Look up 35 mm SLRs' flange-to-film distances, also called registers. When using a lens made for a 35 mm SLR reversed as a macro lens, the minimum "back of lens" to subject distance is the register. The OP has a 44/3.5 lens extracted from a Kodak Signet. It isn't for an SLR and the Signet's register isn't published, but since it is a tessar type its minimum back of lens to subject distance will be around 40 mm.
Originally Posted by BetterSense
I've known the joy of trying things out, also the joy of finding good uses for what appears, at first glance, to be scrap so I don't want to discourage the OP from trying to find a use for his ex-Signet 44/3.5. That said, all the lens is good for on 4x5 or 5x7 is relatively high magnification macro work.
If I were in the OP's situation and wanted to shoot macro on 4x5 or 5x7 I wouldn't start with a 44 mm lens or, for that matter, any of the 35 mm SLR more-or-less normal lenses I have. This because a lens that short will cover the formats only at relatively high magnification. Shooting LF at relatively high magnification is possible, has been done, is very difficult. Shooting at magnifications from 1:8 to 2:1 is hard too, but much easier than shooting above 2:1 or so.
If I wanted to do that, I'd look for a decent process lens, focal length around 210 mm, for shooting up to perhaps 1:2 on 5x7 and for a decent process lens, focal length around 150 mm, for shooting above 1:2 on 5x7 and from 1:8 up on 4x5. First choice for a 150 would be a 150/9 G-Claron even though the one 150/9 G-Claron I've had was noticeably worse than the 150/9 Apo Ronars I still have.
An alternative would be a decent enlarging lens whose cells fit a standard shutter. I'm a little partial to 105/4.5 and 150/5.6 Comparons as low-budget macro lenses because they fit #0 shutters so are easily reversed.