There may be pent-up demand for a device that's going to let you dust off your beloved Nikon F-something and shoot digital with it, but that doesn't mean a crowdfunded project is going to make it possible.
Or, at least, not in a way that's worth the hassle.
Large companies with dedicated engineering departments have worked on the task, yet no such product has yet been produced. That, along with a list of seemingly intractable technical hurdles, lead me to think that it's not ever going to happen, no matter how desirable it might be.
The wisdom of crowds
The latest crowdfunded attempt to bring digital capability to old Nikon SLRs appears to involve the 1/2. 3"-type sensor and lens from an inexpensive action camera and a Raspberry Pi project computer.
"I'm Back" is the latest attempt to bring film cameras into the digital realm and it appears to do a reasonable job of addressing some of the challenges that sank Silicon Film and subsequent crowdfunded attempts to do the same:
Syncing the SLR shutter and digital exposure
A means of changing the digital settings
Keeping the cost reasonable
However, it's unclear or arguable how well it addresses other potential stumbling blocks:
Sensor/film plane alignment
Compatibility across the dwindling supply of film SLRs
Space for batteries and processing hardware
And, with its use of a compact camera sized sensor fitted behind what looks remarkably like the lens from an inexpensive action cam pointed at a ground glass screen, there's every chance it fails to clear a fairly significant hurdle:
Sufficient image quality to make the whole ordeal worthwhile
A history of failed attempts
Companies with significant backing and extensive engineering resources have failed to solve this problem, which doesn't make it an obvious candidate for crowd-funded projects.
Nikon itself clearly investigated the problem, since it got as far as patenting a system for adjusting the sensor, relative to the film plane. But it noticeably hasn't ever released the fruits of this research.
We wrote at the time about why we didn't think it would lead to a product. We've also covered reports of why Silicon Film never delivered.
Do it yourself
If you're really dedicated, can handle a craft knife with some precision and don't mind sanding down the delicate components of several hundred dollars-worth of modern ILC, then you too can mount a Sony NEX upside down in the back of your SLR. So long as you remember to fire both shutters in sequence. (Despite my sarcasm at the impracticality, it's an impressive piece of handiwork).
But, realistically, if you really want to use your old SLR, I'd recommend going out and buying a roll of film. The recently resurrected Ektachrome, perhaps. Or, and I know this is going to sound radical, you could shoot with a camera that's been designed from the ground up to shoot digital. A 'D'-SLR if you will.. dpreview.com