Question about Negafix 6x6 film type profiles

[meredithlmiller]

This may be a stupid question, but I'm a new Silverfast user scanning both 4x5 and 120 negatives on an Epson 4990 flatbed scanner, and I have a question about the "6x6" film type variants I can select using Negafix.

Are these "6x6" film type choices meant for 120 film, as opposed to say 35mm film for the film types cnoices without the "6x6" designation?

If so, why aren't there choices for still larger film types like 4x5??

I would guess that technically the emulsion is the same no matter what size film it's put on...is that not the case???

Thanks for any help you can provide.

:oops:

[LSI_Noack]

Dear Meredith

while 120/220 refers to the length of the film roll, 6x6 is the actual image size. However, on 120/220 film material there also can be 6x7, 6x9, etc., image "blocks". As for the Negafix profile the film material is important, you may be able (generally spoken, i.e. as long as it is the same material on the film roll) to use the 6x6 Negafix profiles for the other 120/220 image sizes.

Best regards
Sonny Noack
- Manager Technical Support, LaserSoft Imaging AG -

[meredithlmiller]

Thanks for the feedback, Sonny.

I do understand the various formats that can be shot on 120 film, and in fact I shoot 6x7 negs on 120 film with a Mamiya 7II camera.

I guess I wonder then why the Negafix variant isn't called, say, Fuji NPH 400 "120" as opposed to Fuji NPH 400 "6x6"?

And why aren't there also "4x5" variants--such as a Fuji NPH 400 "4x5"--for large-format film, if each film size has its own different characteristics?

And finally, I think the reason I posted this question in the first place, is that my preliminary scans of 120 film shot with the Mamiya 7 seem to look so much better when I use the NON-6x6 Negafix variation?

Does that makes sense??

Thanks again for any further assistance you can give me.

[LSI_Noack]

Dear Meredith

sorry the answer took some time... I've been on holidays :)

Our naming convention reflects what film we actually used when creating the profiles. It doesn't imply for what material profiles can be used.
I cannot tell why there are both, 4x5 and 6x6 profiles e.g for a specific scanner and film material, but I guess confidently that this is just due to internal processes and historic reasons: There simply had been both types of the actually same material been available and thus was being profiled.

Hope this helps and with my best regards
Sonny Noack
- Manager Technical Support, LaserSoft Imaging AG -

[meredithlmiller]

As I continue to scan various Kodak 160 Portra NC negatives in both medium format (120 film with 6x6 cm and 6x7 cm crops) and large format (4x5 inch) sizes, I'm still baffled by Silverfast's choice of two different "Negafix" profiles for that film type: one labelled "Kodak Portra 160 NC" and the other "Kodak Portra 160 NC 6x6." For the same film type, selecting one of these profiles over the other gives dramatically different visual results! Can you please try and explain to me the technical decision behind these two choices. If two choices were required because the emulsion for the film is actually somehow different when placed on 35mm versus 120mm versus 4x5", why then aren't there then THREE different profiles for these three film format sizes? Yet if the emulsion is the same, why does Silverfast include the two vastly different profiles in the first place, and why isn't there just a single "Kodak Portra 160 NC" profile. So far I don't think I have a satisfying answer that makes sense to me? They can't BOTH be correct!? Thanks.

[LSI_Morales]

Dear Meredith

You find in NegaFix two different profiles for certain film emulsions. Those profiles do differ from each other sometimes slightly some other times not so.

The reason for this is that we used two different calibration targets of the same film emulsion to generate the profiles on 35 mm the other one 6x6.

But if we used the same film emulsion and the targets used for this purpose were created under certain light conditions under a controlled environment then why the difference?

Because the details and fields in the 35mm target are much smaller than those of the bigger targets, it also means that the grain is bigger in the 35 mm film target and the average in every field will not be as precise as the average of every field in the bigger target. You must also have into account that for the smaller target the scanner will use less pixels of the sensor than the bigger targets, it makes the scanner respond in a different way.

It is important not to forget that also films of the same emulsion can differ from one another because photographic emulsions change constantly and they are produced in batches which are more or less the same but not exactly 100% equal.

These explain the two profiles available and its differences as well as why one profile fits your needs better than the other one.