Talk:Schlieren

visible effect
schlieren is the german word for the stringlike optical effect that you observe while dissolving sugar in your tea. You need schlieren optics to magnify these phenomena when these effects are not visible to the human eye.

Thie first thing you notice when you read this article is that schlieren is "not visible" which is a lie as mixing two clear liquids of different densities gives schlieren. The article should be changed to reflect that.


 * Schliere might be translated as "smear streak". Prior to photography it was used in the German language for the fuzzy effect when blobs are stretched into string form, a clearly visible effect. The word had its usage not only for liquids with distinct color but it is very common for grease stains on (not fully) polished glass - translucent grease streaks on a translucent material and such is hard to see (most people hold a wine glass in front of a light source) and even harder to photograph under normal conditions. Guidod (talk) 19:41, 15 June 2008 (UTC)


 * That doesn't mean schlieren are not visible for the human eye as it is written in this article. It just means that it is possible that you don't see them. This fact should be deleted. By the way, in the German entry they write that you DO see them.--Polis Tyrol (talk) 12:30, 14 June 2012 (UTC)

Merger Proposal
Will be helpful if schlieren photography is included in the flow visualisation section. IMO most of the reader are interested in the technique and having both the articles on the same page will be useful. myth 05:37, 24 January 2007 (UTC)


 * As a reader, I agree. When I was looking for Schlieren, I wanted to know both about the imaging technique and everything else. — Preceding unsigned comment added by 76.20.250.6 (talk)


 * As above. Though primarily interested in the imaging teqhnique, The photography is the same phenomenon and should be included in the main article.209.121.44.132 06:23, 21 March 2007 (UTC)


 * I'm not convinced: the technique of viewing optical inhomogeneities is called schlieren photography, not just schlieren. I'd be in favour of moving some of the history of schlieren photography from "Schlieren" into "Schlieren photography" and keeping just a definition of schlieren and links to the various ways in which they are visualised in "Schlieren". It may be worth adding redirect pages from things like "Schlieren system" to the page "Schlieren photography" to ensure that people who want information about the optical visualisation technique are linked directly to it. Chrisjohnson 12:49, 26 March 2007 (UTC)


 * Keep both pages, but include more information on the photographic method in Schlieren. Fifth Rider 22:26, 28 March 2007 (UTC)


 * Since no agreement was reached, I have removed the merger proposal. -- Myth (Talk) 21:11, 10 June 2007 (UTC)


 * I don't see the case, where no agreement was reached, as Myth pointed out. It seems to me that everybody agreed with the merge, but there is no consensus whether to merge Schlieren into schlieren photography, or to merge schlieren photography into Schlieren. --Rudolf Hellmuth (talk) 13:41, 20 November 2015 (UTC)

Confusing :-/
I'm interested by this, but I've read the article and am still confused. Can someone laymanise this a bit? — Preceding unsigned comment added by 193.63.174.208 (talk) 11:15, 26 June 2012 (UTC)

Request diagram
It would be great to have a diagram of the imaging system (maybe with raypaths?). I don't understand this well enough to know what would make a good diagram, but I think seeing one would make it clearer to me. HLHJ (talk) 16:47, 20 May 2014 (UTC)

No information about what it is
The article describes things about Schlieren imaging, but there is clear description about what it is how it actually works. Is it a coherent light environment where all the photons passing through the test area travel in a parallel path to each other? — Preceding unsigned comment added by Student342 (talk • contribs) 01:58, 30 March 2015 (UTC)

What about MARAT ?
There is no mention of Marat, who is well known of course for his contribution to French Revolution, but tried hard to be a scientist and invented the "hélioscope", which was the basis of the Schlieren effect. He even made the demonstration to Benjamin Franklin. Yet, his theories were mocked and he threw everything away and found rage outlet in revolution. https://books.google.fr/books?id=MB3qCAAAQBAJ&pg=PA5&lpg=PA5&dq=schlieren+marat&source=bl&ots=F8DW4JL4lv&sig=Zd2yYElZTneKIcfSpOkN2XMJTAc&hl=fr&sa=X&ved=0ahUKEwjhu_XFsN3TAhXBuRoKHYPQC-8Q6AEIIzAA#v=onepage&q=schlieren%20marat&f=false — Preceding unsigned comment added by Newtoon (talk • contribs) 08:45, 7 May 2017 (UTC)