Finding Zone 1 on 4x5 Ilford Delta 100 film

[john di nenna]

Hi,

 

I need help with my results of my recent test for Zone 1

They are all over the map.

I took 7 exposures using a Sekonic 508.I spot meter a grey wall in the

shade and closed down 4 stops for each ASA change from the reading.

I developed the film with Kodak D76 deluted 1-1 using a Jobo CPE

procesor at 68 degree for 12 min. and I got my local lab to check the net

desity of each frame.

 

This are my results:

frame 1 ASA 100 net desity 0.15

frame 2 ASA 80 net density 0.20

frame 3 ASA 64 net density 0.31

frame 4 ASA 50 net density 0.39

frame 5 ASA 125 net density 0.13

frame 6 ASA 160 net density 0.09

frame 7 ASA 200 net density 0.08

 

frame 8 unexposed and developed for FB+fog using the same settings above.

net density 0.09

 

I would think that the ASA should be less of the recommended by Mfg

and not higher. At this point looks like frame number 6 is the one

close to Zone 1. Is this test correct?

 

Thanks for all your help.

 

John Di Nenna

[marc_leest1]

Since Zone I is on 0.10 density, it seems your conclusion is correct.

[haziz]

Are these taking into account the unexposed sheet?

 

The definition is 0.10 ABOVE FB+F.

 

Since your unexposed sheet shows FB+F of 0.09 then sheet 2 with 0.20 is the closest to

0.10 above FB+F (assuming you didn't already subtract FB+F) giving you an effective EI of

80.

 

And no it is not unusual in many cases to get a faster film speed than advertised.

Remember

many variables inculding your meter and shutter go into the equation.

 

Sincerely,

 

Hany.

[chuck_pere]

I don't understand frame 8 fb+fog. What does that "net" density mean? Looks to me that fb+fog is .09 and .1 above it would be frame 2 ASA 80.

[john di nenna]

Hany and Chuck

 

The net density values from frame 1 to frame 7

are after I subtract the density of FB+F 0.09

On frame 8 I meant to say density of 0.09 (not net)

Also I forgot to mention that I presoaked the film for 5 min.

Is 12 min. development time too long using the Jobo procesor?

 

Thank,

 

John

[btipton]

I know this is an old thread but I recently went through testing of Delta 100 4x5 in ID-11 1:1 at 68 degrees and developed in a Jobo drum, I ended up with a zone I EI of 160 myself and to get a proper zone VIII I had to cut my processing to 6.5 minutes. I began wondering if I had sticking shutters since I was getting such a high EI but I did some testing today comparing a zone I density made using 3 different lenses and it looks as though my shutters are okay. I also tested tmax 400 improved and got an EI of 400 with a processing time of 7 minutes which seems reasonable and verify's my testing method.

[bill_waldron]

<p>John - my recent tests of Delta100 suggest that the emulsion responds very vigorosly to DD-X developer, when the fillms are processed in tubes. My analysis puts the EFS for a 7-stop subject (development to about a .43 G) at around 160. More development than that, for expansions, will actually increase the film speed further. I am also testing this film with the taditional method you used and will report my results. Everything you and I are seeing suggests a highly under-rated film (with a rather high b+f, don't you think?)</p>