Old thread, but similar question. DroneDeploy mentions slower flight speeds if using LowLight setting.
For mapping? I will assume so. I will also have to assume a minimal altitude of 250' AGL. I hate assuming but your question is vague.
The short answer: Yes and no.
The long answer: It's intuitive that you would fly slower in lower light or lower altitude. However, unless you're mapping at night or 100' AGL, the need to slow down doesn't come into play. You should be able to fly a good 26-27 mph on even the most cloudy days @ 250' AGL. If you fly 400' AGL, you should be able to fly faster...probably closer to the 31 mph you mentioned.
I noticed it changed ISO to 400. Does the drone speed Matter of using X4S Mechanical shutter??
Again, I have to assume the X4S is capable of f/2.8. Assuming so, you should be able to fly ISO 100 on Sunny days and ISO 200 on cloudy days. I rarely slow down my shutter more than 1/1600, but occasionally I HAVE had to slow it down to 1/1000. But that would be when skies are very dark, like pre-rain conditions.
If so, what is a reasonable slow speed? The default is 31mph.
@Donnie Frank ?? Any experience with this?
31 mph is the setting for minimal speed. You can set a slower minimum speed if you wish. I'm not sure why anyone would want to do this, but the option is there. At least that's how it works with Map Pilot. I assume Drone Deploy probably has similar settings for similar reasons. That said...
Again, making more assumptions about the software you're using (I don't have Drone Deploy), the software will generally slow down your drone to compensate for blur conditions caused by slow shutter speeds. Any reason you may have for slowing down a shutter in real photography is moot in the mapping environment. For mapping you would use the same settings as you would action shooting. So I like an ISO of 200 because it allows me to shoot shutter speeds of 1/1600 on cloudy days and as fast as 1/3200 on sunny days. ISO 200 is native on the P4P, so I'm comfortable keeping it there permanently. I'm sure the X4S is happy @ ISO 200 as well.
Generally speaking, .6 inches of motion blur is the most blur your software will allow before slowing down the drone. Shooting Shutter Priority, ISO 200, 1/1600 shutter generally nets .2 inches of motion blur.
This was shot using the exact settings above @ 250' AGL on a cloudy day using a P4P Obsidian @ 26-27 mph. Notice the clarity:
Even digitally zoomed with oncoming traffic traveling 60-70 mph, the photo has almost no motion blur.
And of course, the mechanical shutter insures against digital warping due to progressive scanning.
D