Contrast grades,Colour heads and testing VC paper

[Nick Zentena]

I thought I would use a little paper to test these things out. The test method was the one outlined in Anchell's "The Variable Contrast Printing Manual"

Agfa MCP 312 paper
Agfa Multicontrast developer seasoned
Stouffer 21 step TP wedge
Durst 1000 with a 401mkII head.

With max yellow [150y] I managed much below grade 0. The number is well off the chart.

Using the 60 Y suggested by Agfa for grade 0 I tested just below grade 0.

At 130M that Agfa suggests for grade 5 I got about grade 3.5

At max magenta [150M] I got about grade 4.5.

The problem with the high contrast is likely related to Durst changing things over the years. My head is hardly current.

My main reason for testing was curiousity. I normally spilt filter so was wondering what the extreme filters I use equate to. I was also wondering about the max contrast the head could put out. I didn't try slipping a blue filter into the head's add on filter holder that might have gained me some higher contrast.

Was it worth the paper? Not sure but it does remind me that the suggestions given by the suppliers are just that suggestions. I'm using Agfa paper in an Agfa developer and yet the contrast doesn't match up.

 

[Maine-iac]

Stick with the split filter, for exactly the reasons you've discovered.

Larry

 

[Neal]

Dear Nick,

For fun, you may want to try split filter printing with "pure" green and blue. I built a little under the lens filter holder for blue and green dichroic filters purchased from Edmunds.

However, now that you mention testing, I have never determined how hard or soft I can print relative to what I can do with my dichro head. (It does go far in both directions though).

Neal Wydra

 

[resummerfield]

For what its worth, the type enlarger (condenser or diffusion) will also influence the contrast grade. I once tested a Durst condenser head against a dichro diffusion head, using the same exact under lens filter. The condenser gave me grade 0 or 5.5, and the dichro gave 00 or 4.5.

 

[Nick Zentena]

Neal I used to use green and blue filters with my other enlarger. If I'd thought of it I would have done one test with just the blue filter. My test gave me some very low contrast grades so no real reason to test the green filter but it might be helpfull to have that blue filter in my toolkit.

Personally I find spilt filtering works the way I think so I'm not changing just trying to figure out what my paper and equipment is able to produce.