Setting up "perfect print" for colour analyser calibration

Discussion in 'Color: Film, Paper, and Chemistry' started by pentaxuser, Jun 6, 2006.

  1. pentaxuser

    pentaxuser Subscriber

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    I have recently acquired a Colourstar 3000( the 8 channel version and more questions on that later). I have a Paterson PCA61 which is much simpler to understand and because I was familiar with its method of calibration which is to use the "perfect print route" I was advised that this was probably the best way to set up the Colourstar.

    I had been given a Fuji test neg and a Fuji print from the guy I bought my Jobo from. I am pretty certain the neg and print are Fuji's own and were supplied to customers setting up analysers, doing ring arounds etc

    I think I have learned a lot from getting as close as possible to the Fuji print but a couple of things still puzzle me. I hope some of you can provide answers

    The test neg and print is that of a Japanese girl with a white cardigan in a garden, holding up a colour chart with writing above and surrounded by two colours of flowers( golden yellowand deep red) and a stone statue. In other words all the thing you need to test for colour balance.

    I have got close to the Fuji print in terms of the colour chart but the best filtration compromise leaves the golden yellow flowers not quite as golden. I can get close to the golden colour but only at the expense of making the print too warm. So I end up with correct flower colour but at the expense of an over tanned face. The red flowers are spot on.

    Somehow Fuji seem to have achieved a fairly neutral skin tone and a very golden set of flowers. Fuji's print also looks brighter. Almost as if a brightener has been added to the chemicals. I do use a stabiliser/brightener but can't match Fuji's brightness.

    In my print her white cardigan is slightly less white, her face more tanned and the three squares for the black, dark grey and mid grey are slightly more brown.

    My conclusion was that all this points to increasing Y and M slightly but when I do that with various small combinations of Y and M around the chosen filtration, it helps some things but at the expense of others.

    The Fuji print paper has no brand mark but has to be at least 10 years old as is the neg. It is also glossy whereas mine is lustre. This may account for my print looking slightly less bright.

    In summary the main difference is my print has a more tanned skin tone yet a less golden flower tone.

    Any ideas as to how I might nail this down or could it be that a combination of different Fuji paper and a lustre finish as opposed to gloss might account for the differences?

    Thanks

    pentaxuser
     
  2. Nick Zentena

    Nick Zentena Member

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    Did you get the manual with the analyzer?

    I'd put away the Fuji neg. I would instead either get or make a grey card negative. Colorstar would have shipped one with the unit but you can make one yourself. Take a photo of a grey card. Fill the negative with the grey card. Use this negative with the grey negative setup mode to get the analyzer programmed.

    Okay onto analzying the negative. How did you do it? Spot mode? It takes awhile to learn how get the right balance. You want the important points to get more control then the other points.

    I don't know the negative you're printing but I'd likely start by choosing:

    1) Her face [forehead]

    2) the white cardigan

    3) red flower

    4) yellow flower

    5) statue

    6) A second point of her skin tone. Bare arm? neck? Face?

    7) Her hair. I might have done this earlier to be honest

    8) One more point. Depending on the balance of the negative. If it's mostly one colour then avoid that colour.
     
  3. pentaxuser

    pentaxuser Subscriber

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    Nick. Thanks for reply. Yes I got a manual with the analyser. It refers to the 3000 which has a 100 channels and mine only has 8 but other than that presumably the manual supplied is identical. I intended to calibrate the analyser based on getting a print which was a duplicate of the original Fuji print. I didn't use the analyser initially to arrive at duplicating the original print. I assumed that until the analyser was programmed to the filtration and exposure needed to produce the "perfect print", there was no point in using it.

    I have three sets of negs with the analyser which I think must correspond to a B&W grey neg, a colour neg to produce mid grey( it's looks a bit like the colour mask you get with colour neg film) and a colour transparency neg to produce a mid grey.

    Presumably if I calibrate on the grey neg set up mode I should then get the Fuji neg to produce a print which matches the original Fuji print or if not then at least it will be a properly balanced print.

