FP4+ Personal Film Speed & Mamiya C330

[Todd Barlow]

I am curious about how my personal film speed testing compares to others.

Lens: Black bodied Mamiya 80mm f2.8
Shutter Speed was tested and is acurate

Film: Ilford FP4+
Developer: Ilfotec DD-X
Time: 10m at 20C

My Personal Film Speed: 320

 

[Roger Hicks]

I am curious about how my personal film speed testing compares to others.

Lens: Black bodied Mamiya 80mm f2.8
Shutter Speed was tested and is acurate

Film: Ilford FP4+
Developer: Ilfotec DD-X
Time: 10m at 20C

My Personal Film Speed: 320

Interesting. Ilford's own figures suggest ISO 160+ in this dev and my experience supports that. Yours seems high but hey, don't knock it.

Effective shutter speeds vary with aperture (efficiency variations) but this doesn't help much.

What criterion are use using for speed? Is it 0,10 above fb+f or printable shadow detail (which could easily give you the extra stop)?

Thanks for the info.

Cheers,

R.

 

[grahamp]

How certain are you of your light meter? As long as you get the results you want, then that is your personal speed.

 

[Richard Kelham]

Assuming your aperture is accurate (have you tried other lenses?) I would then wonder about your meter/metering technique.

I give my FP4+ 10 minutes in DD-X and get the sort of negs I like rating the film at 125ISO...



Richard

 

[paul ron]

In old cameras with shutters running a bit slow, testing is the best way to calibrate your equipemnt. Be sure to run the tests on your other lenses.

Results are what matters, not if you are the same as anyone else, it's all relative to what you are using and your style of shooting, metering habbits as well.