The future of Kodak film?

[Stephen Willard]

Hey Drew, just a quick note to says thanks for your help with printing 30x40s on the CPI 40. Everything worked out great. Just for the record I was able to figure out how to make the 30x40 CPI 40 drum Kodak test strip compliant. This allowed me to do determine exposure time, enlarger aperture lens setting, and color head CC settings using my Fujimoto CP-51 to develop 8x10 test prints, and then develop the final 30x40 print using the CPI 40 30x40 drum. It was amazing to get the exactly the same results on both machines. If you are interested I can send you the documentation I wrote for making the CPI 40 Kodak test strip complaint.

That said, I also use TMX100 for my mask. However, I do not try to achieve a straight line characteristic curve when developing my b&w mask for my 5x7 and 4x10 color negatives. I have decide that a curved characteristic curve (CC) is better because it will builds up density faster in the shadows than in the high lights. This produces a better light contrast mask (LCM) for color negative film that results in a more normal looking print. To get a curved CC as opposed to a straight line CC, I develop TMX100 using HC110 at a 1:7 dilution of stock solution. I am attaching a family of curves for both 5 and 10 minute development times that I use to predict my exposure time for the mask.

Ektar 100 is not as great as you may think. Its reds are I slightly more exaggerated then 160VC, but 160 VC is better for greens and blues. The big difference is the dynamic range. 160 VC is around 13 stops while Ektar 100 and 160 NC is closer to 9 stops. I have attach a CC graph that compares the CCs for Portre 160 VC, Ektar 100, and Portra 160 NC. Both the CCs for 160NC and Ektar 100 show notable fall off of gamma or film contrast at Zone IX. The graphs are only through Zone X, but you can see both the CCs for Ektar 100 and Portra 160 NC start to fall off a Zone IX while Portra 160 VC keeps climbing.

I have also attached bar graphs for the red, green, and blue layers for the Macbeth chart as well.

Thanks again....

PS I was not able to upload the blue or green layers for the Macbeth bar graphs(4 files is the limit). I will do it in my next posting.

[Stephen Willard]

And here is the green and blue layers for the Macbeth color chart bar graphs.

[Drew Wiley]

Thanks so much Stephen. I'm slowly fiddling around but otherwise preoccupied with
house remodeling. I picked up a nice 20" processor just for test strips and minor stuff
but haven't had time to get it into operation. I'm still trying to figure out where to put
a 40" machine but will probably stick to the drum for awhile. I haven't actually printed
any Ektar yet, and the results with Portra 160VC sometimes lack sufficient contrast for
me, so I too will be fiddling with contrast enhancement masking. It's nice that there's
someone else out there who still understands the flexibility and potential of real film.

[LF_rookie_to_be]

Hey Drew, just a quick note to says thanks for your help with printing 30x40s on the CPI 40. Everything worked out great. Just for the record I was able to figure out how to make the 30x40 CPI 40 drum Kodak test strip compliant. This allowed me to do determine exposure time, enlarger aperture lens setting, and color head CC settings using my Fujimoto CP-51 to develop 8x10 test prints, and then develop the final 30x40 print using the CPI 40 30x40 drum.

Stephen, would you be so kind to post a few pictures of the CPI 40 processor/drum? This seems to be a rare beast and it may perhaps be of interest to others on the forum - especially those trying to find a way do develop 30x40 prints at home.
Thanks.

LF_rtb

[Stephen Willard]

Hi LF_rtb,

Attached please find four photographs of the CPI 40. In one of the images you can see how I attach a Kodak test strip to the drum using water proof gorilla tape. This is the same test strip that I use for my Fuijimoto CP-51. When both machines are compliant with the test strip reflective densities, then I can do cross platform development and get exactly the same results on either machine. This allows me to develop 8x10 test prints on the CP51 for determining my enlarger settings and then make the final 30x40 print using the CPI 40 processor. It is pretty cool.

Note, unlike the JOBO, the CPI 40 uses no water bath to control temperature. Chemical temperatures must be maintain in a separate water bath.

[Drew Wiley]

I still owe some folks the shots of the gearmoter inside the CPI, but just haven't had
in out lately. One of these days I'm going to see if there's a standard size of industrial or drainage pipe the right size to simply section off and mfg 30x40 drums.
The base cap and ribs are a no-brainer, but to the top fill&drain cap would be tricky
without injection moulding. Still, a standardized cap might be capable of being modified. CPI drums were made of expensive Noryl plastic, so have better internal
temp retention than the thin ABS plastic of Jobo drums, for example.

[LF_rookie_to_be]

Stephen, many thanks for the photos. This certainly seems like a well-designed and made processor. I was just wondering whether the fill/drain cap is similar to those on Jobo drums. From looking at the cap on a 16x20 drum I have, the basic design would be similar to this:


Is this how the cap on a CPI works?

[Drew Wiley]

The CPI cap isn't anything like the Jobo cap. It fills and drains way faster, so in my
opinion is a far better design.