I’m looking to calibrate salt print for my 1500W in the next few days, having never calibrated a process before and am still unfamiliar with how much i1Pro2 works. Not sure if I will mange it so quickly but will give it a try!
A few initial questions about it.
Will I need to limit the master curve?
What is the density of the master quad?
From what I’ve read 1.70 is acceptable for salt.
Cheers
Also, what is the best approach to figuring out standard exposure time? I saw in another thread 1/3rd stop increments. Can anyone give me a good sequence of exposure times?
Cheers
Would
60s
80s
106s
141s
188s
250s
333s
444s
592s
etc
be correct?
The first post should read ‘How my i1pro2 works’ rather than ‘how much’ by the way!
Gareth. I think you really need to take a workshop on digital negative making and alt-process printing. This will answer a lot of your questions related to density, exposing, Salt (that is a world un-too itself), etc.
For example, 1.7 is way way less density than every Salt print needs. Salt needs 3+ optical density of the neg (probably around 3.7 to 4.0 ideal UV transmission density). If the idea of transmission density is new to you, please read up on dig-neg and alt-proc methods (especially salt!).
For figuring out exposure, get a Stouffer strip: http://www.stouffer.net/using21step.htm
The formula for figuring out minimum time for maximum black is printed right on the packaging.
Depending upon your exposing unit (there are lots) you may be counting seconds (after your bulb warms up!) or maybe units (for platemakers, etc) or just winging it out-doors with a UV meter. There are many variables that you can learn that this software/manual and forum aren’t necessarily set up to teach and support. (We can certainly help with debugging exposure units though!)
The master curves for PiezoDN will make decent salt print negs. They will need to be linearized though (this will increase dMax) as this is a printed-out-process.
I’m in the UK so a workshop is off the cards. Would love to but really can’t afford it.
I am getting the value 1.7 from the 1979 Keepers of Light. It did seem low to me. I’m not certain why that value is used.
I have a Stouffer 21 step wedge here. Isn’t this used after the initial rough test strip to fine tune exposure and then subsequently printed with every test?
I’m using a bank of sun tanning tubes and let them warm up for a minute before.
So my question would be, what is the master curve in UV transmission density?
I am using warm neutral ink I should add.
I imagined this would be higher than intended for salt printing and then ‘limited’ as I’ve read in the manual. You are saying the dMax will be increased by linearizing though? I thought the master curve would be the highest density possible.
You will not need to limit anything for salt. Salt takes a ton of density.
Just coat and print the master and see if you see any fog.
Linearization does not increase dMax of the final patch. it increases dMax of all the other patches (something that will be needed for a linear salt print).
Best
Walker
Ah ok, I understand now, thanks.
I attempted a salt print using the palladium curve available to the 1500W. It has enough density because my highlights are white. Albeit not linearized for salt.
What is the UV density of the palladium curve?
I am controlling fog by adding citric acid to my silver
Hopefully I can have a first attempt at linearizing the master curve for salt tomorrow and actually figure out how to read patches with my i1Pro.
What chemistry and paper did you use for creating the salt print curve for the 4800
Cheers