Size difference in Digital Separation Negatives

[Carnie Bob]

I use a Epson P7000 surecolor to make my digital negatives. When doing separation negatives we sometimes see a .05 - 1mm discrepancy between image negs. Usually this discrepancy is in the direction the film travels through the printer and usually when we gang one image above the other using print tool.
Has anyone else seen this issue.?

 

[koraks]

No, but it's unsurprising if you work with large negatives, as you do. The honest take-away is that this kind of machine just isn't fit for the job and it'll remain a compromise. It's not made to do this.

 

[Carnie Bob]

No, but it's unsurprising if you work with large negatives, as you do. The honest take-away is that this kind of machine just isn't fit for the job and it'll remain a compromise. It's not made to do this.

We are thinking of moving to flatbed, we have done thousands of negs that work with thin printer, but every once in awhile we get a size variation which is perplexing.

 

[koraks]

My advice would be to contact the manufacturer and request data on the performance of the machine in this regard. I can imagine that flatbed printers might perform better w.r.t. job-to-job alignment due to (1) their intended application, which includes media/objects that cannot be trimmed after printing and (2) the fact that they're usually aimed at a higher segment and are significantly more expensive, which can be seen as a proxy for better engineering.

Having said that, the flatbed printers I'm familiar with do not appear to be the sort that I would associate with your workshop. They're optimized for productivity, not necessarily image quality. But my familiarity with them is superficial, I admit.

 

[gbroadbridge]

I use a Epson P7000 surecolor to make my digital negatives. When doing separation negatives we sometimes see a .05 - 1mm discrepancy between image negs. Usually this discrepancy is in the direction the film travels through the printer and usually when we gang one image above the other using print tool.
Has anyone else seen this issue.?

Perhaps the roller transport system needs a clean or service?

I don't know how much work you run through the printer, but I've replaced rubber rollers on high end Canon systems in the past.

 

[Carnie Bob]

My advice would be to contact the manufacturer and request data on the performance of the machine in this regard. I can imagine that flatbed printers might perform better w.r.t. job-to-job alignment due to (1) their intended application, which includes media/objects that cannot be trimmed after printing and (2) the fact that they're usually aimed at a higher segment and are significantly more expensive, which can be seen as a proxy for better engineering.

Having said that, the flatbed printers I'm familiar with do not appear to be the sort that I would associate with your workshop. They're optimized for productivity, not necessarily image quality. But my familiarity with them is superficial, I admit.

I am looking at flatbed (miminika) now and the possible problem may be inkset or final print quality vs an Epson. I have not seen the Epson version of flatbed which is about 30% more expensive to evaluate final print quality, Both units are in my bucket list but will take a lot of testing to see if we would commit.
Clay Harmon on another platform mentioned he too has seen this problem , hit and miss and he did not see a solution.

 

[Carnie Bob]

Perhaps the roller transport system needs a clean or service?

I don't know how much work you run through the printer, but I've replaced rubber rollers on high end Canon systems in the past.

I would not know how to look at this potential issue but worth calling my Epson freelance tech, we use this machine four or five days a week.

 

[koraks]

Bob, in general the inkjet flatbed printers are aimed at applications like signage; I see the Epson flatbeds are also UV-gelling ink systems that's consistent with this application field. This means they are optimized for productivity and media compatibility, with an ability to print on virtually any kind of surface (wood, tiles, plastics etc.) The consequence is that the optimization is not in the alignment of the color channels, droplet size, and bleed behavior. Overall, you can expect prints from these systems to look decidedly more coarse with higher risk of banding under certain conditions (although they have improved over the last 15 years).

The take-away is that before investing, please be sure to carefully evaluate the product you're considering and make test prints, especially also on transparency media, and print these negatives with your process so you know what the final output is.

Btw, the advantage of these UV-gelling ink systems is that you may no longer be held to dedicated inkjet transparency materials (i.e. the milky kind of Pictorico, Fixxons etc. film you're using presently), and could likely use a wider range of transparent plastic sheets regardless of their intended application. However, the question is whether this benefit is very relevant as the inkjet media we generally use are perfectly fine as long as they don't get wet.

Please keep in mind when talking to tech reps in the inkjet sector that they probably are totally clueless about what you are doing with these printers and they likely are not capable of advising well on the specific requirements in your use-case. None of these printers are designed with the creation of digital negatives in mind. Inkjet printers happen to work for this, but are never optimized for it.

 

[Carnie Bob]

Bob, in general the inkjet flatbed printers are aimed at applications like signage; I see the Epson flatbeds are also UV-gelling ink systems that's consistent with this application field. This means they are optimized for productivity and media compatibility, with an ability to print on virtually any kind of surface (wood, tiles, plastics etc.) The consequence is that the optimization is not in the alignment of the color channels, droplet size, and bleed behavior. Overall, you can expect prints from these systems to look decidedly more coarse with higher risk of banding under certain conditions (although they have improved over the last 15 years).

The take-away is that before investing, please be sure to carefully evaluate the product you're considering and make test prints, especially also on transparency media, and print these negatives with your process so you know what the final output is.

Btw, the advantage of these UV-gelling ink systems is that you may no longer be held to dedicated inkjet transparency materials (i.e. the milky kind of Pictorico, Fixxons etc. film you're using presently), and could likely use a wider range of transparent plastic sheets regardless of their intended application. However, the question is whether this benefit is very relevant as the inkjet media we generally use are perfectly fine as long as they don't get wet.

Please keep in mind when talking to tech reps in the inkjet sector that they probably are totally clueless about what you are doing with these printers and they likely are not capable of advising well on the specific requirements in your use-case. None of these printers are designed with the creation of digital negatives in mind. Inkjet printers happen to work for this, but are never optimized for it.

Thanks Koraks - I actually am doing tests with known media with the manufacturer who is willing to see if they can help me. I am wondering why there would be a difference in resolution quality of a good epson that I currently and a flattop unit. I am wondering if the head is different animal.
Good call on the milkiness of the current transparency media, I suspect I can find a much more suitable support. I did make lambda negatives silver in the past which had none of the issues I am finding with inkjet, but when it works it really works(inkjet)
If I was into polymer plate photogravure, which is very interesting, one of these units would be very desirable for many reasons.

I saw a Swiss Q in operation in Brooklyn last year and it was pretty amazing with options and quality but the price range does not make sense for my small production team.

 

[koraks]

I am wondering if the head is different animal.

The whole machine is a different animal. Observe that it starts at a very fundamental level with a different ink system: regular photo inkjet printer use an aqueous ink, these flatbeds use UV-gelling inks, which have different jetting properties and thus different requirements on nozzle geometry, piezo control etc. As said, it's made for an entirely different market and application domain.

As to the head - keep in mind it's really not just the head that determines critical performance aspects like banding, although the head will virtually guaranteed to be different to the head in your existing printer (because: different ink system, different productivity requirements). E.g. motion control (how the head moves) is particularly crucial for banding issues as well as the degree to which vibrations are avoided or dampened. So it's really not just the head - or even the printer. To understand the performance, you need to observe the system as a whole, including media and ink.

I don't know what the print quality on these Epsons is specifically, but given the fundamentally different nature of these printers compared to the desktop and (relatively) small printers we typically use in a photographic practice, my recommendation (which you also recognized) is that it's essential to test before purchasing, and especially not to assume that the printing behavior will be similar to your existing Epson just because the printer has the same brand name.