Tri Tone Separation Masking

[inthedark]

I agree with Jorge's concept of bleaching, but I think there is an easier way. Simply underexpose by about one third to one half, then develop in soft developer over diluted by about 3-4 times. This allows lith film to become almost as variable as continuous tone film and thin is possible. Do not try to use regular strength and short time here or you will get uneven results, about 2-4 minutes depending on temp and very dilute. Test and see what gives the results you looking for.

 

[inthedark]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (dnmilikan @ Mar 4 2003, 01:30 PM)</td></tr><tr><td id='QUOTE'>
If my tests using paper developer do not give me what I need then I will explore the Kodak material. It is my understanding that Kodak has split the graphics materials off from the photographic materials operation. Thus it may be more difficult for me to get it. </td></tr></table><span class='postcolor'>
I purchase lith film regularly from Agfa and sometimes Kodak, if I may be assistance to you please let me know. And I also have never heard of dilute dektol giving strong lith film development. The rapid acces or lith works well. BUT if you must use dektol (I have sometimes when I have only one line negative to do and do not want to set up the rapid access) then let it sit in the developer at least 5 minutes. That is what it takes for the black to get completely rich and uniform.

 

[Donald Miller]

The instances in which I used dilute Dektol in conjunction with half-tone film is to give me a low contrast unsharp mask (positive of my camera negative) that I then print in register with my camera negative. The net result is to increase apparent sharpness on the print due to edge effects and to compress the contrast range of the camera negative by an amount equal to the net peak density of the mask produced. I then use additionally masking to expand the local contrast of either/both the highlight or shadow portions of the print which are located on the "toe" or "shoulder" where the slope is not nearly as pronounced as the straight line portion of the characteristic curve.

I have also used A-B developer at times when I want higher contrast from my masks. I have samples of new lith film coming to me for evaluation in separation masking of the camera negative into three distinct density ranges so that I may print these ranges (shadow, midtone, and highlight) at the appropriate contrast setting using variable contrast materials. In other words, I could print the shadow and highlight values at a grade 5 setting (for instance) and the midtones at a grade 1.5 (for instance). The tonal separation on the print would then be more straight line and this would quite effectively bypass the limitations of the characteristic curve of both the camera film and the printing paper.

Any thoughts that you may have regarding this process would certainly be welcome.

 

[inthedark]

Okay, Mr. Milikan, ***biting lip like a child*** I have never heard the term "grade n setting". Obviously I missed another basic. If convenient would you explain. I am hoping I know of the concept with different terminology. Thanks.

 

[inthedark]

Oh, my gosh, your name is Donald Miller, not Mr. Milikan. Excuse me! I must say though, your avatar makes me feel that I should be behaving respectfully when I type to you. Besides you seem to really know your stuff, that in and of itself deems respect. duh, well it is my night to feel stupid. I see you sign lots of your posts. Well I should have noticed sooner.

 

[Aggie]

..

 

[lee]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Darkroom ChromaCrafts @ May 6 2003, 02:53 PM)</td></tr><tr><td id='QUOTE'> </span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (dnmilikan @ Mar 4 2003, 01:30 PM)</td></tr><tr><td id='QUOTE'>
If my tests using paper developer do not give me what I need then I will explore the Kodak material. It is my understanding that Kodak has split the graphics materials off from the photographic materials operation. Thus it may be more difficult for me to get it. </td></tr></table><span class='postcolor'>
</td></tr></table><span class='postcolor'>
Kodak now has a division called KPG (KodakPolychromeGraphics) That is where all the graphics arts stuff is sold from. I think though you may need to find a dealer in your area that carries KPG stuff. Be warned that most of the materials now days are for electronic imaging. Imagesetters are the pre-press name of the game.


lee\c

 

[Donald Miller]

Aggie,
When one arrives at this point, I remember those who have said age is nothing more then "a state of mind"...let me tell you, in my experience that is rationalized b***s****. Then there are those who say that these are the "Golden Years"...I think that there is something called iron pyrite and I will give the folks expressing those sentiments the benefit of the doubt and consider that they may have been confused. I am quite sure that those who labeled the years "Golden" were damn sure not of my ilk.

Jill,
If anyone showed me respect, I would die of shock...so please don't do that to me. Now on to your question about my rambling on the products of an overactive mind.

The process that I want to develop is one in which a black and white camera negative is separated into three density regions for printing purposes. The reason being that when one looks at the characteristic curve of a film or paper we find that the curve is divided into three distinct regions. Those being the toe, the straight line, and the shoulder. In the case of film, the toe region is the area of lowest negative density and is the area on which the shadows are located, The degree of slope of this region is fairly flat and for that reason the tonalities of the shadow region are not as well differentiated, the straight line section has a more pronounced slope and the tonalities are more clearly separated, on the shoulder the slope is again flatter and the highlights that are represented here are again not well separated.

