I'm struggling to reconcile the recommended exposure times of a Holga 120 Wide Pinhole Camera as suggested by Holga, vs the values I am getting via an app like Pinhole Assist (or even when computing times from the EV captured by my Sekonic L-408 - which are in the same ball park as the app)
The specs of the Holga state that its aperture is f/133 (for a 0.3mm pinhole). And the film plane is 40mm/1.6" from the pinhole.
The Holga recommended exposures for ISO 100 is:
Fine Weather 7-9 seconds Overcast 10-12 seconds Morning/Dusk 13+ seconds
But when metering a +15 EV outdoor scene, both the Pinhole Assist app and my calculations give a shutter speed of around 1/2 seconds (which is impossible to accurately time anyway). This is so significantly different from the Holga value that it confuses me.
Can anyone explain why I am seeing this difference, or even if it is critical? (Or is EV 15 considered way more than a "Fine Weather"?)
I have only run 1 roll of film through the camera and haven't yet gotten it processed. But I want to feel comfortable that I am sort of in the right ball park before committing a lot more film to it, but also don't want to waste film/$$ characterizing the exposure of my camera.
And finally, yes I know it's a Holga (I also have a non-pinhole Holga 120 that I have used and enjoyed) and that part of the "fun" is that it isn't a perfect camera, but there is a difference between capturing something interesting and a negative that is either fully clear or totally black.