How fast can you shoot your normal (50mm equivalent) lens handheld, and without optical image stabilization?
The zoom is f/3.5 at the 35mm setting, so I gain about 1.5 stops of light with the f/2 prime. Apart from that I'm okay with bumping the ISO from the auto 3200 I normally use to auto 6400, so I gain about 2.5 stops of effective exposure which I hoped would be enough to offset the loss of optical image stabilization, but it's not even close.
I did some tests and I can get a sharp image with the 35mm prime at 1/128s only about 80% of the time and, even then, it's not a perfectly steady shot. It's much sharper from a tripod. At 1/64 I can only get a sharp image about 30% of the time, and at 1/32s I can't get a sharp image at all.
With the zoom lens at 35mm I can get a sharp image at 1/16s 100% of the time, at 1/8s 95% of the time, and at 1/4s 60% of the time. And if I get a sharp shot, it's as sharp as I can get it from a tripod.
I actually mostly shoot film on Nikon SLRs with old AI/AI-S manual focus lenses, so I believe I have enough experience "bracing myself" for getting steady shots without OIS. With my film cameras I get 100% sharp shots at 1/30s with a 50mm or 85mm lens. I shoot my 135mm lens at 1/60 with no problem.
In other words, with my film camera I can easily beat the 1/f rule of thumb for maximum shutter speed, but I'm nowhere near as good with my digital Fuji camera. And the SLR even has slapping mirrors which would in theory make this harder than on my digital camera.
The problem seems to be that on my Nikon FM3a SLR the shutter release is very smooth, there are no kinks and detents. I can smoothly squeeze the shutter release button, I don't even have to hit the bottom.
On the Fuji there are annoying middle detents, and I have to fully depress the shutter release button to make an exposure. I can set a two second delay, but it's very annoying and still nowhere near as good as what I can get on film.
So what's the problem here? If you're hand-holding your digital camera, what shutter speed can you use and still get sharp shots 99% of the time with a 50mm equivalent lens?
I was thinking that the weight of the film and digital setups are different, so I made a comparison:
Fuji X-T10: 372g Fuji X-E2: 344g Nikon FM3a: 595g Nikon FA: 625g Fuji XF35F2: 165g NIKKOR 50mm f/1.4 AI-s: 250g Nikon Nikkor 85mm f/2 AI-s: 313g Nikon 135mm f/2.8 AI-s: 435g Fuji X-T10+XF35F2: 537g Nikon FM3a+50mm: 845g
So there is 57% more weight with the Nikon setup.
I have also did some more tests between my X-T10 and my X-E2 (same sensor), and strangely enough I am much sharper on my X-E2 at 1/f shutter speeds.
I am comparing 50+ MP film scans downsampled to 16MP (same resolution as X-T10) viewed on the same 5k display at 1:1. I shoot mostly Velvia 50 and sometimes Ektar 100. I have done some more tests, it appears that if I shoot in continuous-low mode (I think around 3fps), the first and last frames are pretty shaky, but the middle frames are sharp even at 1/15 (again I'm talking about the same 50mm-equivalent lens).
Later edit: This is NOT a duplicate of How can I determine the minimum shutter speed to avoid blur from camera shake? because this question is about the differences in camera shake behavior for specific different systems, not about camera shake in general.