[safc]

Just got this flash unit today have you got any handy tips how to use it with my k-r thanks

[mannesty]

The AF280T is an older TTL flash with an analogue interface. You can use it in fully manual, or it's auto modes. It will not give correct exposures in TTL mode because the flash will fully discharge every time. Your camera lacks the in-body electronics to control the TTL mode of the flash. Only the early *istD and *istDS bodies had this facility.

[Ole]

It can be used in red and green auto flash modes or in the manual modes. TTL auto mode is not supported.
You need to experiment.

Using one of the auto flash modes: While the flash probably sets the correct shutter speed I doubt that it will set the correct aperture. So use Av mode on the camera and set the aperture yourself based on the scale on the back of the flash. Remember to dial in the ISO on the back of the flash, or its scale will not show the correct aperture.

https://www.pentaxforums.com/accessoryreviews/pentax-af-280t.html

The link above has an image of the back of the flash. The scale shows that if you use the red AUTO mode the F-stop should be 5.6 at ISO (ASA) 200.

[safc]

Cheers for the great info I be trying the flash out tomorrow