Ilford multigrade filters times

Lumipan · May 6, 2023

I read that Ilford filters 4-5 should be used with double exposure times. So when doing, for example, a 8s exposure should I split 4s of grade 5 or 8s of grade 5 with 4s of 0? If I want to get 2.5 contrast. I worked with the first variant (same for all) and didn't experience underexposed prints.

I bought the filters used, they look good not faded... Did the Ilford always have this rule for exposure times between the filters (4-5 double time, rest all the same). Or they had different rules before?
My filters are the version with 0-5, no 00

Thanks

0, 1/2, 1 etc...

cmacd123 · May 6, 2023

they added enough netral density - where needed - to keep the first few require all the same exposure, BUT the last two do require More light.

Pieter12 · May 6, 2023

I don't think any ND is used for the filters. The emulsion(s) just are slower for the higher contrast filters. Besides, it seems like you are doing split-grade printing. You shouldn't need to be concerned about the contrast grade, just the combination of 0 & 5 filter exposure times that give the result you want.

Lumipan · May 6, 2023

Ok, I understand now. It is not precisely double but a guidance and something to test each time.

Does anyone know about my 0-5 + red safe filter bundle without 00. Is that the older version or just different?

Thanks

hroark · May 6, 2023

I have been trying to understand this too. Maybe the new RC papers are closer in speed across the contrast grades, than the older papers. If I‘m understanding the ISO Speed section from here https://www.ilfordphoto.com/wp/wp-content/uploads/2021/01/MULTIGRADE-RC-Papers-J20.pdf ?

aparat · May 6, 2023

I recently tested the new Ilford MG RC Glossy paper with the under the lens Ilford filters, developed in Dektol 1+2. The first plot shows grades 4, 4.5, and 5 without the extra exposure, and the second plot shows those grades with a stop extra exposure, as recommended by Ilford.

hroark · May 6, 2023

aparat said:
I recently tested the new Ilford MG RC Glossy paper with the under the lens Ilford filters, developed in Dektol 1+2. The first plot shows grades 4, 4.5, and 5 without the extra exposure, and the second plot shows those grades with a stop extra exposure, as recommended by Ilford.

View attachment 337964
View attachment 337965

I hate to admit this, but I don’t know how to interprid these charts. Can you help?

pentaxuser · May 7, 2023

hroark said:
I hate to admit this, but I don’t know how to interprid these charts. Can you help?

Me too Based on your explanation, aparat, can you say what this tells you to do in terms of exposure when using grades 4-5 filters, assuming this explanation is not totally obvious in your explanation. Have you ascertained by means of two prints what the difference is and can you show us?

This has been a question that I have wondered about for a while as I don't have Deluxe paper. My knowledge is limited but looking at the new speeds for the new Deluxe paper it does seem to indicate that less than double exposure is required.

Much appreciated

pentaxuser

Maurizio_AgX · May 7, 2023

hi Aparat and thanks for the graphs
from the second graph the paper seems to be slower with grades 4, 4.5-
and 5

Sirius Glass · May 7, 2023

I make a strip exposure chart for the magenta filter using f/stop exposures and I am done with it. No extensive testing, charts, graphs or tables. Get it done and move on with life, there are more important things worthy of ones time.

bernard_L · May 7, 2023

Thank you for the measurements. My take-away:

1. With the "new", Gen V multigrade, grades 4-5 do not need the extra stop. One just has to look at the datasheet:

https://www.ilfordphoto.com/amfile/file/download/file/1954/product/1701/

The "new" MG RC is the first line: hardly any speed change.

2. There is hardly any contrast change across 4-4.5-5. Grade 5 is, as they say, aspirational. Which I've long suspected, and confirms my preference for slightly mode "beefy" negatives that target printing on grade 2, the middle of the actual range 0-4. Rather than targeting grade 3 as I've read several times.

3. Between grades 00, 0, 0.5, 1, 1.5, all hat happens is an increase of contrast of the dark printing tones, the toe remains virtually unchanged.

