Negative to Positive scans

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LSI_Ketelhohn
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Re: Negative to Positive scans

Postby LSI_Ketelhohn » Fri Dec 01, 2017 3:39 pm

One correction here.
The raw data in HDR(i) RAW files IS the real raw sensor data. The misunderstanding here is that the line sensors of a scanner directly creates valid RGB data. It does not require any complicated transformation like a digital camera's area sensor does.

Kind regards
Arne

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Re: Negative to Positive scans

Postby Kapelonis » Sat Dec 02, 2017 8:48 am

Dear Arne
after your analysis about HDR, JPG, RAW, etc...
But ... the theme there isn't this. For me, and five (#5) other customers (Elen Rutcick, PhotoMike, tim48v, andrewwross an MrChris) the theme is "Negative to Positive scans"
If there is a misunderstanding it is from LSI stuff. Can you understand that there is a problem with interface of the program?
I will repeat something I wrote in my previous message:
"there is a problem with the software interface: two opposite selections for "Select material to scan" (Positive OR Negative) give the same (NEGATIVE) RAW product"
I repeat: "TWO OPPOSITE SELECTIONS GIVE THE SAME PRODUCT" (Sorry for uppercase, but I can't read one more answer about RAW, HDR, etc)
Your programmers must solve this issue... If HDR files are unchanged files (and -I suppose- must stay unchanged) when someone user scan a film (positive or negative) in HDR mode, then the program MUST INACTIVATE THE SELECTION BETWEEN "POSITIVE OR NEGATIVE". It is very simple for a programmer...
Today I spent more time about this issue: I scanned a film negative in 48bitHDR two times: first as Negative and then as Positive. Believe me, I can't find difference between the TIFF images I received. [If you have any comments about that, please open another discussion... ;) ]
Kind regards
George

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Re: Negative to Positive scans

Postby LSI_Ketelhohn » Mon Dec 04, 2017 10:30 am

Dear George,

Thank you for your feedback.
The Negative selection is necessary because it allows users to store the negative film type in the HDR(i) RAW images. The film type is stored in the metadata and automatically loaded in SilverFast HDR Studio.

Kind regards,
Arne

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Jossie
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Re: Negative to Positive scans

Postby Jossie » Mon Dec 04, 2017 12:05 pm

Dear George,

may I extend the explanation by Arne Ketelhohn somewhat for clarity.

But ... the theme there isn't this

Yes, this is exactly the topic since you have to understand what the 48bitHDR format is and is not.
If there is a misunderstanding it is from LSI staff.

No, the misunderstanding is on your side, sorry!

You (and others) selected the output format 48bitHDR. This is defined such that SilverFast does not change the data as they are delivered from the scanner to the SilverFast application and these are negative as you are scanning a negative. LSI calls these data "raw" although they are not (this is a confusing issue and here the misunderstanding clearly is on the LSI-side). Whatever you select as the material type (positive or negative) for the scan does not have any effect on the scanner data, it only effects the following processing of the scan by HDR (this output format is meant for HDR processing, users have to accept this definition), because HDR reads the metadata and acts accordingly (i.e. inverts the image). This has nothing to do with proprietary issues since you can readily use the HDR output format in other applications (and invert them there, e.g. in Photoshop). This is just how LSI has set up their workflow. But of course e.g. PhotoShop does not know about the SilverFast-internal metadata it thus will not automatically invert the image for you to a positive. You have to do that manually if you are not using HDR.

Why do you scan in 48bitHDR format? I would assume (unfortunately you do not tell us which SF version you are using) to take advantage of the 48bit output, which is only supported in your SF version by the HDR formats?

Hermann-Josef

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Re: Negative to Positive scans

Postby LSI_Ketelhohn » Wed Dec 06, 2017 11:40 am

Again,

No, there is no misunderstanding on our side what the word raw means. Please check the Webster dictionary (Especially 2.c)if you do not know what the word raw means. This is not the .raw file format it simply is the word raw.

Kind regards,
Arne


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