60. I let the camera/flash do the rest. The thyrister does the light output adjusting. Seems to work O. K.

I think I read that the FT1 shutter speed is set to 1/100th sec when using automatic flash with the X-24 and shutter speed set at 1/60. Is this so?

When in outside bright light, what settings do you use for fill flash?

If you need a faster shutter speed in bright light or to freeze action, do you then need to use the manual settings for fill flash? What settings are then required to remove shading from the bill of a cap? (Do you use the rule G.N./distance=f/stop for fill flash outside?)

Alan Myers gave a very good rendition of off brand flashes a couple weeks ago. Are any of these handier for fill flash than the X-24, or are they just different?

Taking the family to Disney World FLA. next month and wish to get the optimum use/performance of my camera to record the trip. Your advice is much appreciated.

Thanks, David Smith

-- Anonymous, March 08, 2001


X-24 filling the flashes

I was hoping someone else would answer you about the x-24 fill flash question, but I will do my best with what I know. Hopefully, someone else will jump in!(hint!) Your first question about the FT-1, and the flash overriding the shutter is correct. You can, in fact have the FT-1 set to any speed, and once the camera denotes a computer compatible flash sending a ready signal, the camera processor switches the shutter speed to 100 automatically. The nice feature about this, is you can leave your flash connected, but in the off position while shooting a standard shot, assuming you want to lug around the flash on top of the camera, and then power it up when you need the flash. The only other way of using the X-24 to fillflash, is to set it to manual, and set the FT-1 to 1/60 to get proper flash sync, as the copal shutter in the FT-1 is trigged by selenoids, not mechanically, as in the older Konica T's. If your going to use fill flash, I would stay with the automatic mode, seeing as you are getting a faster shutter speed, and be watchful of your flash range. If the shot is to fast, or out of the flash range, try a faster film, since otherwise would might just get a well lit blur. Anything else, and you might be totally distracted from your vacation, and what fun is that? Hope that helps, Jefferson

-- Anonymous, March 10, 2001


Regardless of the type of 35mm SLR camera or electronic flash unit being used, satisfying fill-flash results can be achieved by using this 3-Step technique:

1. Set the camera's shutter speed dial to the highest shutter speed at which it can synchronize with flash. (The Konica FT-1 can sync with flash at 1/125th second and all slower shutter speeds).

2. Without the subject being included in the scene, compose the background first and take a light meter reading of the background. Manually set the lens aperture (f/stop) for proper exposure of the background.

3. Set the flash unit to manual mode, and adjust the flash-to-subject distance so that the flash illumination falling on the subject is 1 f/stop less than the background exposure.


Now, that was the short answer. What follows is the long answer:

Perhaps the most mis-used and misunderstood term in all of photography is "Fill-flash." In the early days of electronic flash photography, the practice of mixing flash illumination with sunlight outdoors was called "syncho-sunlight." The term "fill" is borrowed from studio lighting technique, where a "main" or "key" light is used to create highlights and shadows on the subject and a second, less bright light source is used to lighten or "fill-in" the shadows caused by the main light. To re-emphasize, the sole purpose of a "fill" light is to lighten the shadows created by the "main" light.

When taking pictures of people outdoors in daylight, using electronic flash as "fill" is almost never appropriate or beneficial. The reason is because outdoors in daylight, a perfectly adequate "fill" light is already present. The open sky which always surrounds an outdoor subject can always be used as a "fill" light, whether the sky is clear, cloudy or overcast - summer or winter - and whether the time is morning, mid-day, or late afternoon.

Since the direct light from the sun is always brighter than the open sky, in can be considered as the "main" light which creates the highlights and shadows on the subject. On a clear, cloudless day, the shadows on a subject's face will be about 3 f/stops darker than the highlights. This contrast ratio is normally too high for pleasing outdoor portraiture, and suggests that the "fill" light coming from the open sky is too weak. Using electronic flash to replace the open sky as the "fill" light is a wrong-headed approach, which has given birth to more amateurish looking snapshots that about anything else one can do.

The real problem with shooting outdoor portraits in bright sunlight is not that the fill light from the open sky is too weak. Instead, the problem is that the "main" light provided by the direct sunlight is too bright. The solution, and the problem solving technique which professionals use to produce pictures good enough to get paid for, is to stop using the direct sunlight as the "main" light.

Now, why would the photographer not want to use the sun as the "main" light? It's because when direct sunlight falls on a person's face, it causes them to squint their eyes and contort their faces. What difference does it make if you've successfully used electronic flash to lighten the shadows in the eyesockets of your subject if they still have a squinty, pained expression on their faces?

The solution begins by turning your subject's back to the sun. When you have done this, the subject's eye-squinting and facial contortions will disappear. But something else which is even more dramatic happens. The subject's face is then illuminated only by the open sky, making the open sky become the "main" light on the subject. The status of the sun has changed from "main" light to what in the studio would be called a "hairlight." When the sun illuminates a human subject from the rear, it creates bright highlights on the subject's hair and a bright rim around their shoulders. This creates excellent separation between the subject and the background, adding depth and diminsion to the image - which is a very desirable effect.

However, using the open sky as the "main" light presents some problems which require solving. The light from the open sky which is falling on the subject's face will be about 2 f/stops less bright than the background illumination provided by the sun. If you expose for the background, the subject's face will be 2 f/stops underexposed. If you expose for the subject's face, the background will be 2 f/stops overexposed. This is where electronic flash can be used to solve the problem.

An object of "average" reflectance reflects 18% of the light falling on it. Assuming you have composed the background so that it does not contain any bright objects, such as white houses, white automobiles, concrete sidewalks, bright reflections on water, etc., the background will be of average reflectance. Typical caucasion skin tones reflect 35% of the light falling on them, which is 1 f/stop more than average. So if you use electronic flash on a person's face, and the flash is set to output 1 f/stop less brightness than the background illumination, then the subject's face will be the same brightness level as the "average" background.

Now, what happened to the concept of always using the open sky as "fill" light. If you use flash on camera to illuminate the subject's face at 1 f/stop less than the background exposure - there will be no shadows on the subject's face which need to be "filled-in," and therefore the "fill" light from the open sky will have no effect.

The interplay between highlight and shadow on a subject's face is called shadow modeling, and this is what reveals texture and gives the subject depth and dimension. When there are no shadows on the subject, this is called "flat lighting" - generally a bad thing and to be avoided. The "deer-caught-in-the-headlights" effect is a typical example of flat lighting.

The way to avoid flat lighting is to simply move the flash unit off-camera. If the flash unit is positioned 30 to 45 degrees away from the camera-to-subject axis, it will create shadows on the portrait subject's face which are identical to what studio portrait photographers normally achieve. The flash unit can be connected to the camera with a long PC extension cord (10 or 15 feet), or can be triggered wirelessly with a radio slave. The flash unit can be mounted on a lightstand, or simply held up above the head-level of the subject by an assistant.

In summary, direct sunlight is almost always best used as a hairlight/backlight/background light instead of the main light. In bright sunshine, simply turn your subject's back to the sun and work from there. Electronic flash should almost always be used as the main light instead of the fill light. When you use flash as the main light, positioned off camera to produce shadow modelling instead of flat lighting, the diffuse light from the open sky will provide perfectly adequate "fill" light to lighten the shadows created by the flash unit. Always set the lens aperture to provide proper exposure of the background. Set the flash to put 1 f/stop less brightness on the subject than the background illumination.

-- Anonymous, March 11, 2001

Moderation questions? read the FAQ