Talk:Flange focal distance

From Wikipedia, the free encyclopedia
Jump to: navigation, search
WikiProject Film (Rated Start-class)
WikiProject icon This article is within the scope of WikiProject Film. If you would like to participate, please visit the project page, where you can join the discussion and see lists of open tasks and regional and topical task forces. To use this banner, please refer to the documentation. To improve this article, please refer to the guidelines.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
Checklist icon
Taskforce icon
This article is supported by the Filmmaking task force.
 
Note icon
This article needs an image (preferably free) related to the subject, such as a picture of the set or a film poster. Please ensure that non-free content guidelines are properly observed.
WikiProject Photography (Rated Start-class)
WikiProject icon This article is within the scope of WikiProject Photography, a collaborative effort to improve the coverage of photography on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Start-Class article Start  This article has been rated as Start-Class on the quality scale.
 

Diagram source[edit]

Recreating a diagram should be straightforward for someone with SVG skills; there are a few available to recreate if you google for "flange focal distance". A diagram could show an internal view of an SLR camera, with the distance between the lens mount and the film plane highlighted. Perhaps something derived from Slr-cross-section.png. grendel|khan 06:50, 26 July 2006 (UTC)

After spending quite a while drawing a piture myself, I did a search in Wikicommons and found this one which is much simpler and clearer than what I had come up with. Yay Wiki! Egmason (talk) 08:35, 3 February 2012 (UTC)

Back Focus Adjustment[edit]

This article might be a good place to point out that some camera bodies (especially CS and C-mount) incorporate a (screw) mechanism for moving the sensor along the optical axis. The movement is typically very small (and usually not calibrated) but allows compensation for any "irregularities" in the lens mounting that would upset the flange focal distance. Usage procedure is 1/ mount the lens, 2/ set focus to infinity, 3/ point the lens at a distant building, then 4/ adjust the "back focus" until you obtain the sharpest possible image of the building. 87.102.83.121 (talk) 18:36, 18 August 2008 (UTC)

And B4 Mounts - move lens away from the flange. Often needed to ensure zooms are 'par-focal' - ie focus doesn't shift when zooming. Procedure is to zoom to a long focal length and focus the lens, zoom out to wide-angle, adjust back-focus at camera; repeat. --195.137.93.171 (talk) 05:55, 21 October 2014 (UTC)

Number of lenses, which lenses to include?[edit]

Which lenses should be counted for the "number of primes/zooms produced" columns? In production only or including legacy? Manufacturer only or including 3rd party? Should new issues of the same lens (MkII) be counted separate? I have added Samsung NX (also counting 3 samyang primes, but I think there are more), and Pentax K (counting only Pentax lenses, but everything listed in pentaxforums.com, including legacy lenses). --200.120.12.145 (talk) 02:42, 13 March 2012 (UTC)

Include all legacy lenses, for as long as they use the same mount (don't count lenses using mount adapters). List only lenses by original manufacturer(s), not third-party lenses (as this would be impossible to maintain). Any update (officially distinguished by the manufacturer as a new lens) should be counted (don't count color variants available at the same time, don't count mere firmware updates or internal-only changes). If there is more than one original manufacturer for a mount (f.e. Minolta, Konica Minolta, Sony), distinguish between them and combine the numbers using a "+" symbol. If a mount supports lenses for more than one format (f.e. 35mm full-frame and APS-C format), distinguish between them and combine the numbers with "+". If possible, link the numbers to WP articles or lists discussing these lenses. If possible, leave a <!-- source code comment --> indicating when a number was last updated in order to make it easier to keep the numbers up to date without recounting from scratch. --Matthiaspaul (talk) 23:25, 26 March 2014 (UTC)