There are many methods to digitize film. Which is best or most economical depends on your specific needs. There's usually a trade-off between image quality and time. Equipment capable of higher bit depths and resolution often take longer to scan. However, if your requirements are modest, you can adjust settings to scan more quickly.

Batch scanning saves your time, so even if the scan speed is slower, it would be more convenient, unless you're working against a deadline. Since you would be absent for the scanning process itself, you could scan at higher resolution to avoid having to rescan in the future.

• Flatbed scanner with transparency adapter. Many people seem to have good results with Epson Perfection V### scanners. They usually include the backlight and film holders needed to scan a variety of film formats. This is probably the most economic way to scan medium format film. Image quality is good, but not the best. Scanning tends to be time consuming.

• Dedicated film scanner. The highest rated film scanners, made by Nikon and Minolta, appear to no longer be in production. Mid and low-end models from other manufacturers are still available. Image quality may be better or worse than flatbed scanners, depending on the particular unit. Scanning tends to be time consuming.

• Film digitizer. These use digital camera sensors to capture the image at once. They're much faster than true scanners, but have reduced image quality from the small sensor size and color array. Some models capture directly to SD card. Image quality is usually good enough for small prints or sharing on social media.

• Slide-copy attachment. There are several types.  The quality of captures depends on how careful you are with setup, lighting, and post processing. Capture is quick, but images usually require post processing before they are ready for use. Inverting and color correcting negatives can be especially time consuming.

  • Some attach to the filter threads of a lens. This type of slide duplicator is easiest to use on crop-sensor bodies. Image quality depends mainly on the quality of the lens. Color quality depends on the light source (use a flash).

    The duplicator is basically a slide attachment and a tube with a diopter filter inside. The macro filter may introduce some barrel distortion, which can be corrected in software. Any loss in image sharpness won't be significant as long as you are able to visualize and focus on the film grain.

    Use a zoom lens to find the appropriate focal length, then switch to a sharper prime, if you have one available. You can also remove the dioptre and use a macro lens.

    Use the minimum ISO available on your camera, and stop down to the sharpest aperture of your lens (usually F5.6 to F8). You don't have to worry too much about long exposure times since the attachment is motionless relative to the sensor. If your camera or lens has image stabilization, turn it off.

    

  • Some attach directly to the camera. All necessary optics are built into the duplicator. Some allow zooming from 1x to 2.5x. You can zoom in on sub-miniature formats, but you won't be able to zoom out to capture entire 35mm frames on crop-sensor bodies. You can capture and stitch multiple sections of each frame.

  • Some are intended for use with bellows. Lens selection and bellows operation may require some trial and error. As the bellows is used to move the lens away from the sensor, sharpness is decreased and a "glow" may appear.

    

    You can use the thin lens formula to figure out approximate distances and focal lengths you'll need for a given reproduction ratio (magnification, m = v/u).

    1/u + 1/v = 1/f

    u = subject distance
    v = image distance
    f = focal length

    For 1:n, u = (n+1)f, v = (n+1)f/n. So for a 50mm lens with a reproduction ratio of 1:1.5, u = 83mm and v = 125mm.

• Copy stand. Copy stands are for duplicating prints and documents, not film. While you can use a copy stand with macro lens and light box, using a slide copier is far easier and cheaper.

• Slide copying device. These are all-in-one units that combine copy stand, light box, flash, bellows, etc. An example of this type of device is the Bowens Illumitran. Use is similar to a slide-copy attachment. The device tends to cost more. Results are more consistent, less subject to minor setup changes.

• Have someone else scan your film for you. Most labs offer this service along with development.