Alt Process Exposure Calc helps you lock in a reliable “standard exposure” for alternative photographic printing. Enter your baseline time, the first max-black step from a wedge where you can not see a line from the transparency or white if you are calibrating polymer, and steps-per-stop—then the app does the maths and records your setup.

Made for
Cyanotype, Platinum/Palladium, Salt, Carbon, Photopolymer & other alt processes.

What it does:

Calculates a precise standard exposure from a step wedge.

Simple process picker (Cyanotype, Platinum/Palladium, Salt, Carbon, Photopolymer, Other).

Optional notes for paper, ink, and aquatint timing.

Export your records to Google Sheets (with an included Apps Script you paste once).

Newest-first log with pastel row tinting by process.

How export works
You’ll paste a small, safe Google Apps Script into a Sheet (instructions in-app). Tap Export to push a new row with the date, process, exposure, and notes. The sheet auto-formats and keeps the latest records at the top.

Why it helps

records exposures across papers and processes

A clean archive of what actually worked




Subscription
Alt Process Exposure Calc uses an auto-renewing yearly subscription for full access (pricing shown in-app).
• Payment is charged to your Apple ID at confirmation of purchase.
• Subscription renews automatically unless cancelled at least 24 hours before the end of the period.
• Manage or cancel in Settings → Apple ID → Subscriptions.


Happy printing!

Full access is available with an annual subscription.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://itsasalfordthing.squarespace.com/privacy-policy-exposure-calculator