Above vs Below the lens filters

Mark J said:

I believe those red filters were conceived for use with graded papers that were just sensitive in the blue. There is probably enough orange or green light leaking through it to affect MG paper.

Click to expand...

If I have done what the OP appears to have done i.e forgot to focus on occasions, I usually prefer to remove the sheet, place it back in its box and then focus at f2.8 or f4 if it's a MF neg then adjust the f stop down to say f8 for exposure but on occasions I have tried a "run through" for my dodging and burning routine with the actual sheet and at say f8 for several seconds and have never found that the red safety has "leaked light" with MG papers

pentaxuser

Milpool said:

Although the Ilford MG filters will give you the widest contrast range (not the biggest deal) dichroic colour (or B&W VC) heads are more convenient.

I don’t think it helps to try to match colour head settings with filter numbers but if you want some starting points I suggest using the following Ilford document in conjunction with the documentation for whichever paper you are using.

Note this exercise will be approximate since it depends on the spectral output of the light source, but plenty good enough for ballparking starting points.

https://www.ilfordphoto.com/wp/wp-content/uploads/2017/03/Contrast-control-for-Ilford-Multigrade.pdf

Click to expand...

I can't wait for my filters to arrive, I have to test this now. If I understand this document correctly, I should use the Durst (170 max) settings for my Kaiser enlarger? My enlarger’s color wheels go up to 180.

hiroh said:

I can't wait for my filters to arrive, I have to test this now. If I understand this document correctly, I should use the Durst (170 max) settings for my Kaiser enlarger? My enlarger’s color wheels go up to 180.

Click to expand...

Yes, Kaiser seems to be listed under the Durst settings so I’d go with that as a starting point. Since your wheels go up to 180 use the suggested Durst settings in the column that go up to 170M (not 130M). And you’ll notice there is an asterisk next to the 170M (max contrast) indicating if your enlarger wheel goes higher, use whatever the highest setting is to approach a grade 5 MG filter. Just remember all of these things are just suggested starting points.

You’ll also notice there are two tables, one for using Yellow and Magenta wheels individually, and a second table for using combinations of Yellow and Magenta for settings in between min/max contrast. The idea there is to reduce the amount of exposure change required when changing contrast. This is how some B&W VC(CE) dichroic heads work, such as the one on my Saunders/LPL - you only turn one knob and inside the head a mechanism moves different amounts of M and Y filters into the light path. It’s an attempt at getting closer to speed-matching the contrast settings, but will generally only be approximate as it depends on the paper and light source.

Speed-matching is what Ilford tries to do with the MG filters when combined with Ilford papers, but this still depends on the light source. The idea is for the paper to have the same speed for all filters from 00-3 1/2, and then half that speed for 4-5. While not perfect, it’s a benefit vs calibrating M/Y(/C) combination settings on colour heads.

hiroh said:

I ordered both above and below the lens ILFORD MG filters, so I'll compare them to see which works better for me.

In the meantime, since the filters won't arrive until the end of next week, can I use the color head dials as filters? How can I find the exact settings that are equivalent or close to the ILFORD grades I've used before? I checked the enlarger manual, but it doesn't mention anything about using these settings.

Click to expand...

This will get you started

Use the Ilford document and/or the document shared by Ralph to get you started.
Observe how the appearance changes as you move through the suggested settings.
If the contrast "steps" look reasonably linear to you, go with those. If not, interpolate new numbers in between to use instead and make up your own chart.
There is nothing magical about the numbers on the individual filters. Familiarity with either those or the settings chart you rely upon is what matters.

I tested the color head filters today, and they worked well. They are definitely reliable, and I was able to make some decent prints fairly quickly.

However, one thing I found quite inconvenient is that on my enlarger, the dials are only lit during exposure. This makes it difficult to see the numbers when I need to change settings for split grading. I have to cover the paper, then bring a safelight very close to adjust them. Because of this, I think I’ll stick with using ILFORD filters instead. It’s just easier to replace the filter than to mess around with the dials in the dark.

What’s your experience?

In my LPL 7700 enlarger with a variable contrast head there is room to leave a small LED light source (essentially a dollar store pen light) inside the head, in a location that illuminates just the dials.
At the beginning of a darkroom session, I flip open the cover for the head and I turn the pen light on.
At the end of a darkroom session, I try to remember to turn it off. Mostly, I've been successful .
If I forget, I replace the AAA battery in the pen light.
A small red LED kept pointing at the dials isn't hard to organize.

MattKing said:

In my LPL 7700 enlarger with a variable contrast head there is room to leave a small LED light source (essentially a dollar store pen light) inside the head, in a location that illuminates just the dials.
At the beginning of a darkroom session, I flip open the cover for the head and I turn the pen light on.
At the end of a darkroom session, I try to remember to turn it off. Mostly, I've been successful .
If I forget, I replace the AAA battery in the pen light.
A small red LED kept pointing at the dials isn't hard to organize.

Click to expand...

I checked my Kaiser VCP 9005, and I’ve got 8 screws to remove the head cover. It’s not as easy as just flipping it open like yours.

EDIT: 5 screws, not 8

Get yourself one of those red LED coin-size lights that operate by pressing them between thumb and fingers. Keep it in your darkroom apron pocket (or wherever if you don't use an apron). Use that to illuminate your dials when needed.

Are you sure that there isn't a switch somewhere to turn on the light for dial illumination?

Alternately, you can cap the lens, turn on the enlarger, adjust the dials, then remove the cap to expose.

And, while all that calibration that you're doing is laudable, keep in mind that your negatives aren't going to be anywhere near that calibrated. For me it boils down to: need more contrast? = more magenta or less yellow and vice versa. Who needs to know what exact "grade" (that's not even standardized) a print is made at?

Best,

Doremus

hiroh said:

I checked my Kaiser VCP 9005, and I’ve got 8 screws to remove the head cover. It’s not as easy as just flipping it open like yours.

EDIT: 5 screws, not 8

Click to expand...

For you then, a clamp on light is in order.
Something like these, but smaller and filtered to be safe:

Doremus Scudder said:

Get yourself one of those red LED coin-size lights that operate by pressing them between thumb and fingers. Keep it in your darkroom apron pocket (or wherever if you don't use an apron). Use that to illuminate your dials when needed.

Are you sure that there isn't a switch somewhere to turn on the light for dial illumination?

Alternately, you can cap the lens, turn on the enlarger, adjust the dials, then remove the cap to expose.

And, while all that calibration that you're doing is laudable, keep in mind that your negatives aren't going to be anywhere near that calibrated. For me it boils down to: need more contrast? = more magenta or less yellow and vice versa. Who needs to know what exact "grade" (that's not even standardized) a print is made at?

Best,

Doremus

Click to expand...

There's only one switch for filters, but it doesn’t affect the LEDs—it just turns the filters on and off. The LEDs only activate during exposure, if they are turned on.

Honestly, I'm not too concerned about calibration or comparing them to ILFORD filters. That's more for the beginning, just to see how they perform against a reference I'm familiar with. Later on, I'll probably focus more on contrast and less on the exact grade number. But I do need the numbers because, for example, if I made a test print with certain settings and want to add a bit of contrast to the next one, I need to know where I was (like 40Y/30M) so I can tweak from there.

What I usually do is cover the paper with thick black foamboard and bring the safelight closer to the dials.

My ILFORD filters should arrive any day now, so I'll probably use them for the time being.