Plotting software BTZS

jejes

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Hello, i'm discovering the world of densitometry and i'm amazed by zone system and all that can do with that.

Wich tool do you use to plot your film?

1. BTZS plotter (i think was done 2012 and not updated) 29$. It's nice when used with sheet film and Expodev.
2. https://bnxvs.shinyapps.io/cc_film_plot/
3. Excel sheet (i don't have any to test)

I would like to have a fast way to find EI of the film, N ideal developing time and dynamic range of my developing time with the plotting software

Please if you have some free resources and want to share with the comunnity please reply to the thread.


Thank You
 

Andrew O'Neill

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Have you used that shinyapps film plotter? How is the data entered? I've always done all my curves, etc, by hand
 
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jejes

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Open the web page and put some deinsity readings from Stouffer. I found quite nice but not as option 1.
 

ic-racer

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I wrote my own spreadsheet to do the calculations. There are various levels of this. For example you can easily plot the data and get the equation to your curve. Solving for to find X when Y= 0.1 from your quadratic equation can be the challenge in most spreadsheets. I use a simple interpolation to do it, that is I don't use the equation that I can't solve easily.
 
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jejes

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Could you share it?
 

Thorsten

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My enlarger is equipped with a Heiland Splitgrade Controller. This allows you to measure the density of the image quite easily.

I take some shots of a white board at 15 different exposures, develop the film and put it on the enlarger. Then I place the sensor exactly in the center of the projection and pull the strip so that the sensor is exactly in the space between two frames (base + fog), start the measurement at this position and then pull the strip of film until I am exactly in the middle of one of the exposures. The controller now tells me the density of this exposure - base density.

Not only does this perfectly well but I also use exactly the equipment I use to take the images and to enlarge the images so even if there are errors in measurement, they do not really matter.

I then use Excel to look at the data and if necessary create a curve.
 

Thorsten

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Here is one of the tests I recently did on FP4+ in XTOL 1+1, 20 °C, 10 min, inversion method (1 min constant, then 10 s at the beginning of every minute):



The first two lines show what I was expected to shoot. I then used my Nikon FM3a (which is my most precise camera and the easiest to use for this test) to shoot at the values in line 3 (line marked ISO).

Frame 4 (column E) was supposed to be Zone I with a density of 0.10 or 0.11, Frame 10 (column Q) was supposed to be Zone V with a density of 0.72 and frame 13 was supposed to be Zone VIII with an expected density of 1.29

As you can see I got density 0.11 not at frame 4 but at frame 6, so the lower two lines need to moved to the left by two steps. After that the table looks like this:


At Zone 5 (Q) you now see that we are at ISO 64. And while there is no frame shot at exactly this exposure, you can still check the other exposures and you will see: At ISO 50 density should be 0.78 and is 0.78, At ISO 25 it was expected to be 0.97 and is 0.95. So this is an almost perfect match. ISO 64 and XTOL 1+1 10:00 gets perfect results for my camera/enlarger.

Here is the table reduced to only actual test values and the curve, for standard development the blue curve should cross thegrey line exactly at Zone V and the orange line at Zone 8. I think I hit them close enough:
 

Thorsten

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Yesterday by the way I tested Delta 100 with exactly the same method, also XTOL 1+1, 10:30. Here is the result:



As you can see it is overdeveloped a bit. This is actually a perfect N+1 curve. I made another test yesterday and developed it for 9:30 instead of 10:30, but have not measured the results yet.

so if you have a controller at your enlarger that not only measures the densities but also shows you the difference between lowest and highest density, you have all you need to do an actual test in the environment you actually use for enlarging.
 
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jejes

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Please if you can post your file, i would like to use
 

Thorsten

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Sadly I messed it up somehow. I have perfectly fine results for Acros, FP4 and HP5 now, but the Delta curve is wrong. I will redo it, but only in two weeks or so.
 
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jejes

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Krefey said:
Sadly I messed it up somehow. I have perfectly fine results for Acros, FP4 and HP5 now, but the Delta curve is wrong. I will redo it, but only in two weeks or so.
Click to expand...

could you share your excel with us? I like to see your results but here I was asking about free tools
 

L Gebhardt

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The BTZS Plotter app works fine and is easy to enter data into and the included curves are quite useful to get a feel for the tested films and papers. Having said that a spreadsheet works just fine. Also Plotter can run on a Mac with Wine.
 

RalphLambrecht

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I use my self-developed spreadsheet (attached); it never failed me, but I'm not sure it's self-explanatory.
 

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  • filmtestevaluation 2.xls
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MattKing

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Krefey said:
I would, but how? I clicked "attach files" and select the folder, but the xlsx file is greyed out, I cannot select it.
Click to expand...

He hasn't uploaded/attached the file to any post yet.
The "Attach files" link is there to enable you to upload your file to Photrio.
 

tih

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Back when Ralph first published that spreadsheet, there was also an accompanying PDF document, which was based on the relevant chapter from the book. I'm attaching a copy of that here, for completeness.
 

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ic-racer

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I have about 20 versions of this Excel file, but Excel does not run on my computer anymore after I was forced to "upgrade" operating systems some time ago. So this one may or may not work, I have no way of knowing:

 

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RalphLambrecht

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Krefey said:
I would, but how? I clicked "attach files" and select the folder, but the xlsx file is greyed out, I cannot select it.
Click to expand...

sorry for your troubles but, I cannot replicate your experience. I can download it just fine on my computer. if you send me a private email request to rwlambrec@gmail.com I'm happy to send it to you via email with the pdf.
 
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