The upper bellows of the 23C should be usable for adjustment of the condensers to focus the light onto the pupil of whatever lens you are using. That’s the theory anyway. Beware though – I own an excellent 80mm Schneider lens which covers 6x6 but will not cover 6x7. Another lesser quality lens, a Beseler 75mm, will! Go figure. I use a Schneider 100mm for 6x6 and 6x7 and the 80mm for 35mm. Good luck.