Does anyone know what color Velvetlite tint was and who made it? Also, I think Crookes was a light blue but I can't learn who made it either.? Does anyone disagree with the following:?
True-Color, grey tint by AO
Calobar D, dark green by AO
G-15, green-grey by Ray Ban
Cruxite AX, oops another question, I can't find what the AX regards, I think it's pink by AO?
Thanks for the help
Does anyone know what color ......................
Crookes was a redish brown (England)Originally Posted by OptiStudent
Cruxite A was a pink by AO
Cruxite AX was skin colored light brown with about 20% absorbtion, also AO
Never heard of Velvetlite maybe some of the oher old geezers know about it.
Are we sure Crookes is reddish-brown tint and not light blue tint? I've been reading that Sir William Crookes discovered Thallium which Encarta says gives off a bluish-grey tint when exposed to air. I was wondering if this was related to the Crookes' tint. I can find any resources to substainiate any of this.
Crookes Alpha was a light blue tint, with a crrokes A2 being a darker blue. To quote Prof Mo Jalie:
Shortly before the Great War, sir william Crookes, at the instigation of the Royal society, began his experiments on the production of a series of filters which would absorb the harmful radiations to which furnace workers were exposed. his experiments culminated in the production of a group of filters which absorb all the ultra violet rediations below 350nm and at the same time reduce the luminosity of the visible spectrum. The original Crookes filters, Crookes A, A2, B and B2 were widely used until the increased popularity of CR39 and the finish (in the UK) of the NHS spectacles. The original Crookes A was a very pale green colour containg Uranium, this was replaced by the Crookes alpha. the transmission details of the range are set out below
Approx Transmission details
(%) 2mm thick
Shade Colour LTF T350 T550 T750 T1000
Alpha Very Pale blue 82 3 89 85 89
A2 Pale Blue 76 8 84 85 92
B Smoke 47 4 48 65 55
B2 Dark Smoke 19 19 0 30 13
Lewy
At AO we used a lot of Therminon lenses, light blue (wonder what happened to them??) Never in 37 years have I heard of Velvetlite.
Velvetlite may have been Titmus' (or maybe Meyer's?) tradename for Rose, as Cruxite was AO's (Cruxite AX was Rose 2, wasn't it?).Crookes was most definitely bluish, like Therminon.
Here are the real cruxite lenses:.................
Here are the real cruxite lenses:
Cruxite Lenses
Old tinted lens display
1.523 Cruxite Lens BlankRefraction index Nd=1.523
Okay, thank-yous to everyone for the help! I am in a library; so please excuse the absence of my spell checker!
Lewy's response to Crookes is absolutely correct. I have M.Jalies' book "The Principals of Ophthalmic Lenses" next to me. Like Crookes, and Lewy(?), she is English and gives a more detailed definition of the Crookes filters than the US books do. The manufacturer of these lenses was Chance Pilkington-Crookes. I have a second book here by another English-person which substantiates M. Jalie's book. A third book I have by Ralph Drew explains how Crooke created a very dark green lens for the glass workers in 1913, and shortly after that made the other lenses Lewy listed. Drew states that Crooke is not historically associated with the valuable glass workers lens but with the very light blue tinted lens (Alpha).
True-color C medium gray AO
True-color dark gray AO
Calobar B,C,D C=green, D=drk green British American Opt./AO
G-15 dark gray B&L who sold RayBan to Luxottica
Cruxite A very pale pink British Amer Opt.
AX pale pink
B pale brown
C brown
VELVETLITE Professor M. Dowaliby, O.D. says PINK
Dr. Brooks says Amethyst (which Webster says is a pupleish tint)
made by Titmus Optical Company
similar to Softlite by B&L
And the 1st chemically compounded absorption lens was yellow-green, made in 1880's and called.........Hmm, I'm acting like a "hot shot" now that I have a 8 smelly old books in front of me.:o I like that old book smell! Gotta go I am getting kicked off of this PC for some class that is coming in.
Thanks Again!
Last edited by OptiStudent; 10-25-2006 at 03:57 PM.
Thank you!!
You are the first one that I can remember that has actually used us as a reference rather than the primary source. I don't know what you're studying but I'm betting you'll be successful at it :cheers:
Days where my gratitude exceed my expectations are very good days!
TY, I am studying to be an optician. In retrospec, I should have consulted the library first as my primary source! The internet makes me lazy and forgetfull how to utilize a library.
Last edited by OptiStudent; 10-25-2006 at 03:58 PM.
When I was a little schoolboy in London, there were a few kids in our class who wore glasses and one of them had these strange light blue tinted lenses (I later discovered these were Crookes Alpha)
Kids can be cruel, and this boy was tormented as having strange eyes (he actually did!!).... a couple of years later when I was told I needed glasses, the optician recommended that I have this crookes tint........ no way was I having this colour with the stigma attached....even though it was considered very special and not just given out by patient request.
