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Author Topic: Cyan GLASS filter ...
Osi Osgood
Film God

Posts: 10204
From: Mountian Home, ID.
Registered: Jul 2005


 - posted June 17, 2019 10:55 AM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
I broke my cyan glass filter some time back and I've forgotten to put it in the "wanted" area here.

Please note: I am looking for a GLASS filter, not a gel filter or an analglyph 3D blue filter.

The reason?

While a cyan gel will work, if you aren't using an ELMO, you're going to get a fairly dark image. Only glass really allows the light thru.

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Melvin England
Jedi Master Film Handler

Posts: 707
From: Hull, East Yorkshire, UK
Registered: Feb 2016


 - posted June 17, 2019 11:36 AM      Profile for Melvin England     Send New Private Message       Edit/Delete Post 
Osi - Your PM mailbox is full.

I always seem to get confused with filters. Is cyan the one that turns pink / red films into half decent copies on the screen?

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Brian Fretwell
Phenomenal Film Handler

Posts: 1785
From: London, UK
Registered: Jun 2014


 - posted June 17, 2019 03:38 PM      Profile for Brian Fretwell   Email Brian Fretwell   Send New Private Message       Edit/Delete Post 
Yes, cyan is the light blue/bluish primary colour used in printing.

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Maurice Leakey
Film God

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From: Bristol. United Kingdom
Registered: Oct 2007


 - posted June 18, 2019 02:30 AM      Profile for Maurice Leakey   Email Maurice Leakey   Send New Private Message       Edit/Delete Post 
Osi
I use an 80A Cyan glass filter. It's relatively darkish but works well with faded prints, there are lighter toned Cyan filters but they don't work as well as the 80A.
Here's a sample on Amazon.
https://www.amazon.c o.uk/Tiffen-5280A-52mm-80A-Filter/dp/B00004ZCAF/ref=sr_1_fkmr1_2?keywords=wratten+80A+filter&qid=1560842796&s=electronics&sr=1-2-fkmr1

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Maurice

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Osi Osgood
Film God

Posts: 10204
From: Mountian Home, ID.
Registered: Jul 2005


 - posted June 18, 2019 12:01 PM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
Yes Melvin. It helps immensely!

Thanks for that link, some fairly affordable prices as well!

Just to add, I actually found that blending different "gels" or plastics, I found that a light cyan and a light green, together, tended to give the best results for "restoring" color to a projected print, though as i said earlier, darkish.

Though that cyan filter will certainly help, what would be perfect is one of those "sliding scales" glass filter that goes from a cyan to green from left to right and allows you to "adjust" the color to you're specific need.

Those are pretty rare, however.

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"All these moments will be lost in time, just like ... tears, in the rain. "

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Luigi Castellitto
Jedi Master Film Handler

Posts: 715
From: Campobasso, Italy
Registered: Jun 2013


 - posted June 18, 2019 02:10 PM      Profile for Luigi Castellitto   Email Luigi Castellitto   Send New Private Message       Edit/Delete Post 
Osi, for "cyan" that you say 80A is ok? Or is it something else?
Do you notice differences with a "normal" blue?

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Matthieu van der Sluis
Master Film Handler

Posts: 373
From: Barendrecht, The Netherlands
Registered: Aug 2017


 - posted June 21, 2019 05:32 AM      Profile for Matthieu van der Sluis   Author's Homepage     Send New Private Message       Edit/Delete Post 
Hey Luigi.
Cyan is in the middle of Blue and Green.
Cyan, Magenta and Yellow are secundairy colors,
Red, Blue and Green are Primairy colors.
Magenta is in the middle of Blue and Red.
Yellow is in the middle of Green and Red.
In the centre of all perfect White.

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This Diagram shows how far the human eyes can see colordepth.

Clever indeed, correcting decoloration with a filter.

I don't think the decoloration of film is consistant enough to get it right all the time, otherwise it might be possible to messure the exact tint for the color filter thats needed to get 6500Kelvin, on a GS1200 Xenon that is. Most other projector bulbs are to warm and around 3500Kelvin. I can tell my calibration software to aim for 3500Kelvin instead.

During calibration of the digital projectors, I place all 6 colors perfectly on their spot, for their Heu, Luminance and most of the times Saturation with the Whitebalance and CMS (Color Management System).

[ June 23, 2019, 06:14 AM: Message edited by: Matthieu van der Sluis ]

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Osi Osgood
Film God

Posts: 10204
From: Mountian Home, ID.
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 - posted June 21, 2019 11:09 AM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
Matthieu ...

