Tiny Dot-line on the OHP with Epson 3800

[Ben Altman]

First, so far as I know it is not possible to slow down the printing speed with QTR. You can slow down the speed if you print with the Epson driver but I don't think there is any way to do it with QTR. I actually asked this question on the Quadtone RIP group on Yahoo and so far no one has offered a solution.

Sandy King

Hi All, I've been doing other things for a bit but now getting back into QTR etc. I just bought a 3800 cuz the price was so low (or will be when I get my rebate...).

Anyway I can tell you that it is possible to increase the drying time with QTR - having just read the manual and tried it. All you have to do is set up a Special Paper Configuration (page 45 in the spiral bound handbook) and then select that configuration FROM THE PRINTER. This overrides the configuration in the driver. Didn't seem to help the pizza tracks much, but I didn't really work with it. Could be that opening up the paper thickness or platen gap controls (on the same menu) would help, but that may mess up something else...

Best, Ben

 

[Andrew Ren]

Kerik,

I don't know why. two of those(8 or 9 8x11) test prints are ok, I really mean it turned out pretty well. all the rest were ugly. they have been tossed on the coffee table for weeks and I even don't want to look at them.
have to encourage myself to start from the scratch again.
1. set the exposure as 200unit on the nuarc instead of 275unit, as I found there is some solarization again.

2. I think Colin is right, what can I do to avoid the steep curve on the darker size to save some loss? I think I am the one to test it all out, eh?

3. I am thinking Clay's suggestion, after found the final "right" exposure time, might decrease the exposure time for 2%-5% see what's the difference? or just pull the print out off the potassium developer quicker instead of waiting its full-development?

and this is for clay, I remember you mentioned that set the input level and let the output to 96%, what do you mean? you mean in QTR? I don't recall there is such adjustment...


Thanks ALL!


Andrew

-----

sorry, just noticed i was off the topic a little bit, here we are talking about the PIZZA wheels. as the front load is the way to go.

 

[R Shaffer]

One thing I recently did is create this multiple 21 step test sheet. I coat a single sheet and then alter the exposure on each strip. It helped me to get my curve dialed in and a solid exposure time to go with it. I was going crazy with what I thought was my minimum exposure time maximum black for OHP & pd. Turned out I needed a longer exposure and then things fell into place.

 

[Kerik]

Andrew...

1. Solarization is not necessarily an exposure issue. It's often caused by too little sensitizer and/or spreading it too thin. You need to give enough exposure to overcome the base fog of your clear film.

2. I'm not quite sure what you're asking... what loss are you trying to save? The comments regarding the amount of LLK black were in relation to lowering the amount of ink to prevent pizza wheel marks.

3. Pulling the print quicker out of the developer is NOT the answer. Development happens almost immediately and you can't pull it fast enough to have any real effect.

 

[Kerik]

Rob, this is a good idea. There's nothing wrong with giving a little more exposure than what is necessary to print through the base fog as long as the deep shadow values don't merge. However, if one gives less exposure then they will not reach maximum black anywhere in the image.

 

[R Shaffer]

Yes it was the shadows that were giving me grief. When I tried to reduce my ink level to get the shadows right, my hightlights & midtones got weak separation. My curve has pretty low ink volume, so by upping the exposure it all eventually balanced out. Definitely no pizza wheels though.

It also worked well when I was working on my three color gum curve. I think it's Loris who recommends using a cyanotype curve for gum. So I incrementally reduced the contrast in my cyanotype curve and tried it with gum & cyanotype. The shorter exposure with cyanotype compensated, to a point, for the lower contrast and it just reduced my deepest blue. But works great with the gum with a little extra exposure.

 

[clay]

No, I'm talking about an adjustment of the image in photoshop. When you do a levels adjustment on the image or on an adjustment layer (recommended non-destructive approach), you can modify the output levels. So what you would be doing is modifying the file so that wherever the image file reads 100% black, it will output the value 98% for example. So this would have the effect of changing the contrast in the shadow areas before the file is sent to the printer.

