[pure-silver] Re: [ot?] e-6 process question
- From: Claudio Bonavolta <claudio@xxxxxxxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Wed, 5 Apr 2006 12:01:40 +0200
----- Message d'origine -----
De: Gianni Rondinini <bugbarbeq@xxxxxxx>
Date: Wed, 05 Apr 2006 10:32:38 +0200
Sujet: [pure-silver] [ot?] e-6 process question
À: pure-silver@xxxxxxxxxxxxx
>i'm not sure this is on topic: if i'm off topic, i'll be glad to move
>to a different list but would need an advice about which one.
>
>i recently got a 6 bath e-6 kit [1]: chemicals are to be diluted to
>make 5 liters of each bath, and this is the easy part.
>each bath will have to be kept at very precise temperature, and this
>is the almost-easy part since i'm going to use a jobo cpa-2 i bought
>on ebay (well, i see 38 +/- 0.3 and cpa-2 guarantees +/- 0.5/1 degree,
>but i hope it won't be that big issue).
>how much chemical to use is the hard part: i can't figure out this and
>need some help.
>
><foreword>
>the kit should allow you to develop 60 rolls of 135/36 or 120 color
>slides, which should mean 12 rolls each liter of each chemical...
>to be quich and rough, a 4x5" is about 103x125 = circa 13.000mm^2.
>120 is about 62x62x12 = circa 46.000mm^2 [2]
>135/36 is about 26x40x42 = circa 44.000mm^2 [2]
>this suggests that every 135/36 or 120 roll is equivalent to 3.5 4x5"
>slide (this is important since i'm going to do mostly 4x5" and some
>120's at home - 135/36 is sooooo cheap that i don't even think about
>doing it at home).
></foreword>
>
>the following is pasted from the instructions leaflet:
>[...]
>the colour density of the slides is determined by the liquid-to-film
>surface area ratio. minimum quantity: 160ml /135-36.
>[...]
>
>now my doubts:
>1. minimum is minimum, not what you *have to* use. anything more than
>that will be ok, but let's assume that minimum is ok because if i use
>more than that my thoughts get even more foggy...
>2. if i can process 12 rolls per liter, i guess i should be able to do
>them in a single batch, right? but 12x160 is 1920ml, not 1000ml.
>what am i missing?
>
>there's a table in the leaflet with looks like the following:
>1000ml 1-4 films 5-8 films 9-12 films
>step 0 5 minutes
>step 1 6 minutes 6 min. 15 6 min. 30
>step 2 2 minutes
>step 3 2 minutes
>step 4 4 minutes 5 minutes 6 minutes
> ... ... ... ...
>
>does the above mean that *anyway* i have to split the 12 rolls of each
>liter of chemicals in 3 batches of 4 rolls each? this is ok, but i'm
>not sure about it.
>the "x-y films" way of writing (which is the same in all languages,
>then it's no wrong translation - i understand well english and french
>and italian is my first language) is equivalent to "films number x to
>y"?
>
>i understand also that this is just a chemical requirement and that i
>need to check also the labels on my jobo drums to be *sure* that all
>the film will get in contact with chemicals, but this will come after
>i got the whole thing.
>
>i thank in advance anybody that will suggest anything about this
>(apart from "let it be done by who knows" :)
>
>regards,
>
>[1] i *now* know there are easier to use 3-bath e-6 kits, but i didn't
>know of them before, so next time i'll get the smarter one; however i
>have to use this one before getting a 3-bath one.
>[2] i put some extra for head and tail and the perforated side bands,
>which will consume some chemicals.
>--
>Gianni Rondinini (30, tanti, RA)
>Nikon user - Bmw driver
>http://bugbarbeq.deviantart.com
There is the Chroma list that is specific to color discussions but the least we
can say is that it is pretty silent ...
The CPA-2 is fine for E-6 processing provided you set it up carefully. What is
important is that the temperature *inside* the drum is very close to the
theorical one.
With my CPA-2 I did tests during an afternoon (water has a high temperature
inertia and needs time to stabilize) until the temperature was right and stable
inside the drum.
I used water in the drum, a quantity similar to the one required for processing
E-6 (I do very little C-41).
Once the temperature is fine and stable in the drum, I've measured the
temperatures in various parts of the processor and specially one point that
became my reference point.
Now, when I heat the processor, if the temperature at this reference point has
reached the value measured during the tests, I know the temperature inside the
drum will be close to the optimal one.
My page on the cpa-2:
http://www.bonavolta.ch/hobby/en/photo/cpa2.htm
Nothing rocket science ...
My main reason of doing 35mm E-6 at home is not the price but the quality of
the results, similar to the best pro labs (and if you compare to these, then
the economy is interesting).
Regarding your kit, it is a Tetenal one, right ?
I'm nearly sure it is, as Tetenal is specialized in such
"so-easy-to-understand" instructions booklets :-)
As I've never used this kit, please take the following accordingly, maybe
someone on the list uses it and can be more precise.
Often with Tetenal kits, you have to re-use the chemistry to develop the
quantity of films indicated on the box.
I assume this is the case here as 5 litres divided per 60 (135-36, that's my
unit of measure for the rest, up to you to adapt to 4x5") gives 83.3ml and in
the leaflet they say you need nearly double this quantity per film.
If you use 160ml per film one-shot then this makes only 31 rolls.
Is there something in the leaflet that indicates re-use of the chemistry ?
If not, I would try the first roll with the minimal quantity (check also the
minimal quantity to wet the film completely for your tank).
This one should turn out fine, then try to re-use the chemistry with a test
film (ideally same subject and light conditions as the first one).
Normally there may be some time adjustment to re-use the chemistry but if
nothing is indicated on the instructions, it is hard to tell exactly, I would
try the same time.
If the result is to dark then lengthen the first developer time and vice-versa.
For color work (for B/W too, but we're going off-topic :-) ), I really prefer
one-shot for constant results and thus use the Kodak 5 litres one-shot kit.
I also like this kit because, beside its outstanding quality, the quantities
are well-suited for Jobo 15xx tanks. One liter develops 8 rolls which is just
the number of films I put in a 1520 + 2x 1530 and which the maximum for a CPA-2
(length of the tank and maximum weight allowed for the motor).
I have a page about this kit used together with 15xx Jobo tanks:
http://www.bonavolta.ch/hobby/en/photo/e6.htm
The table seems to indicate you need to increase the processing time (step 1 is
the first developer, step 4 either a pre-bleach or the bleach) depending of the
number of rolls you process simultaneously (the Jobo 15xx series can be
assembled to vary their film capacity).
You assumption regarding x-y notation is right, this means "from x films to y
films then ...".
Regarding the 3 steps kits, they are simpler to use (less products to mix) but
aren't significantly cheaper than the 6 steps (in fact 7).
Best regards,
Claudio Bonavolta
http://www.bonavolta.ch
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