    As I said, my print on which I have calibrated the analyser is very close to the Fuji print except for the slight differences in the skin tones( mine is warmer) and flower colour( mine is not as golden)and the black to mid grey squares are very slightly brown. There seems to be just a hint of browness in her hair whereas the original is black. If I get the flowers golden then the whole print is warmer and the girl's skin tones are distinctly warmer than the Fuji original print. I couldn't reconcile what appears to opposites in terms of effect.

    To quote filtration and exposure values, I have calibrated on 38Y and 32M at 2.9 secs. 40Y and 32M at 3.3 secs matches the golden flowers but makes the skin tones even warmer, presumably a function of extra exposure. 40Y and 32M at 2.8 secs comes closer on skin tones but the white square starts to look slightly blue.

    Your reply has caused me to look again at my test prints and overall 44Y and 36M at 2.6 secs comes very close on the white to mid grey and black to dark grey squares and the white cardigan. It is lighter on skin tone and hair and the other coloured squares.

    If I were to increase exposure slightly this would increase colour saturation and might get the skin tone, hair and flowers spot on but what would happen to the white square and white cardigan?

    It's worth a shot, I think. Glad you made me look again at the prints.

    On a couple of other points.

    1. Your comment on taking readings from several points. Is this the process of averaging readings which I read about?
    2. I have the diffuser which fits under the lens and two kinds of diffuser other than the clear spot cover. One is a translucent cover and the other is the same cover but with an inverted white plastic dome underneath which has a hole in the middle about half an inch wide so the light from the enlarger is blocked once it passes through the translucent top except for this half inch hole. One is presumably for a semi-integrated process. This plus the diffuser under the lens is presumably for full integration. So what the inverted plastic dome cover for?
    3. In using the fully integrated process the manual says place the probe directly under the lens. As there is no point of reference as everything is diffused, is it sufficient to simply aim for the middle of the light rectangle i.e. placing the probe in the middle of the 5x7 rectangle if its a 5x7 print that's being projected.

    4. Finally is there a website or other source of information that helps. The manual is OK but seems to make unwarranted assumptions about the user's knowledge as most user manuals do.

    Sorry if this seems to be very basic but the way the 3000 works is quite different to the Paterson which is what I am used to.

    I had identified you and Ed as colourstar users on the site and frankly unless I had known of knowledgeable users, I doubt if I'd have bothered to get one. There's nothing worse than having a complicated tool that you can't use.

    Thanks

    pentaxuser
     
  4. hka

    hka Member

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    For an good practical explanation for using and calibrating the Colorstar 3000 look at the article of Frances Schultz, editor for Darkroom User Magazine. BTW the 3000 with 100 channels works the same as the 8 channel model. The only difference is that you can use the other channels for more different calibrations. I can tell you that this analyser is the best and easyist gear I ever bought for my darkroom.
    The link to this article is: http://www.xs4all.nl/~colors/info/articles.html
    After reading all your questions will be answerd.
     
  5. Ed Sukach

    Ed Sukach Member

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    Nick
    Uh .. no, not necessarily ... the grey Color Negative sample furnished by JOBO / ColorStar/ Lici may not have anything like the base filtration of a "ten-year-old Fuji negative". One uses those samples to set the ColorStar to produce a "neutral gray test strip" ...

    Unfortunately I am **BURIED** with work at the moment... I am committed to providing prints for a models' portfolio, among *dozens* of other obligations .. and I can't take time for an extensive reply. I WILL - promise!! - when the pressure eases.

    I have both the manual for the "old" 8 channel ColorStar and the one for the 100 channel. When I get chance, I'll compare them.

    Right now my rump is directly over the swamp - filled with alligators - and rising rapidly!!
     
  6. Nick Zentena

    Nick Zentena Member

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    Personally I've come to the conclusion the analyzer doesn't care about the film. Awhile back I got a head for my old Beseler. I installed the head and move the analyzer over. I couldn't wait to calibrate the new head with the analyzer so I just made a print. It came out fine. Made some more and they're all fine.
     
