Talk:Depth of field

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Depth of field was nominated as a Natural sciences good article, but it did not meet the good article criteria at the time (September 18, 2019). There are suggestions on the review page for improving the article. If you can improve it, please do; it may then be renominated.

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Contining Violence

I've been continuing my near-violent changes. I think we are nearly there thought.

The three things that I think need to be done before submitting for GA review are:

Consistent referencing
Sort out formula section
Thorought proofread.

I got most of the way thought the referencing a while ago - it only needs a bit more work - particular on the difraction section that came back. I did a fair amount of work on the formula section today - getting steadily more unhappy with it as I went. I think we need to get a single consistant mainstream textbook or source and start it from scratch. At the very least we should be using the same symbols thoroughout the section. Will investigate the library and come back in a few days to see were we are.Joe (talk) 17:17, 17 February 2019 (UTC)

Oh yeah, rewrite the lead - the article has changed a lot so it will probably need an overhaul.Joe (talk) 17:18, 17 February 2019 (UTC)

It's looking good. But an awful lot was lost; did you collect it some place? Dicklyon (talk) 03:15, 24 March 2019 (UTC)

Lead, 1st caption, section title and content, POV

LEAD
The lead still seems too POVish; but, now the POV is not hidden from the casual reader. Salvaggio et al clearly stated their assumption. The reference and link to "focus stacking" was removed because that article seems to have no reliable basis. Also the 'can't be done by traditional methods' comment was removed as being unsupportable.

1st CAPTION
Reworded the caption

SECTION TITLE AND CONTENT
Changed section title to "Overcomming DOF limitations" to more accurately reflect the intent. Made a few improvements to the wording. Left "focus stacking" in but maybe "image stacking" is a more widely used term (Adobe uses "image stacking") and there doesn't seem to be a reliable reference for "focus stacking".

POV
The article is written from the POV that cameras have a lens axis perpindicular to the sensor plane; that can be very misleading. May want to consider using Conrad, Merklinger, Ray, Wheeler, and others that show what DOF is more generally. The general still applies to the current POV.

208.54.86.201 (talk) 02:00, 8 June 2019 (UTC)

Reviewer: Kingsif (talk · contribs) 01:56, 17 September 2019 (UTC)

GA Review

This review is transcluded from Talk:Depth of field/GA1. The edit link for this section can be used to add comments to the review.

Hi, I'll be reviewing this with comments posted soon (if just to learn more about f-stops myself) Kingsif (talk) 01:56, 17 September 2019 (UTC)

Style

Lead could be a little longer per length of article
Please change "techniques/equipment" to 'techniques and/or equipment'
Wikilink circle of confusion - the first time it's used. A brief explanation may also help.
Some random capitalized words?
Is there a need to italicize "circle of confusion" in exactly one instance that it's mentioned?
In the Factors section, the first line is just repeating the lead (and copyvio)
Should have wikilinks and brief explanation of other technical terms (assume the reader knows nothing of camera tech)
Inconsistency with how depth of field is capitalized
Factors affecting... does not seem well structured, with some perhaps irrelevant content that would belong in a different section. In fact, the other sections have the same problem.
Article doesn't seem to have a good sense of direction.
Later sections especially seem to be a quick collection of information from personal knowledge tacked on the end without consideration
Fail - re-write may be necessary, with a good structure

Coverage

Lead does not cover main points, only outlines what dof is. (Also, it's copyvio.)
Top section of Factors affecting depth of field seems to cover more what dof is and how to calculate it and functions of it more than factors affecting it.
Scheimpflug principle illustrated but not otherwise mentioned
- There is no need to mention the "Scheimpflug principle" in every article that discusses swing or tilt. It seems to be promoting the annoying misunderstanding of the principle that, swivel of lens or sensor causes swivel of POF. Although it is true that one causes the other, that is not the principle. And, one doesn't need to know the geometric relationship of POF, lens plane, and film plane to understand DOF (or even how to use swing or tilt). - NewageEd (talk) 09:47, 23 January 2020 (UTC)
Fail areas covered in appropriate sections, clear examples of info missing

