Pentax 280T Operation Manual - Page 18

;,:TTL AUTO. FLASH OPERATION Using the AF 280T on the Pentax cameras featuring TTL flash metering system enables you to take flash photographs in the TTL Auto Flash mode. The LX couples with the flash within the camera's ASA/ISO range of 6 - 800, while other models featuring TTL flash metering system, 25 800. In this mode, the flash is directly controlled by the amount of light coming in through the lens and reflected from the film plane. This automatic flash mode permits you to use any lens aperture within the flash unit's operating range and eliminates all the complicated calculations in using filters and close-up accessories. Moreover, bounce flash operation is made easier, while full integration with the camera's automatic exposure system enables metering of both ambient and electronic flash lighting during the exposure. 16 TTL AUTO-1 ALCM MS IU o H LM Il Shooting 1) Set the ASA/ISO film speed in the ASA/ISO window on the back of the flash unit (see page 7). 2) Set the flash mode selector to "TTL AUTO." 3) Leave the camera's shutter dial set to "Automatic," and switch the flash unit "ON." The camera automatically synchronizes for flash at "X" when the flash unit charges. In addition, both the flash ready indicator in the finder and the ready lamp on the back of the flash unit illuminate as ready lights. 4) Select the desired f-stop, then after checking that the subject is within the flash range offered at your f-stop (see following paragraph or TTL Auto Flash Range Chart), take the picture. F-Stop Selection The flash range varies of course depending upon the f-stop in use. At small apertures, distance is reduced considerably. It's a good idea to check that the f-stop in use will offer adequate exposure.