Digital grades

pkr1979 · Jun 4, 2024

Hi all,

So, I just shot 8 black and white films to compare them (with a P67ii). Its 4 different scenes (also with and without filter). The weather changed half way but thats relevant for only two of the scenes. I intended to get analog contact sheets (at the local lab), at both grade 2 (as this is the 'regular' one I suppose) and 3 (as this is the grading for the Lupex paper), to compare the different films.

However, this is going to get costly, so I was wondering if its is easy to imitate this digitally. ColorPerfect has grade 2 and 3 presets, but I have never really tested how close to paper they are.

Any insight from anyone on this? Is there a (easy) way to imitate paper prints from negative scans?

Cheers
Peter

xkaes · Jun 4, 2024

I always encourage testing -- whatever -- but you haven't said exactly what the purpose of your tests are -- other than "to compare the different films."

Are you trying to compare the ISO of the films, the C.I. of the films, the grain of the films, or what? Comparing each of these by themselves is enough work.

What is your purpose or goal? Throwing in other variables, such as scans vs prints, only complicates matters.

koraks · Jun 4, 2024

pkr1979 said:
grade 2 (as this is the 'regular' one I suppose) and 3 (as this is the grading for the Lupex paper)

How exactly is Lupex' grade 3 defined?
Grade 3 is generally understood to be ISO-R 70-90
Grade 2 would be around 90-110.
So one manufacturer's grade 3 might be another one's 2 and they're both 'right'.

That's not counting the actual H/D curve shape which can / will be distinctly different for any two given papers especially around the shoulder and (perhaps more importantly) the toe.

I assume you will scan your film with a flatbed scanner and a step tablet as a reference in the same scanned image so that you have an absolute benchmark. Otherwise all bets are off anyway as to determining the actual density ranges in your negatives.

All considered, the best you may be able to do is a very, very rough approximation of what the end result may look like. Really, I'd forego the whole thing and just print the negatives. Maybe select one representative strip from each roll if you worry about having to contact all 8 rolls.

pkr1979 · Jun 4, 2024

xkaes said:
I always encourage testing -- whatever -- but you haven't said exactly what the purpose of your tests are -- other than "to compare the different films."

Are you trying to compare the ISO of the films, the C.I. of the films, the grain of the films, or what? Comparing each of these by themselves is enough work.

What is your purpose or goal? Throwing in other variables, such as scans vs prints, only complicates matters.

I was hoping to more than assume what kind of film Id prefer for Lupex paper as this is a contrasty paper.

pkr1979 · Jun 4, 2024

koraks said:
How exactly is Lupex' grade 3 defined?
Grade 3 is generally understood to be ISO-R 70-90
Grade 2 would be around 90-110.
So one manufacturer's grade 3 might be another one's 2 and they're both 'right'.

That's not counting the actual H/D curve shape which can / will be distinctly different for any two given papers especially around the shoulder and (perhaps more importantly) the toe.

I assume you will scan your film with a flatbed scanner and a step tablet as a reference in the same scanned image so that you have an absolute benchmark. Otherwise all bets are off anyway as to determining the actual density ranges in your negatives.

All considered, the best you may be able to do is a very, very rough approximation of what the end result may look like. Really, I'd forego the whole thing and just print the negatives. Maybe select one representative strip from each roll if you worry about having to contact all 8 rolls.

Where in the grade range 3 it is, I have no idea. As far as I know its a contrasty paper: https://www.adox.de/Technical_Informations/TA_LUPEX(EN).pdf

Considering your reply, Im probably not scanning the negs to figure this out... as Im probably not going to find it out that way anyway. I'll get the lab to to do two contacts of each roll.

koraks · Jun 4, 2024

pkr1979 said:
Where in the grade range 3 it is, I have no idea. As far as I know its a contrasty paper: https://www.adox.de/Technical_Informations/TA_LUPEX(EN).pdf

Ah, alright. Well, comparing the curve in the Lupex datasheet to Fomaspeed (which I have handy) shows that their interpretation of grade 3 is about the same.

pkr1979 said:
I'll get the lab to to do two contacts of each roll.

I think that would be more representative than a digital mockup. The latter tends to be tricky.

Digital grades

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