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  1. #81
    Photo Engineer's Avatar
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    Sandy;

    I see a sharpness difference as well in the spine of the second book from the center.

    However, in an earlier post I mentioned the contrast difference as well. And a poor quibble is that D23+NaCl is not Microdol or Microdol-X. An interesting post script to this is that Patrick said they all had the same apparent speed and you would expect the Microdol family to yield lower speed. No?

    PE

  2. #82

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    Quote Originally Posted by Photo Engineer View Post
    Sandy;

    An interesting post script to this is that Patrick said they all had the same apparent speed and you would expect the Microdol family to yield lower speed. No?

    PE
    Pat may be wrong about the film speed. The Microdol sample print does appear to have more density in the low and mid-tones, suggesting to me that it did indeed yield a lower effective film speed than the SPF.

    However, the only way to verify the above would be to expose step wedges with a sensitometer, develop them identically in the two developers, and plot the curves.

    Sandy

  3. #83
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    Well, there are too many imponderables then at this point for me. An attempt at a good experiment with some loose ends. BTDT myself. No criticism to Patrick on this one.

    PE

  4. #84
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    Contrast and effective film speed are too interdependent to make a firm conclusion from these tests. When I use the term "appears to be" let it be understood from now on that I mean just that.

    I could probably supply a little more information about film speed by a contact sheet showing all three negative strips and exposure brackets side by side, but the fact is that using box speed on all of them will get no one in trouble who knows how to use box speed.

    If I gave the impression that I was trying to prove something that is not obvious to be true , I apologize for giving the wrong impression. The scientific method is strongest when it demonstrates by evidence that something is false. I had hoped to show that high sulfite content is not essentially a correlary of fine grain. Could we improve the Phenidone-C-Borax by adding sulfite? I didn't try because the solution is nearly saturated as is. I see another argument there, but I'd sooner leave it there. Suffice it to say, if you have a box of borax and some ascorbic acid, you need only a little Phenidone or a little more Metol and some water to develope them. You could probably stabilize the negatives with a strong salt solution long enough to get back to civilization.
    Gadget Gainer

  5. #85
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    1:30 AM explains why a lot of what I said above doesn't make good sense.

    IIRC, from the start I called the D-23 + salt a "Midrodol X expedient". I should have left it out. I used Rodinal 1+25 as per recommendation of the original Rodinal bottle for HP5+. No time was given for the 1+50 dilution because HP5+ does not reach CI = .65.
    Gadget Gainer

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