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dennis_oconnor6

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Posts posted by dennis_oconnor6

  1. I found out today that visual inspection of negatives can be deceiving. I thought that the 'Mytol' developed ones had more contrast when I viewed them on my light box. However. When I put each of them in my enlarger (both negatives of the indentical scene) and used my analyser pro to sample them - they gave me identical readings. Oh well it was interesting to find out.

  2. Yep you have to pay for quality I'm afraid. Yes it does switch off the safe light during exposure. I guess it makes sense to do a separate calibration at each grade. It would be nice if you could do a calibration at say Grade 2 and let the analyser sort all the rest out.

     

    I'll have some time to do the sequence during the coming lockdown.

  3. I have been reading how to calibrate this analyser by Andrew Smallman. Although it is a simpler method than the analyser calibration manual uses I have one question I hope someone can answer. Do I have to take a 'light reading' for each grade of paper. What I mean is. If I want to create a test strip for Grade 1, do I have to take a reading with the analyser set to Grade 1. Then for grade 2, do I have to take a reading with the analyser set to Grade 2. and so on?

     

    It's a brilliant piece of kit - but complex to calibrate.

  4. I was able to pose this question to a GIMP instructor on the web. His answer was 'unfortunately not'. It would have to be re-coded in order to be understood by GIMP. It could probably be done by someone with good coding skills - I don't have any so that is that. I did think of creating a 'step wedge', but it is the reading of the printed chart that would not be possible. Anyone up for a challenge?
  5. <p>Oooohh Dear. Shortly after posting I stumbled upon the answer. It is to do with the scanning area of the printed chart. I have been scanning just the central squares that are used for analyzing. But I think there must be some relationship in the Charthrob programming that positions the analyzing areas, not in the centre of each square being analyzed, BUT at an X and Y coordinate from the outside edges of the chart! When I tested this idea and scanned the 'whole' chart all the analyzing areas were central to each square. All I can hope is that this piece of information proves useful to someone else.</p>

    <p>Dennis</p>

  6. <p>While I was analyzing a scanned Charthhrob printed greyscale image I noticed that the outlines of the analyzed areas did not correspond to the centres of the printed squares. In some cases it was analyzing the corners of 4 squares! However. When I generated another 'on-screen' Charthrob greyscale image and analyzed that. All the 'areas' were centralized on each square! I noticed that the size of my printed and scanned image was a different size to the original screen image. I re scaled the next print to be the same size as the original. However even this had the same 'analyzing area' problem as the first scanned image I had.<br>

    Has anyone else noticed this? How did you overcome it?<br>

    Dennis</p>

     

  7. <p>Colin. I feel your pain. I am just an amateur photographer. But as a retired engineer I am always searching for solutions to problems. I too would like to make wet monochrome prints in my darkroom from digital images. In fact I have just come out into daylight about 30' ago, disappointed with my latest efforts. I have been converting the images to monochrome in photoshop and applying the 'chartthrob' curve making app. Sadly the 'wet prints' result in way too much contrast. I have tried variations on film speed, developers and developing time, without success. I do use the 'OHP transparency' method with success. But it is a 'one size print' from each 'negative'. I believe in the book 'Way Beyond Monochrome' it is suggested that to achieve what we are after, is to photograph a print onto negative film. I will have a look at the thread mentioned here about photographing computer screens. Sadly I think we are looking for a solution that does not exist with our available (home) resources.<br>

    Dennis</p>

  8. <p>Thank you for the responses. I want to experiment with creating digital negatives I can 'wet print' at specific grades in my darkroom. I have tried an application that is supposed to give different paper grades, but on screen I cannot detect any differences (unlike a wet print). I guess I will have to just keep experimenting.</p>
  9. <p>My word what a fantastic response to my question. Loads of good advice which I will consider and have a chat to his son. From my conversations with his father, I gather he wants to 'understand' the effects of exposure (apertures/shutter speed) on black and white film so it will have to be a body with manual functions.</p>

    <p>Thanks for all the responses. I think I will look at the Nikormat range.</p>

  10. <p>Hello all.</p>

    <p>I have been asked by a friend of mine if I would teach his 14yr old son how photograph with and process black and white films. Apparently he is fed-up with Photoshop or its clones, which is what they use at his school. Obviously he does not want to spend a lot of money on a camera body if his son should decide not to continue B&W film photography as a hobby.</p>

    <p>My thinking is as follows. The camera body just holds the film and providing the shutter speeds are reasonably accurate something like a Nikon EM might suit him. I think for 'ordinary' photography all singing super duper bodies are of no use to someone of his level. I am prepared to loan him one of my zoom lenses (Nikon fit). I believe the image quality is dependent on the lens rather than the body (please no technical arguments).</p>

    <p>What suggestions do you have. Am I approaching the project from the correct point of view?</p>

    <p>Thank you.</p>

    <p>Dennis</p>

  11. <p>Not a contribution but a developer % concentration question.</p>

    <p>If 300ml of Rodinal developer at a concentration of 1:100 (a figure I have seen quoted many times) is used for stand development of a 36 exposure of 35mm film. Does that mean if I only shoot and process 18 shots (half the roll). Should I reduce the concentration of the developer to 1:600 (1/2:100) to prevent over development due to the higher concentration at 1:100 on the reduced film area to be developed?</p>

  12. <p>Alan Klein. That photograph A+++.<br>

    So it would appear from the many responses that there are only three possible advantages of scanning film negatives.<br>

    1. You can view the image on screen (or decide if it is worth darkroom printing it).<br>

    2. You can print without a darkroom.<br>

    3. The ability to 'improve' the subject matter (digital dodging and burning. And the removal of unwanted objects).</p>

    <p>Thank you for all your responses. I'm off to my darkroom now to have some fun.</p>

  13. <p>"I wish I could give a simple answer! Optical prints are much more desirable than digital ones. Digital prints are easy and cheap. But because of that they have little value.<br /> Optical prints can be mass produced as well, but by their nature cannot be imitated by digital prints.<br /> OTOH if you do not have a darkroom, there's no point worrying about it."</p>

    <p>Thank you for your response.<br /> I do have a darkroom. Hence the question regarding 'Digital Negatives'. I usually make them from digital images taken with my Nikon D90. I was just wondering if there might be a longer 'grey scale' if the negative were made from a digitised B&W negative.</p>

  14. <p>Thank you all for the prompt responses. I had not considered the longevity of film compared to digital storage. So it looks like (apart from the pleasure of shooting/processing film) for digital negatives - shoot digital. I have a Nikon D90 bye the way.</p>
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