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QCDN for non Ilford paper?

Petr Slunecko All Messages By This Member #19168 Hello, ? I would like to start using digital negative for silver gelatin prints, printing on Fomatone Multi-Grade papers which I use for my work. I have no experience with DN and would appreciate if anybody can help me with answering following questions... ? 1) I wonder if QCDN could be used to adapt its Ilford starter curve to this, or any other MG paper. Or do I need to consider the Pro version to built curve from scratch since my paper can behave totally different? ? 2) I try to read up on the whole process of creating DN but I got confused by QCDN documentation on Establishing Your Base Exposure page with following text: ? ... Start with a grade 0 or even 00 filter to activate the low contrast emulsion and then use the magenta inks along with the gray and black inks to activate the high contrast emullsion to reach a full range of tones. Link: ? I think I understand the logic behind determining base exposure, blocking density, starter curve and and its subsequent linearisation however I am not clear on - ? 2a) whether I set my enlarger to grade 2 during the whole QCDN calibration process and then just use enlarger gradation to control the print contrast.? ? 2b) or whether there is actually no need to play with gradation since any contrast is set in photoshop when making DN and using correct curve it nicely translates to the print and no further contrast adjustments are needed (but still G2 is used for calibration).? ? 2c) or if I perform calibration using low-contrast grade (as suggested above, 0 or 00) and then somehow combine it with adding magenta into the mix to achieve different contrast? ? I am sorry if these questions are out of place or just plain stupid. I feel I need to understand how playing with magenta inks relates to DN curve I assume gets primarily created with K, LK, LLK inks and how it all relates to gradation of MG papers. ? Regards, Petr ? PS: I use Epson P600 and plan to use Pictorico OHP media. ?
Christina Z. Anderson All Messages By This Member #19181 开云体育 Peter, You do not need the Pro version to make curves. QCDN works fine for BW. Here are some steps that will help, below, but generally the reason why I engage the filter in the enlarger is that it gives me the choice to lower or raise contrast if I want to on a particular image. I have one profile I have calibrated for each paper (Ilford WM, Reg, Foma, etc.) and any fine tuning is done at the enlarger if I want, but usually not needed since my initial profile was calibrated with the 2 filter in place. I hope that makes sense. Chris When ready to print the negative in the darkroom, always set up the enlarger the same way to achieve consistent results. ? The bottom of the enlarger head rests at the same height (about 25? from lens to contact frame) ? The lens is set to the same f-stop each time, e.g. wide open or a stop or two down ? The light path is focused to cover the entire contact printing frame ? The filter pack is set at a 2 filter and the filter pack is engaged. Example: with an enlarger raised to 25? from lens to contact frame, a 50 mm lens wide open to f2.8, a 35 mm carrier in the enlarger head, Ilford MGIV will expose in 20–25 seconds and Ilford Warmtone in 32–40 seconds. With the same setup, but a 150 mm lens set to f5.6, and a 4??~ 5? negative carrier in the enlarger head, Ilford MGIV will expose in 8–11 seconds and Ilford Warmtone in 12–16 seconds. ? ? ? From: [email protected] <[email protected]> on behalf of petr.slunecko via groups.io <petr.slunecko@...> Date: Thursday, October 24, 2024 at 12:08?PM To: [email protected] <[email protected]> Subject: [QuadToneRIP] QCDN for non Ilford paper? Hello, ? I would like to start using digital negative for silver gelatin prints, printing on Fomatone Multi-Grade papers which I use for my work. I have no experience with DN and would appreciate if anybody can help me with answering following questions... ? 1) I wonder if QCDN could be used to adapt its Ilford starter curve to this, or any other MG paper. Or do I need to consider the Pro version to built curve from scratch since my paper can behave totally different? ? 2) I try to read up on the whole process of creating DN but I got confused by QCDN documentation on Establishing Your Base Exposure page with following text: ? ... Start with a grade 0 or even 00 filter to activate the low contrast emulsion and *then use the magenta inks* along with the gray and black inks to activate the high contrast emullsion to reach a full range of tones. Link: ? I think I understand the logic behind determining base exposure, blocking density, starter curve and and its subsequent linearisation however I am not clear on - ? 2a) whether I set my enlarger to grade 2 during the whole QCDN calibration process and then just use enlarger gradation to control the print contrast.? ? 2b) or whether there is actually no need to play with gradation since any contrast is set in photoshop when making DN and using correct curve it nicely translates to the print and no further contrast adjustments are needed (but still G2 is used for calibration).? ? 2c) or if I perform calibration using low-contrast grade (as suggested above, 0 or 00) and then somehow combine it with adding magenta into the mix to achieve different contrast? ? I am sorry if these questions are out of place or just plain stupid. I feel I need to understand how playing with magenta inks relates to DN curve I assume gets primarily created with K, LK, LLK inks and how it all relates to gradation of MG papers. ? Regards, Petr ? PS: I use Epson P600 and plan to use Pictorico OHP media. ?
