Digital Negatives, QTR, and the 3800

[andy138]

I just bought a 3800 and downloaded QTR for making digital negatives.

I read through Ron Reeder's PDF on how to create your own profiles in QTR for digi negs. As far as I can tell I followed his instructions exactly and created a test profile and attempted to print his supplied step wedge on inkpress transparency. When I printed the first one, the ink was laid down FAR too thick and it would simply smear off. My first thought was I printed on the wrong side of the media, nope. (Also tried a sheet of OHP so I KNEW I had the right side, same thing happened). Then I thought it had to do with the media type under printer features. I tried transparencies and matte paper. Neither helped. Then I thought maybe it was because I was trying to use matte ink on a glossy surface, so I switched inks, that didn't help. I looked back to the profile text file and it looked ok to me, nothing was not set, or set too high (at least to my eye, I'm new at this). I reinstalled the profile and tried one more time. Same thing, ink puddles that smeared easily. I even tried an ordinary positive print on epson media using epson drivers just to rule out a problem with the printer. That print looks lovely. So if you've actually read through all this crap and have any advice I would love to hear it.

Andy T.

 

[clay]

Can you post the profile so we could take a look at it? I have had very good luck using QTR

I just bought a 3800 and downloaded QTR for making digital negatives.

I read through Ron Reeder's PDF on how to create your own profiles in QTR for digi negs. As far as I can tell I followed his instructions exactly and created a test profile and attempted to print his supplied step wedge on inkpress transparency. When I printed the first one, the ink was laid down FAR too thick and it would simply smear off. My first thought was I printed on the wrong side of the media, nope. (Also tried a sheet of OHP so I KNEW I had the right side, same thing happened). Then I thought it had to do with the media type under printer features. I tried transparencies and matte paper. Neither helped. Then I thought maybe it was because I was trying to use matte ink on a glossy surface, so I switched inks, that didn't help. I looked back to the profile text file and it looked ok to me, nothing was not set, or set too high (at least to my eye, I'm new at this). I reinstalled the profile and tried one more time. Same thing, ink puddles that smeared easily. I even tried an ordinary positive print on epson media using epson drivers just to rule out a problem with the printer. That print looks lovely. So if you've actually read through all this crap and have any advice I would love to hear it.

Andy T.

 

[seans]

Can you post the profile so we could take a look at it? I have had very good luck using QTR

Clay - by any chance do you have a QTR 3800 profile? I have just started this process this week but would appreciate if someone had a curve to start with.
Thanks for any help!
Sean

 

[andy138]

The profile is on another computer, but I will post it as soon as I am able to get access to it. I'm thinking of using one of the profiles that came with the rip and leaving it alone (just deleting out aspects that dont pertain to negatives i.e. toning info) and printing a step wedge on OHP and just using that as a starting point. Will one of those profiles, maybe something simple like enhanced matte, be close enough to give me something to work off of?

 

[clay]

Yes. Especially if you convert your grayscale file to RGB before printing it. This is what Kerik is doing very successfully with that printer. All you need to add is a curve prior to printing.

The profile is on another computer, but I will post it as soon as I am able to get access to it. I'm thinking of using one of the profiles that came with the rip and leaving it alone (just deleting out aspects that dont pertain to negatives i.e. toning info) and printing a step wedge on OHP and just using that as a starting point. Will one of those profiles, maybe something simple like enhanced matte, be close enough to give me something to work off of?

 

[andy138]

Well I successfully printed a neg with QTR, haven't tested on vandyke emulsion yet because im still waiting for more to come. I think the key was, as many of you said, Ron's guide was for the 4000 which lays ink down much differently than the 3800. I used an RGB file and the enhanced matte curve in QTR, the neg looks ok, might need some boost in the shadows, and i dont have a UV densitometer to read the dmax, but that brings me to my question. is there any real advantage or disadvantage to deriving a correct curve in photoshop and applying it to the image rather than creating a custom profile with the curve embedded in that and having the rip handle it?

Andy

 

[donbga]

Well I successfully printed a neg with QTR, haven't tested on vandyke emulsion yet because im still waiting for more to come. I think the key was, as many of you said, Ron's guide was for the 4000 which lays ink down much differently than the 3800. I used an RGB file and the enhanced matte curve in QTR, the neg looks ok, might need some boost in the shadows, and i dont have a UV densitometer to read the dmax, but that brings me to my question. is there any real advantage or disadvantage to deriving a correct curve in photoshop and applying it to the image rather than creating a custom profile with the curve embedded in that and having the rip handle it?

Andy

Andy,

It's best to let QTR to the heavy lifting and tweak if necessary with a process adjustment curve in PS.

I don't want to sound discouraging but it's not likely that a profile/curve made for EEM will produce a good print on the first pass. Most likely you will need to adjust the DEFAULT_INK_LIMIT to determine the proper amount of ink to print pure white in your print, or a very light tone.

Since you do not have a UV densitometer you will need to make test prints to determine your basic ink limits. Rather than using an image file initially I would print a digital step tablet since this will give you solid feedback about how your QTR curve is working for the VDB process. A UV densitometer only serves as a guide anyway, the proof os in the print.

You should plan making several tests initially, working itteratively. Ron's guide is a good howto to get started in the right direction.

The best thing is to relax and prepare your self for some testing. If you want to test print an image make small prints. It will save you from wasting materials until you get your bearings.

Good luck,

Don Bryant