[pure-silver] Re: Agitation and contrast
- From: Dana Myers <dana.myers@xxxxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Tue, 12 Nov 2019 21:52:01 -0800
On 11/12/2019 9:04 AM, Robert Shanebrook (Redacted sender makingkodakfilm for
DMARC) wrote:
Keep it simple:
Use time-and-temperature to control contrast/density. Yes, T-Max Films are more sensitive to time-and-temperature
differences than 3D films. T-Max Film development time differences of +/- 15 seconds are enough to make a difference. For
3Ds 25% is an appropriate difference.
I was just amazed to be reminded just how sensitive T-Max is. Not a bad thing,
just a thing to manage. Way back when, I'd use a Coleman as a water bath
to stabilize temperature, but then I became perhaps a bit lazier and started
adjusting processing time to match temperature, processing between 70F
and 75F depending on the time of year. J-109 gives times for 70F and 75F,
and I've been linearly interpolating over that range.
Because I don't manage temperature, I adjust for it, all I had left was time.
This is when I remembered I historically hadn't been adjusting the time
from the J-109 times - and realized my agitation had become more aggressive.
Hence, I re-read J-109's directions for small-tank agitation, which specify
initial agitation of "5-7 cycles in 5 seconds" and then 2-5 cycles every 30
seconds and remembered that I'd adjusted agitation years ago (I always
agitate by inversion). My old habit of agitating for the first 30 seconds, then
5
cycles every 30 seconds, had returned.
It's a good point to generally adjust time/temperature, because technique is
harder to objectively measure and can vary, as it did in my case. Though I
remembered that the time/temperatures had been working in my case,
so I reviewed technique. Whatever works and you can do consistently, right?
time > 5 minutes
Stainless steel tanks that can be inverted are much better than hand tanks that cannot be inverted. best for roll film. If
they leak too much tape the seam after the first 30-seconds.
8, 16, 32 oz. tanks are better than 64oz tanks
Put liquid in the tank then insert reels then put top on
Wrap the bottom of the tank 5 times (5 seconds) on a hard surface to dislodge
air bells,
Indeed; I also habitually rap the tank on the counter after agitation.
Old habits.
Thank you so much,
Dana K6JQ
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