If one were able to create masks using lithographic film of each of these density regions, and printed the camera negative in register with each of these masks then the toe and shoulder region of the negative could be printed at a higher contrast filtration, using variable contrast paper. This higher contrast filtration would better separate the tonalities located in these regions. The midtone region where the degree of separation is more pronounced would then be printed at a lower contrast filtration then the toe or the shoulder regions.

In printing, this would involve three separate exposures through the individual masks followed by an exposure through an unsharp mask to blend the demarcation points of the individual masks and to increase the apparent print sharpness by the "edge effects" produced by such a mask.

I know that this process is possible, since it has been used by at least one other individual of which I am aware. The print quality was the best that I have ever witnessed, bar none. The materials used by this individual are closely protected and this is why I am engaged in seeking lithographic materials which will provide the sharp cutting and high contrast effect required for the production of the respective masks. As I mentioned yesterday, I do have a new material on the way to me for evaluation. Additionally, Les McClean has kindly volunteered to visit with the folks at Ilford. I am not sure whether Ilford is involved in graphics film manufacturing. I would appreciate any input that you may have, if you are aware of a graphics film/developer that would be applicable to this application.

I hope that I have made myself clear. Any thoughts, considerations etc. by any and all are greatly appreciated.

 

[inthedark]

Jeepers, creepers, I am a moron sometimes. I know what you need to do. Okay, if you want to use the line film for this it will actually be quite easy. Line/halftone films work as mentioned in an earlier post on the principle that only black and white exist. And you want to keep the solid rich black white contrast that is found when developed hard. Right?

Put a gray scale next to the image while masking. For highlights mask print the negative with the exposure/aperature dropped by about half. Develop as usual you will find a hard black that only "caught" the highlights. Use the grey scale to determine if the white/black break occurred where you wanted it.

Do the same for any level of midtones, then shoot reversals of those.

Line film sees white, it actually does not see black. So the longer it is exposed the more of the page/print will seem to be white to the film. Exposusre length for example is very different for bold type versus say wedding invite type even on same paper, same typesetter, etc.

Anyway this should work and I am stupid for not getting it yesterday. If I have time this weekend I will do some tests and try to post the results of the masks visually this weekend.

 

[inthedark]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (lee @ May 7 2003, 04:14 AM)</td></tr><tr><td id='QUOTE'> </span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Darkroom ChromaCrafts @ May 6 2003, 02:53 PM)</td></tr><tr><td id='QUOTE'> </span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (dnmilikan @ Mar 4 2003, 01:30 PM)</td></tr><tr><td id='QUOTE'>
If my tests using paper developer do not give me what I need then I will explore the Kodak material. It is my understanding that Kodak has split the graphics materials off from the photographic materials operation. Thus it may be more difficult for me to get it. </td></tr></table><span class='postcolor'>
</td></tr></table><span class='postcolor'>
Kodak now has a division called KPG (KodakPolychromeGraphics) That is where all the graphics arts stuff is sold from. I think though you may need to find a dealer in your area that carries KPG stuff. Be warned that most of the materials now days are for electronic imaging. Imagesetters are the pre-press name of the game.


lee\c </td></tr></table><span class='postcolor'>
Lee, I buy from the reprography racks at kodak and agfa so I have suppliers and it is not strictly for image setters.

Anyway, Don, if your greyscale is in place when you set for you masks you will be able to determine exactly where you "split" or "break" black and white, just do that where you want to. For a "proper" shot obviously the break would be between 5-6 on a 10 scale. Use less time to break it high and more to break it low. Process hard and or long for good density wear it is exposed and reacting

 

[inthedark]

Sorry, for these little add ons. I am trying to get ready for work and head off to get something done and think "OH!" one more thing. Use a continuous tone greyscale not a halftoned one. The half tone would probably give you some info but the continuous tone will be more accurate to your purposes.

 

[inthedark]

correction from earlier post (LOL) *where it breaks. You can tell I was getting dressed. tee heeeeeee gotta goooooo.

 

[Aggie]

Don,
you're right about just being. In my family we don't stop til they close the lid. My grandmother got a 10 speed bike for her 90th birthday. Why? she lived at an old peoples home in Denmark. She didn't want to ride the bus with all the other old ladies and be thought of as one of them. She wanted to be thought of as young. It didn't matter she was the oldest one at the home.