4. Your graphs have a lot of empty, unused space along the X-axis (exposure). You could expand that scale by almost a factor 2, better separate the curves, and make the graph more legible. Maybe also omit the half-grade, with the same goal of clarity.

5. Besides the universal toe and shoulder, many of your curve show a strange "knee" around density 0.4. Any comment?

pentaxuser · May 7, 2023

bernard_L how much extra exposure in percentage terms would you or do you give for grades 4-5?

Thanks

pentaxuser

hroark · May 7, 2023

pentaxuser said:
bernard_L how much extra exposure in percentage terms would you or do you give for grades 4-5?

Thanks

pentaxuser

If it were me, I’d start at log_2(240/220) stops, which is 0.12 stops (about an 1/8 stop, not much) as a starting point. If I understand these charts at all.

aparat · May 7, 2023

Sorry to respond so late - my son took my mouse and mouse pad to improve his gaming performance .

In my experience, grades 4, 4.5, and 5, in my process, with my equipment and chemistry, benefit from the one extra stop of exposure in the sense of creating a more seamless printing experience, for me. Admittedly, I rarely use grades 4 and 5, and on rare occasions when I use a split-grade printing technique. This can be programmed into a timer/controller to further automate the process. Based on my analysis, this is something that each printer can choose to interpret to suit their own style and methodology.

Having said that, there are several caveats that need to be taken into account. I am going to mention a few that come to mind:

For these plots, I used projection printing, rather than contact printing. Why? It works better in my process. Either method should work, however.
With projection printing, the densities of the step tablet are measured as on-easel exposure values in stops, rather than with a bench densitometer.
The plots show raw data, without fitting a curve model, which my software can do, if needed.
The curves intersect close to the middle of the 31 step tablet, which is to be expected.
Around the middle of the step tablet, there is going to be more noise in the data, as expected. There is no actual knee in the data, just more noise around that exposure.
There are a few additional sources of variability, such as some non-linearity of the step tablet itself, light fall-off toward the edges of the print, lens flare, exposure meter accuracy, etc., so we need to treat all the resulting values only as approximations of paper performance.
Indeed, grades 4,4.5, and 5 show virtually identical performance.
My software gives the user a number of plotting settings and analysis options, such subsetting the data set, changing axis limits, tick marks, colors, line width and type, and many other such details to tailor the plot to one's personal preference.
The plots were taken out of a PDF report, so they were automatically scaled to fit a US letter size page. I should have used custom settings and print them as PNG directly to show the curves more clearly, but I guess I was just lazy.
I used stops as a unit of exposure throughout my analysis, but the software also allows for relative and absolute log exposure and density values, if needed.

Here's a summary table of the data:

aparat · May 7, 2023

I thought it would be interesting to include a different paper test to see how it compares to Ilford. Here are my results of a recent test of Fomatone MG Classic 131 VC FB:

bernard_L · May 7, 2023

pentaxuser said:
bernard_L how much extra exposure in percentage terms would you or do you give for grades 4-5?

Thanks

pentaxuser

hroark said:
If it were me, I’d start at log_2(240/220) stops, which is 0.12 stops (about an 1/8 stop, not much) as a starting point. If I understand these charts at all.

@ hroark: Correct. Or, if using "ordinary" timing, less than 10%.
But, IMO, "extra exposure" is misleading. The sensitivity of paper is related to a specific point in the logE-D curve, D=0.6 IIRC. So you have decided that your print needs more contrast, and you change from grade 3 to 4; do you really want to maintain the tone of precisely the speed point at D=0.6?
I don't know about you, but when I change the grade, I re-do a series of test exposures; not from scratch because I have a fairly accurate idea of the proper time, and am in a position to do a fine-step series, or maybe fewer exposures on a larger, more informative area.

