Pentax Spotmeter ASA settings

**Michael Wainfeld** · 16-May-2009, 13:23

Hi-I've started to do some tests and I noticed that there are two lines between 200 and 400 on the Pentax Digital Spotmeter. What are we calling those? 266.6 and 333.2? 240 and 320?
Thanks-Mike

**Bruce Watson** · 16-May-2009, 13:30

Originally Posted by Michael Wainfeld

Hi-I've started to do some tests and I noticed that there are two lines between 200 and 400 on the Pentax Digital Spotmeter. What are we calling those? 266.6 and 333.2? 240 and 320?
Thanks-Mike

That would be 250 and 320. It's 1/3 stop increments.

**Michael Wainfeld** · 16-May-2009, 13:38

Right- Of Course!-Thanks-Mike

**Gem Singer** · 16-May-2009, 13:38

There are 1/3 click stops between all of the film speeds.

Not enough room to print every possible film speed on the little blue ASA dial.

As an example, Tri-X film with a box speed of ASA (ISO) 320. Guesstimate that the film speed is represented by ASA 200 + two click stops. Close enough.