query: Does the diameter of the aperture increase with increases in the focal length with constant F-number(F-stops)?
positive_passages.docid: 145622
positive_passages.text: How do constant aperture zoom lenses work?
negative_passages.docid: 129613
negative_passages.text: Why does illuminance stay the same for a given f-stop even when focal length changes?
negative_passages.docid: 11197
negative_passages.text: How do I convert lens focal length (mm) to x-times optical zoom?
negative_passages.docid: 128590
negative_passages.text: Is the formula for object image size given focal length, etc. independent of sensor size?
negative_passages.docid: 153578
negative_passages.text: Variable focal length for macro lenses?
negative_passages.docid: 56452
negative_passages.text: What happens to waves when they hit smaller apertures than their wavelenghts?
negative_passages.docid: 52326
negative_passages.text: Why does a ray passing through optical centre remain undeviated?
negative_passages.docid: 29080
negative_passages.text: How do extension tubes affect focusing distance?
negative_passages.docid: 142585
negative_passages.text: Is there a theoretical maximum for refractive index?
negative_passages.docid: 79654
negative_passages.text: What is the effect of the number of cross-type focus points on sharp focus?
negative_passages.docid: 4389
negative_passages.text: How can a lens with a single focal length focus on more than one plane?
negative_passages.docid: 74363
negative_passages.text: Why is the bokeh shaped like the aperture?
negative_passages.docid: 70481
negative_passages.text: Relationship between the the slit width $w$ and source distance $d$
negative_passages.docid: 19362
negative_passages.text: Can a smaller sensor's "crop factor" be used to calculate the exact increase in depth of field?
negative_passages.docid: 6598
negative_passages.text: How to calculate the correct focal length needed for a subject of a given size and distance?
negative_passages.docid: 58265
negative_passages.text: What happens to a lens when you turn the focus ring during AF mode?
negative_passages.docid: 81660
negative_passages.text: Does autofocus work better with f/2.8 lenses vs f/4 or slower?