Bottom line: it is not just increasing the time by x%.

hroark · May 7, 2023

bernard_L said:
@ hroark: Correct. Or, if using "ordinary" timing, less than 10%.
But, IMO, "extra exposure" is misleading. The sensitivity of paper is related to a specific point in the logE-D curve, D=0.6 IIRC. So you have decided that your print needs more contrast, and you change from grade 3 to 4; do you really want to maintain the tone of precisely the speed point at D=0.6?
I don't know about you, but when I change the grade, I re-do a series of test exposures; not from scratch because I have a fairly accurate idea of the proper time, and am in a position to do a fine-step series, or maybe fewer exposures on a larger, more informative area.

Bottom line: it is not just increasing the time by x%.

Yep. I too would likely just do another test strip, but knowing that there is little difference now between the contrasts I’d just keep it in the same range.

Slightly off topic -
There was a post called the Ilford way of split printing. https://www.darkroomdave.com/tutori...ing-ilford-multigrade-under-the-lens-filters/

Summary, do a test at 2.5 grade. Take the selected exposure duration, divide by two to get the duration for each grade. Do a split grade print at 0 and 5 as a base then adjust from there.

Well I just tried with with MGRC V, and the grade 5 exposure was way too long….just made all the shadows way way dark. I cut the grade 5 exposure in half again, and then redid the print. Much better starting point. In-line with the sensitivity we are seeing here.

Reminder to self: know the underlying assumptions before taking processes at face value. They are not often made explicit.

pentaxuser · May 7, 2023

Thanks aparat and bernard_L for the info. It would seem, if I have understood what seems a point of agreement between you, that about 10% additional exposure may be required when changing to grades 4-5 which is in line with the speed changes we see when comparing the former MGIV paper with the new Deluxe.

Ilford does appear to have changed the wording about increase exposure for grades 4-5 in that it now says:"The exposure time for filters 00–3½ is typically the same and for filters 4–5 will require and increased exposure time" This is somewhat vaguer than previously and may reflect a desire to allow the user to set the increased time to his taste .

I accept that the "look" of a grade 4 print at 10% additional exposure may not be what each printer may want but if new users of Deluxe need a figure for what Deluxe paper needs should he decide to move to Grades 4-5 then 10% may be a useful starting point

pentaxuser

aparat · May 7, 2023

@pentaxuser I can agree with the 10% starting point, though it is probably not going to be sufficient in my process. It's always best to test one's process rather than rely on entirely others' (or the manufacturers') results.

@bernard_L Very interesting comments! Do you happen to have your own plots/analysis that you could share? I haven't seen many tests of the current Ilford RC paper emulsion.

For those of you located in the US, B&H carries an RC paper called "Multitone RC Glossy," which I find to be of very good quality, particularly if you can selenium tone it. In my experience, the paper not only responds beautifully to under-the-lens filtration, exposure, and development, but also achieves very respectable Dmax with selenium toning. A 100-piece box sells for $63.49, which is less than the Ilford 50-piece box of 8x10 RC paper ($68.50). In Europe, it may be different.

bernard_L · May 8, 2023

aparat said:
@bernard_L Very interesting comments! Do you happen to have your own plots/analysis that you could share? I haven't seen many tests of the current Ilford RC paper emulsion.

I bought some Ilford "pearl" (44) and some Fomaspeed 313. All I can say from limited testing is that both are good products, while the Ilford has a higher Dmax. Not sure the higher Dmax is significant under average viewing conditions; and I'd like to see if the Fomaspeed Dmax might be improved via dilute Se toning, without color change.

pentaxuser · May 8, 2023

aparat, do you happen to know who makes this Multitone RC Glossy.? I don't recall seeing any of it in the U.K. yet Might this be the same paper that someone called czygeorge from Beijing posted on in April of this year? I think he said it was by Lucky. Here's what he said:
"Chinese new B/W multigrade paper

pic attached were hand printed by using lucky multigrade paper(D73)

I was very surprised that the result this new paper gave me.Very nice tone and deep dmax.It was newly produced recently by Lucky factor in China" .

Thanks

pentaxuser

Ilford multigrade filters times

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