I have been told that our family all dies when we hit our 80's but we are so stubborn we refuse to lie down til we are over 110. Leaves a long time for photography for me. They better have film and chemisty around. I am stubborn enough and yell rather loud, I will demand my film.

 

[inthedark]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Aggie @ May 7 2003, 09:31 AM)</td></tr><tr><td id='QUOTE'> Don,
you're right about just being. In my family we don't stop til they close the lid. My grandmother got a 10 speed bike for her 90th birthday. Why? she lived at an old peoples home in Denmark. She didn't want to ride the bus with all the other old ladies and be thought of as one of them. She wanted to be thought of as young. It didn't matter she was the oldest one at the home.

I have been told that our family all dies when we hit our 80's but we are so stubborn we refuse to lie down til we are over 110. Leaves a long time for photography for me. They better have film and chemisty around. I am stubborn enough and yell rather loud, I will demand my film. </td></tr></table><span class='postcolor'>
Wow, I think your Grandmother rocks! Self-sufficient, and fixes what she doesn't like. You must have good genes. If your avatar is your image, then I am sure you must, because you seem to glow. MORE FILM! I can hear it now.

JL

 

[inthedark]

Don, this idea of yours is keeping me awake because I am so intrigued by its usefulness. Anyway I really think I have it figured out.

1. Take an underexposed shot appropriate to "blacken" only the highlights.

2. Take a neg of #1. Now you have a negative with "open" highlights to print only the highlights.

3. Take an overexposed shot so that all but the shadows are "blackened". Now you have a negative with "open" shadows.

4. Take a negative of #3.

5. Now stack #1 and #4 and take a negative of this which will give you "blacken" midtones.

6. Take a negative of 5 for open midtones.

There maybe now I can sleep. I will still test it if I have time this weekend. I hope it is okay that I ramble around about things online instead of waiting till I'm sure to post and then obviously repost and so on.

 

[Donald Miller]

Jill, I don't know that I follow your reasoning. I have a different idea of how to accomplish this, you tell me if it is possible to accomplish judging from your experience. O.K.?
1. Measure the density range of the camera (photographic) negative.
2. Taking a Stouffer 21 step tablet, shoot an exposure of the step tablet to determine an exposure that will expose the density range of the camera negative onto the lithographic film that you are using.
3. Make an unsharp mask of the photographic negative. (typical peak density of .35)
4. Taking the camera (photographic) negative, and register this with a sheet of unexposed litho film. Shoot an exposure through the camera negative to cover the density range of Zones I-III (example of densities .10-.35). Process the litho film. This will produce a positive (high density) of the low density areas of the camera negative.
5. Contact print this litho positive with an unexposed sheet of litho film to produce a negative of this positive. (This will become the mask, when place in register with the camera negative, through which one of the print exposures (shadow) is made.
6. Take the positive litho mask produced in step 3 and register this with the camera negative. (effectively blocks low density regions of the camera negative) and another sheet of unexposed litho film. Shoot an exposure to cover the densities of .10 through 1.00) Zones I through VI. Since we have blocked the low densities with the litho mask previously produced only the camera negative densities of .35 through 1.00 will be exposed. This will produce a positive of the camera negative.
7. Take the positive produced in step 5 and register it with an unexposed sheet of litho film, expose it to produce a negative of the positive. This will become the mask through which the midtones of the camera negative are exposed when producing the print.
8. Taking a Stouffer step tablet determine exposure on the paper used to cover the density range of the camera (photographic) negative.
9. Take the positive produced in step 4 and the positive produced in step 6 and register them with the camera negative. Dial in high contrast filtration and expose the highlights of the camera negative onto the printing paper. The high contrast will effectively separate the high values which are placed on the characteristic curve of the film's "shoulder".
10. Take the negative produced in step 7 and the positive produced in step 4 and register with camera negative and expose the enlarging paper with lower contrast filtration then the previous exposure. This produces the midtone print exposure. Since the midtone densities reside on the "straight line" portion of the film characteristic curve, they are typically already well separated.
11. Take the negative mask produced in step 5, register it with the camera (photographic) negative and expose the enlarging paper with high contrast filtration to create greater separation of the shadow ranges. Densities represented on the "toe" of the films characteristic curve.
12. Make an exposure with the unsharp mask( step 3) in register with the camera (photographic) negative. To blend the various demarcations that may exist in the previous exposures and increase the prints apparent sharpness through edge effects.

I might add. That the print exposures previously addressed would need to be adjusted by the peak density value of the unsharp mask (typically .35). Since this exposure will be added in the last (step 12) exposure.

