Re: Very Large VC Filters
You may want to ask this on APUG as well.
There are those here who use Lee filters or Roscoe filters.
You can buy their sample packs cheap and lay them on paper to see which filter works for your application.
Does not sound strange one bit.
Quote:
Originally Posted by
Fragomeni
Hi all,
This will probably sound a little strange but I've come to find that many here are exceptionally helpful with my random and obscure projects.
I need the 00 and 5 Ilford VC filters...in 11x14 and 20x24 sheets. I haven't contacted Ilford about this yet but I plan to on Monday to see if its possible at all. My other option is to determine the exact colors of the 00 and 5 and try to find large gels that match or closely match. I'm working on a project in which I'm contact printing some large paper negatives and I'd like to test an experimental exposure method being developed by a friend of mine. Its basically a light box concept so the gels will need to cover the full surface area of the neg.
If anyone has any ideas on this please share.
I'm curious how important matching the color of the filters exactly will be. Also, how do density and thickness play in?
Any ideas and insight you might be able to share will undoubetedly be very helpful.
Thank you!!
Re: Very Large VC Filters
What Bob said. Forgo the built-in red of the Ilford filters and just go with some Magenta and Yellow from Rosco.
A set might look like this:
Green or Yellow Cinegel in 15, 30, 60 and 90
Blue or Magenta Cinegel in 15, 30, 60 and 90
Actually, this is one place where I'd do split printing, You will need only two filters. Either blue or green and either yellow or magenta (I have done both with 14"x14' Rosco filters and they work the same).
For split printing I used Primary Blue #80 and Primary Green #91
You might also want to look at these. A new line of dichroic plastic filter sheets. Looks very interesting, but was not available when I was doing those experiments.
http://www.rosco.com/us/filters/dichrofilm.cfm
Re: Very Large VC Filters
As large Ilford VC filters are in short supply, you might want to try Rosco Calcolor filters in 24"x24", or roll: http://www.rosco.com/canada/filters/calcolor.cfm
Ilford provides a table for those using colour heaads on their enlargers, so that should provide you a starting point.
Also there is an article by Howard Bond on using the Rosco filters.
Re: Very Large VC Filters
Thanks everyone!! Very much appreciated!
I plan on using these filters for split printing so all I need is an appropriate soft (00) and hard (5) filter or equivalents.
I'll check out all of the options and recommendations that you've made! I love how helpful the people on this forum can be! Invaluable! Thanks again!!
Re: Very Large VC Filters
To really get to a #5 filter you may want to get 'bluer' than primary blue. I think "Congo Blue" is the deepest, but it is a pretty low transmission.
Re: Very Large VC Filters
I use Roscoe. This info is from a fews years ago so present availability may now differ
"minus green" and blue, and green- as those are the colors the VC responds to.
They come in 1/4 and 1/2 versions, so fine tuning is easy
No red means faster but [more] variable printing times, and I am used to that.
Yellow is said to make the spectrum of coldlite more like tungsten/daylight, but if it ain't coming out of the tube one is just blockiing other color, so use blue and green.
Yellow MAY be good to get standard filters [with the red] to behave in a more familiar way- just more light loss [ I make 8x40 inch enlargements from 6x17 cm negs, so i need all the light i can squeeze thru]
Re: Very Large VC Filters
Hey everyone, I've noticed something in some of your resposnes that has me a bit confused. My assumption was that I would need to find filters matching the Magenta and pale Yellow color do the Ilford VC filters. However, some of you have mentioned using Blue and Green filters. Can someone explain how and why this works? I'm confused as to how Blue and Green filters can achieve the same result as the Magenta and Yellow filters. I'll start looking for some of the articles written on this including the Howard Bond article mentioned above and perhaps these articles will shed some light on this for me. If any one has links to these articles and other recommended articles could you post them. Google is my best friend so I'll be spending some time searching tonight.
Again thanks everyone for the help with this and for reassuring me that I'm not crazy :)
Re: Very Large VC Filters
Quote:
Originally Posted by
Fragomeni
Hey everyone, I've noticed something in some of your resposnes that has me a bit confused. My assumption was that I would need to find filters matching the Magenta and pale Yellow color do the Ilford VC filters. However, some of you have mentioned using Blue and Green filters. Can someone explain how and why this works? I'm confused as to how Blue and Green filters can achieve the same result as the Magenta and Yellow filters. I'll start looking for some of the articles written on this including the Howard Bond article mentioned above and perhaps these articles will shed some light on this for me. If any one has links to these articles and other recommended articles could you post them. Google is my best friend so I'll be spending some time searching tonight.
Again thanks everyone for the help with this and for reassuring me that I'm not crazy :)
The paper is sensitive to blue and green light. You can use separate blue and green light sources and expose with additive amounts of light to get your effect.
Or, you can subtract green and blue from a single light source with filters (magenta subtracts green, etc). These colors are naming conventions for us humans. The paper does not care. In fact in the scientific literature a 'green filter' looks magenta to our eye (but we call it a magenta filter).
Only Ilford makes the exact shade of filters in the sets. The key to those sets is added neutral density so all the filters print with the same time.
Read the Ilford PDF file on Multigrade printing. It explains it very well.
Re: Very Large VC Filters
Thanks very much for the clarification! Very helpful. So realistically, the paper is responding to the same light whether it is blue light transmitted by a blue filter or the blue light produced by subtracting green light using a magenta filter, etc?
I'm not worried about the neutral density of the filters with how I print. When I split, I give however much time is necessary to print the tone and texture I'm looking for on the soft side and then however much time is need to print the tone and texture on the hard side. The filters having the same neutral density doesn't really become a factor for me so the Rosco filters should work just fine.
Thanks for the help!
