Digital negatives for carbon transfer printing:Agfa Copyjet / QTR / Epson 2100 (2200)

[Tom Kershaw]

I've started to consider producing digital negatives for carbon transfer printing, especially while learning, (less potential damage to original camera 8"x10" negatives), from 120 format scans. I do however have a few questions:

1. After firing up the Epson 2100 for the first time in a few months and printing with the Harman Crystaljet paper (much sharper print at 360 dpi compared to 300 dpi) I noticed that even at the very finest setting some dither / dot pitch is visible in the lightest areas. As Quad Tone RIP controls the printer externally to the Epson drivers, is this dither pattern something to be concerned about (i.e. will it show up) on the final carbon print?

2. If I do decide to make digital negatives I intend to start with Agfa Copyjet. Is there anything about the Agfa film that prohibits its use for making digital negatives for carbon prints that I've missed?

Tom

 

[jeffreyg]

Tom,
Checkout Dan Burkholder - he has a Photoshop app for making digital negatives for contact printing. It is very easy to use although you may find some tweeking ie contrast etc might be necessary to get the results you want. It is inexpensive ( about $20 ) when I purchased it.
Jeff

 

[sanking]

I've started to consider producing digital negatives for carbon transfer printing, especially while learning, (less potential damage to original camera 8"x10" negatives), from 120 format scans. I do however have a few questions:

1. After firing up the Epson 2100 for the first time in a few months and printing with the Harman Crystaljet paper (much sharper print at 360 dpi compared to 300 dpi) I noticed that even at the very finest setting some dither / dot pitch is visible in the lightest areas. As Quad Tone RIP controls the printer externally to the Epson drivers, is this dither pattern something to be concerned about (i.e. will it show up) on the final carbon print?

2. If I do decide to make digital negatives I intend to start with Agfa Copyjet. Is there anything about the Agfa film that prohibits its use for making digital negatives for carbon prints that I've missed?

Tom

I have made many carbon prints from negatives produced with the 2200 (same as 2100 I believe). The dithering pattern does not show on the print, perhaps because I always use a thin sheet of mylar between the senstized tissue and the negative during exposure.

My suggestion would be that you learn to use QTR as it will give you much greater flexibility than the Burkholder method.

Sandy King

 

[Tom Kershaw]

Sandy,

I've just downloaded the QTR software and printed out the Mac OS X print tutorial. I found 'The QuadTone RIP manual - Using QTR to make optimal digital negatives' by Ron Reeder, February 2009; which appears to be useful, although the author bases the tutorial around the Epson 3800.

Tom

 

[Bob Carnie]

Tom
I saw Kerik, David, and Sandy pounding out digital negatives at Photostock, and have to say was very impressed with QTR 's ability to make negatives for alternative processes.
David has run a script that is completely amazing , but I am not sure if he visits this site.

 

[Tom Kershaw]

Tom
I saw Kerik, David, and Sandy pounding out digital negatives at Photostock, and have to say was very impressed with QTR 's ability to make negatives for alternative processes.
David has run a script that is completely amazing , but I am not sure if he visits this site.

David A. Goldfarb?

 

[sanking]

Sandy,

I've just downloaded the QTR software and printed out the Mac OS X print tutorial. I found 'The QuadTone RIP manual - Using QTR to make optimal digital negatives' by Ron Reeder, February 2009; which appears to be useful, although the author bases the tutorial around the Epson 3800.

Tom

Using QTR with the Epson 2100 is not all that different from using it with the 3800. I still use the 2200 (same as 2100 I believe) for printing some of my digital negatives and have a profile for printing carbon I would be happy to send you. However, it prints with very high contrast (about log 2.80 with PK ink, log 3.4 with MK) so you would need to use a tissue similar to mine and sensitize as I do in order to use the profile. Let me know if interested.

Sandy King

 

[sanking]

Tom
I saw Kerik, David, and Sandy pounding out digital negatives at Photostock, and have to say was very impressed with QTR 's ability to make negatives for alternative processes.
David has run a script that is completely amazing , but I am not sure if he visits this site.

Bob,

Exactly what does the script do?

Sandy

 

[Tom Kershaw]

Sandy,

I would be very interested to see your profile. Thank you. Even if I may not be able to use it directly for my workflow it might be useful for guidance.

I'll pm you my e-mail address.

Tom.

 

[clay]

Sandy, the script is a Javascript routine that Ike (David Eisenlord) wrote that will allow you to do a flatbed scan of a 21 step test print using your QTR digineg preliminary profile and then create a curve that can then be inserted in your QTR profile to linearize it. Basically makes the whole thing a closed loop. Find an ink combination that gives you the desired transmission Dmax for your process - in my case about 2.9-3.0 for palladium, then print the 21 step pattern on your pictorico with no curve applied. Then print it in your desired process, dry it and scan it. Bring the scan into photoshop and then run this little routine on it and it will calculate the curve necessary to imbed in your QTR profile that will linearize it. Easy as pie.

I think we need a QTR summit with Ron Reeder and Ike and any other interested people where we can spend two or three days and systematize this process for the average user. It is incredibly powerful, but a little intimidating for the beginner.

 

[Tom Kershaw]

Clay,

Is this script available?

