SHUTTER ISLAND: CHOOSING YOUR CAMERA BODY

The camera body affects the resolution of your digitized photos. The sensor's overall pixel number and the distance between pixels set the ultimate limit for actual resolution. Note that typical sensors with Bayer array have approximately half of the nominal or advertised megapixels.  Pixel shift technology considerably improves the resolution. Other features, such as dynamic range, also matter, but even an entry-level camera will typically have a higher dynamic range than negative film. See next item for details.

I think what's crucial here isn't so much the choice of camera, but the entire setup. 

Slides present a number of unique challenges you'll need to consider. 

• They have a relatively high dynamic range, which could influence the choice of camera body. 

• Additionally, some slides might be warped or damaged due to the heat from a projector's lamp. 

• Mounts, even from the same manufacturer, can vary in thickness, necessitating refocusing for nearly every frame. 

• Your rig needs to be robust and sturdy, especially since inserting and removing slides can require significant force, potentially affecting focus. 

• One advantage of slides is that you can see the quality of the capture in real time, allowing for on-the-spot adjustments. 

You'll likely need a camera with an excellent dynamic range, although bracketing for HDR might still be necessary—though that's not a significant concern. A camera with reliable tethering capabilities is essential.

Plan ahead for the file size you'll need; it's doubtful you'll require more than 30 MP. If you opt for hi-res and pixel shift, ensure your setup is exceptionally stable to eliminate any vibrations. Pixel shift can be useful for down-sampling images since you'll need a way to reduce the grain that becomes very apparent at higher resolutions, like 61 MP and above.

Essentially, determine the kind of digital images you want, the software you'll use for processing, and the necessary tethering capabilities. Only then you can decide on a camera. Personally, I feel the choice might come down to either Sony or Canon, but of course, I could be mistaken.

The difference lies mainly in the sensor size and pixel pitch. Full-frame cameras often have larger pixels, which can provide slightly better detail and dynamic range. The reproduction ratio for APS-C camera is 1:1.6 vs 1:1 for full-frames (for 35 mm originals).  In combination with certain lenses the  smaller sensor may even provide certain advantages. Both  APS-C and Full frame cameras can  deliver excellent results while APS-C systems can be more affordable and easier to handle. 

Yes, mirrorless cameras are excellent for film digitization. They offer a permanent live view mode that adjusts image brightness in the viewfinder automatically, which allows you to comfortably work with lenses already set to the working aperture. Short flange distance makes these camera compatible with a broader range of lenses, including older, high-quality enlarger lenses. Another advantage is their well developed capacity for tethering, which allows real-time viewing and more precise adjustments on a computer. 

DSLRs have an optical viewfinder, which some photographers prefer for its direct view of the subject, and they typically have longer battery life. However, they can be bulkier and the mirror mechanism may add extra level of vibration. While they also offer a live view mode, it can be slower and less responsive compared to mirrorless cameras. 

While newer camera models offer improved features and better sensors, older cameras can still produce high-quality digital copies of film. The most important factors are the resolution, or megapixel count and dynamic range, rather than the age of the camera. Theoretically older cameras may produce images in RAW format which may no longer be supported, but so far we are not aware of such cases.  

The required megapixel count depends on the level of detail you want to capture. For 35mm film, a camera with 18+ megapixels can capture pretty  high level of detail, 24 MP is generally considered enough to capture everything worth capturing on 24x36 mm frame.  

Use manual mode for complete control over the camera, set the ISO to its lowest value to minimize noise. Use of autofocus depends on whether camera /lens handle AF fine. That's vary widely between camera brands. There are few schools of thought on whether to use built-in light measuring system while taking pictures of the film frame. Most common recommendation is to overexpose by one stop. White balance setting does not really matter as in the vast majority of cases the digitizing is performed in RAW mode. We will discuss those nuances in another section.  

Shutter count isn't crucial for film digitization. High-speed shooting that might wear out a shutter isn't necessary. However, a camera with a very high shutter count might be nearing the end of its life. 

For digitizing film, it's advisable to always shoot in RAW format. This format captures more data and offers greater flexibility for adjustments during post-processing. However, if you're scanning color slides and using a certain type of backlight, such as the Sun, JPEG can be a workable option to get results faster. Note that for color negatives, which require an inversion process, JPEG is not a suitable format. If your camera supports HDR mode, you can use it to improve dynamic range when scanning slide film. Shutter speed bracketing is also advisable as it allows to creat HDR in post and also almost guarantees that at least one shot will be on the money.