Adding An Extra Magenta Filter

[MattKing]

If this is a recurrent problem then:

Develop more to start with
Check your magenta filter to see if it has faded; replacing it with a new/good used filter may help

Best,

Doremus

It is rare that I would consider disagreeing with Doremus, but ...

If the filter is a dichroic filter, it is an interference filter that won't fade.

They do, however, become less effective if they become dirty.

[Gerald C Koch]

While dirt on a filter might cut down on the amount of light there should be no change in its spectral response.

[RPC]

for printing black and white you don't use cyan, so it shouldn't be a big loss. Color , a different story,

The cyan filter is not used when printing from color negatives, slides may require it.

[ic-racer]

I can't get really high contrast with the current magenta alone

You have a problem that will not be solved by additional magenta filtration.

Start from the beginning, how are you determining your printing contrast?

[Bill Burk]

Dug around your earlier posts where you say the maximum for a Chromega is 170 units, and you do split-grade printing.

So burying an additional Magenta inside the housing would become a chore. I'd put a 30-50 Magenta filter in front of the lens so you could go up past 200 if you wanted to.

[boswald]

There is a basic difference in the way dichroic heads and filter drawers use their filters. A filter in a drawer filters all of the light while a dichro head(subtractive w/moving filters) filters some of the light till you get to the maximum position, leaving some of the light unfiltered most of the time.
A second magenta would in fact reduce the light for the high contrast layer, rebalancing the output toward the low. You would need to use a separate filter to get rid of the light that goes past the edge of the moving filter. Not much- a 40m in the drawer would let you get all the contrast available when added to a fully magenta blocked aperture.

[MartinP]

Ilford under-lens filter kit, with white-light from the enlarger?? Works for me anyway, and I made holders from foamboard that allow easy lens changes (the holder that comes with the set, mounts on the lens thread).

[cowanw]

Not to make things more confusing, but I have the same enlarger and head, and I find the Dichroic filters can be a bit short on maximum contrast. My serrendipitous solution was to get an old set of dupont or kodak under the lens filters, with bakelite screw on the lens holder. The number 5 there gives a contrastier result.
On the assumption your dichroic filtes act as perfect filters, doubling up on the same filter will only let the same image developing wavelengths pass twice, but will make it harder for your eyes to see the image on the easil.

[Bob Carnie]

filtering filtered light.. you are right , I was thinking of the relationship on colour paper when you add magenta..

... also, adding another filter of the same exact color will not gain you anything. The strongest filter (assuming one is stronger than the other) will prevail and the other will do exactly nothing, except to increase your exposure time a little (not as much as Bob suggests above though, since you are filtering already filtered light and the transmission will be close to 100% minus the neutral density characteristics of the filter).

If you need more contrast for a particular negative, try the following:

Try a different paper (I've heard that Fomabrom Variant 111 is more contrasty than other VC papers)
Use the MG grade 5 filter (it may be more contrasty than the magenta in your color head by a bit)
Use a stronger/more contrasty print developer
Bleach back the whites after printing a bit darker


If this is a recurrent problem then:

Develop more to start with
Check your magenta filter to see if it has faded; replacing it with a new/good used filter may help

Best,

Doremus

[Bob Carnie]

If you are printing crossed processed colour negs then you will indeed need to use the cyan filter.
As well introducing the cyan filter will give you nuetral density which may be needed if your exposure time is too fast with a good apeture.

The cyan filter is not used when printing from color negatives, slides may require it.