Kerik,


and this is for clay, I remember you mentioned that set the input level and let the output to 96%, what do you mean? you mean in QTR? I don't recall there is such adjustment...


Thanks ALL!


Andrew

-

 

[Colin Graham]

It's a great time-saver making arrays when profiling with QTR- I'll print out the same step wedge many times on a single sheet of OHP, each one with a different combination of ink, and then contact print and process them all at once- saves a lot of time zeroing in on the right balance. You can refine the stepwedge and print only shadow or highlights with expanded steps if that's where your troubles are and find any issues quickly.

 

[Andrew Ren]

Kerik,

what I mean is how to "Pre-modifying" the Non-curve profile i got from you, to get a smoother raw curve @ first hand.

Andrew

 

[Andrew Ren]

Rob,
this multi-wedge you created are the array of the same single step wedge, right? not like Colin mentioned of printing each wedge with different ink profile, baked with one standard exposure time and see which one is smoother on the first hand then which one is more linear after apply the correction curve.

your purpose on that is just to determine the right base exposure time?

sorry, I am very frustrated on this and now my brain is run low and slow...

Andrew

 

[Andrew Ren]

Clay,

again, do you mean change the numbers on the output? can you describe it with more detail should you don't mind?


Thanks.

Andrew

 

[clay]

Just 'squeeze' the image a little. What once was a 100% black will now be a 97%. See the dialog box for a levels adjustment posted below

Clay,

again, do you mean change the numbers on the output? can you describe it with more detail should you don't mind?


Thanks.

Andrew

 

[R Shaffer]

Rob,
this multi-wedge you created are the array of the same single step wedge, right? not like Colin mentioned of printing each wedge with different ink profile, baked with one standard exposure time and see which one is smoother on the first hand then which one is more linear after apply the correction curve.

your purpose on that is just to determine the right base exposure time?

sorry, I am very frustrated on this and now my brain is run low and slow...

Andrew

Ciao Andrew,

Yes, I just copied the 21 step wedge from Ron Reeders fine website and then copied & pasted it multiple times in a single file. Just make sure you save it as a .tiff without compression.

What you'll see with the different exposures is the tones will be shifted, more white squares on the under-exposed strips and more dark squares on the over-exposed strip. Just make sure your least exposure is well under what you think you need and the maximum is way way over what you think you need.

With a bit of luck, one of them will look pretty good. Check the max black on that strip and make sure it's hit your max black. Then try and tweek your curve for that strip. After tweeking, print with multiple exposures again, but you tighten the exposure steps. After two runs, you should have your exposure nailed. Then use Colins' suggestion, and print several curves on a single sheet of OHP and expose it. If you got a curve that is close, just go make a print & screw the curve. It don't need to be perfect to make a cool print.

So patience, patience, patience.

PS: My wife laughs at me all the time when she peeks at my creations and sees that they are nothing but TEST STRIPS.

 

[clay]

This advice should be in bold! The best single piece of advice in this thread, in my opinion. And remember you are trying to fine tune a hand-coated process with more than a few variables. At some point, your printing chops will do you a lot more good than a perfect curve.

If you got a curve that is close, just go make a print & screw the curve. It don't need to be perfect to make a cool print.

 

[sanking]

This advice should be in bold! The best single piece of advice in this thread, in my opinion. And remember you are trying to fine tune a hand-coated process with more than a few variables. At some point, your printing chops will do you a lot more good than a perfect curve.

Completely agree. It seems that many alternative printers who start with digital negatives rely much to heavily on digital controls to fine tune their negative rather than on printing controls. It happens not infrequently that I will make a digital negative that does not print exactly as I expected, but the "printing chops" from past experience allow me to apply contrast and exposure controls to get the print I want without making another negative. This works out much better an economic point of view because a little more dichromate in the sensitizer is a lot less expensive than a sheet of 13X19" Pictorico, or the equivalent.

