Talk:Parallax

message: The example given involving the needle type speedometer is not a clear, helpful, or accurate example of parallax.  — Preceding unsigned comment added by 74.61.24.190 (talk) 04:24, 24 September 2011 (UTC)
thread_title:  Needle gauge not relevant 

message: Following is incorrect:
x radians = xo . 180 / pi = x" . 180 . 3600 / pi
Should be changed to:
x radians = xo . pi / 180 = x" . pi / (180 . 3600)
--AndyBryson (talk) 10:36, 1 July 2009 (UTC)
thread_title:  Error in Formula Derivation 

message: This is a good description of parallax.  But it's a difficult thing to explain and I think a picture would help.
The article should be expanded in relatioship with cameras.
:I have a question at talk:Single-lens reflex camera.  --KQ
Mention added! - MV
The animated example makes the reading of the text difficult.  The apparent back and forth motion creates a sort of motion sickness effect. Jef McKenzie (talk) 14:04, 26 April 2012 (UTC)
replies: text: What is this? Rmedia65 (talk) 18:00, 15 August 2023 (UTC)
thread_title: Needs a picture

message: Is this another type of parallax of just another name for a certain type already listed in the article?Tmchk | Talk 01:05, 20 May 2007 (UTC)
replies: text: Secular parallax is based upon the motion of the Sun, rather than the Earth. It provides a longer baseline because the Sun is moving along a galactic orbit, whereas the Earth only circles the Sun. So yes, I think it should be included under the more general topic of statistical parallax. Here is a reference that discusses it.—RJH (talk) 18:00, 20 October 2008 (UTC)
thread_title:  Secular parallax 

message: fgdgdgfdgdgdgfdgfdgdgdfd
: added reference for Zizek Drabauer 04:39, 12 July 2007 (UTC)
thread_title:  References? 

message: 1 quibble: recent research puts age of the universe @13.8GY, doesn't it?  Trekphiler 07:23, 29 December 2005 (UTC)
thread_title: I'm old! 

message: What does "The parallax p = \frac {au} {d} \cdot 180 \cdot \frac {3600} {\pi}  in arc seconds" mean?  I think the equals sign is substituting for the word "equals"?  This wording needs to be clarified. --AySz88^-^ 21:55, 9 February 2006 (UTC)
thread_title:  Confusing wording 

message: To what range can parallax methods reliably determine the distance to a star? Is it any more than 6000 light years? If it is, than this is an excellent method for proving the universe is older than what biblethumpers declare. Wouter Lievens 12:09, 14 June 2006 (UTC)
replies: text: It's about 1000 parsecs, and that comes to 3300 light years.Magmir 02:40, 23 February 2007 (UTC)

text: It wouldn't help anyways. I asked one about this, and he claimed the light from the stars was already set in motion. In other words, the light from a 10,000 lya (light years away) star would have been created at 6,000 lya to appear to be 4000 ly further away. -- trlkly 09:33, 28 November 2007 (UTC)

text: It should be possible to measure stellar parallax from Mars with one of the existing telescopes already there, or to design a telescope to be placed on Mars for that purpose.  Target stars would be selected for existence of very distant background stars in the field containing the target.  It might not be an expensive project, and could add some precision to terrestrial measures of the same targets. -- SyntheticET (talk) 06:20, 30 July 2015 (UTC)
thread_title:  Stellar parallax 

message: This is where I first met the word parallax: In an old CRT oscilloscop, the electron beam (cathode ray) draws a pattern on the phosphor inside the glass, which the operator reads along a grid pattern drawn on the outside of the glass. If the operator moves his head, a parallax reading error might occur. The same kind of reading error can occur in moving needle instruments (analog voltmeters, ampèremeters), which is why precision instruments had a mirror in the scale. When the needle covers its own mirror image, the operator's head is straight above the scale, without any parallax. --LA2 23:33, 26 January 2007 (UTC)
thread_title:  Oscilloscopes 

message: Maybe this has been discussed, or maybe someone has a clear idea, but: why is this section here?  As written it describes three methods of distance estimation, none of which is based on parallax.  It also discusses the end goal, estimating the size of the universe, which again has nothing to do with the topic in question.
I don't believe this section belongs.  If no one can give a good justification, I am going to delete it. atakdoug (talk) 19:59, 7 January 2008 (UTC)
replies: text: I agree, and the material is all covered in cosmic distance ladder anyway. I added a bit to the intro mentioning that parallax is the basis of the distance ladder. Ashill (talk) 09:24, 15 January 2008 (UTC)
replies: text: And I deleted the section, which I forgot to mention. Ashill (talk) 09:26, 15 January 2008 (UTC)
thread_title:  The Scale of the Universe -- Why? 

