During the silver era SLR cameras were equipped with an optical viewing system which allowed through-the-lens viewing of the camera image. The resulting image could be composed using through-the-lens viewing during setup before any actual exposures were made.
When using studio flash, the customary practice is to set the ambient exposure to admit very little light making, the actual exposure depend on flash only. Manual exposure mode is inevitably used. A flash meter will read the amount of light on the subject, which results in a combination of aperture and ISO (if necessary). A typical studio flash has a duration of 1/1000 second or less. The shutter is set to the "X" sync speed, usually about 1/125 second
Example: using the flash meter, the flash sends f/11 of light on the subject. Therefore, to reduce ambient light, the camera is set to 1/125 sync and f/11. Testing with flash yields a correctly exposed image. However, during setup the LCD screen shows the black screen of nothing. In a perverse view of the world, this is the correct preview since the objective of the ambient exposure is to register as little of the room light as possible, hence blackness. The camera is showing the ambient results since the camera is unaware of any studio flash. The black screen of nothing makes manual focus and composition tweaking impossible.
The solution is to avoid showing the ambient light exposure preview on the LCD screen. A wide open aperture preview will allow focus and composition adjustments before exposure. Avoiding the death-by-preview is a setting which reads intuitively backward. Naturally, the setting is called something different by each OEM. The preview mode needs to be set to "off"!!!! So the solutions are:
Olympus works the positive of fujifilm, canon, and sony. "Live boost" = on shows viewfinder image brightened. "Live boost" = off shows simulated exposure (hence black screen of nothing).
fujifillm e series => wrench set up => screen set-up => preview exp / wb in manual mode => off
sony rx100 II => menu => gear => 2 => live view display setting effect => off
olympus pen => menu => D. disp / *)) / pc => live boost => manual shooting on1 => bulb / time on1
canon g5x => menu => camera icon => 3 => expo simulation => disable (LCD will show disp or ExpSIM)
All written content of this web site is solely the editorial opinion of Jeffrey Sward. All images, graphics, and written content of this web site, including the html files, are creative products covered by copyright law. All content copyright Jeffrey Sward 1975-2016. All rights reserved. No portion of this web site or its constituent elements may be reproduced in any form, by any means, without prior written permission. So there.