Great post you put up there for everyone. Many thanks!

To update, I have just ordered a cyan glass filter off the internet. This one, however, is a Vivtar, but the same cyan color. I tell you, it's much more affordable to go on ebay than amazon!

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"All these moments will be lost in time, just like ... tears, in the rain. "

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Matthieu van der Sluis
Master Film Handler

Posts: 373
From: Barendrecht, The Netherlands
Registered: Aug 2017


 - posted June 21, 2019 04:01 PM      Profile for Matthieu van der Sluis   Author's Homepage     Send New Private Message       Edit/Delete Post 
Normally I buy my camera UV filters from B+W with the MC coating, they are the best quallity glas filters.
Not sure if they have cyan filters too. I could not find them.

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Matthieu van der Sluis
Master Film Handler

Posts: 373
From: Barendrecht, The Netherlands
Registered: Aug 2017


 - posted June 22, 2019 07:41 AM      Profile for Matthieu van der Sluis   Author's Homepage     Send New Private Message       Edit/Delete Post 
Hey Osi.

I searched for the Vivitar glass Cyan filter, but all I could find are the (undersee) Cyan correcting filters that are redish.
Can you add a link please?

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Brian Fretwell
Phenomenal Film Handler

Posts: 1785
From: London, UK
Registered: Jun 2014


 - posted June 23, 2019 05:29 AM      Profile for Brian Fretwell   Email Brian Fretwell   Send New Private Message       Edit/Delete Post 
To be 100% accurate Red, Green & Blue are additive primaries (as with light and phosphors on TV screens) and Yellow, Cyan and Magenta are subtractive primaries as used in printing.

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Matthieu van der Sluis
Master Film Handler

Posts: 373
From: Barendrecht, The Netherlands
Registered: Aug 2017


 - posted June 23, 2019 06:04 AM      Profile for Matthieu van der Sluis   Author's Homepage     Send New Private Message       Edit/Delete Post 
Ahh yes, that is indeed for printing on paper and than mixing CMY becomes black.
While mixing RGB light becomes white.
This has always fascinated me

Of course this diagram shows the primaIry colors RGB for light and than CMY are secondairy colors.

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Melvin England
Jedi Master Film Handler

Posts: 707
From: Hull, East Yorkshire, UK
Registered: Feb 2016


 - posted June 23, 2019 08:57 AM      Profile for Melvin England     Send New Private Message       Edit/Delete Post 
Taking the above advice from Osi and Maurice, I have invested the grand total of £4.50 (including postage!) in an 80A filter which I await with anticipation. I am really looking forward to trying it out on The Bridge on The River Kwai.

I am sure one will understand why that 400' in particular...…..then perhaps Till The Clouds Roll By,then The Godfather.....

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Brian Fretwell
Phenomenal Film Handler

Posts: 1785
From: London, UK
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 - posted June 24, 2019 02:24 AM      Profile for Brian Fretwell   Email Brian Fretwell   Send New Private Message       Edit/Delete Post 
I have wondered whether, if it is possible to print onto clear plastic film, you could take a photo or scan an original black section of a faded film, identify the colour the print a complimentary colour filter to correct exactly for that film.

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Matthieu van der Sluis
Master Film Handler

Posts: 373
From: Barendrecht, The Netherlands
Registered: Aug 2017


 - posted June 24, 2019 04:55 AM      Profile for Matthieu van der Sluis   Author's Homepage     Send New Private Message       Edit/Delete Post 
I think you'll end up with a fussy picture.
Like buying sunglasses for €4 of which the glasses are painted somehow, at least the world does not look sharp and clear, compared using sunglasses with optical glasses for at least €30.
That is why I rather buy more expensive glass filters as well. Otherwise I have an expensive projector with a good lens end at the end I distroy that quallity with a cheapo filter.
But now I am comparing a €30 sunglasses with a €200 serengeti.

On the other side,... I don't have perfect LPP Derann prints either. So who am I to talk hahaha.

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Melvin England
Jedi Master Film Handler

Posts: 707
From: Hull, East Yorkshire, UK
Registered: Feb 2016


 - posted June 25, 2019 10:13 AM      Profile for Melvin England     Send New Private Message       Edit/Delete Post 
Am pleased to say that my 80A filter has arrived and been put to the test.

My verdict?

