Quote Originally Posted by Tom1956 View Post
Can we see a photo of your Pentax OM-4?
+1 on that

Anyways, everyone here has about covered it. If it is a Pentax, and a bayonet mount, I believe all but the cheapest models have voltage regulating circuits in the body, so battery choice isn't super critical to meter performance. However, I always run a roll or two in new cameras just to see how the meter behaves, and how far it is off, then a second roll to dial in my development.

Development looks pretty good, just be sure to use exposure compensation when necessary!