Ilford HP-5 test/D-76

Discussion in 'Black and White' started by chris_autio, Jun 27, 2020.

  1. Because every lens is different regarding precise aperture opening, and every curve different with different developers, I nonetheless endeavored to do a test with my Toyo 45 with Ilford HP-5 in D-76. Tray processed. One sheet over the other very slowly. I will try Ilford DD-X developer next. Umbrella reading is f/22 throughout. Results? f/22 exposure should have been developed at 6.5 minutes, not 8:
    f/32 exposure is best looking negative at 9.5 minutes(n-1). f/45 exposure shy in the darkest of gray scale blacks but is still very nice (n-2). f/64 exposure falls off the scales. Perhaps HP-5 is best rated at ISO 800, therefore, for my camera.

    These are not prints. They are rephotographed negatives at same exposure without any photoshop correction aside from flipping the curve. Check attached file for a sense of these negs.

    HP-5 test D-76.JPG
     
  2. Depends if you want any shadow detail or not.
    The f/22 shot is the only one that retains the same amount of detail as the colour example - shot digitally?
    See cap of horizontal bottle - far left - against dark background.

    The 400 ISO shot only looks too light because it's not been post-processed to the correct tone curve.

    So absolutely no surprises in those results.
    Maybe by an insignificant third of a stop.
     
  3. James G. Dainis

    James G. Dainis Moderator

    Am I understanding this correctly? The above photos were all shot with the umbrella flash manually set for f/22? No wonder the f/22 shot looks about the best. The f/64 shot would have been three stops underexposed like setting the 400 film to 3200.
     
  4. AJG

    AJG

    I don't think your results warrant your conclusions. Rodeo Joe is correct that the f/22 version has good shadow detail, as I would expect. Varying the developing time as you did and then converting negatives through photoshop provides for a lot of subjective manipulation that could account for much of the variation seen here.

    In my experience with large format lenses (5 Rodenstocks and a Nikkor-M) I have found no discrepancies in f/stop settings with thousands of sheets of color transparency film, a much more critical test than B&W negatives. If I were you I would worry a lot more about consistent metering and developing technique than the accuracy of f/stop settings on almost any large format lens.
     
  5. "If I were you I would worry a lot more about consistent metering and developing technique than the accuracy of f/stop settings on almost any large format lens." Minolta ambient metering f/22.0 on each and every shot. Films processed beginning @ 20 minutes, each respective one (f/22 removed at 12 minutes, f/32 @ 11.5 min, f/45 @ 7 minutes.) I placed in cold running water (not stop, as I didn't want to affect other films with my fingers). Once 20 minutes up, dipped all in stop 10 seconds and then fixed.

    Also, rephotographing negs was set to same exposure and no post manipulation was used in Photoshop other than flipping the curve for all.

    I am surprised actually by how I began to lose overall density in progression of 400 to 3200. In looking at the grey scale in photos, the ISO 400 just looks too flat. But it may be the best negative once printed.

    I am an artist but I know that good science requires retesting of which I will do. Ansel Adams said the best photo starts off with the best negative.

    Unrelatedly, I had my Caltar 135 lens shutter tested at exposures 1/500 thru 1 second. It was "good" among all speeds, except for 1/250 and 1/500 where it was wildly off and needs up to +60% correction!
     
  6. My experience of film photography is that a bit more than half a stop is not ‘wildly off’, its normal!
     
  7. AJG

    AJG

    I'm not surprised that an older leaf shutter is off at high speeds--even when they were new 1/500 was probably a bit optimistic, especially if the lens is stopped down to f/22 or smaller, and the time that the blades are open is effectively longer.

    How did you decide on your processing times? If you've done much research you probably know that pushing film (overdeveloping) doesn't increase sensitivity of the film, especially shadow detail, but will potentially block up highlights and increase grain and contrast.
     
  8. All the 'testing' you'll ever need has already been done for you by the technical staff at Kodak, Fuji, Agfa or whoever you buy your film from. They don't print those ISO numbers in a large font on the film box for nothing!

    Farting about 'testing' this film in that developer and at this, that and the other E.I. is the bitter enemy of actually producing any pictures worth a damn. Choose a film, choose a developer, and stick with them until you know their characteristics inside out.

    FWIW, most of Ansel Adams' best pictures were produced before he started teaching and devised the ridiculously complicated Zone system to 'help' his students get to grips with two simple concepts: Pre-visualisation of the print tones, and the pre-existing maxim of 'expose for the shadows and develop for the highlights'. Good technique need be no more complicated than that.