It HAS made a difference. On "The Bridge on The River Kwai" the blue sky becomes more noticeable (obviously) and there is now a faint glow of green in several uniforms. But as this is the 400' of "Kwai" we are talking about, a film which seems to have been transferred to super 8 in a furnace, the red hue is still very much present but, admittedly, subdued a great deal.

Osi - Hope your filter arrives soon.

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Matthieu van der Sluis
Master Film Handler

Posts: 373
From: Barendrecht, The Netherlands
Registered: Aug 2017


 - posted June 29, 2019 12:14 PM      Profile for Matthieu van der Sluis   Author's Homepage     Send New Private Message       Edit/Delete Post 
Thanks for the update.
What brand filter did you receive and are you loosing a lot of brightness?
Like 30% or 50?

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Melvin England
Jedi Master Film Handler

Posts: 707
From: Hull, East Yorkshire, UK
Registered: Feb 2016


 - posted June 29, 2019 02:47 PM      Profile for Melvin England     Send New Private Message       Edit/Delete Post 
It is a Hoya filter and I estimate I lose about 40% of the brightness.

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011


 - posted June 29, 2019 05:08 PM      Profile for Janice Glesser     Send New Private Message       Edit/Delete Post 
I used the 80A filter last night to watch my faded 16mm print of "The Goodbye Girl" and although the 80A does reduce the brightness... the colors are much truer than compared to my gel filters. Whites are white not green/yellowish. I find my eyes adjust to the lower brightness after awhile. I wouldn't call this 80A filter "Cyan"...it is primarily "Blue." Cyan has more yellow in it... rendering more towards the blue/green tones. My Elmo 16CL has a 250W bulb which isn't as bright as other projectors. The brighter the bulb...the better the colored filters will perform.

[ June 29, 2019, 09:00 PM: Message edited by: Janice Glesser ]

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Osi Osgood
Film God

Posts: 10204
From: Mountian Home, ID.
Registered: Jul 2005


 - posted July 08, 2019 10:45 AM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
UPDATE!!!

I found out what brand these are! I never noticed before, but in the upper corner there is VERY SMALL print on the filters, and it states "COKIN" as the brand, and, the plastic carrier also states that as well.

It was easy to miss that extremely small print, but I'm surprised that i missed that on the plastic carrier.

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"All these moments will be lost in time, just like ... tears, in the rain. "

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Adrian Winchester
Film God

Posts: 2941
From: Croydon, London, UK
Registered: Aug 2004


 - posted July 11, 2019 10:16 PM      Profile for Adrian Winchester     Send New Private Message       Edit/Delete Post 
This thread has also convinced me to give a 80A a try, but I'd be curious to know what diameter filter Forum members have opted for, and what they use to hold it in position? I've used Blu Tac to hold the edges of another glass filter I've used.

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Adrian Winchester

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Melvin England
Jedi Master Film Handler

Posts: 707
From: Hull, East Yorkshire, UK
Registered: Feb 2016


 - posted July 12, 2019 03:38 AM      Profile for Melvin England     Send New Private Message       Edit/Delete Post 
Adrian - Mine is a 52mm which can nicely hang onto an Elmo / Bell and Howell / Sankyo lens at least.

I think Blu Tac-ing it would also be a sensible idea as it could easily fall off. I wouldn't bother with cellotape…. too much gunge left on the outside of the lens on removal.

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Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
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 - posted July 12, 2019 06:11 AM      Profile for Maurice Leakey   Email Maurice Leakey   Send New Private Message       Edit/Delete Post 
I have a specially made adapter which screws into the 50mm lens of my 16mm Bell & Howell projector. Into this I screw my filters.
This was made to order by SRB Photographic.
https://www.srb-photographic.co.uk/adaptors-649-c.asp

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Maurice

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Osi Osgood
Film God

Posts: 10204
From: Mountian Home, ID.
Registered: Jul 2005


 - posted July 12, 2019 11:16 AM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
UPDATE!

I did get my cyan glass filter. It does make a grand difference, (all depending on the level of fade, of course). I also got a new light green filter of the same size as the cyan filter and the neat thing is that they screw onto each other, (then i just take a light bit of tape and put it on the lense).

The only problem with having both on there, however, is, even though the light green one is in fact, light green, it completely overpowers the cyan blue filter, so, I like my idea of combining the two, but I'll have to see if I can find an even lighter green one, just a tad bit O green, and THAT will probably work!

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"All these moments will be lost in time, just like ... tears, in the rain. "

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