I asked about this before at other photo forums but got no response, so I thought I'd try again here, since it's directly tied to using my Pinstra:
I'm new to analog photography, and have always relied on my camera to both focus and determine exposure. But now ....
I am using an iPhone app called Pinhole Assist, but I find myself still challenged at getting good exposures. I'm wondering:
If I'm shoot a mostly bright scene will my meter tend to push the exposure towards mid-tones; and conversely, if I'm shooting dark shadow areas, will the meter also push the exposure towards the middle?
And does anyone have any other recommendations for iPhone metering apps that will work for long exposures?
Finally, I've seen websites that explain using a regular light meter and then converting your exposure times to match what's need for a ISO 2, f/229 setting. I'm thinking of trying this, but using my camera, set to ISO 100, f/16, Has anyone every used this method, and can you tell me about it.
Again, I tried finding this info on other forums, without success, but I think it may be of interest to other Pinstra users, especially us newbies.
Best, David

I've had the same issues as metering can be tricky but thing to remember is it's all trial and error anyway.
I use a handheld meter (Minolta Autometer IV) set to ISO 3 to take a reading at F/16 or F/8. I've then done some maths and made a spreadsheet with corresponding exposures times when corrected to ISO 2 for Harman paper.
I've printed out and taken with me. I adjust slightly on the fly but gets me pretty close.
I'll see if I can upload and share the spreadsheet here later. Might be useful as a starting point.