  7. Nick Zentena

    Nick Zentena Member

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    http://www3.sympatico.ca/nick_zentena/colorstar3000.html

    That's the manual for the 8 channel. I've seen at least two different types of 8 channel but they only differ in how they plug in. Once you've got it turned on they act the same.

    I never liked the perfect print method to calibrate. It's too subjective. What happens when you make your grey strip? How close to the target are you?

    1) Yup it lets you make choices. It also lets you avoid problems caused by too much of one thing.

    2) I'm having trouble visualizing what you mean. I don't use the under lens diffuser. Are you talking about the probe covers?

    3) I don't do the intergrated. If you're in a rush it might be okay but using the other method isn't much slower. It lets you choose what's important and not over do what is most common in the image.

    Once you get it calibrated it's actually pretty simple to use. It takes a bit of time to learn which points to choose with the spot probe but not that long.
     
  8. pentaxuser

    pentaxuser Subscriber

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    Thanks Harry. Perhaps I should have mentioned that I also got a copy of the Frances Schultz aricle with the analyser. It looks quite good but of course describes the grey neg mode of calibration and only passing reference to calibration from a known neg and perfect print, as indeed that's all Frances could do in terms of this method.

    I am coming round to the conclusion that this grey neg method of calibration might have been better. What seems a quicker and easier method using the Fuji neg and print has turned out to be lengthy and frustrating. Primarily because try as I might I cannot replicate the Fuji print but don't understand why I can't.

    pentaxuser
     
  9. pentaxuser

    pentaxuser Subscriber

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    Thanks Nick. My spot probe cover is just as is shown in the manual i.e. clear plastic with a hole and underneath on the bottom of the plastic, again as in the manual is a slightly diffused piece of plastic. This seems to be in exact accord with the manual. The manual also shows an intermediate piece of plastic which fits on top of this bottom piece of diffused plastic. This has a 4mm hole and is called the 4mm spot disc. It is used for small prints(unspecified).

    I don't have this 4mm spot disc. 2 questions. 1. Is this spot disc clear plastic? 2. What is small prints? I am presuming that anything at 5x7/8 is small. I often do 5x8(I get two prints per 8x10 that way). Will I need this spot disc or could I get away with the normal spot disc? If it's clear plastic then no problem as I could probably shape it myself or get a friend who has access to an accurate machine for plastic cutting. If it is a diffused material then does it matter that its the exact diffusion coefficient of the original accessory. If it has to be an exact specification then do you know of a source. Shipping from N America might not be a high cost as it is very small and light in weight.

    Yes I am talking about the probe covers. One has a white translucent cover which is smooth on top and rough underneath( covered with small inverted pyramids). The other is the same except that if you turn it upside down so the smooth white translucent surface is on the table's surface then the underneath from the bottom of the cover is covered in normal white plastic and is shaped like a dome( like the kind covering indoor arenas) but the dome roof has a hole in the middle which is about half an inch across. So using it as probe cover would seem to only allow light to penetrate vertically to the actual probe with a few degrees beyond vertical but not allow light from the enlarger to enter the whole cover.

    The manual talks of a probe diffuser for selective integral measuring. It doesn't show the underside but I suspect it is the probe cover without the inverted plastic dome with a hole in the top of the dome. So it's a mystery. The manual doesn't seem to cover it in the accessory section.

    Finally separate to all this is a sheet of diffuser material which is 7x7cm and can be cut to fit under the lens like the red filter for B&W paper. I haven't used this but have used instead the Paterson diffuser material which seems to be a little more dense. If it is marginally more dense then is this likely to alter anything except may the amount of light getting to the easel?

    Mind you I have just discovered a mistake which is that full intergral reading is taken using the spot probe not the probe diffuser for selective integral measuring. I had noticed that I needed to increase the aperture opening as my LEDs, usually in yellow, often blinked indicating lack of light. No wonder as I had two diffusers under the lens.

    Finally I did change the filtration for the "perfect print" as I said last night. It's now almost spot on in terms of everything except that the print isn't as "bright" for want of a better word.

    I can only conclude that my paper is different OR the fuji neg( it has to be at least 10 yrs old) has deteriorated and producing a copy of the original print from this neg is now impossible.

