Have a general question on the Ilford 500 Multi Contrast Light Head.

I have a Ilford 500 H head on a Durst 138 enlarger with a 500 CPM control panel that I have been using to contact print Ilford multi grade warm tone paper through a Nikkor 180mm enlarging lens. I have been contact printing 8x10, 11x14 and 8x20 using a 6x9 mixing box in the light head. My Durst 138 has a set of condensers under the light source.

I just acquired another Ilford 500 light head with a different control panel listed as a 500 C (maybe older one) that is on an Omega 5500 4x5 enlarger that has no condenser. This light source has a 4x5 mixing box in the light head.

My question regards the apparent lower intensity of the light source on the Omega enlarger through a 135mm Nikkor lens as well as a shift in the color of the light that reaches the easel which appears to be a mostly green to my eye whereas the quality of light through the Durst 138 with the same head appears relative white in color through the contrast range.

I have printed with the Durst and its Ilford 500 head and it appears to shift contrast as intended to my eye.

Can anyone comment on the lower light intensity in the newly acquired llford Multi Contrast Head as well as the green color of the quality of light hitting the easel which is different than I am seeing coming out of the Durst?

Thanks!