Support our Sponsors, they keep FADU free:   AG Photographic   Keyphoto   The Imaging Warehouse   Process Supplies   RH Designs   RK Photo   Second-hand Darkroom Supplies   Silverprint Ltd

Notices

Go Back   Film and Darkroom User > Monochrome Work > Monochrome printing techniques

  ***   Click here for the FADU 2015/2014 Yearbooks   ***

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 26th February 2009, 09:53 PM
kennethcooke's Avatar
kennethcooke kennethcooke is offline
Friend
 
Join Date: Dec 2008
Location: West Riding
Posts: 459
Default Ilford Multigrade with dial in filtration?

I would be interested in your views about yellow and magenta filtration and its uses with Ilford Multirade papers. I have a colour head on my newly acquired Durst M670 anlarger and I assume that yellow will give a flatter softer contrast whereas, I guess magenta will give a harder contrast. I am thinking of using magenta with C-41 negs which tend to be a quite soft contrast.

I also assume that one will need to up development times or open up the enlarger lens to compensate for filtration?
__________________
"Die Zukunft der Erinnerung" -Leica-"The Future of Memories"

Regards Kenneth
Reply With Quote
  #2  
Old 26th February 2009, 10:16 PM
Bob's Avatar
Bob Bob is offline
Administrator
 
Join Date: Aug 2008
Location: London(ish)
Posts: 2,414
Default

Each box of Ilford MGIV has an instruction sheet with a table of filtration values for all the popular colour enlarger heads. There is A PDF somewhere on the Ilford/Harman site on Contrast Control that goes into slightly more detail, but the table is all you need. In fact, there are two tables: one that just uses yellow OR magenta and the other that combines yellow AND magenta filtration to allow the same exposure times (in theory) when changing from one contrast grade to another.

The filters do attenuate the light somewhat so exposure will be longer than without filtration, or as you suggest you can open the lens a stop or so, but that will be taken care of with a normal test strip. Most people develop MGIV to completion so development time will not change.

[Addendum: OK found the PDF - direct link here ].
Reply With Quote
  #3  
Old 26th February 2009, 11:39 PM
Argentum's Avatar
Argentum Argentum is offline
Friend
 
Join Date: Sep 2008
Location: Sceptred Isle
Posts: 3,066
Default

The old speed matching across changes of contrast problem.

adding or subtracting yellow or magenta filtration alters the amount of light reaching the paper and must be compensated for by increasing or reducing print time accordingly. This can be overcome by adding or subtracting both yellow and magenta at the same time which results in a constant amount of filter density across different grades. Sounds simple but in practice it is very hard to get it right and it varies for each specific paper used and very importantly, the "speed point", which is print density fulcrum around which the contrast is changed, must be known. That speed point is usually a middle grey or a highlight value but it depends on who works out the values of the Y+M filtration.
As bob points out, ilford gives the combined values for Y+M in the data sheet which comes with your box of paper, or you can find it in the datasheets on the ilford website. So using both Y+M together will give you relatively constant print time when you change contrast. But without knowing and accurately applying your change based on the speed point of the filtration, you can expect to have to make small print time changes as well. The ilford speed point is a middle grey I think.

But as you point out, you can also change contrast by just adding yellow or just adding magenta. In this case you must change print time to compensate. How much I hear you ask? Well I'm not sure for your enlarger but the following is a chart of print time factors for my durst L1200 which goes up to 130 units of filtration and is very accurate. My modular 70 goes upto 170 and I don't have the numbers for that.

L1200 Filter Factors.pdf

You should note from the graph I created that magenta has a much greater density than yellow and requires bigger time changes than adding yellow does.

There is another way which overcomes the problem of speed matching filters completely, and that is to print using the split grade method which quite a lot of people here use. Using the split grade method means you use only maximum magenta or maximum yellow and do time test strips for each which doesn't require knowing any print factors or combinations of Y+M to acheive your desired print contrast and density. It is done purely by visual inspection of your test strip results. This is one big positive thing about split grade printing and it works the same for any paper type without having to recalibrate your Y+M for that paper. I hear Les Mclean's book is good on this subject but I haven't read it (yet).

If in doubt and you want a quick start, then just use the combined Y+M figures from the ilford sheets but read up on split grade printing.

Also, carefully calibrated neg exposure and development makes printing a lot simpler. If your exposures are all over the place, then printing is much slower.

And finally, there are other devices such as those sold by RH Designs which help a lot of people but I would spend some time learning the craft by experience using different methods before making a decision on any one device or method for printing.
__________________
An old dog learning new tricks
Reply With Quote
  #4  
Old 27th February 2009, 12:41 AM
Argentum's Avatar
Argentum Argentum is offline
Friend
 
Join Date: Sep 2008
Location: Sceptred Isle
Posts: 3,066
Default

I uploaded the wrong chart. This a better one with the graph.