    Thanks for all your help so far. I have a feeling that I will need to seek more help in the days/weeks to come.

    pentaxuser
     
  10. pentaxuser

    pentaxuser Subscriber

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    Thanks ED. Don't worry about not being able to reply as extensively as you'd like. What you've said helps already. Between you and Nick( and anyone else who is a colourstar user) I should eventually become competent

    I look forward to more correspondence in the future.

    pentaxuser
     
  11. Nick Zentena

    Nick Zentena Member

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    IIRC the older spot covers were 4mm. The newer ones 6mm. The 4mm lets less light in. This is a problem with bigger printers or dense negatives. I guess it might have been better with smaller prints. I don't change anything when I change sizes.

    http://www3.sympatico.ca/nick_zentena/colorstar3000/0011.jpeg

    Look at the diagram. The round top thing is clear. The second round piece [the one closest to the probe] is frosted.

    O don't use the under lenses diffuser. It's for intergrated mode.

    It may be the Fuji print isn't perfect.
     
  12. bob100684

    bob100684 Member

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    I'd either get a grey card and shoot it, or get a new target neg/print, a 10 year old target is not something I'd want to calibrate to.
     
  13. Bob Carnie

    Bob Carnie Subscriber

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    Pentaxuser

    As others suggest the old negative and print that you have may be misleading.
    As other suggest try making a new negative with the film stock you most commonly use, Include a large *new*grey card a pleasing flesh tone and most importantly a area of nuetral gray that in a perfect setup would be lit from light to dark.
    The grey card will help you set up the analyser for nuetral grey if it has a probe to read this area., The flesh tone will be good for a basic flesh reading when setting up for images with people. In the old days we would set the probe just under the mouth and to the side to get a density reading for flesh* an area that is not in shadow or highlight.
    The graduated background is useful for seeing quickly any colour inbalances as the colour will show itself in a graduation better than a flat field of grey like a greycard.
    Having a lot of vibrant colours in the scene will only confuse the issue as different papers have *basically falloff* and will record some colours differently and this is what is happening to you with the fuji test negative.
    Remember that in colour printing the complimentary colour theroy, and if you are trying to colour correct lets say add more blue, you are basically making the yellows *suffer* or be less pronounced.

    For our balancing our product here we use a 21 step grey card and basically when each step is nuetral and equal density from each other we are ready to print. We do not look at the colour patches at all which seems to be odd .
    The Kodak Shirleys are the same and I remember balancing to nuetral the analysers for a under neg, normal neg, over neg, this created a balanced slope for different types of exposed negatives.

    I don't know if the above ramble is of any help, but try to start very simple and nuetral , when sorting out a analyser. As time goes on you will find out how to probe different scenes properly . If you find you are always light in your balances or off colour in one direction, you can easily adjust the analyser.
     
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  15. Nick Zentena

    Nick Zentena Member

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    The grey card method is fairly straight forward with this analyzer. A little repetive but simple enough.

    1) Stick a film with a full grey card image into the enlarger [Colour negative, B&W Negative or colour slide just use the one that matches what you need to program]

    2) Project the image on the baseboard with the lens wide open.

    3) Analyze the projected image. Adjust the filters to null out the lights. Then adjust the F/stop so you get 5 seconds on the timer.

    4) Expose and process a strip about 1" wide. Make sure half is unexposed.

    5) Dry it. Hair dryer helps alot.

    6) If it's too wide to fit the probe opening cut it to size. Place the unexposed part under the probe after you've removed the negative from the enlarger and opened the lens up. Zero the analyzer with white part in the probe. Then measure the exposed part.

    7) Write down the readings. IIRC you're looking for 0.55 on the channels. If it's off that by more then say 0.02 then hit the reprogram button. That will adjust the analzyer.

    8) Go back to #1 repeat until the values are 0.55 or fairly close to that. If you don't start too far off it won't take many test strips to get things right. Maybe 3? Something like that.
     