Illustration

Good choice of top image
The scientific diagram at factors is good and clear, but relies on the description. Not sure there would other wise be a way to show this, though.
Nice illustrative use of resultant image with building blocks
- The building blocks illustration could be improved if the plane of focus was on the middle stack of blocks. Then it would show that depth of field works in both directions; maybe add a couple stacks of blocks. - NewageEd (talk) 09:22, 23 January 2020 (UTC)
Seems like the 4 dial images are all for the DOF scales section, and overflow severely - should put a gallery at the bottom of the section
Needs attention

Neutrality

Yes, good
Pass
- At this stage it is written from the narrow point of view of cameras with no swing or tilt of lens or image plane. Maybe when it is rewritten to include camera movements it will become neutral. I'll start by rewriting the "Camera movements" section. - NewageEd (talk) 09:13, 23 January 2020 (UTC)

Verifiability

Has a citation needed tag, that seems to have been added today
Good range of RS
However, large parts of article unreferenced
Likely some OR in 'most cinematographers, though' kind of writing
Fail - a cn tag is a cn tag

Stability

Had some edits today for general improvement. Nothing major, though.
Pass

Copyright

Nearly the entire lead is copied here
- Copied to there you mean; that's obviously not a place anyone would copy from, just an assemblage of snips from WP. Dicklyon (talk) 13:03, 21 September 2019 (UTC)
  - I did check the context; the lead is random snippets of the source text, which is a really long paragraph in answer to a question on a forum about depth of field. It would be unusual to have a lot of someone's own writing with whole sentences of only the WP lead incorporated so naturally at random points... Not saying it has been taken, but it would be odd for the text to have been copied to that source, given its presentation. Kingsif (talk) 14:30, 21 September 2019 (UTC)
    - This is not a copyright violation or plagiarism. The journal page referenced above, here, are personal notes under the title of "Monster Hunter World white sharpness". The snippet was obviously taken from Wikipedia after 8 June 2019, not the other way around. However, reliable sources are clear in describing depth of field in relation to the POF. The current wording misses this clarity in comparison with the previous wording of 10 Feb 2019; which, appears to accurately represent illustrations and descriptions contained in reliable sources. - NewageEd (talk) 08:52, 23 January 2020 (UTC)
Images seem correctly licensed
Fail - please rewrite lead

Overall

Needs a significant restructure and more citations throughout. Also copyvio and obviously missing info. It looks like the main editor has a lot of knowledge, has worked hard creating it. Main reason for immediate fail is the poor structure. Kingsif (talk) 21:12, 18 September 2019 (UTC)

Blurry hearts picture

The blurry hearts illustration has more to do with the fact that aperture shape affects the shape of blurry spots; but within the DoF, the blurriness is not noticeable. This is looking like a "how-to" photography-art guide. Seems appropriate for an article that discusses aperture shape and artistic blur; which, might not belong in WP (textbook stuff?). - NewageEd (talk) 10:24, 23 January 2020 (UTC)

Estimate dof in image dimension

This is a new logic I have been working on, no publication so far but I will appreciate if somebody is interested in writing an article on this topic. Feel free to contact me, thanks.

he key point is that when we work in the image dimension instead of the scene the equations become very simple. The size of the focus blur varies linearily along a plane in the image

The relation is;

$s={\frac {a}{h}}\times d$ where:

a is the numerical aperture
h is the "altitude" above the plane. This value can be adjusted if the camera is tilted with the cosine of the angle with the plane.
d is the distance of the point from an origin in the focus plane (where s=0)

The demonstration is here

A first conclusion is that the focus is at exactly at the middle distance between the near and far dof limit. Again this is true in the image and along a plane.

Then we have a relation to set the f# for having everything in focus between the focus plane and the near/far limit

$f_{\#}=f\times {\frac {k}{h}}\times r$

f is the focal length, h the altitude.
k is a constant representing the minimum resolution, k =800 is consistent with the results given with common circle of confusions with classic dof calculators
r is the ratio of the image height between the focus and the near or far limit (for instance 1/3 of the height).

There is also a relation taking into account diffraction:

$n=134{\sqrt {\frac {rf}{h}}}$ The links are here:

The theory
DOF calculator]
A video on youtube to use the calculator — Preceding unsigned comment added by Chrisinparis (talk • contribs) 16:48, 28 January 2024 (UTC)

Do not hesitate to give me your feedback, I want to do it the clean way. The equations are disclosed, it is quite simple in fact,it simply uses a different logic Everything is explained in the links. Feel free to contact me !!