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  1. #11

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    Quote Originally Posted by Steve Roberts
    Likewise, I've used Ilford Multigrade and a 4/5 filter. Exposure times are nearly long enough to go and make a cup of tea whilst it's do-ing, but the results can be surprisingly good, especially when considering that it's really making the best of a bad job and trying to get the film to do something for which it was never intended. I have a shot I took of Acker Bilk in action on 400 ASA print film that is far better as a "fudged" B/W print than it ever was in Glorious Technicolour!

    Steve
    Steve. Any chance of a thumnail of the print?
    Can you recall even roughly the exposure time and aperture. I'll have to do test exposures of course but narrowing it down would help. My lens will open up to f2.8 which even allowing for the increased exposure, would reduce exposure quite a lot compared to my usual f11 opening for about 8-10 seconds for B&W negs. I know that conventional wisdom says that it ought to be stopped down at least a couple of stops but this raises the interesting question of what difference to quality it makes to stop down weighed against the convenience of a shorter exposure.

    Clearly the current Cyan setting on my colour analyser for exposure using a diffuser under the lens is irrelevant as it is set for colour prints but would it be applicable once I get the exposure right if it was then re-calibrated or would it make sense to use my B&W analyser which has a spot probe and re-calibrate this. The exposure is measured against the darkest part of the B&W neg. Is there an equivalent part of a colour neg against which to place the probe or if there isn't then would the use of the diffuser under the lens for an intergrated reading result in reasonably accurate exposures once the first colour neg had been properly exposed and the probe calibrated to that setting under the diffuser?

    Or is any exposure aid of no value and it is simple a question of a test strip each time?

    My understanding is that with a grade 4/5 filter and Ilford paper the exposure has to be doubled compared to grades 1-3.

    This will be a voyage of learning by doing but any comments anybody has on my questions above will be very welcome. It may save some paper!

    Thanks

    Pentaxuser

  2. #12
    Mick Fagan's Avatar
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    Hello, first post here and although I've been looking around for a while, nothing got me going until I met this thread.

    I run a Durst Printo for RA4 and I have used Portra paper through it for C41 B&W prints. All the prints I've done have been using Reala 35mm film, from the first type through to the latest incarnation. One exception was a picture on Ektar 25 Professional.

    I will say though, that I only purchased one box of 8x10" Portra and eventually used that up. Prior to that I used Panalure, I still have a few sheets left.

    Normally though, I've just use standard Ilford B&W paper with quite aceptable results.

    The way I see it is this:-

    Portra works brilliantly if you can do it with, and, it's the quickest way to do great B&W from C41 negs, especially if you have a roller transport machine.

    Panalure is great and it was really a boon for when I was printing B&W prints from C41 negs prior to RA4 being available

    Normal B&W paper (Ilford) is acceptable, except if you have a lot of blue or red in the picture. Blue goes white so someone with blue eyes will end up with whiteish eyes, or a blue dress goes white, or the blue sky goes virtually colourless. Reds go dark to almost black and this can be a problem for a girl wearing red lipstick as her lips will go black.

    Normal paper also has a bit of a contrast problem, which I think comes from there being some of the colours in the negative not printing. One of the ways I tried to alleviate this quirk was to pre-flash the paper to lower contrast. This was a bit of a hit and miss affair and I sort of gave up on that practise, although it can and did work in lowering the contrast on negs I really wanted to print.

    Normal paper will also show an increase in grain, which isn't grain but it looks like grain. I think this is due to it's inability to see all of the colour sprectum that colour paper does.

    None of the so called problems I've mentioned will, or should stop you from making a B&W picture from a C41 neg onto standard B&W paper.

    In short, it's another interesting facet of the analogue world

    Mick.

  3. #13
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    another possible solution...

    Quote Originally Posted by Mick Fagan
    Normal B&W paper (Ilford) is acceptable, except if you have a lot of blue or red in the picture. Blue goes white so someone with blue eyes will end up with whiteish eyes, or a blue dress goes white, or the blue sky goes virtually colourless. Reds go dark to almost black and this can be a problem for a girl wearing red lipstick as her lips will go black.
    Does this mean that if a suitable colour combination is dialed up with a colour enlarger such that reds are attenuated and blues are accentuated, then one could faithfully reproduce the image onto regular B&W paper?

    regards
    Peter

  4. #14
    Mick Fagan's Avatar
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    Peter, I see you'e up late as well.

    In short the answer is no!

    This is because "B&W paper is sensitive mainly to blue light". That is a quote from my 1974 fifth edition Kodak publication of Printing Colour Negatives. I went to the dark room to check this out before I replied.

    I run a free standing Devere 4x5 colour enlarger with a colour head. I can tell you that I've run the dials around the clock trying to get B&W prints out of C41 negs. No discernible amount of attenuation or accentuation occurs from memory, although it would be nice.

    Actually, using coloured filters can get you more dramatic results over a colour head, as the dichroich filters run out of steam, compared to the filter gels at the extremes. However I've been running colour heads for about 17 years now and wouldn't go back.

    Mick.

