Older Ilford Multigrade Filters - fading

[snusmumriken]

Those old filters are definitely faded (ie the lighter circle in their centre) but they are also a different colour to the new filters because the MG v1 filters were not "speed matched". The newer filters incorporate some neutral density to match exposures when changing filter.

That's a very clever observation! I had assumed that the speed change in later versions of MG was in the emulsion, not in the filters.

Anyway, I've sent an enquiry online to Ilford technical support, including that question of whether and when the filter colours have changed. I will report back as soon as I hear.

 

[Bill Burk]

I never owned an Ilford set but have a Kodak and a Durst set that are very old but 4 is deep magenta for both.

Those reddish “4’s” sure look suspicious to me. They look obviously and seriously faded.

Can anyone show us a fresh set of Ilfords?

 

[snusmumriken]

I have had a really helpful reply from Ilford. My enquiry first, then their answer.

<<
There is a discussion thread on the forum Photrio (here: https://www.photrio.com/forum/threa...ade-filters-fading.177968/page-2#post-2567516) about the longevity and apparent variability of filters for Ilford Multigrade papers. The thread was started in 2020 but has recently been re-opened by chance, and it's evident that the issues raised are still unresolved. I wonder if I could persuade you to comment?

The specific issues are:

1. Ilford technical staff have previously commented that unused MG filters should not deteriorate, but I think most of us expect them to fade over time through exposure to light and heat. This could happen in use in the enlarger, or perhaps more rapidly if the filters are left out in sunlight. Do you agree with this assessment?

2. Comparison of different sets of MG filters shows variation that can't be attributed solely to a fading process, especially for the highest contrast grades 4-5. We are unclear whether this is due to changes in the specification of the filters as MG has evolved, or manufacturing variation, or what?

3. If the filter specifications have changed over time, what are the implications for the use of older filters with current versions of MG paper, or vice versa?

4. How frequently should we expect to buy new filters, given relatively brief exposure in the enlarger, and storage in the dark when not in use? Your recommendation on safelight filters in (what amounts to) professional use is to change the filters once a year. For many amateurs like myself (presumably the bulk of your market now) this would be a pretty daunting annual expense, so less cautious guidelines would be very welcome. If fading has never been specifically investigated (which would be understandable), it would be helpful to know that. It would also be helpful to have an image showing the current official filter colours.

Your comments on these questions would be greatly appreciated. And please, please keep making these wonderful products!
>>


<<
Good morning Jonathan,

I’ve read the chain you attached from Photrio, so hopefully our views below can be helpful/clarify all your q’s.

1. We don’t actually give any definitive guide expiry dates for filters, as typically - so long as they’re not left in sunlight or in constant room lighting and are not being subjected to constant light in enlargers every single day - they’ll perform optimally indefinitely, and really shouldn’t fade. In labs or situations where filters are used every day/all year round – the increased hours will potentially mean fade arises within perhaps 4-5 years.
2. The colouration differences you refer to - between old and new/current sold sets, is real. But to help put that in perspective, the current sold filter set has been in existence since we launched MG IV in 1994. Ie This 1994/current sold set is totally compatible with the prior MG IV paper, as well as current MGFB Classic and MGRC Deluxe (launched respectively Dec 2017 and Oct 2019). So we don’t actually change our filter sets very often. I’ve attached an image to show the colours of the filter set we currently sell. Ie the set sold in 1994/still sold - and thats totally compatible for MG IV papers as well as current sold MG 5 papers (MGFB Classic and MGRC Deluxe).
3. If you use the old pre 1994 filter set - with current sold MG papers, contrast would be compromised for grades 00 and 5 (you’d likely not attain the same softness/hardness). But you likely still will be able to attain acceptable prints using the mid grade filters. All though, would not enable as optimum prints as with current sold filters.
4. As mentioned above, we mostly have only ever introduced new filter sets (colours) when we launch new paper versions of MG. But its not always the case that we change them every time we launch a new paper version - as is the case with MG IV and MG V (current papers) and them both using exact same filter sets. So, assuming you store your sets out of sunlight, and don’t use them every day/all day long in enlargers, its unlikely you’d every need to replace your set - until a next MG paper version comes out (should that require a new filter set).

I hope this addresses all your q’, and you can determine which filter set you have - and assuming its the set that worked for MG IV papers, it certainly would be the right set to use for current sold MG papers.

Kind regards,

Sue Evans
Technical Services
technical@harmantechnology.com

@ilfordphoto

HARMAN technology ltd
Ilford Way, Mobberley, Cheshire, WA16 7JL, UK
harmantechnology.com ilfordphoto.com
>>

 

[MattKing]

Sue Evans and the other people at Harman's technical services department are great.
But I think you better check the filter grade numbers on her photographed examples, if the paragraph numbering in her reply is any indication!

 

[snusmumriken]

Sue Evans and the other people at Harman's technical services department are great.
But I think you better check the filter grade numbers on her photographed examples, if the paragraph numbering in her reply is any indication!

That’s my fault in copying the text. Can you put it right?

 

[MattKing]

That’s my fault in copying the text. Can you put it right?

Will do . And I think it is done.

 

[snusmumriken]

Thanks, Matt.

I think it is probably the case that if the filter set includes the grade 00 filter it is post-1994. Pre-1994 sets of under-lens filters included
a red safe filter instead. But I'll not argue if anyone can refute this.

 

[AgX]

Thank you for making this conversation public.

-) the answer to #1 contradicts some samples discussed here, thus remains some enigma.

-) the set of filters on that bench at the end of that conversation, are these by Ilford showing their current set in new condition?

 

[snusmumriken]

Thank you for making this conversation public.

-) the answer to #1 contradicts some samples discussed here, thus remains some enigma.

I'm not sure about that. Certainly there is evidence of fading, notably in the OP's post, but we don't know the history of light exposure of those, nor of all the others. In my photo (post 42), the pre-1994 right hand set was bought second-hand and shows some signs of mis-use. The other two sets were stored in the dark when not in use.

-) the set of filters on that bench at the end of that conversation, are these by Ilford showing their current set in new condition?

Yes, correct.

 

[snusmumriken]

By the way, I've tweaked my earlier image for tilt and colour temperature, and it seems completely consistent with Sue Evans' answers. So my interpretation is pre-1994 on the left and right, post-1994 in the centre. Using Apple's digital colour meter to compare the latter with Sue's photo on-screen, the differences in RGB are no bigger than I would have expected given the inherent vagaries of phone snaps.

 

[DREW WILEY]

They ALL eventually fade, depending on how much UV , heat, and humidity they get. If you were able to take a before-after densitometer reading, that would be apparent. In a filter drawer above the negative stage, you can choose from a variety of filter materials including lighting gels. But beneath the lens, there's a penalty to sharpness if using the wrong material. One elegant solution is to use high-quality coated glass filters, blue versus green, in what is termed "split printing". A deep blue by itself, like a 47B blue filter, will give more contrast than a magenta Gr 4 filter.

 

[pentaxuser]

Well both I and snusmumriken went to considerable trouble to ask Ilford for information and have presented it on Photrio. So presumably we have clarified and debunked some of the beliefs such as the filters fade even
if not used and kept in a box. Snusmumriken has gone to even greater lengths than I to try and clarify matters and congrats to him for so doing.

Hopefully some of the misapprehensions have now been cleared up for good

Sadly the OP has not visited us for some 15 months so he may not benefit from the findings

pentaxuser

 

[DREW WILEY]

Colorheads are so much easier to use. Dichroic filters can slowly degrade if repeatedly overheated to the point some of the coating begins to spall or flake off. But they'll take vastly more torture than any dyed filter material.