I just printed the same negative on an Omega D2 and Focomat Ic. Both have 50mm Focotar lenses. I used a the same paper on each and adjusted exposure to get each as close to the other in overall exposure and tone. It seems to me that the Focomat has more shadow detail. Has anyone else had experience using these two enlargers? If so, I would appreciate your thoughts.
I noticed that on mine also. My guess was that the condensers on the Focomat are precisely designed for 35mm. That's all it does. The D2 condenser system is adapted to work for 35mm. The better the focus of the light rays, the less you have light scatter.
You don't menition what the light sources are but I will assume - as John did - that they are condenser heads. If that is the case, John gave you your answer. But they are different light sources, please tell us so we can help you.
The double condensers are slightly more contrasty deepening the shadows.
On a scale, point light source, opal bulb double condenser, opal bulb single condenser, V35 by Leica, diffusion head or cold light, contact print. Total spread about one paper grade not counting the point light.