You know all those bracketed exposures you used to take on 35mm...

Discussion in 'Casual Photo Conversations' started by Karim Ghantous, Sep 19, 2021.

  1. ... well, I had a realisation just recently. You could scan them all and combine them via frame averaging to minimise graininess. Of course the tighter your bracketing, the more useful the result. But, it's worth a thought.

    I have no idea whether or not this is even necessary, given the seemingly very advanced NR in DxO PhotoLab. If anyone has actually tried frame averaging their film frames, do let me know. I'd like to see the end result.
     
  2. See this thread I posted some time ago.

    I never persued it because of 2 issues mentioned in that thread:
    1. The frames have to match exactly, so 'random' handheld shots are almost useless.
    2. The scans also have to exactly align - otherwise there's a fair amount of work in post de-skewing them.
    A tip if you're going to try this: The keyboard direction arrows perform a one-pixel shift in Photoshop. Trying to align layers exactly with the mouse is highly frustrating!
     
    Jochen likes this.
  3. You can use 'merge' to combine handheld shots for some effects, if you like
    IL-DuQuoin-120829_hd-combined.jpg
    All hand held time sequence
     
  4. In Lightroom I use Masking when sharpening so the large areas like the sky don't sharpen as much as everything else. Combine that with Noise reduction to reduce grain too if you find it's getting predominate.

    Since I'm normally shooting Tmax 100 lately, the grain is unobservable in 4x5, while more so in 35mm. Tmax 400 has a little more grain than Tmax 100.. So if grain really bothers you, use Tmax.
     
  5. The same tools which automatically align bracketed digital exposures will work for film scans as well. Some, like Skylum Aurora HD, will use masking to split out objects which move between frames.
     
  6. Teton Canyon night 11-19 composit s2.jpg
    The program Starry Landscape Stacker works this way for nightscape images, where a series of of exposures of the moving night sky, including a non-moving foreground, are combined to form a single image. The program separates the moving and non-moving parts, then adjusts the positions of stars in the moving part to overlap. It is quite effective at reducing noise in typically high ISO exposures.

    Here is an example where I combined five 20s exposures using the program, (images taken at f:1.4 and ISO 800 using a Sigma Art 24mm f:1.4 lens on my Canon 5D IV).

    The program should work with a series of scanned film exposures to reduce graininess since grain positions would not repeat from frame to frame. How close the subject would overlap is a question, since it would require exact frame to frame registration or work in Photoshop. (In the old days we used "pin registered" movie cameras to record data where tracking position in an image was important).
     
    Last edited: Sep 19, 2021
  7. Seems my knowledge of software tools has become outdated then. I'll have to investigate some of those nifty auto-alignment apps listed above. Thanks for the pointers people.

    My interest in reducing film grain is almost zero these days. As Alan says, if you want grainless, there's T-Max 100, or just using a larger format than piffling 35mm. Or digital.

    Film has always been relatively expensive, both in time and money. So who has a stock of bracketed almost-identical shots on film? That's what a light meter and experience were there to avoid.
     
    Last edited: Sep 20, 2021

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