Some examples Robert:
Here's 3 90mm lenses:
A 90mm f6.8 Grandagon N, 90mm f5.6 Super Angulon and a 90mm f6.8 Angulon
The tiny Angulon is a considerable saving in terms of weight and size however it only just covers 5x4 but very capable if used acrefully, quality of early one's was sometimes suspect but all OK after SN 5,000,000
Weight IC mm f22
90m f6.8 Angulon 211.1 g 154 (f16)
90mm f6.8 Grandagon 492.7 g 221
90mmf5.6 Super Angulon 589.5 g 235
Here's another example 8" - 210mm lenses:
A 203mm f7.7 203mm (8") Ektar very late US version and a 210mm f5.6 Symmar S
Plenty of coverage with both as they cover 7x5 with room for movements.
Weight IC mm f22
210mm f5.6 Symmar S 569.8 g 294
203mm f7.7 Ektar (US) 256.7 g 216
210mm f6.3 Osaka Commercial 255.4g g 235
210mm f6.3 Geronar 323.1 g 230
You can see a very significant weight and size difference between the Ektar and Symmar S. The Ektar is a very sharp lens an excellent from Infinity to 1:1, if you can find a late UK made version they are in a Compur #0 shutter (with preview lever) earlier versions are in Epsilon and later Prontor shutters you need to set to B or T to focus. The US version is usually in a Supermatic shutter excepth the very last ones made which are in a Graphex Compur #1 (as above).
Other alternatives are the 210mm f6.3 Congo/Osaka Commercial based on the Kodak Commercial Ektar or the 210mm f6.8 Geronar which is a Multi Coated Cooke triplet - good for portraits at wider apertures and very sharp stopped down to f22. Both are small light lenses.
There's less saving in size and weight with 150mm lenses but the lightest and smallest would be a late 150mm f5.6 Xenar, Robert white was selling them new around for 2000 for about £100.
Ian