It had to be prescribed and authorised.
What I distinctly remember about the frame choice at this optical store, was that I requested Brown Mottled frame with wide temples like one of the 'cool set' boys had....you know, Buddy Holly specs.... "No", said the optician, "this is what you can have" and he gave me a choice of a spindly thin '524' NHS in Black or Brown... that was it! There was no choice or hardly any private dispensing back in the early 50s.
Anyway, back to the present, even today when a Pt says they want a light blue fashion tint on their lenses, I'm not comfortable with it because of old associations.
Ozzy is kool to me, I like the look of blue lenses in a silver frame.
Out of many reasons blue is the worst color to wear.
My thoughts exactly!
Come on Chris. . .
you weren't born old!! At some point your folks must have yelled at you to turn that stuff down!!
I hope you're having fun and making money!!
Days where my gratitude exceed my expectations are very good days!
blue light alone can damage the powerhouses of the retina cells
They alway's yelled to turn it down.............but those were the stupid young years.
Blue lenses do NOT block, but transmit blue light, so I got to start by giving you one reason of many......................
Read the whole artice at: http://www.sunnexbiotech.com/therapist/main.htm
Recent studies on light exposure of mammals, as well as in vitro studies and post-mortem analysis of the human retina that examine the mechanisms by which cumulative blue light exposure induces retinal degeneration, all support the thesis that repetitive exposure to blue wavelengths of visible light promotes the development of ARMD.2
A June 2005 paper in the Journal of Biological Chemistry found that "blue light alone can damage the powerhouses of the retina cells, called mitochondria, and in particular the DNA of these energy producing cells." Reporting on this paper, ScienCentral News quoted the author, B. F. Godley, as having proposed that "these changes may play a role...[in] macular degeneration". 3
To state that blue is the worst colour to wear is far too simplistic.
In tests of optimum visual performance in optimised colour space this is just not true - whilst accepting that blue light can have denaturing properties it can also have significant positive effects on the magnocellular system, liver function (in babies) and many other physiological processes.
It can also be the best / most comfortable to wear, but colour must be prescribed with knowledge - eg the effects of trying to match crookes alpha lenses for existing wearers (when it was being withdrawn in the seventies) with plastic "equivalent" tints was often disastrous. Metameric effects of a spiked transmission curve were often not understood and optometrists / opticians often prescribed by appearance - a reasonable action for those that do not understand colour, but for those that do - stupid.
but for those that do - stupid......................
Not everybody out in the field is a specialist in color applications that will affect brain and body functions. You might be the only one.
On the other hand I would not discard any medical research publication.
Not only one by any means - good news is that I have just written syllabus for a post grad course (20 weeks) that is due to start next Jan.
hopefully optical professionals will know what the effects of tints are in the future - then prescribing will increase (tenfold) with remarkable results for the patients
it is possible to measure the physical effects of tints - positive or negative - we do it as a matter of routine now but there is relatively few with sufficient knowledge and training.
how professionals can be happy with current prescribing methods (poor to non existent) is sad - the opportunities in this area will become apparent as the numerous clinical trials become public - or will the professions try to ignore the inevitable? only when the litigation starts perhaps we shall see change! the first cases have already been settled without publicity in uk.
I said I liked the LOOKS of blue-tinted lenses in reply to Nobel's post which was reflecting on peer criticisms. As a student I am aware of, and being taught, the pros and cons of selective filters, thanks anyway! The "dummy is as dummy does" comment was a prime example of the peer criticisms I was relating to. As far as turning up the volume, I don't care if it's Ozzy or Costello-- (both wear blue-tints), try dancing barefoot (Pattie Smith song), to your likes on a great audiophile system like mine. Shostakovich, Mahler, and Billie Holiday are ageless!
""And the 1st chemically compounded absorption lens was yellow-green, made in 1880's and called.........Hmm, I'm acting like a "hot shot" now that I have 8 smelly old books in front of me."" As time has passed... I regret, I can not qoute my source, however I did scribble that the lens was made by a Frenchman named Fieuzel, the lens was designed to absorb UV, in a dark shade upto 3800 Angstrom units. How do we convert angstrom units to nano-meters? This answer I don't have "scribbled" anywhere!
Petes article in Review of Optometry has some details as to the effects of high energy visible light. I would not suggest dispensing blue tinted lenses for this reason.
You can read his article at
http://www.revoptom.com/index.asp?Ar...ransitions.htm
1st* HTML5 Tracer Software
1st Mac Compatible Tracer Software
1st Linux Compatible Tracer Software
*Dave at OptiVision has a web based tracer integration package that's awesome.
crookes lense were most definely blue, as i made hundreds and hundreds if not more of them , as in the early 70,s they were one of the favorites of the hippies, usually in an octagon metal frame
Velvet Lite was the Tradename for Titmus's Rose or Pink lens series.
Jerry
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote
Bookmarks