>>3860236>If I use a manual prime lens made for 35 film or mirrorless FF, will the focus distance scale/hyperfocal markings still be accurate if slapped on a mirrorless APSC body(1.5x)?More or less, yes. Not 100% exactly, but close enough that you don't have to worry about the difference.
As
>>3860249 says,
> if you crop an in focus photo does it become out of focus?which is mostly correct, except it forgets the unspoken step that you then blow it up to the same size as the uncropped photo. When you increase the size like that, details that were acceptably in-focus at the smaller magnification might not be anymore. Kind of like how a photo can look in-focus at a normal size but you can see it's not perfectly sharp when you blow it up to 100%.
(The other takeaway from this being that depth of field markers on lenses have an unspoken caveat of "when viewed at a normal size/distance", too. They're not exact because there's not a way to make them perfectly exact because the lens doesn't know if you're printing a 4x6 or a 4'x6')
>>3860317> for all intents and purposes you multiply by 1.5x or whatever crop factor and that's it, fuck youI was prepared to be on your side in this thread, because for ALMOST all intents and purposes you multiply by the crop factor, but in the specific case of DoF markings, you don't need to.
Depth of Field is different on crop because, to get the same framing, either (a) you use a wider focal length or (b) you step back a little bit. Neither of those have any effect on whether the depth of field markers on the lens are accurate--the wider lens is going to have more depth of field for where you're standing, regardless of whether it's cropped in or not. The longer lens is going to have more depth of field if you take a step back, regardless of whether it's cropped in or not. So, taking into account my caveat above, the DoF scale on a lens moved to a smaller format is gonna be close to accurate, and certainly not off by the crop factor.
