Macro Lens for Sinar F

[StudioKroes]

Hello,

New here!

I shoot a lot of digital macro work and recently bought a Sinar F that came with a Schneider 210mm lens. I have been doing some macro work with flowers and have had to extend the bellows about 12 inches to get the type of magnification I desire.

I found some videos about the Nikkor AM ED 120mm Macro lens and then read that the coverage might not be enough for a 4x5 camera?

Are there any other recommended lenses that would allow me to get a 1:1 magnification without racking out the bellows a foot?

Attached a sample image I shot

Thanks!