This weekend I tested three lens; a Fuji 300mm 5.6, a Cervees 250mm f 4, a silent film projector lens 300mm seems to be f4 ish. The Cervees is probably a B&L rebranded. The projector lens is named for a silent film studio and I can only say it is a 4 element lens.
Images shot midday sunny wide open in full shade 5 Mississippi , UVX collodion 6 months old, developed FeSO4 coffers, fixed with KCN.
What I notice is the projector lens is the softest, has less contrast maybe too much for my taste. The Cervees is sharp but a bit of contrast loss and probably good for flattering portraits, the Fuji is sharp and contrast.

Click image for larger version. 

Name:	IMG_0593.jpg 
Views:	58 
Size:	35.8 KB 
ID:	243835Click image for larger version. 

Name:	IMG_0597.jpg 
Views:	54 
Size:	35.5 KB 
ID:	243836Click image for larger version. 

Name:	IMG_0592.jpg 
Views:	50 
Size:	31.4 KB 
ID:	243837