TAMRON'S LARGE FORMAT LENSES

Fuji and Nikon are the names that quickly come to mind when Japanese large format lenses are the topic, but there are several others that sometimes are mentioned. Tamron, however, will probably not be one of them.

Around 1970, for a short period of time, Tamron dipped its toe into the pool of large format optics by making a full line of high-quality, achromatic, coated, large format lenses based on the well-known Dagor 6/4 design. Ranging from 105mm to 300mm focal lengths, these lenses were intended to be an alternative to expensive, German-made, large format lenses. To accomplish this, these lenses reduced cost by offering smaller maximum apertures -- f6.8, instead of the more common f5.6 -- and had less covering power. But unlike most Dagor-type lenses, Tamron added lens coatings to their line-up. They all have a 70° angle of coverage, and they are all symmetrical -- and quickly convertible. By simply unscrewing the front lens group, the focal length of the lens nearly doubles -- as do the f-numbers. Consequently, every Copal shutter has two f-stop scales -- depending on if the lens groups are used "combined" or "converted". The shutters were all Copal -- #0, #1 & #3 -- and appear overly large for these otherwise very compact and light lenses. They can be hard to find, due to their short production period -- which can result in much higher than reasonable prices for a "budget" lens.

The results are softer when the front lens group is removed, but that makes these lenses great for portrait and other soft-focus work. And for even softer results, the rear lens group can be removed instead of the front lens group.

Tamron COLOR-TAMRON Large Format Lens Table

Combined Focal Length	Combined Maximum f-stop	Elements / Groups	Shutter	Covering Power / Angle of Coverage	Image Circle at f16	Coating		Converted Focal Length	Converted Maximum f-stop	Elements / Groups
105mm	f6.8	6/4	Copal #0	70°	147mm	Single		180mm	f14.0	3/2
135mm	f6.8	6/4	Copal #0	70°	190mm	Single		235mm	f14.0	3/2
150mm	f6.8	6/4	Copal #0	70°	210mm	Single		260mm	f14.0	3/2
180mm	f6.8	6/4	Copal #1	70°	253mm	Single		315mm	f14.0	3/2
210mm	f6.8	6/4	Copal #1	70°	292mm	Single		370mm	f14.0	3/2
240mm	f6.8	6/4	Copal #3	70°	336mm	Single		420mm	f14.0	3/2
270mm	f6.8	6/4	Copal #3	70°	378mm	Single		470mm	f14.0	3/2
300mm	f6.8	6/4	Copal #3	70°	420mm	Single		530mm	f14.0	3/2