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Would a stacked photo give increased resolution?

Discussion in 'Open Discussion' started by walter_j, Sep 18, 2016.

  1. walter_j

    walter_j Mu-43 Veteran

    364
    Sep 10, 2013
    Hagwilget, B.C., Canada
    Walter
    I printed a 30"x40" photo from a E-M1 recently, and think it may be too big for the resolution. I was thinking that perhaps a focus stack of 3 or 4 images might give me a higher resolution image for large prints. Would this be so? Or perhaps a HDR type shot.
     
  2. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    Focus stacking won't give you higher resolution per se, but it will give you more detail across the frame, especially if you are having to stop down past f/8 in order to get all your subjects in focus, at which point diffraction will limit the amount of detail you can achieve.

    HDR won't increase resolution, but some people believe you can get better resolutions out of "super-resolution" software by stacking a large number of images with slight offsets in order to 'read in between the lines.' It's basically a dumbed down version of what the E-M5 II and PEN F high-res mode does, but instead of requiring a tripod, it typically requires that you handhold the multiple shots in order to achieve the micro-offsets. It's less precise, and I believe it typically happens after the demosaicing process so you don't get the full-RGB pixel advantage that sensor shift gives you, but you can try and experiment. I think PhotoAcute is the only software on the market that people really use for this.

    The last option is an improve up-ressing algorithm, that can supposedly improve the interpolation and give you smoother, better looking results when doing large prints. You're not adding any more detail, but it supposedly eliminates a lot of the scaling artifacts (like stair-stepping / pixellation / blurring) that tend to be the tell-tale signs of a file that is too small for the job. I have heard Alien Skin Blow Up is a good one for this, but it's $100.

    The easiest and most certain way to improve image quality for larger prints is to use a good lens with a longer focal length and then do a panoramic stitch. However, this only works for still subjects, so if you're trying to print an action shot it is obviously not suitable.
     
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  3. Speedliner

    Speedliner Mu-43 All-Pro

    Mar 2, 2015
    Southern NJ, USA
    Rob
    Stacked images can reduce noise which might be part of the problem.
     
  4. fader

    fader Mu-43 Regular

    101
    Aug 20, 2016
    Brest, France
    Isaac
    doesn't quite work that way ... I've been looking into image stacking myself. It seems you need at least 20 or more images to begin to see good effects, that is if you're trying to average out ISO noise and increase saturation etc. some of the macro guys are stacking 100~ 150 images for tack sharp, noise free results ... but the resolution of the file is still the same.

    when you want to print something in the large, going from 300 dpi to 150 dpi is typically safe. which did you print at? 11x14 is considered to be the max with full resolution at 16 megapixels, but you can push that depending on the image. look closely at movie posters or ad banners and the like and you'll see that they hardly have detailed resolution. the distance from the image to the observer factors heavily into what you want to print. If you want to scale something up, think about where you want to hang it - like over a fireplace or some out of the way wall where it's hard to stand nose-to-print. 5 to 10 feet back and you won't notice any loss of detail.

    there are plugins in photoshop to scale up images but I haven't used them. others can pipe in with that.
     
  5. Carbonman

    Carbonman Mu-43 All-Pro

    Jul 10, 2014
    Vancouver BC
    Graham
    You can also output tif and jpg files from OV3 at up to 8000 pixels on the largest dimension. It's not really an increase in resolution but minimizes pixelation in large prints.