All Questions
Tagged with effective-aperture focal-length
4 questions
2
votes
1
answer
2k
views
How to calculate the focal length of cell phone cameras when none of the required parameters are available?
There are many camera phones for which the focal length, aperture size, and sensor size are not available. Is there a formula to calculate these parameters or a site which provides these details for ...
- 21
2
votes
2
answers
2k
views
Help me understand effective f-number
If I set a lens to, say, f/2 but my focus is set to its closest point, my effective f-number won't be f/2 any more but it will be higher by a factor that depends on focal length, image magnification ...
- 265
13
votes
2
answers
629
views
Does focus breathing make a lens slower when close focusing?
I've heard that focal length of some lenses will become noticeably longer when focusing to a close distance, an effect called "focus breathing". Since f-number is focal length divided by diameter of ...
- 32k
14
votes
1
answer
2k
views
Does focal length affect diffraction, in addition to aperture?
The reason I ask is that f/18 on a 24mm lens = 1.5mm, and f/18 on a 180mm lens = 10mm. I thought diffraction is due to the small physical size of the aperture, rather than the f-ratio, yet I only ever ...
- 1,436
Hot Network Questions
- Disregard equation alignment in one line
- What's the safest way to improve upon an existing network cable running next to AC power in underground PVC conduit?
- What does, "there is no truth in him" mean in John 8:44?
- C.c.c. forcings cannot introduce diamond (Kunen Exercise IV.7.57)
- How does this Paypal guest checkout scam work?
- If someone falsely claims to have a Ph.D. on the jacket of a book and they profit from that claim, is that criminal fraud?
- As an adverb, which word’s more idiomatic: “clear” or “clearly”?
- Useful aerial recon vehicles for newly colonized worlds
- What's the difference between '\ ' and tilde character (~)?
- Name the book with human embassy on small island
- Equation of standing waves
- A website asks you to enter a Microsoft/Google/Facebook password. How do you know it is safe?
- How to achieve infinite rage?
- Why are the black piano keys' front face sloped?
- The coherence of physicalism: are there any solutions to Hempel's dilemma?
- The ten most fundamental topics in geometric group theory
- Can I split the rendering in external displays between the GPU and CPU?
- Can we judge morality?
- Role of thrust during take off
- What is an Inaugural Fund?
- Did the Japanese military use the Kagoshima dialect to protect their communications during WW2?
- How to keep meat in a dungeon fresh, preserved, and hot?
- Why isn't there an "exterior algebra"-like structure imposed on the tangent spaces of smooth manifolds?
- Covering a smoke alarm horn