  16. pentaxuser

    pentaxuser Subscriber

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    Thanks for the additional replies. I will have a go at the grey neg method of calibration. I had begun to come around to this way of thinking but your replies have just reinforced that.

    There is another issue that I need to raise which I hope you will say will go away once I calibrate properly on a grey neg.

    Having calibrated on the Fuji neg and "perfect print", the process I followed from the manual seemed to do exactly as the manual said it would. Once calibrated I then used the Fuji neg as if it were a new neg just as a test that I had done things correctly. The analyser on the analyse sequence reproduced the filtration and time for the perfect print as I would have expected. So far so good.

    When I then moved to my own processed negs, most of them, on pressing the analyse button, seemed to light up the cyan part of the star. To null the star then required me to dial in some C so I ended up with Y, M and C which as I understand it shouldn't happen. So I have neutral density dialled in which increases exposure.

    I printed with all 3 colours dialled in and the prints looked reasonable colour balance-wise or not so far out as to have a noticelable cast. As an experiment I then noted the amount of C and attempted to subtract equally from Y and M. So I had say 42Y, 62M and 20C. I then nulled the C dial and attempted to null the Y and M. To null the M I had to reduce the M dial to 42M as I would have expected. However to null the Y I only had to reduce the Y dial to 30 NOT 12 as I would have expected. This print at 30Y, 42M and OC was appreciably warmer than the 42Y 62M and 20C again as I should have expected. I suppose I really needed to dial in 12Y, 42M and OC and just ignore what was happening on the LEDs to see if this would have replicated the original colour balance but I imagine it would. I didn't try this as I had run out of both time and patience and I am going through a lot of paper without getting anywhere.

    Maybe I could get to the bottom of what is happening here eventually but I am so unfamiliar with the colourstar.

    Any suggestions as to what is happening? Why should I be able to replicate the Fuji balance when I treat it as if it was a new neg and in so doing the C LEDs don't light up but in changing to other negs the C LEDs do light up and I end up dialling in C to null the star.

    I wondered about the effect of my DUKA sodium light being on. I hope I can dismiss this as a cause. It wasn't a problem with my Paterson analyser and I would have thought that even if it does affect the exposure reading then provided the best exposure was arrived at with it on and that is calibrated in then other exposures should be OK. My prints seem OK exposure wise.

    If having it on affects the analyse function in terms of colours then I would have to print in total darkness but I think I'd go back to the Paterson rather than struggle in the darkness. The DUKA is not a light that you can turn on and off, given the time it takes to get to its correct operating wavelength. There is a dial on the lamp you can turn to zero. This moves a metal cover with slits round the lamp to cut out the light as opposed to turning it off but even at zero some light escapes.

    I am getting a little downhearted. You guys are doing your best with me but it's a little like learning to operate on your own appendix by exchanging e-mails with a doctor as opposed to watching him doing it on several people and then having a go.

    Thanks for your patience

    pentaxuser
     
  17. Nick Zentena

    Nick Zentena Member

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    You can check if the light is causing issues by first analyzing with it on. Then trying with it off. If it's not a problem you'll get the same results.

    Do the at least one grey strip test and see what the box tells you. Come back and tell us how far you are from the targets. My guess is you aren't on target but close.

    Are you keeping the lens wide open when you analzye? Max amount of light? I only see the C lights when I stop down the lens. Not an issue then. Get the filters right then stop down and get the time right.
     
  18. pentaxuser

    pentaxuser Subscriber

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    Thanks Nick. If I have understood you correctly when I insert a new neg I press analyze on full aperture i.e. f2.8. with my 50mm lens. So colour balance is done on full aperture then I stop the lens down to get a "proper" exposure which I think the manual suggest should not be less than 3 secs and ideally not more than 10 secs.

    Presumably I get to a reasonable exposure before the light level via stopping down drops to a level at which the Cyan LEDs come on or if they come on then it doesn't matter as the dials have been already set and do not require altering and I should just ignore the C LEDs.

    I hadn't realised that analyze should be done at full aperture. Either the manual doesn't make that very clear or more likely I am overwhelmed by it's depth.

    pentaxuser
     
  19. Nick Zentena

    Nick Zentena Member

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    Might not be mentioned in the manual. It might be buried in the section on low light use.