L1200 filter factor chart.pdf
__________________
An old dog learning new tricks
Reply With Quote
  #5  
Old 27th February 2009, 05:58 AM
Dave miller Dave miller is offline
Friend
 
Join Date: Aug 2008
Posts: 6,322
Default

Kenneth, are the C41 developed negatives that you want to print from monochrome, or standard colour film?
__________________
Regards
Dave
www.davids.org.uk
Reply With Quote
  #6  
Old 27th February 2009, 04:00 PM
Argentum's Avatar
Argentum Argentum is offline
Friend
 
Join Date: Sep 2008
Location: Sceptred Isle
Posts: 3,066
Default

One thing that I should have included is that if you are using combined Y+M filtration, then your starting point should be the figures provided by Ilford for a nominal grade 2 which are 52Y/20M for a durst which has 170 maximum units of filtration or 45Y/24M on a durst which has 130 units of maximum filtration.
You should calibrate your negative Exposure Index (personal film speed) and development using those grade 2 figures if you intend to use combined Y+M filtration as your method of printing. That will result in a properly exposed and developed negative printing pretty well using those figures.
__________________
An old dog learning new tricks
Reply With Quote
  #7  
Old 27th February 2009, 05:00 PM
kennethcooke's Avatar
kennethcooke kennethcooke is offline
Friend
 
Join Date: Dec 2008
Location: West Riding
Posts: 459
Default

Quote:
Originally Posted by Dave View Post
Kenneth, are the C41 developed negatives that you want to print from monochrome, or standard colour film?
Kodak BCW400 CN and Fuji Neopan 400 CN. Negs negs and 5 X 7 produced by Jessops but the negs look a little soft contrast
__________________
"Die Zukunft der Erinnerung" -Leica-"The Future of Memories"

Regards Kenneth
Reply With Quote
  #8  
Old 27th February 2009, 05:02 PM
Dave miller Dave miller is offline
Friend
 
Join Date: Aug 2008
Posts: 6,322
Default

Quote:
Originally Posted by kennethcooke View Post
Kodak BCW400 CN and Fuji Neopan 400 CN. Negs negs and 5 X 7 produced by Jessops but the negs look a little soft contrast
The will probably be printed digitally on colour paper so will not be a good guide to what can be achieved from them.
__________________
Regards
Dave
www.davids.org.uk
Reply With Quote
  #9  
Old 27th February 2009, 07:08 PM
Mike O'Pray Mike O'Pray is online now
Friend
 
Join Date: Oct 2008
Location: Daventry, Northants
Posts: 7,977
Default

Interestingly Ilford in its previous handbook on MG papers and the darkroom pointed out that obtaining density balance with dual filtration was difficult and maybe with cheap enlargers almost impossible whereas its own density balanced MG filters( either above or below the lens) meant no exposure change for filters 00 to 3.5 and double exposure for filters 4 and 5) Density balance is apparently guaranteed for mid tone grey as others have said.

It goes on to point out that extremes of grades may be difficult to obtain with dichroic heads. Nevertheless it gave both single and dual filtration values.

Anyway and maybe even more interestingly in the latest handbook labelled Ilford Multigrade IV RC Deluxe it now has deleted dual filtration, giving only single filtration and this time advises that even if you have a dichroic head there are good reasons to still obtain and use MG filters.

So it has clearly come down on the side of MG filters to the extent it hadn't a couple of years ago in the last issue of the booklet.

Of course this could be driven by the need to sell MG filters and or its own MG heads. On the other hand it may have concluded that for printers and especially new printers, MG filters offer some real advantages to get them producing better prints sooner.

It has caused me to consider purchasing a set of below the lens MG filters instead of using my dichroic head. So what's stopping me? Well I still wonder if its a change I need to make and whether the benefits are real enough to make a difference or is it largely marketing speak?

Mike - undecided of Daventry
Reply With Quote
  #10  
Old 27th February 2009, 07:35 PM
PMarkey's Avatar
PMarkey PMarkey is offline
Friend
 
Join Date: Nov 2008
Location: Bradford West Yorks
Posts: 255
Default

Somewhat off topic but I wonder if there is any advantage in using the additive system of colour filtration ? as I have a Philips PCS130 enlarger with PCS150 TRI-ONE unit and a PCS2000 TRI-ONE enlarger both of which use the additive system and the Philips advertising of the time does claim
Quote:
An increased contrast range and control with VC papers due to exact matching of light to paper . No change in exposure when changing contrast.
I don't have enough print experience personally but just wondered if anyone had any opinions ?


Paul
Reply With Quote
Reply
Support our Sponsors, they keep FADU free:   AG Photographic   Keyphoto   The Imaging Warehouse   Process Supplies   RH Designs   RK Photo   Second-hand Darkroom Supplies   Silverprint Ltd

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Ilford Multigrade Warmtone Papers knikki Darkroom 13 22nd August 2009 08:04 PM
Ilford Multigrade IV RC in 10x8 - Fair Price Larry New products and offers 7 27th June 2009 12:23 PM
Ilford Multigrade John51 Photography in general 12 27th April 2009 11:42 AM
Ilford Multigrade Filter and exposure compensation Stephane Darkroom 17 27th March 2009 08:15 PM
Ilford Multigrade IV Fibre RH Designs Monochrome printing techniques 9 8th February 2009 08:30 AM


All times are GMT. The time now is 11:53 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.