message: The current equation seemed very lacking. Surely a formula to work out the error given the perpendicular distance and parallel distance, or the angle from perpendicular, combined with the distance from the observed object and frame of reference, would be very desirably and helpful? It would certainly have helped me. Larklight (talk) 10:13, 30 January 2008 (UTC)
thread_title: Formula

message: "In astronomy, parallax is the only direct method by which distances to objects (typically stars) beyond the Solar System can be measured" - what about SN1987a? 98.221.27.220 (talk) 01:14, 14 August 2008 (UTC)
replies: text: There's no direct measurement. Any "direct" measurement of the distance to SN 1987A requires an estimate of the intrinsic luminosity of the object. With parallax, once you know the distance from the Earth to the Sun, you can measure distance purely geometrically, without assumptions about something about the nature of the object. —Alex (ASHill | talk | contribs) 01:30, 14 August 2008 (UTC)
thread_title: Comment

message: I was wondering whether this article could discuss statistical parallax, or if it should be on a separate page? (See part D of this, for example.) Thank you.—RJH (talk) 23:23, 18 October 2008 (UTC)
thread_title:  Statistical parallax 

message: When planets move around the sun, the sun itself also moves (but of course slower and in a smaller ellipse), and Jupiter causes the Sun's position to change by about 1.5 million km within 6 years. Earth orbits Sun in a close orbit compared to Jupiter, so it can be expected to follow this movement of the Sun (in addition to orbiting it). This should produce an additional parallax of about 7 milliarcseconds at α Centauri - this should be measurable e. g. with Hipparcos. Does this additional parallax have a special name? Maybe the article should mention it. Icek (talk) 22:32, 20 November 2008 (UTC)
thread_title:  Parallax caused by outer planets 

message: This section is entitled Parallax compensation for firearm and archery sights, but doesn't mention archery.  —Preceding unsigned comment added by 91.84.176.32 (talk) 21:10, 28 September 2010 (UTC)
thread_title:  Archery 

message: Is this correct?    \sin p = \frac {1 AU} {d}
Shouldn't it be:    \tan p = \frac {1 AU} {d}
:This is probably a matter of defiition. And don't forget that when the angles involved are very small, both sin (φ) and tan (φ) converge to the same value.
:HHahn (Talk) 10:09, 17 July 2010 (UTC)
thread_title:  sin or tan ? 

message: The following is the first sentence of the As a metaphor section. I think it should be revised, does anybody agree?
"In a philosophic/geometric sense: An apparent change in the direction of an object, caused by a change in observational position that provides a new line of sight."  — Preceding unsigned comment added by 207.177.213.116 (talk) 14:26, 5 August 2011 (UTC)
thread_title:  Confusing Sentence 

message: The section "Parallax compensation for firearm and archery sights" starts out just plain wrong. "the distance between the sighting mechanism and the weapon's bore" is "Sight Height". I am not seeing any reference that it is referred to as "parallax". "Parallax is the apparent movement of the target relative to the reticle when moving your head up and down," (or left and right for that matter) per this document (page 16). "parallax compensation" does not correct for Sight Height, it corrects for miss matches in planes of focus at different distances, i.e. it is a correction in the sight to keep it aligned in relationship to itself (its optical axis). Fountains of Bryn Mawr (talk) 13:31, 23 August 2011 (UTC)
thread_title: Parallax in optical sights

message: Proper motion is not measured in arc seconds -a unit of length-. The correct units are arc seconds per year. JuancitoxTw (talk) 16:53, 29 February 2012 (UTC)
thread_title:  Little mistake in the section "Dynamic Paralax" 

message: Is there any scope for the use of parallax in animation? For example, the 1988 film Akira has an opening scene in which parallax is exploited to produce the effect of panning by moving different layers of background across each other at different speeds. — Sasuke Sarutobi (talk) 13:36, 7 January 2014 (UTC)
replies: text: Sounds like a good idea for an addition to the article. Its actually not Parallax, its a simulation of it called "multiplane", made using a Multiplane camera. In modern computer graphics and phone interfaces, etc these simulations are called Parallax scrolling. I removed an overlong (redundant) section on it a while ago since it was out of place but I can see a section on all aspects of "simulation" it in a section title like "Simulated parallax",  maybe right above the "As a metaphor" section. Fountains of Bryn Mawr (talk) 15:28, 7 January 2014 (UTC)
thread_title:  Use in animation 

message: I’m assuming this undetectable transitioning image in the background of my phone display that was placed on my devices is a motion parallax or similar of the sort. I would like this removed. This motion parallax or something similar is being placed on devices and compromising them. Rmedia65 (talk) 17:53, 15 August 2023 (UTC)
replies: text: And Wikipedia is responsible how?  Lithopsian (talk) 20:14, 15 August 2023 (UTC)
thread_title:  Remove from devices