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Thread: Improving B&W resolution

  1. #1

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    Improving B&W resolution

    Does anyone have a good method for improving the resolution on 4x5 B&W negs? My sharpness is there I'm just missing that grain free print that a 4x5 neg gives you.I've had some negs that give that"grain free" look but it's not consistant enough.I also have the disadvantage of having to send out my film for processing. I use Ilford Delta and the lab uses Ilford ID11 developer.Any thoughts.I rate the film at 100 iso and my negs have good density to them.

  2. #2
    Octogenarian
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    Re: Improving B&W resolution

    I'm surprised that you found a lab. that still develops B&W film.

    I suggest that you develop your negatives in Pyrocat-HD. Do them yourself.

    And switch to Ilford FP-4+ film.

  3. #3
    ic-racer's Avatar
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    Re: Improving B&W resolution

    If you shoot at f22, then your max resolution is going to be somewhere around 60-70 line pairs per mm at the very best. That will likely be way less resolution than the film resolution, no mater how poorly they process it.

    I'd bark up a different tree

  4. #4
    Resident Heretic Bruce Watson's Avatar
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    Re: Improving B&W resolution

    You're seeing grain in prints? How big a print are we talking about here? From properly processed (Dmax less than say 1.5) Delta 100, you should easily be able to make a "grain free" enlargement in the 6-8x range, perhaps bigger. So how big a print are we talking about?

    Bruce Watson

  5. #5
    ic-racer's Avatar
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    Re: Improving B&W resolution

    BTW grain and resolution kind of go together. The less-grainy developers smooth the edges of the grain clumps and impair resolution.

  6. #6
    Nicholas O. Lindan
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    Re: Improving B&W resolution

    Quote Originally Posted by ic-racer View Post
    BTW grain and resolution kind of go together. The less-grainy developers smooth the edges of the grain clumps and impair resolution.
    Funny, my experience photographing test targets is just the opposite: fine grain developers such as Microdol allow more resolution than 'acutance' developers like Rodinal.

    It is a difference between perceived detail and real detail. Rodinal is great at making it look like there is lots of sharp detail in the print but it is illusory as the large (though sharply defined) grain and "edge effects" can only create artifacts that obscure the real detail. Unsharp masking, the ultimate in edge effects, produces the effect of extra detail, but the actuality of the process is that it removes information from the image.

    It isn't that Microdol "smooths away" detail, my understanding of the action of the S. Chloride is that it keeps grain clumps from forming when an exposed halide crystal would otherwise cause an adjacent unexposed halide crystal to develop. There is misconception that Microdol is a 'high solvent' developer, it isn't - it has the same quantity of S. Sulfite in it as D-76/D-23.

    One method of evaluating a film/developer combination's granularity is to measure the decrease in resolution due to large grain size.

    Ref. Mees et. al. Theory of the Photogaphic Process, revised ed., Ch 24 The structure of the developed image.

  7. #7

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    Re: Improving B&W resolution

    Quote Originally Posted by Bruce Watson View Post
    You're seeing grain in prints? How big a print are we talking about here? From properly processed (Dmax less than say 1.5) Delta 100, you should easily be able to make a "grain free" enlargement in the 6-8x range, perhaps bigger. So how big a print are we talking about?
    16x20 on a Epson 3800 printer.

  8. #8

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    Re: Improving B&W resolution

    My experience matches that of Nickolas. I used to use Microdol X with Panatomic X and under 5X mag. prints were essentially grainless for normal type development. Don't know about using Microdol with Ilford Delta though. I think you're in a world of hurt if you send out your film - there is simply little or no control over the negative process.

    Nate Potter, Austin TX.

  9. #9
    Resident Heretic Bruce Watson's Avatar
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    Re: Improving B&W resolution

    Quote Originally Posted by ignatiusjk View Post
    16x20 on a Epson 3800 printer.
    Ah. And how was the film scanned? The reason I ask is this sounds like possible grain aliasing from scanning. A 4x enlargement from any modern film should be nearly grainless unless something is seriously or intentionally wrong. But some scanners exaggerate the heck out of silver grain clumps. Has to do with the pitch of the photoreceptor sites matching up with the average grain clump size and distribution -- you get the optical equivalent of a beat frequency. Sometimes described as "pepper grain".

    Bruce Watson

  10. #10

    Re: Improving B&W resolution

    I second what Bruce wrote.

    I don't think anyone can mess up 4x5 Delta 100 badly enough to get any visible grain at that reproduction size.

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