    In fact there's a discrepancy of half-a-stop between Adams' verbal description of the Zones, from V to VIII, and their actual sensitometric values. So much for his insistence on 'accurate' exposure.

    'Calibration', 'testing' and constant adjustment of technique is an insidious black hole that will entirely swallow up any creativity and involvement with your subject-matter, if you let it.
     
    robert_bowring likes this.
  9. For my taste and experience, all of the images produced are flat. The f22 image is the best, but could have used EITHER more exposure at the printing stage, harder paper or more development. I can't tell which from this thread. Your blacks aren't black in the f22 image and I don't think that the whites are white in the other images.

    Over all . . . This is about finding what works for you. Film, rating, developer and time. When I was shooting TMax films, I usually over exposed by up to a full stop and then overdeveloped by about 10 or 15%. Everything printed on grade 2, Zone VI, paper. Later, I switched to Tri-X and PMK Pyro developer. I also over exposed that by at least a 1/2 stop but found that development time was very forgiving.

    I'm not going to get into the Adams thing . . . I learned a hell of a lot from his books but put much less than I learned into practice.
     
  10. f32 post processed, lots of detail and good range of tones. f22 didn't respond the same way, it has blown-out highlights. f32 is my pick.

    Screen shot 2.png
     
  11. Really?
    There's still no deep shadow separation.
    How can you tell anything about 'blown-out highlights' from an already digitised JPEG? Only the original negative can tell you anything at all about its scannable or printable range.

    If the highlight density doesn't exceed 2.1D, then it'll scan or print just fine, and be on the 'linear' part of the H&D curve with excellent separation.
     
    Last edited: Jun 30, 2020
  12. James G. Dainis

    James G. Dainis Moderator

    Underexpose and overdevelop loses shadow detail. Increased development effects highlights, it has no effect on shadow.

    "All this shadow detail really bothers me. I will underexpose to make all the shadow detail black and overdevelop to bring up the highlights."

    I don't understand that.

    If you knew the Zone system you would have developed the f/22 at 6.5 minutes to keep the shadow detail and lower the highlights
     
  13. James G. Dainis

    James G. Dainis Moderator

    Once you can "see" and understand what happens to film when it becomes developed, the Zone system becomes clear. Let's pretend that you take a picture of a black square next to a white square (black square on the left) on a sheet of film. Let's also pretend that you can see the film as it develops (pre-fixed and everything.) Place the film in the developer and what do you see? The black square is already there! Remember, this is a negative, the black square will show as clear and the white square will show as black when the negative is fully developed.

    After about a minute or so, you start to see a light gray square starting to form on the right side of the negative. After 2 or 3 minutes it will get darker and darker. The longer you have the film in the developer, the darker it will get until it appears pure black. (and hence will print pure white) What happened to our square on the left? Nothing. It was going to show as a clear square on the developed film (so it would print pure black). That's the way it started out and that's the way it ended up. The silver halides of the emulsion were not "triggered" by light on the left side so the developer did nothing. Increasing or decreasing development time can only change the highlights, never the shadows.
     
    stuart_pratt and kmac like this.
  14. It is probably worth observing that the unexposed film edge in the f/22 and f/32 examples is most definitely not black. If the levels are adjusted to make the unexposed area black, and the steps on the Kodak gray scale are probed and their values measured, it becomes apparent that the f/22 example is correctly exposed and the f/32 example is underexposed. (The f/22 image may be slightly overexposed, but it's pretty close.)

    However, the steps on the gray scale are too light through the mid-tones and too dark in the brighter tones. My guess is that the camera (JPEG?) and Photoshop are probably contributing significantly to this. Consequently, I would be very reluctant to judge development times based on these images.
     
    rodeo_joe|1 likes this.
  15. Absolutely!
    There's also a difference in producing a B&W negative that's ideal for scanning, and one that makes a good wet-print. There's some overlap WRT shadow detail and separation, but scanning can generally drag a little more out of the highlights, without resorting to extensive dodging and burning or split grade printing.

    The naked eye isn't a good judge of a negative anyway - too influenced by viewing brightness and adjacent tones. A densitometer is needed to get the full picture, if you'll pardon the pun.

    I'm not saying that a densitometer is essential. Just that if you are going to muck about switching and swapping film and developer combinations and E.I. settings, it makes comparisons much quicker and more objective.
     
    Last edited: Jul 2, 2020 at 10:51 AM

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