• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Do Ilford below-the-lens filters degrade over time?

gone

Member
Allowing Ads
Joined
Jun 14, 2009
Messages
5,504
Location
gone
Format
Medium Format
The color on the filters is a dye, right? Dyes, in fine art anyway, are fugitive. It's just a question of how much and when, and some colors will be more fugitive than others. I can't see how it would be any different under a bright enlarger lens, depending on the exposure times. Mine are pretty short, and I'll probably replace them due to scratches and handling before they fade appreciably.
 
Last edited:

reddesert

Member
Allowing Ads
Joined
Jul 22, 2019
Messages
2,603
Location
SAZ
Format
Hybrid
OP, it would be useful to post pictures of the filters, and to say what kind of light source you are using.

The Ilford contrast control datasheet explains how multigrade filters work: https://www.ilfordphoto.com/wp/wp-content/uploads/2017/03/Contrast-control-for-Ilford-Multigrade.pdf

Basically, you get low contrast by exposing the paper to green light (or green + blue), and high contrast by exposing to blue only. The high contrast number filters cut out the green light.

It is easy to understand why a faded filter would cut less green light than intended, so a #2 filter might yield lower contrast than normal.

But the OP says "I am not getting the results I expected, finding myself printing at 0 or even 00 when I would have expected 2 or 2.5." It sounds like he is printing with an #0 filter to get "normal" contrast. That seems really odd, as I can't see how filter fading would produce this result, thus I would also look for issues elsewhere in the process.
 

AgX

Member
Allowing Ads
Joined
Apr 5, 2007
Messages
29,972
Location
Germany
Format
Multi Format
High quality MC glass filters work just fine below the lens, just like they do over a camera lens.

I do not know of the existance of such. If they existed they would be organic dyes in foils (most probably in gelatin) laminated between two colourless glas panes.
And then thus show similar dye degradation.
Only positive effect would be that of flatness and good cleanability. But then the thickness of the laminate again may be an issue over a thin foil.
 

DREW WILEY

Member
Allowing Ads
Joined
Jul 14, 2011
Messages
14,866
Format
8x10 Format
I not only know of the existence of such, but use them quite frequently. All kinds of glass and resin filters can be used for VC papers. They don't need to be specifically marketed as such like Ilford Multigrade filters. At one time full ranges of glass CC filters were available M and Y as well as B and G, and sometimes still turn up. I often just use a med blue conversion filter like an 82B versus a med green Hoya X1, or for full strength split printing, a 47 blue versus a 61 green (a more readily available 58 green could be substituted). Tiffen does make laminated glass filters, which collect haze more easily, so need more regular cleaning. But reasonably intense multicoated glass contrast filters are routinely available from various leading manufacturers. And yeah, anything but the internal dichroic filters of a colorhead are going to contain some kind of dye, just like sheet filters do.

I really can't understand why people get so hung up about needing this or that "grade" of filter for VC paper. They aren't made for graded papers, few of which exist now anyway; and VC papers present a contrast continuum that can easily be manipulated any number of ways. For example, a deep blue filter will give even more contrast than any so-called no.5 magenta sheet material. Want optimal minimal contrast instead - use a deep or possibly even medium green glass filter.
Of course, each combination of specific VC paper brand and specific developing agenda presents its own personality, so there's simply no substitute for making test strips to learn the truth, case by case. With practice and experience, this all gets very intuitive and fast. But working with filter sheet drawers sounds Mesozoic to me.
 

snusmumriken

Subscriber
Allowing Ads
Joined
Jul 22, 2021
Messages
2,774
Location
Salisbury, UK
Format
35mm
I thought we had done this subject to death in the earlier thread already referred to. That thread included a photo that Ilford sent me of a current new set of filters. If, for whatever reason, your filters look different from those in the Ilford photo, you could either buy new ones and have peace of mind; or struggle on with what you’ve got and lingering uncertainty. I did the former myself.
 

Hilo

Subscriber
Allowing Ads
Joined
Apr 19, 2011
Messages
922
Format
35mm
For nearly 20 years I had a workspace with a large darkroom that had no windows. There was a large ventilator but no daylight came inside from that either. Often, after printing, I left the filters in the filter drawers of the enlargers and in an under the lens holder of one particular enlarger. I printed every week, a couple of days for sure. Never any fading.

In 2016 I moved into a smaller workspace with windows overlooking the city and sun coming in after 14.00 hrs. This entire space is also my darkroom, I can block the light. I still forgot to put the filters back into their boxes and some months ago I ran into the problem. Some filters had faded. I found out when printing: nothing made normal sense anymore. I compared their colors to a fresh set and the ones I use most had changed a lot. The ones I never use had also changed, but less.

Maybe it was all coincidence, but I have now created my black box, where I put the filters after printing . . .
 

Roger Cole

Member
Allowing Ads
Joined
Jan 20, 2011
Messages
6,069
Location
Atlanta GA
Format
Multi Format
Here is the thread where I asked about this ten years ago. I didn't post after receiving the new ones but they were shockingly visually different and gave much better results than the old faded ones:

 

Pieter12

Member
Allowing Ads
Joined
Aug 20, 2017
Messages
8,174
Location
Magrathean's computer
Format
Super8
No one has suggested why or how his #0 filter gives #2 grade prints. Does the yellow dye fade or change to something more magenta?
 

MattKing

Moderator
Moderator
Joined
Apr 24, 2005
Messages
55,147
Location
Delta, BC Canada
Format
Medium Format
No one has suggested why or how his #0 filter gives #2 grade prints. Does the yellow dye fade or change to something more magenta?

Yellow blocks blue. A faded yellow filter transmits more blue = more contrast.
Magenta blocks green. A faded magenta filter transmits more green = less contrast.
 

Pieter12

Member
Allowing Ads
Joined
Aug 20, 2017
Messages
8,174
Location
Magrathean's computer
Format
Super8
Yellow blocks blue. A faded yellow filter transmits more blue = more contrast.
Magenta blocks green. A faded magenta filter transmits more green = less contrast.

Maybe one could just renumber the filters to get somewhat more predictable results. But a new filter set isn't outrageously expensive. I assume the fading of the dyes is fairly gradual and one wouldn't notice it until it is pretty obvious to the eye or how prints turn out. Since all my printing is split-grade, I think I am going to go the blue/green LED route so I won't have to worry about filter life.