(Digital) photography, F-stops and polarisers
Posted by jpluimers on 2025/03/24
My filter removal tool broke, so while I had new ones on order, I had to figure out how many F-stops I would need to compensate for especially because I would be shooting during the evening.
Here are some links that gave me an impression:
- [Wayback/Archive] How to Compensate for Exposure When Using a Polarizing Filter · Urth Magazine
Although 1.3 f-stops is the average amount of light a polarizing filter blocks, this can vary according to the scene and your position relative to the light waves coming from your light source. The average is slightly different between linear polarizers and circular polarizers.
- [Wayback/Archive] CPL vs Linear Polarizing Filters · Urth Magazine
If you own a modern DSLR camera, it will probably have a partially reflecting mirror. The presence of this partially reflecting mirror can cause metering errors if you use a linear polarizer with a DSLR camera. A CPL filter does not interfere with the lens metering system, however, so is the right choice of polarizing filter for a DSLR camera.
- [WaybackSave/Archive] A Quick Guide to F-Stops: Examples & Photos · Urth Magazine
- [Wayback/Archive] Camera Lens F-Stop Chart
Don’t you love the accessibility (a11y) awareness of people that put tables as images on their web-pages? The last link above did (see the image on the right below), I don’t: I love plain HTML with plain old rules and left-alignment content when it makes things more readable, so I converted it into a plain HTML table (:
Full stops f/2 stops f/3 stop f/1.0 f/1.0 f/1.0 f/1.1 f/1.2 f/1.2 f/1.4 f/1.4 f/1.4 f/1.6 f/1.7 f/1.8 f/2 f/2 f/2 f/2.2 f/2.4 f/2.5 f/2.8 f/2.8 f/2.8 f/3.2 f/3.3 f/3.5 f/4 f/4 f/4 f/4.5 f/4.8 f/5 f/5.6 f/5.6 f/5.6 f/6.3 f/6.7 f/7.1 f/8 f/8 f/8 f/9 f/9.5 f/10 f/11 f/11 f/11 f/13 f/13 f/14 f/16 f/16 f/16 f/18 f/1 f/20 f/22 f/22 f/22 f/25 f/2 f/29 f/32 f/32 f/32 f/36 /38 f/40 f/45 f/45 f/45 f/51 f/54 f/57 f/64 f/64 f/64
These tables aren’t hard to create as f-number – Wikipedia f/N all have N equal to powers of the square root of 2 truncated down to 1 digit after the decimal dot when N < 10, or to integers when N >= 10. Similar for shutter speeds (see Shutter speed – Wikipedia) and ISO numbers (see Film speed – Wikipedia) but at large numbers rounded to multiples of 1000, 2000 or 5000.
On the to-do list do the same for the images in these pages (typo and lack of low ISO values theirs):
[Wayback/Archive] Shutter Speed Chart – Photography 101 [Wayback/Archive] Photography ISO Chart
Queries:
- [WaybackSave/Archive] polarizer filter stops – Google Suche
- [WaybackSave/Archive] f-stop table – Google Suche
--jeroen
The Wiert Corner - irregular stream of stuff 
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