Richard Boutwell Member Profile All Messages By This Member #19192 Edited Yes, you can use the Ilford MG curves for any MG paper because they are all slight variations of a two layer emulsion with silver chloride for low contrast and silver bromide for high contrast that are activated by yellow/green or blue/magenta light, respectively.? The whole reason to use a low contrast filter in the enlarger stage (above the negative) is to minimize the contrast between the ink dots. The ink dots are high contrast, and when combined with a hard/glossy baryta paper surface won't get smoothed like they do with watercolor papers using hand-coated processes.? ? If you start with low contrast light coming through the gaps between the dots, the contrast of those gaps will be lower (and give you better shadow separation) and the higher overlapping ink load with the K and Lm/M inks in the midtones and highlights will activate the higher contrast emulsion to get a full tonal range in the print ? ? If you edit your image properly to get a full range of tones and built the contrast where you need it in the image, then there will be no need to change filters in the enlarger to throw off your well-calibrated curves. ? Hope that helps,? Richard Boutwell? ? ? ? ? ?
Richard Boutwell Member Profile All Messages By This Member #19193 Also. Use the Pictorico White Gloss Film for enlarging papers (as in Multi-grade chloro-bromide or graded pure silver-bromide papers) and Ultra-Premium OHP for contact printing papers (as in pure silver-chloride papers like Azo/Lodima/Lupex)
Petr Slunecko All Messages By This Member #19196 Arghhh... beginner's mistake I suppose, I've just bought A3+ Pictorico OHP and thought I would use it as a negative for contact print on silver gelatine enlarging paper (either Fomatone or Ilford) - would it work? Is the quality substantially different compared to White Gloss Film? ? My aim is to achieve similar quality to enlargements from 6x6 negatives in terms of tone and sharpness however I have no idea if that's at all achievable. ? How would you describe difference between OHP and white film for this purpose? ? Thanks! Petr ?
Petr Slunecko All Messages By This Member #19197 Oh ... so if I am getting this right, for the sake of example, I can calibrate QCND curve using either 0 or 2 grade filter during the calibration process and get the same looking image (if given image contrast is edited accordingly) but would get smoother gradation/less grain with 0 grade filter curve? ? So to find the sweet spot, would I start from 0 filter and only go up if required contrast can't be achieved using such curve? Or what would make me want to go above, except for the flexibility of being able to go up/down from grade 2 for example? ? When you say... ? If you start with low contrast light coming through the gaps between the dots, the contrast of those gaps will be lower (and give you better shadow separation) and the higher overlapping ink load with the K and Lm/M inks in the midtones and highlights will activate the higher contrast emulsion to get a full tonal range in the print ? ? ...how and when does it happen, that K/Lm/M inks will activate - does it happen automatically by the calibration process/algorithm when using grade 0 to compensate? ? Best Regards and count me in as QCDN customer :) ? Petr ? ?

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