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  1. #41

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    Quote Originally Posted by albada View Post
    Here are full-resolution crops of HP5+ shot and developed identically in XTOL and the concentrate. XTOL is on the left; concentrate on the right.
    XTOL: Attachment 53991 Concentrate: Attachment 53992

    The scanner is a Nikon Coolscan IV-ED, which has a resolution of 2900 DPI on the negative.
    What do you think of the grain and sharpness?


    Mark Overton
    They certainly look very close to me.

    A few questions - have you looked at higher densities than in your plot? Is the shoulder the same shape? What about D-Max? Actually, rather than N+1, development of a roll to D-Max is probably a good test for capacity.

  2. #42
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    Nice work Mark. I note that there is just a tad more grain in your developer. Do my eyes deceive me? The curves are certainly close though.

    PE

  3. #43

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    To me it does look very slightly grainier but only in some tones. Also looks very slightly sharper but quite difficult to tell from scans. These differences could be entirely imagined, or real but trivial in practice. I would really need to see physical prints/negatives in order to finalize my subjective opinion.

  4. #44

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    Quote Originally Posted by Michael R 1974 View Post
    To me it does look very slightly grainier but only in some tones. Also looks very slightly sharper but quite difficult to tell from scans. These differences could be entirely imagined, or real but trivial in practice. I would really need to see physical prints/negatives in order to finalize my subjective opinion.
    Grain: I've compared on two monitors, both CRT and flat-screen, rapidly switching from one to the other. Flat-screen monitors are best for comparison because their focus doesn't vary, and grain is more conspicuous on them.
    Anyway, I see some areas where grain is a hint worse; others where it's a hint better, such as the left house-window.
    BTW, the scanner was manually focussed on one of the two house-windows.
    The rolls are mostly identical frames, so I can scan more frames.

    Sharpness: The photos were taken about 20 minutes apart, and the sun had moved a little, so deeper shadows on the tile roof might increase percieved sharpness in the concentrate. The sharpness of the other lines in the photos look the same to me.

    Mark Overton

    EDIT: On further critical exam, I notice that other lines are a bit sharper in the concentrate, such as the window-frames. I wonder if this is a focus-issue with the scanner (which would affect grain-perception), or if the concentrate is actually sharper. I'll definitely make some more scans.
    Last edited by albada; 07-16-2012 at 02:57 PM. Click to view previous post history.

  5. #45

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    Storage in the refrigerator or freezer

    I left the bottle of concentrate overnight in the refrigerator, and there is no precipitate on the bottom. I even put it in the freezer, and nothing precipitated out of solution. It simply became thick, like cool honey. This tells me that the concentrate can be refrigerated or frozen for storage, taken out only when needed.

    Chemical reactions slow down with decreasing temperature. Would that mean the concentrate would last much longer if stored cold?

    If so, perhaps it would last a decade or more in the freezer, or a few years in the refrigerator.

    Mark Overton

  6. #46

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    Here are more scans of XTOL and concentrate. These were saved at a higher JPEG-quality than my prior scans, so everything should be slightly crisper, hopefully making comparison easier. In these, I manually focussed the scanner on the rear window of the car.

    Frame 15: XTOL: Click image for larger version. 

Name:	hp5-xtol-crop15.jpg 
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ID:	54029 Concen: Click image for larger version. 

Name:	hp5-conc-crop15.jpg 
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ID:	54030
    Frame 16: XTOL: Click image for larger version. 

Name:	hp5-xtol-crop16.jpg 
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ID:	54031 Concen: Click image for larger version. 

Name:	hp5-conc-crop16.jpg 
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ID:	54032
    Frame 17: XTOL: Click image for larger version. 

Name:	hp5-xtol-crop17.jpg 
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Size:	139.5 KB 
ID:	54033 Concen: Click image for larger version. 

Name:	hp5-conc-crop17.jpg 
Views:	44 
Size:	137.7 KB 
ID:	54034

    Can you see any consistent difference between the pairs?

    Mark Overton

  7. #47

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    While waiting for comments on the new scans above (hint hint), I figured I'd reply to some suggestions:

    @Michael R: No, I have not checked higher densities yet. But I have the leaders of HP5+ from both rolls, so I can measure them tonight if I remember. I like your idea of developing an entire roll to D-max. Exposing such a roll will be easy: Just load it onto the reel in the light!

    @Murray Kelly: I hadn't thought of adding metaborate first and then drying it before proceeding. That's an interesting idea and easy to test.

    @relayer: Yes, a two-part developer could be made where part B is sulfite + metaborate. The problem is that part B can not be concentrated much due to the solubility limit of sulfite, so it will need a large container using much space, and it's likely to oxidize because it's aqueous. And it can not be stored in the refrigerator. So I prefer to keep the two parts as (1) concentrate and (2) sulfite powder, because both take little space and should store a long time in the refrigerator. Well, I *think* the concentrate will last long when refrigerated.

    Mark Overton

    EDIT: I just measured the leaders of the two test-rolls. XTOL is 2.40, and the concentrate is 2.39. Very close.
    Last edited by albada; 07-17-2012 at 11:51 PM. Click to view previous post history.

  8. #48

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    I hope you're not storing your developer in your food refridgerator. It's just bad practice to mix the two - food and chemicals.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  9. #49

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    Quote Originally Posted by albada View Post
    Yes, a two-part developer could be made where part B is sulfite + metaborate. The problem is that part B can not be concentrated much due to the solubility limit of sulfite
    I have two suggestion
    1) try to use Potassium Sulfite instead Sodium Sulfite
    2) try to decrease amount of slfite to 30-40-50g/l

  10. #50

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    Hi Mark - regarding the most recent scans, I'm having a hard time finding any consistent differences one way or the other (essentially the same experience I had with the first scans). And I know your curves are essentially identical. My two cents: given the magnification, for practical purposes any differences in apparent graininess or sharpness between the concentrate and XTOL with this film are trivial.



 

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