Sandy King

 

[Colin Graham]

It don't need to be perfect to make a cool print.

With respect, for some anal folks like me it do need to be perfect.

Of course, everyone has different goals and different approaches. What I love about the digital approach is it's potential to give perfectly repeatable and expected results every time.

 

[Andrew Ren]

Got it clay.

Andrew

 

[Andrew Ren]

Thanks Rob.

Andrew

 

[sanking]

With respect, for some anal folks like me it do need to be perfect.

Of course, everyone has different goals and different approaches. What I love about the digital approach is it's potential to give perfectly repeatable and expected results every time.

That is one of the main reasons I switched to digital negatives some years ago. However, while you can get great consistency in making digital negatives it is very difficult to get 100% consistency with hand made proceses. For that reason it is very important to have full control of the process in order to make adjustments in exposure and contrast that may result from conditions beyond our control.

Sandy King

 

[PVia]

That is one of the main reasons I switched to digital negatives some years ago. However, while you can get great consistency in making digital negatives it is very difficult to get 100% consistency with hand made proceses. For that reason it is very important to have full control of the process in order to make adjustments in exposure and contrast that may result from conditions beyond our control.

Sandy King

Yes Sandy...however, after having seen the Irving Penn exhibit (252 silver and platinum prints!) currently at the Getty, I must say that the gentleman had a ridiculous amount of consistency in traditionally enlarged negatives, and many times he'd print a single platinum print from several negatives tailored to specific tonal areas of the print...my God!

 

[sanking]

Yes Sandy...however, after having seen the Irving Penn exhibit (252 silver and platinum prints!) currently at the Getty, I must say that the gentleman had a ridiculous amount of consistency in traditionally enlarged negatives, and many times he'd print a single platinum print from several negatives tailored to specific tonal areas of the print...my God!

Granted, but we don't know what proces adjustments the printer made in printing the work. I suspect that if were had a log to his printing of each of the prints you would see a lot of contrast and exposure adjustments, and probably some dodging and burning.

Sandy

 

[PVia]

Penn experimented so extensively it would put even the most insane gum printer to shame...I've seen some of his notes, almost indecipherable, but notated so many different combinations on one page that it's mind boggling. In fact, there's a page of notes in one of his books, A Notebook At Random...

 

[Ben Altman]

Yep, use the front feeder. The matte black (which I use for digi-negs) does the same thing if using the auto sheet feeder.

You can use an 11x17 sheet of light cardboard as a base for the film to use in the front feeder, since the feeder likes to see a thicker media there. I put a few tiny pieces of double stick tape in a few spots along the edge, out of any image area, to help the OHP stick to the cardboard backing as it goes through the printer.

A word of caution - I didn't stick the OHP down thoroughly enough yesterday and it caught the head, causing a nasty noise and an error message telling me to send the printer back for service. Then I found a tiny coil spring in the output tray... Printer still seems to work, so I have my fingers crossed. Moral - stick the OHP down well, particularly the sides!

 

[sanking]

A word of caution - I didn't stick the OHP down thoroughly enough yesterday and it caught the head, causing a nasty noise and an error message telling me to send the printer back for service. Then I found a tiny coil spring in the output tray... Printer still seems to work, so I have my fingers crossed. Moral - stick the OHP down well, particularly the sides!

This is one of the reasons I prefer to use the sheet feeder if posssible. A couple of years ago the OHP got caught when I was using the front feeder and it put it out of service. HP replaced it but it has made me cautious about using the front feeder with the 3800.

Sandy King

 

[pschwart]

This is one of the reasons I prefer to use the sheet feeder if posssible. A couple of years ago the OHP got caught when I was using the front feeder and it put it out of service. HP replaced it but it has made me cautious about using the front feeder with the 3800.

Sandy King

I rarely use the front feeder on the 3800 -- even with paper, it often misfeeds and returns a skewed paper error. The 3800 has more features than the cheap desktop printers, but the build quality doesn't appear to be any better.