Shutter Speed vs Resolution

I'd like this thread to elaborate on this concept of higher resolutions needing more shutter speed and also what shutter speeds the experienced photogs here use for a given situation.

The 1/FL rule was created when and with how much resolution?
Do you double it for a crop sensor?
Do you double it as resolution doubles?
Flash vs no flash vs high speed synch?

Edit: how these situations' required SS vary with regard to resolution:
What shutter speed do you use to freeze motion:
Portraits?
People conversing in dim light in a living room or restaurant?
Sports arena with good lighting? Bad lighting?
Water skiing?

etc.....

1/Focal Length isn't a "Rule" really but a Memory Aid to remember that all things being equal, you should increase your shutter speed as glass length increases because the longer the glass, the more amplified are errors in stability.

AFAIK, you do take crop factor into account as well.

Me? I'm fine with hand holding 500mm @ 1/30 if need be and there's a helicopter in sight.

YMMV...

If Flash is your primary source of light, then Flash is your "shutter" and flash duration rules the roost. HSS can't throw enough light (at low ISOs) to be primary so mechanical shutter speed rules.

If you plan to use all the stinkin' megapixels (see that thread ) then the more MP you hvae the greater will be the geometric enlargement of the information captured when you print. Thus anything that might contribute blur to the image will accordingly be enlarged. Hence the fuss about diffraction limits. To your question, you are asking about either subject motion or camera shake and whether increased shutterspeed is needed. If you imagine either one causing some small amount of blur, then the visibility of that blur will increase as you enlarge the image (cf. DoF goes down as you increase enlargement but keep viewing distance the same). So, yes, if you are using the increased resolution to make bigger prints and viewing them from the same distance, it makes sense that the shutterspeed at which you detect such blur will differ from using fewer MP or making same size prints from more MP. If you plan to use the MP, it will be wise to shoot faster than you used to. I think this issue contributes to some of the "My 7D is soft" complaints! How rhe numbers change is hard to generalize about, but the concept makes sense.

Higgs Boson wrote in post #13620178
The 1/FL rule was created when and with how much resolution?

It is not a rule and it started with film.

Bill Boehme wrote in post #13620489
It is not a rule and it started with film.

rule of thumb? you know what i mean. i hope.

Bill Boehme wrote in post #13620489
It is not a rule and it started with film.

In the days when "standard" conditions involved viewing 8x10s from about a foot - the same that gave us the famed DoF scales on older lenses..... Thus if you use a crop camera you need to use the "apparent FL" in the calculation and if you print bigger than 8x10 then make the shutterspeed even faster by the same amount....

it's only an issue factor for the pixel peepers and poster printers.

So anyone who makes large "fine art" prints is actually only making "posters" huh?

Ok, let's assume we are talking about 24x36 prints, posters, whatever.

Let's say 10MP 1/FL works great, how much faster do you want your shutter speed at 21 MP?

If your subject isn't moving and your camera is on a tripod, shutter speed does not affect resolution. This assumes the use of remote shutter release or timed shutter and mirror lock up; or rear focus screen.

Ianfp wrote in post #13620945
If your subject isn't moving and your camera is on a tripod, shutter speed does not affect resolution. This assumes the use of remote shutter release or timed shutter and mirror lock up; or rear focus screen.

So does this mean that more SS for more MP is only for hand shake, not necessarily subject motion?

If you really wanted to freeze subject motion so that a 21MP image wouldn't show any evidence of that movement, you'd be surprised how short an exposure would be required.

Higgs Boson wrote in post #13620986
So does this mean that more SS for more MP is only for hand shake, not necessarily subject motion?

Yes, a higher shutter speed is required to minimise any kind of movement in the camera if hand held. As has already been mentioned, the longer the focal length of the lens, the more chance of introducing movement in the camera. Hence the requirement for faster shutter speeds or use of tripods or mono pods. If the subject is moving, that is an additional consideration if freezing the action is what you wish to do.

Here's the example I had in my mind when I made my previous post. The train was travelling something like 40-50mph across the field of view at some distance from my position. The camera was tripod-mounted and fired by remote switch. The sensor (40D) is only 10MP and the shutter speed was 1/400s and at the pixel level you can see the train has moved.

^ curious as to what focal length was used?