Densitometer Aperture?

[edward_zimmermann]

I'm having a bit of trouble thinking conceptually about aperture in

the context of photographic films (and not quality control targets). A

1mm aperture is with 35mm film already nearly the equivalent of a

half-inch circle on a 8x10" print so does it really make any sense and

should one, as with standard target testing, remain with 2mm or 3mm

apertures and perhaps turn back to baseboard probes for fine

measurement of null densities?

[conrad_hoffman]

IMHO, reading details on 35mm film with a densitometer is hopeless. Big test patches, maybe, but I don't know of any common densitometers with really small apertures and some way to know what you're looking at. Baseboard probes are the way to go. I've never seen a microdensitometer, but those are for looking at fine details and edge effects. Probably expensive and not suited to general sensitometry anyway. Since you typically read a neg to determine how to print it, having the flare of the enlarging system as part of the measurement is probably good.