The effects of this means of printing are to defeat the characteristic curve of the camera negative and to also create much more tonal separation throughout the print. (Open shadows and well separated tonality in the highlights).

This is where I am in the process. As a person working in graphics materials, does this seem plausible?

 

[inthedark]

Don,

I can say I think so, but you are using terms I am not quite sure. Let me try to replay in my pitiful wording and tell me if I understand.

Essentially, it appears that you are originally analyzing to find exposure goals.

1. Then you are doing my step 3 first, right? Over-expose (from what a 50/50 break would be), to expose all but the shadows. And the shadow is open.

2. Take a neg of #1, use this to block the shadow region for step three.

3. Repeat #1 with #2 registered over original neg and not such a high exposure such that the mid-range is printed.

4. Take a neg of #3. Midtones are open.

5. Use 1 & 3 registered over original negative to block shadow and midtone, take a neg, printing only highlights.

6. Take a neg of that, open highlights.

IF, this is what you are saying then I think we are doing the same basic thing from a different perspective, and yes I think yours would work fine and maybe even better.

My particular reasoning was simply based on #1 how to isolate the tone ranges (particularly the midtone) and #2 making sure they would be clear in the desired region rather than black.

In case you want to educate me. The wording I am intuiting, I think< but am not sure of are

peak density-is this the highest , lowest, or an aim density.

Stouffer 21 step tablet- is the a color/grayscale type of tablet?

Zones - again I am imagining that this refers to highlight vs midtone vs shadow but stepped with more than the three steps I appear to speak about.

JL

 

[Donald Miller]

Jill,
It seems to me that where we are failing to communicate is that the first generation mask of a camera (photographic) negative will be a positive. On a camera (photographic) negative, the shadows are the lowest density. Therefore, when placing the camera negative in register and contact printing with unexposed lithographic film, the shadow (low density negative regions) will be the first to expose the lithographic film. This exposure of the lithographic film would be represented by density on that film.

Ultimately the aim is to have three litho film masks which are clear (no density) in the areas of the desired densities (shadow, midtone, and highlight) which exist on the camera (photographic) negative to expose the enlarging paper. All other densities apart from these must be blocked by high densities on the lithographic film masks.

The Stouffer 21 step tablet is a calibrated tablet of 21 densities separated by values of .15 or 1/2 stop. Each stop is a log value of .30 or a doubling or halving of the amount of light which is exposing the film or paper. Thus this tablet will cover 10 1/2 stops of exposure.

Peak density is the highest density which would exist on an unsharp mask. An unsharp mask is a low density unsharp positive of a camera (photographic) negative. It is a continual tone mask. It is for this reason that I use dilute (1-30) Dektol to develop the half tone ortho-litho film. The highly dilute Dektol will cause the high contrast litho film to act as a continuous tone material.

Zones are the terminology which Zone System photographers refer to as stops of reflected light defined within a scene or object. The lowest would be Zone I which has a density of .10 above film base plus fog (unexposed but developed film)--it would be defined in a print as the deepest black possible and would not represent any texture. Zone II would be the next stop (doubling) of light exposing the film. This progression continues to Zone X which is typically represented as paper base white with no texture represented. The highest Zone which we normally concern ourselves with is Zone VIII which is the highest value showing texture within a print. This Zone (VIII) is typically targeted to a camera negative density of 1.25, when printing with a diffusion light source enlarger.

The characteristic curve of a film or of a paper is a depiction of the densities, placements of densities, and degree of slope of the contrast within that materials design. It would best be described as an elongated and gradual "S" shape. The lower and upper terminus of this shape are what are commonly termed the "toe" and the "shoulder" of this curve. It is in these regions that the slope is diminished from that represented on the "straight line" section that joins these two regions. Because the degree of slope in the upper and lower terminus are reduced the contrast, and by consequence, the tonal separation is not well differentiated.

I hope that I have cleared some of the miscommunication that seems to be occurring and that I have answered your questions.

 

[inthedark]

OH< OH< You're absolutely right! I think I figured out where we are differing. . . you are starting with the original negative and I am starting with a print. DUH! Dummy me, up till recently, no one ever brought in their own negatives. Everything that needed this kind of quality control has come in as prints or artwork, so I was starting with the positive image. I should be exactly backwards. I will ponder this and evaluate if it is so and reply later. Of course I will still be testing it ASAP, which now looks like sometime next week, I'm swamped.

I am really looking forward to trying this because, wow! couldn't it do wonders in a difficult situation.

Lunch is over and my day is gonna be long. Bye.

JL