(focal length, subject distance), blur circle is directly proportional to aperture diameter (or 1/ f.stop number). Indeed, you can get almost the same blur with 55-250, if using the long end of the zoom. However, IQ drops slightly at 250mm for that lens, so it's a bit of a ...
So as a seller, I view eBay through this lens. I want buyers who think like me - buyers who know what they want and are not already considering how easy it might be to return it if I decide "I guess I don't want this". I have offered 30 days returns (not...
ex03.py Finite-diameter lens 4. ex04.py Aperture behind lens acting as Field Stop 5. ex05.py Simple microscope system 6. ex06.py Kohler illumination 7. ex07.py Focussing through a dielectric slab 8. ex08.py Virtual image at -f with object at f/2 9. ex09.py Infinite telecentric ...
All example code on your machine is found at: /somedirectory/on/your/machine 1. ex01.py A single lens f = 50 mm, infinite diameter 2. ex02.py Two lenses, infinite diameters 3. ex03.py Finite-diameter lens 4. ex04.py Aperture behind lens acting as Field Stop 5. ex05.py Simple...