Astrophotography

Calculate exposure value from aperture, shutter speed, and ISO. Free exposure triangle (ev) calculator for camera exposure, lens settings, and print sizing.

Calculate morning and evening golden hour windows for outdoor photography. Free golden hour timer calculator for camera exposure, lens settings.

Calculate total daylight hours for a given latitude and date. Free daylight hours calculator for backpacking trips, trail planning, and day hikes.

Calculate diagonal angle-of-view focal-length equivalence from actual focal length and exact source/reference image-area width and height.

Calculate thin-lens near/far focus limits and hyperfocal distance from actual focal length, focus distance, f-number, and an entered CoC criterion.

Calculate EV100 and ISO-normalized setting indexes plus an equal-exposure shutter time from aperture, seconds, ISO, and comparison aperture.

Translate a documented or tested flash guide number to a target ISO, then solve a nominal direct-flash f-number or same-unit distance.

Calculate thin-lens hyperfocal distance and its exact entered-criterion near limit from actual focal length, taking f-number, and explicit circle of confusion.

Calculate the largest whole-pixel golden-ratio candidate rectangle inside a source image, including exact edge exclusions and retained pixels.

Calculate print size at entered image PPI, then audit retained pixels, fill crop, effective PPI, and pixel differences for one exact target.

Reconcile one source-owned visual telescope and eyepiece train. Calculate magnification, exit pupil, and an explicit field model without hidden specifications.

Reconcile two already comparable published stellar magnitudes in one photometric system and passband, with source, calibration, uncertainty, and report evidence retained.