  5. #15
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    Quote Originally Posted by Mick Fagan
    In short the answer is no! .... Actually, using coloured filters can get you more dramatic results over a colour head, as the dichroich filters run out of steam, compared to the filter gels at the extremes.
    So it sounds like the relative intensities of the red and blue components required is much larger than the dynamic range capable using either dichroic or gels.
    I still think that it must be possible to make a custom dichroic colour filter which could do the job. Surely a sufficient attenuation of blue light could can be achieved. This may result in a long exposure time and the need to tailor the filter to the particular response of the B&W paper being used. Is there an aspect of dichroic filter technology that would prevent this from being fabricated?

    regards
    Peter

  6. #16
    Mick Fagan's Avatar
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    Peter, if you are using normal B&W paper, you must remember it is blind to certain colours, otherwise you wouldn't be able to use a safelight. It is this blindness that is the problem when using C41 negs.

    Normal B&W film is panchromatic and therefore sees the whole spectrum (well for these purposes anyway). When in the darkroom you use the B&W neg which only contains shades of grey, going more or less, from black to white. As the paper is sensitive to all of these shades you are able to obtain the entire tonal range of the image on the neg.

    With C41 negs, some of the image is in a part of the range that the paper cannot see, therefore you cannot get the entire tonal range of shades. But one can certainly get quite acceptable results, even with this so called set back.

    Mick.

  7. #17
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    Quote Originally Posted by Mick Fagan
    Peter, if you are using normal B&W paper, you must remember it is blind to certain colours, otherwise you wouldn't be able to use a safelight. It is this blindness that is the problem when using C41 negs.
    Very good point, however I STILL think it is possible!! The normal B&W paper is not totally blind to red light, just very insensitive. Which is the reason that safelights will eventually fog the paper given a sufficient amount of intensity and/or time.

    So.... as I suggested above, just make a filter that transmits as close to 100% of the light at the red part of the spectrum and only say 1% of the light at the blue part of the spectrum (of course the exact filter characteristics would need to be determined), et voila! Who cares if the exposure time is 5 to 10 minutes!

    Call me crazy, but I still think it's possible

    regards
    Peter

  8. #18
    Mick Fagan's Avatar
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    I'll call you crazy.

    Also anything is possible, but I don't think it's feasible, in this case!

    If you do though, let us know.

    Mick.

  9. #19

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    Quote Originally Posted by Mick Fagan
    Hello, first post here and although I've been looking around for a while, nothing got me going until I met this thread.

    I run a Durst Printo for RA4 and I have used Portra paper through it for C41 B&W prints. All the prints I've done have been using Reala 35mm film, from the first type through to the latest incarnation. One exception was a picture on Ektar 25 Professional.

    I will say though, that I only purchased one box of 8x10" Portra and eventually used that up. Prior to that I used Panalure, I still have a few sheets left.

    Normally though, I've just use standard Ilford B&W paper with quite aceptable results.

    The way I see it is this:-

    Portra works brilliantly if you can do it with, and, it's the quickest way to do great B&W from C41 negs, especially if you have a roller transport machine.

    Panalure is great and it was really a boon for when I was printing B&W prints from C41 negs prior to RA4 being available

    Normal B&W paper (Ilford) is acceptable, except if you have a lot of blue or red in the picture. Blue goes white so someone with blue eyes will end up with whiteish eyes, or a blue dress goes white, or the blue sky goes virtually colourless. Reds go dark to almost black and this can be a problem for a girl wearing red lipstick as her lips will go black.

    Normal paper also has a bit of a contrast problem, which I think comes from there being some of the colours in the negative not printing. One of the ways I tried to alleviate this quirk was to pre-flash the paper to lower contrast. This was a bit of a hit and miss affair and I sort of gave up on that practise, although it can and did work in lowering the contrast on negs I really wanted to print.

    Normal paper will also show an increase in grain, which isn't grain but it looks like grain. I think this is due to it's inability to see all of the colour sprectum that colour paper does.

    None of the so called problems I've mentioned will, or should stop you from making a B&W picture from a C41 neg onto standard B&W paper.

    In short, it's another interesting facet of the analogue world

    Mick.
    I thought my original thread had come to an end until you and a few others added to it. Many thanks for that.

    While B&W paper may be acceptable and I will give it a go, your listing of the difficulties suggests that it is a very poor second to Portra paper. I sometimes end up with poor skies even in B&W prints from B&W negs so would rather not accept white skies if I can avoid it. If there are no skies such as in mainly people shots, white eyes and black lips sound novel but not particularly inviting. My viewers belong to the school that says that the world is in colour and prints should be the same. They believe as do many non photographers that B&W belongs to the poverty stricken world of the 1950s which they escaped from in the 60s and 70s when colour and better cameras became affordable. I have been able to sow elements of doubt in this philosophy with some B&W shots of a wedding. If I show them white eyes and black lips then I undo all my good work on demonstrating a place for B&W. I can just see them saying: Who are these people with white eyes and black lips - the Adams family?

    I think I'll take your reply as a vote for Portra for tone authenticity. I may need to keep my Ilford people prints for my next wedding assignment in Transylvania where flash is always needed as available light photography is forbidden.

    Regards

    Pentaxuser

  10. #20

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    Pentaxuser

    I have had mixed results with colour negs on B&W paper and it all depends on content colour as to how it looks on the resulting paper. However I printed this elephant image this evening from a C41 neg and it looks great. It was on Sterling Fibre warmtone MG, image was 7x15 inches, exposure was 64 seconds@f8. The work prints on Ilford multigrade took 40.2 seconds but were slightly smaller in size.

    I dont think the times are unreasonable but the flat colour range cerainly helped.

    Phill
    It is not tradition that secures the survival of our craft, its the craft that secures the survival of our traditions.

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