Tom

 

[Bob Carnie]

Thanks Clay
I could not have given this response.Even though I watched it in use while David and Kerik were making negs.
Bob

Sandy, the script is a Javascript routine that Ike (David Eisenlord) wrote that will allow you to do a flatbed scan of a 21 step test print using your QTR digineg preliminary profile and then create a curve that can then be inserted in your QTR profile to linearize it. Basically makes the whole thing a closed loop. Find an ink combination that gives you the desired transmission Dmax for your process - in my case about 2.9-3.0 for palladium, then print the 21 step pattern on your pictorico with no curve applied. Then print it in your desired process, dry it and scan it. Bring the scan into photoshop and then run this little routine on it and it will calculate the curve necessary to imbed in your QTR profile that will linearize it. Easy as pie.

I think we need a QTR summit with Ron Reeder and Ike and any other interested people where we can spend two or three days and systematize this process for the average user. It is incredibly powerful, but a little intimidating for the beginner.

 

[Bob Carnie]

A summit at Photostock 2010 is fine with me , I would love to spend more time with like minded individuals.
David Eisenlord basically blew me away with his easy approach to this subject, enough to want him in Toronto to help set up my Lambda negatives, I hope to get him here in the early winter.

 

[PVia]

ChartThrob is an available script for Photoshop that does something similar.

Google it, download it and check it out...works with CS2 and later.

The whole digi-neg process is very intimidating at first, but you're doing the right thing by asking questions, reading everything about QTR, reading all of Ron Reeder's info...

It will take a while to wrap your head around it all, and testing your negs/prints, but in the end it is all so worth it.

 

[Jim Cole]

Using QTR with the Epson 2100 is not all that different from using it with the 3800. I still use the 2200 (same as 2100 I believe) for printing some of my digital negatives and have a profile for printing carbon I would be happy to send you. However, it prints with very high contrast (about log 2.80 with PK ink, log 3.4 with MK) so you would need to use a tissue similar to mine and sensitize as I do in order to use the profile. Let me know if interested.

Sandy King

Sandy,

Could I get you to send the profile to me as well? I am just going to start experimenting with digital negatives and want to give my 2200 as well as my Z3100 a try.

Thanks,
Jim

 

[sanking]

Sandy,

Could I get you to send the profile to me as well? I am just going to start experimenting with digital negatives and want to give my 2200 as well as my Z3100 a try.

Thanks,
Jim

Sure,

Send me your email address in a pm.

Sandy

 

[Ron-san]

ChartThrob is an available script for Photoshop that does something similar.

Friends--

I think you are missing something in this rush to automate formation of the correction curve (whether in Chartthrob or to make a corrective gray curve for QTR). In my experience consumer flat bed scanners very often give erratic readings-- maybe the fault of the scanner, maybe the problem with scanning a not quite flat piece of matte paper-- who knows? But if you blindly let a black box function create and insert a curve into your profile, you run a real chance of getting garbage back out. I find value in making the readings by hand (you can use some judgement in which points to believe and which to reject). Also I like to see the finished curve before it is inserted into the profile. At that point I have a chance to smooth the curve by hand if needed. If you do not understand the process enough to make the curve by hand, then chances are you have not learned enough to trouble shoot it and decide where it needs fixing.

In short I am suspicious of this type of shortcut.

However, I also think there are ways to simplify deriving QTR profiles and would greatly enjoy a brainstorming session with like minded folks. How and where do we get together?

Cheers, Ron Reeder

 

[Kerik]

Ron - just to clarify, Ike's script only generates the curve. You then manually tweak the curve as necessary in Photoshop, save the .ACV, then bring it into your ink descriptor file manually (edit the .TXT file on a Mac, or use the QTRgui on a PC). Plus, you can then re-run the script on your next stepwedge print and check to see if you've hit linearity.

 

[Ron-san]

Ron - just to clarify, Ike's script only generates the curve. You then manually tweak the curve as necessary in Photoshop, save the .ACV, then bring it into your ink descriptor file manually (edit the .TXT file on a Mac, or use the QTRgui on a PC). Plus, you can then re-run the script on your next stepwedge print and check to see if you've hit linearity.

OK, as usual my initial assumption was a bit off the mark. So this script saves you 3-5 minutes with pencil and paper? Wahooo! sign me up. Cheers, Ron Reeder

 

[Tom Kershaw]

Ron,

How essential is a densitometer in the process of calibrating the process? I understand how it could be helpful, but is it realistic to hope to produce good digital negatives via Quadtone RIP without one?

Tom

 

[PVia]

There are so many methods of arriving at good digital negatives and it seems everyone does it a bit differently and all I've seen produce great results.

A densitometer is definitely not necessary. It might be nice to have one and could make life easier if you follow a particular methodology but there is no great abiding reason to own one to make digi-negs in particular.

 

[PVia]

Also, re ChartThrob mentioned above...it also generates a curve for any process and helps with linearization. The curves are all smooth-able by hand if needed.

There's a huge thread here on the script if you search for it.

Kerik's post above describes the process for bringing it into QTR.

 

[Ron-san]

Ron,

How essential is a densitometer in the process of calibrating the process? I understand how it could be helpful, but is it realistic to hope to produce good digital negatives via Quadtone RIP without one?

Tom

Tom--

You do not need a densitometer. A consumer grade flat bed scanner works just as well. The method is described in the QTR manual, v3, free from my website ronreeder.com

Cheers, Ron Reeder

 

[Kerik]

Well Ron, there's nothing to sign up for and it may seem worthless to you, but the script saves most people WAY more than five minutes. I've taught this QTR approach for over a year now in about 8 workshops, and I've found it's VERY intimidating for most beginners. What seems trivial to those in the know can seem impossible to those who aren't.

 

[jag2x]

Hi Ron,
QTR manual v3 you say? I'm not sure where on your qtr website it is?
Cheers
jacek