    You've got it easy. When I got my unit the probe was busted. The analyzer would do the exact opposite of what it should do. That was fun :mad:

    3 to 10 seconds should be a safe number. I use more then 10 when need be with Kodak paper without any problems.
     
  20. pentaxuser

    pentaxuser Subscriber

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    Nick, Ed and Bob. I think this is primarily addressed to you as you seem to be the ones with colourstar 3000 knowledge. Ed I hope your new machine is now fully operational

    I have now tried the grey neg calibration as recommended by Nick, following the instructions in the F Schultz article. I tried to see if my DUKA affected the analyser and at a light setting of 10 it affected the exposure by 0.1 sec which is nothing but the M setting by about 6 which on a Durst head is appreciable. However at a setting of 5 which is just about enough to see, things were unaffected. So do you guys use a DUKA and if so how do you guys cope?

    I set the analyser as per F Schultz's starting values of 600Y 550M and D520. Like hers my first test was a dark blue grey. After 6 tests I managed to get to logD 0.55; logY 0.56; logM 0.55 and logC 0.56.

    The print still didn't look very grey in daylight but did under the enlarger's white light. I have had to assume that my negs are the correct negs to produce a correct grey print but as there are three packs of negs with the analyser for B&W, colour neg and colour pos then it seems likely they are the correct negs for the test.

    Anyway folowing the grey neg test print calibration, I thought I'd try a neg I had recently developed and the print looked far better than the one produced from the same neg but based on my Japanese girl in garden test neg on which I had previously tried to calibrate and have previously talked about.

    My neg was a coastal scene with cliffs, people in the foreground and a large area of sea and a little sky. I think I had used a polariser. The sea and sky were very blue as I would have expected and looked great but overall the print was a little overexposed and some clothes which were blue looked a very dark blue which I assumed to be the result of overexposure.

    I wondered if I could correct the problem if I continued to test print until I had all the readings at 0.55. Big mistake. The next test print's readings were all under 0.55 by 0.02 .

    Anyway I continued to do grey neg test prints all evening but have ended up farther away from 0.55. By the 10th test print I was at 0.60.

    At these log readings of 0.60 the YMC I have dialled on the dichroic head has only changed from 69Y and 54M( getting me very close to 0.55) to 69Y and 53M which seems strange.

    The two proper prints I have done are too blue and too dark.

    I notice that if I colour analyse at full aperture with filters in the way and then attempt to get to 5 secs by stopping down as the manual advises then one green LED
    and a red LED usually light up. I can then remove both by dialling in some C and M and I then attempt to remove all LED lights by reducing the Y and M by the amount of the C dialled in, then removing the C. This usually gets me close to( but not the same as) my original Y and M at full aperture.

    Can you confirm once again that in fact I should analyse at full aperture ensuring all LEDs are extinguished and then just ignore any yellow red or green LEDs that light up on stopping down.

    I have the colourstar density strip which is simply a piece of paper and is presumably meant to be used to compare the grey of the test print with the various grey log densities. When I compare this strip to my grey neg test prints, they don't look as grey although the density as far as I can tell looks similar.

    My Y M and D values ended up as 605, 566 and 497 on the test prints which came closest to logD,Y,M and C of 0.55

    I suppose I could decrease the D and Y channel values until I got a lower exposure and decreased the blue in the print but that's back to the guessing game approach which I had thought the grey test neg print would avoid.

    Should I simply stick with the calibration I have got and try to programme a channel for semi integrated analysis. If so it isn't clear to me how I determine a neutral section or which points I measure on the neg of the coast, cliffs and people to get a better v balance. Would this lower the exposure reading which is what I need as well.

    I really don't know how to proceed from here. There are so many variables involved.

    Any advice will be gratefully received. I suspect I may need to be talked through this. The colourstar should only be sold witth a course of instruction. It still puzzles me

    Thanks

    pentaxuser
     
  21. Nick Zentena

    Nick Zentena Member

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    You can make your own grey negative if you're worried that the ones you have are faded or whatever. Just prop up a grey card in daylight and fill the viewfinder with the image. Then process.

