1. Technically, why is the out of focus area blurred more when using a bigger aperture?

  2. Is there an easy way to tell the size of an image circle a lens has?

  3. Do lenses affect color fidelity?

  4. Does say a 35mm on an APS-C camera have the same facial/other deformations as a 35mm?
  5. Lens equivalent depth of field

  6. If a camera has two lenses, where is the focal plane? In the sensor or in the second lens?
  7. How to choose a good smartphone if the top priority of the user is photography?
  8. What could cause this visible artifact which seems to a be a glowing inverse of something outside of the frame overlayed on this photograph?
  9. What is a "diffraction limit"?

  10. How do I design a conceptual lens schematic?
  11. Why do light sources appear as stars sometimes?

  12. What limit do lens manufactures come upon first when making a wide range lens with large aperture (besides economics)?
  13. Understanding focus distance of Nikon f/1.8D lens with D5600 Camera

  14. How do phone attachment lenses affect depth of field?

  15. What does the number of elements and groups in a lens mean?

  16. Does the sensor size matters in the size and weight of an equivalent lens? Why?

  17. Design and Fabricating My Own Lens

  18. Why is the hole in a pinhole camera usually a circle?

  19. What does lens flare from a catadioptric (mirror) lens look like?

  20. Do convex lenses make parallel light rays of different wavelength converge to different points?
  21. Do convex lenses make light from different points converge to different points?

  22. Pentax k-30: can i buy all lens not stabilized?

  23. Determining the size of the smallest resolvable detail for a given camera
  24. How to know if a lens will work for my camera
  25. What is the (real) meaning of binocular magnification number?
  26. How does the human eye compare to modern cameras and lenses?

  27. Confused about different optical zoom on different lens
  28. Color consistency across equal cameras but different lenses
  29. What causes lens flare along specific axes?

  30. How would apodization impact landscape photography?

  31. What's the opposite of a fisheye lens?
  32. Is focal length internal or external?

  33. Why do zoom lenses and compact cameras have varied maximum aperture across the zoom range?

  34. How to measure field-of-view of a camera with fisheye Lens?

  35. Why are objects far away inverted through a lens but not through the viewfinder?
  36. What's the intended use of lens with f-numbers close to or "faster" than f/1?
  37. What is the "Circle of Confusion?"

  38. How do I interpret an MTF Chart?
  39. How many times is the image inverted inside a DSLR camera?
  40. How can I increase the flange focal distance (back focal length) of DSLR lens?

  41. What are these vertical light lines on pictures taken with my smartphone?

  42. How do I clean a Yashica Mat-124g taking lens?
  43. What are the theoretical minimum and maximum apertures?

  44. Size of the entrance pupil vs size of the aperture
  45. How to prevent fringing?

  46. Why do mirror lenses have poor contrast?

  47. What is the difference between perspective distortion and barrel or pincushion distortion?

  48. Why might focus fall off at the edges?
  49. Concept of focus for a pinhole camera?

  50. Does sensor size impact the diffraction limit of a lens?

  51. Are thermal imagers inherently more expensive than visible-light digital cameras?
  52. How do catadioptric camera systems show the whole frame despite mirror obstructing the center?
  53. Projector Design and lenses
  54. What is a Proj.-Tessar lens?
  55. 30x Optical Zoom vs. 30x Magnification on Binoculars?

  56. What is bokeh, exactly?

  57. What is the difference between a pentaprism and a pentamirror?

  58. What is the pre-computer version of Photoshop's blending modes?

  59. How does an apodization filter improve bokeh?

  60. Size of an image given the mm of a lens

  61. How do anamorphic lenses produce lens flare "streaks"?
  62. How many optical aberration types are there in lenses? And what are they?

  63. Need help to find proper camera and lens specification
  64. Where is the aperture?

  65. Do lens optics/formulas, of the same lens model number, get updated as it is being produced?
  66. Is there any physical reason a mirror lens could not have a variable aperture?

  67. What differences will there be when stacking add-on lenses?

  68. Are there any 24-70 2.8 lens with no length change in zooming?
  69. Why is the area in focus in front of the focus distance narrower than behind it?

  70. When you zoom in with a lens on an SLR why does the lens go in then out?
  71. Why not have the diaphragm in camera body instead of the lens?

  72. What is focal length and how does it affect my photos?
  73. What is the light called that is outside the area of the capture medium?
  74. How to calculate the radius of the bokeh of a subject, while out of focus, relative to the print size?
  75. What are groups and elements in lenses?

  76. What is the shape of the focal plane?

  77. Is a two-prime lens possible? E.g. 35mm and 50mm

  78. Why is depth of field affected by focal length?
  79. Does wide angle equivalent in crop sensor skew image?

  80. What are Barrel and Pincushion distortion and how are they corrected?

  81. How does a 'reversing adapter with automatic system' deal with the *inverseness* of the reversed lens?

  82. Numerical Aperture of an Inverted Webcam Lens

  83. Looking for an iPad lens that makes it possible to capture a person head to toe from up close
  84. Why are large zoom ratio constant apertures lenses not generally available?
  85. How can I find a compact camera where I can change the lens?
  86. Lens/Mirror system for stereo photography?

  87. What is the cause of this non-uniform bokeh effect?

  88. How is a lens's bokeh determined by its construction?

  89. Do lenses have focal planes or focal spheres/ellipsoids?
  90. Are points off-center from the lens axis out of focus?

  91. Mirror vs Lens: do either or both invert the image?

  92. Point two cameras through the same lens, with the same perspective

  93. How does a focus ring bring a subject in or out of focus?
  94. What happens if anti-reflective coating is fully ruined or removed from lens' most outer surface?

  95. Why don't cameras ordinarily zoom by moving the whole lens as a unit?
  96. How can I test that the image is inverted in a pinhole camera?
  97. Limits of camera lens capabilities
  98. Clear-cut black corners with some superzoom photos
  99. Is there development in the world of lenses?

  100. Will using a full frame lens with extension tubes on a crop sensor camera reduce the "crop"?