With the following constrains: Camera a2A2600-20gcBAS at 100 microSec shutter
Film edge-to-edge overscan
Film speed 16fps
For 16mm and Standard 8 the calculation works to ~2 vertical pixels. In practice it would be lesser or equal to 3 pixels. Note this is not the worst case, which would be if instead of over scanned, the film is cropped at scann.
That may be further reduced if the flash is less than the shutter.
That is basically the effective vertical resolution. If one prefers a crop scan, set a vertical overscan percentage, and it is simple math from the sensor vertical resolution.
Yes, that’s right. The calculation is straightforward if both the capture height and the vertical overscan percentage are known. By “the labels ‘2K’ and ‘4K’” I simply meant that they alone do not give that information.
Imo the mechanical stability of the scanner is still important since any relative movement between the film, the lens and the sensor while the exposure is taking place can cause extra blur.
I also have a question regarding the lighting—if LEDs at different positions are used in sequence, could the change in the position of the light source cause slight apparent shifts between the individual captures and result in additional blur when the captures are combined?
(This also applies to captures taken with the film stationary)
You can make the light be at the same location for all 3. For example, using an integrating sphere.
The displacement of LEDs may be an issue for light uniformity, more than for shifts between separate captures.
The actual issue on all forms (color/monochrome white/RGB led) is that the focus point for each color channel is slightly different. If one wishes perfection, the focus point would be different for reds, greens, or blues. Again, the same issue regardless of sensor or light type.
I agree that illumination uniformity is a concern, but could different illumination angles also cause slight image shifts, particularly if the film is not perfectly flat or precisely in focus? I wouldn’t rule that out without testing it.
Or mount the LEDs on a pivoting arm so they can be positioned beneath the film frame one after another for each capture, but that starts to get a little complicated.
Ultimately, we’re still missing the definitive comparison: scanning the same film with the film stopped at each frame and multiple exposures per frame, versus scanning it with continuous film transport and a single exposure per frame, using the same camera and lens in both cases. The results should be compared both before and after post-processing.