    Any chance your paper is off? The grey strips should look grey under daylight. How white is the unexposed section?


    Yup analyze full aperture then ignore the leds when you stop down. The Jobo website used to have an article on doing large prints that mentioned the method. I don't know if it's on the Omega website now.

    The Y etc numbers change with the probes. Different probes will calibrate differently. That's why on the bottom they have handwritten numbers to start with. If you have a notebook keep track of the numbers when you reprogram. It helps keep track of the chemicals.

    How did you analyze the prints you made? Spot mode? If so what spots did you choose? It does take a little learning to get a good feel for picking the spot points. If you did use spot mode then try picking some different spots and see how that affects the filter pack and exposure. Don't even need to make the prints. Just see how different choices change the filters and time. You said the print is overexposed so I'm thinking you picked too many spots that are dark coloured.
     
  22. pentaxuser

    pentaxuser Subscriber

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    Nick. Thanks for very quick reply. It's possible, I suppose, that the grey negs pack with the analyser have changed over time. I have no way of knowing how old they are.

    I have looked at the print strips from the grey neg again in daylight and they are definitely not grey, although as I said they look grey under the intense white light of the enlarger lamp at full aperture.

    The paper is a replacement from Fuji and is only a few weeks old. Its the new Fuji Crystal Archive. I previously had Fuji Crystal Arcive MP but was having problems with the yellow filtration. To get the colour balance right I was using little or no Y. On the same negs I switched to Kodak paper which I still had and the problem disappeared. Fuji asked to see copies of my prints. I sent them copies of Fuji paper prints and the Kodak print. They weren't able to give an answer which explained the problem but sent the new paper which seemed to be free of the issue of needing very low values of Y on the dichroic head.

    So am I right in concluding that it is unlikely to be a paper fault. The chemicals are Paterson and fairly new. I use a replenishment system so the developer is being replaced quite frequently.

    The white part of the test print seems to be completely white - no sign of any grey or other cast.

    My plan of action now is to:Try making up completely fresh developer. If that doesn't get me to a grey print then I can switch to Kodak paper.

    If none of this produces success then I'll have to get a grey card and do a fresh neg. If the grey neg has faded would this result in a print which is a grey/green colour and also result in the 3000 calibrating to a level which produces an overexposed print?

    After my calibration to my grey/green neg but at 0.55 I then printed my coastal scene. I did this by using the fully intergrated system which as the manual suggests involves using the clear spot probe but a diffuser under the lamp. I used the Paterson diffuser and not the one supplied with the 3000. They look the same although the Paterson one may be slightly more diffused. Is not using the 3000's diffuser square under the lens likely to result in the print problem? I wouldn't have thought so.

    I used full integration as this is all I know. My Paterson analyser does it all by full intergration.

    I could try semi- integrated measuring by replacing the clear spot probe with the diffuser cover and taking one or more measures from the neg. Could it be that because deep blue predominates the scene from sea and sky then under full intergration this has resulted in a predominance of blue in the print and a slight overexposure?

    Ah well, back to the drawing board.

    pentaxuser
     
  23. Nick Zentena

    Nick Zentena Member

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    Okay if I understand you did the following

    1) Programmed the unit with the spot probe and acheived the target 0.55 or close enough to it.

    2) You then switched to a diffuser and tried to analyze. I'm guessing you didn't program a new channel for this. Right?

    You need a channel programmed for each mode. Once you've got the unit programmed with the spot probe then leave the settings alone and switch to a new channel. Program this channel using the perfect print method. You've got the filter settings etc at this point so it should be quick enough. Then use this channel for when you want to use the diffuser.

    I'm not sure what issues the other diffuser will cause you. It might pass light differently. Might not be neutral.

    Something is up if you can get a good white on the test strip but not a good grey. I think you've said you're using room temperture chemicals? Maybe PE could pipe in on what happens when you have too cold a developer.

