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raghu_kuvempunagar

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Posts posted by raghu_kuvempunagar

  1. So once you have the scanned file, what do you do in PS?

    Negatives that were souped in Obsidian Aqua (a Pyro staining developer) are generally quite sharp in all channels. The histograms are different because of the stain which acts as a color filter. I apply different gamma for each color channel in levels so that the histograms align the best possible extent (see attached pics for histograms before and after). Then convert to grayscale, process to my taste, downsize to 3000x2000 size (in case of 135 film) and sharpen minimally.

     

    Negatives that were souped in non-staining developers - use only the green channel as described here: Kenneth Lee Gallery - Scanning The Green Channel

     

    histo1.JPG.784aefc22d26ad9ec0a8bcdd2b1490b8.JPG

     

    hist2.JPG.ddd544638f28889dd52361e541158fde.JPG

  2. Raghu: So how would you suggest we should scan? In 16 bit color? And then only use the green channel? Can you extract that channel using Lightroom? Thnaks.

     

    Alan, I scan b&w negatives as 48 bit color positive at 3200 resolution on my Epson V600 using Epson's software with all corrections (including unsharp masking) unticked (ie no corrections). I basically do a linear scan with the scanner and all corrections later in LR/Photoshop.

     

    I've only LR V3.6 with me and it gives me no obvious ways of accessing the individual color channels. Photoshop is useful for this purpose and I guess some free image editing tools can also be useful.

  3. The answer to your question is complicated. Firstly, if you're using a staining developer like Obsidian Aqua or other Pyro developers to develop your film, the black and white negatives have a color stain. As a consequence, there is significant difference in the color histograms when you scan the negative as color positive. Because the three channels don't have identical histograms, naive greyscale conversion doesn't make the best use of the information in those channels. Secondly, at least on some scanners, the green channel has been found to give the sharpest scan even when the negative has no stain. See Kenneth Lee Gallery - Scanning Tips with Epson and VueScan Software for a discussion. Scanning as color gives you more control over grey scale conversion.
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  4. Bill,

     

    I see you add Part A to water first and then dissolve carbonate in this solution. I remember reading in some other forum that a) dissolving carbonate in 2/3 volume of water first b) adding Part A, stirring the solution adequately so that Part A is properly mixed c) adding 1/3 volume of water, stirring the solution is the recommended sequence of steps for preparing OA working solution. The resulting solution is ready for use immediately as can be ascertained visually by the change in colour but I wait for a couple of minutes nevertheless. Not sure if this makes any difference because for PMK Pyro, the formulary instructions sheet says the order of mixing Part A and Part B doesn't matter. But then PMK uses a different alkali.

     

    Using a little more Sodium carbonate than prescribed by Jay (5gm/1000ml) is not going to change the Ph (around 11) significantly. So carbonate might not be the cause of the white dots.

     

    I sourced Catechol locally in India and it came as small brown colored flakes not powder. I dissolved 100gm in 400ml water at 30C. The resulting stock solution was dark chocolate in color. I use 2ml per 36 frames roll in 600ml water with 4gm Sodium Carbonate anhydrous. I arrived at this ratio after a bit of experimentation.

     

    I've had happy experience with Kentmere 400 ( EI:250) and OA. 13-14 minutes at 20C in Patterson tank. No white dots so far.

  5. Do you stir the solution adequately after adding the Pyro chemicals? Next time you might want to first mix part A in water, stir thoroughly for a minute, add part B, stir thoroughly for a minute, wait for a couple of minutes, check the color and then pour the developer working solution into the tank. If you have already done this, please ignore my suggestion.
  6. I've not attempted stand/semi-stand on the three films you've mentioned but I've been quite pleased with semi-stand on Arista Edu Ultra 400 in both 135 and 120 format. I use 3-4 ml of either HC-110 or Rodinal in 500 ml of water for this film depending on the scene contrast. After the initial agitation, I do two gentle inversions at 2, 6, 14, 30 minutes and dump at the end of 60th minute. I use Patterson tank and the start temperature is 19-20 C. I presoak film for about 5 minutes in tap water at 19-20 C. Fix, wash and dry normally.
  7. Rick, you've some of the best scans I've seen on Photo.Net and in the rest of the Internet. Clearly, you've evolved a workflow that produces consistently good results for you. Scanning is a frustrating and perplexing process to many like me partly because not much is known to us about how a scanner + scanner software combination work together. I wish we had someone who worked on Epson or some such scanner R&D in this group to help us understand scanners better (someone like PhotoEngineer). Having said that, I'm not really sure the alterations you make thru scanner software have any effect on the raw scan that the scanner hardware produces. Like Alan I believe that all the alterations that you make using the scanner software are postprocessing operations on the raw scan and is done by the scanner software after the raw scan has been produced by the scanner hardware. A linear/raw scan has all the tonal details that the scanner was able to get. Whether you do alterations using the scanner software or on Lightroom/PhotoShop is a matter of taste and convenience. A lousy scan is one where one is sloppy with the controls that the scanner software provides. More often than not, scanner software's default setting produces lousy scan. A linear/raw scan is not a lousy scan. It doesn't appear visually pleasing but it has all the tonal details which can be adjusted to one's taste in Lightroom/Photoshop to produce a pleasing final 'print'.
  8. Arguably the best way to find out whether your scan has adequate shadow and highlight details is to study the raw/linear scan ie before applying any adjustments (contrast, brightness, curves etc) on either the scanner or photo editor. A linear scan might not be visually appealing but it holds all the information that the scanner was able to get from the negative without distorting/destroying it. Often the information is distorted/destroyed because of scanner's auto exposure/tone curve settings rendering subsequent analysis/comparison of scans meaningless. Linear scan allows you to compare results of one developer against another in a reasonably meaningful way.
  9. are the optics anywhere near the best slr cameras or high end rangefinders like the Mamiya six and or even?

     

    GS645W lens is very good. Is it as good as Mamiya 6 or SLRs for your needs, I've no idea. If you can loan the camera from someone and shoot a few rolls, you should be able to find out yourself. It might also not be a bad idea to buy one and test.

    As the camera is quite popular among buyers, you can always sell it if it doesn't meet your needs and recover your investment.

  10. I'm considering buying a Fuji GS645W as a low tech manual camera with which to enter medium format photography.

     

    Fuji GS645W is a nice medium format camera with simple manual controls. It is not compact but it is also not too big or heavy compared to several other medium format cameras. Scale focus can be both advantageous and disadvantageous depending on how you see it. You can always use a shoe mountable external rangefinder like I do. The camera is capable of producing superb pictures. Only caveat would be about the suitability of the focal length for your needs. Not everyone likes to shoot with a wide angle lens all the time. If you're on a tight budget, you might want to take a look at Koni Omega Rapid which is an affordable medium format system camera with nice lenses. It's ugly and heavy but it delivers. Rapid negatives (6x7) are bigger than Fuji's (6x4.5) and that can be useful in some scenarios.

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