Equivalent Exposure Calculator

[Lancashire Lad]

Several people have commented on previous threads, that they have difficulty in understanding which equivalent settings would give correct exposures.

Just found this online interactive equivalent exposure calculator, for use in answering a query by htcdude, but thought it might be worth posting as a new thread in its own right, so that other viewers are likely to see it.

The instructions are nigh on useless, but once you get the hang of it, you can see every available option at the click of a mouse button. (Don't take any notice of the written list below the calculator, as it isn't relevant).

What you need to do is input the three variables ISO / Shutter Speed / f-stop, which you know gives correct exposure.

Depending on what baseline values you have used, the table might now be saying over or under exposed.

Just keep clicking on different letters in the first column, until the table says "Good Exposure".

For example, if you highlighted 1/125th sec., ISO 400, and f5.6, then you need to click on letter G to get the table to show your baseline values as Good Exposure.

From this point, you can try the effect of altering any one of the ISO / Shutter Speed / f-stop variables.

All you need to do is adjust each of the three variables up or down, one at a time, to find whatever equivalents to your original three values would still give Good Exposure. (You don't alter the reference letter again, until such time as you enter another complete set of baseline known good exposure values for which you need equivalents).

Extended Range Exposure Guide

Regards,
Mike.

[nightshade]

Thanks Lancashire Lad that is pretty nifty, I was sure of my exposures (I
thought) but forgot that 35mm film has around 3 f-stops either way! and half a stop for slides
Very useful thank you

[Lancashire Lad]

Just noticed on the (presumably American) website where this calculator resides, I=Pod and I-Phone versions of it can be purchased, as well as a good old fashioned cardboard (or maybe it's plastic) rotating wheel low-tech version.

Some folks might find them handy.
NB: I have no involvement with that company whatsoever.

Regards,
Mike.