    Try using the spot mode to measure. It's not that hard. It does take a touch longer with simple negatives but it will handle complicated negatives better. So in the end you save time IMHO.
     
  24. pentaxuser

    pentaxuser Subscriber

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    Thanks Nick. The answers to your questions are: to Q1 Yes; to Q2 Yes and yes. I use a Jobo CPE 2 at 35 degrees C. There is a thermometer at either end and both read identically.I think we can rule out a temp problem with the developer.

    So if I want to try fully intergrated measuring then given that the grey neg calibration gives YMD values that gets me close to what I think would be the perfect "coastal print" i.e a little less blue and a little less exposure, I now choose another channel and guess how much extra Y on the dichroic head dial and how much less exposure to give and then when I arrive at the perfect print, I then key the head filtration and exposure into the 3000 which will give me another set of Y M and D values in that channel, hopefully making it OK for neg which lend themselves to fully intergrated readings.

    I then need to be able to recognise those negs which do not lend themselves to full integration and use semi-integration for which I also need to programme a channel.

    The same is true of achieving warm prints. Here at least the F Schultz article recommends what you do with the Y M and D values to achieve this.

    Presumably having gone to the trouble of calibrating for the grey neg using the spot probe, I could try to achieve the perfect "coastal print" by using the first channel set up for the grey neg spot.

    If I am right then this is unknown territory for me. The manual covers spot reading but only in a peremptory fashion using a portrait neg. For semi- integrated measuring the manual uses a crowd picture and shows where to measure. Most negs are not like this.

    In the neg in question I have only one face of any size(the skin tone looks very accurate or certainly how I like it), the rest is blue water(45%), lighter blue sky(12%) and rocks, both dark and light(30%).

    What areas should I spot analyse to get as accurate a colour balance and exposure as possible? As I said before the print I have produced is a little dark and a little too blue but only slightly so.

    Of course all the above depends on getting a grey neg print which is grey.

    I may as well change the diffuser to the one with the 3000. It can't hurt and could improve things if diffusers are designed to be compatible with the analyser.

    Thanks

    pentaxuser
     
  25. Nick Zentena

    Nick Zentena Member

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    It overexposed because the diffuser cut some of the light out. Won't hurt to program a channel for the diffuser. Just put the grey negative in. Analyze it the same you did for the programming [with the spot probe right?] then without changing any settings on the enlarger switch channels on the analyzer. Hit the buttons to program the perfect negative. Then make a grey test strip to check. With some luck you should be very close to the target numbers. That should give you a channel that handles the diffuser better.

    On to the coastal negative.

    "In the neg in question I have only one face of any size(the skin tone looks very accurate or certainly how I like it), the rest is blue water(45%), lighter blue sky(12%) and rocks, both dark and light(30%)."

    If it was me I'd choose a spot in each of those.

    1) Skin tone

    2) Blue water

    3) Sky

    4) light rocks

    5) Dark rocks

    You can use up to eight spots. The person in the negative I'd pick some of thier clothes for #6. For #7 I think I'd go back and hit the sky and the skin tone again.

    Any negative that is dominant with one colour can cause problems. Worse any one that the important thing isn't filling the frame will cause problems.

    http://groups.google.ca/group/rec.p...blue+ra-4+print&rnum=5&hl=en#5bfdb98e9b417f16

    That link claims blue might be a chemical issue. At least it gives you something to consider.
     
  26. Ed Sukach

    Ed Sukach Member

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    The negative itself does NOT have to be a "perfect" grey. A test strip obtained from any uniformly distributed close-to grey negative that prints out as a perf--- or rather acceptable grey ... the same densities for each of the color layers: .55 Magenta; .55 Yellow; .55 cyan ... and therefore .55 overall density ... will be useful in printing; mainly in establishing the stability of the process, with emphasis on the chemistry.

    The application of an "Average Grey" channel depends on the the theory that most scenes recorded on color negative, or reversal film will AVERAGE, out to be .55 Magenta/ Yellow/ Cyan.

    I would suggest the process described in Section 14 of the ColorStar 3000 manual, "Reprogramming With the Grey Test Negative."