For Best Definition at Very Low Altitude : Mavic 2 Pro OR Mavic Zoom ?

[BobbyBob]

Which drone will produce the clearest images of the ground at just 5m altitude?

Why do I want to do this ? I have a machine-learning program that (back at the lab), will identify and count tiny wild flowers on each photo BUT.... it will only count them if they are Clear enough on each photo for it to see! I'll be flying very low, probably about 5m altitude, over a few hundred square meters of flat grassland, that is always moderately windy. Photographing every couple of seconds on a flight plan.

So I really need to maximize the definition, and minimse all the things that cause blur (oh, and not crash !!)

The question is plz : Which drone do You think will give me the best chance at this - the Mavic 2 Pro, or the Mavic Zoom ? .......

 

[MrYKBQdV]

Mavic 2 Zoom is better for your use case, given the constraints.
The reasons are perfectly explained here: Why the Mavic 2 Zoom is better for you - DroneDJ
“The Mavic 2 Zoom can resolve finer features at 2X zoom than the 20 MP sensor on the Mavic 2 Pro.”
The downside is that you will need to take more pictures, but to maximize detail at 5 meters AGL the Zoom beats the Pro.

 

[BobbyBob]

Very useful article, thanks MrYKBQdV. It's given me a lot of food for thought, as it actually shows pro's and cons for both. I'm a bit worried about the high winds in my location. Would the zoom's smaller aperture = higher f-stop = slower shutter = more blur caused by buffeting of the moderate to high wind ?

 

[Florida Drone Supply]

Mavic 2 Zoom would be best for what you are trying to accomplish like what was said above. I wouldn't worry about blur in any moderate winds. The Mavic 2 is extremely stable and you shouldn't have any problems unless it is very high winds.

 

[BobbyBob]

ah, good to know. Thanks

 

[Dave Maine]

The wind effect will cause motion,,which a low shutter speed will pick up. Choose a shutter speed above 1/250 if you can, without causing the ISO to go above 100.

Be careful using the zoom feature, as the 2x zoom will multiply the motion blurring by a factor of 2 as well.

Whatever drone you pick, make sure the lens is perfectly clean before each flight, as a dirty lens will blur the image.

Shoot when the light is modeling the terrain with good shadowing.

 

[BobbyBob]

Thanks Dave, very intresting insight. It is very seldom sunny here. Less sun, means harder to keep shutter speed at 1/250 or faster , especially with a widest aperture of only f3.8.(mavic 2 zoom) or the slightly better f2.8 (mavic 2 pro). I guest its about which of these several factors have be biggest impact.......

 

[Dave Maine]

Yes, it is a very complicated problem with no quick answers. You might want to read up on the image processing software you intend to use to find out what factors are most important to it. Pattern recognition software is still struggling. Human beings do it effortlessly, but doing it by manipulating bytes is very compute intensive and not completely satisfying.

 

[BobbyBob]

Good suggestion - mavic 2 zoom defnitiely gives a better GSD as alluded to by MrYKBQdV and Florda above. I think it might be one of those that only fully plays out in field testing. Not keen on forking out on both both models, lol. My other half has suggested I hire someone who has both models to run a test

 

[Meta4]

Very useful article, thanks It's given me a lot of food for thought, as it actually shows pro's and cons for both.

Using the Zoom and zooming in is going to cover a much smaller (1/4?) area than using the 20MP M2 Pro.
It would require a lot more images for the same area.

 

[BobbyBob]

Good point. just did some calculations - after messing around with overlaps and stuff, it looks like 1/2 So if I start wanting to do this over lager areas, as as a hectare (100m x 100m), I'm thinking that could be the difference between 3000 images or 1500 images... Less images is much better on the one hand, but not if they do not contain the required detail. - tricky - you can see my dilemma !

 

[Keule]

I'm thinking that could be the difference between 3000 images or 1500 images

A flight at 5m height with M2P results in 3705 images taken to cover a 100x100 m area. You need more than 200 min. pure flight time and around 13 batteries. Your GSD would be 0.1 px/cm.

 

[Meta4]

Good point. just did some calculations - after messing around with overlaps and stuff, it looks like 1/2 So if I start wanting to do this over lager areas, as as a hectare (100m x 100m), I'm thinking that could be the difference between 3000 images or 1500 images... Less images is much better on the one hand, but not if they do not contain the required detail. - tricky - you can see my dilemma !

Getting some sample shots with a 20MP camera should be easy so you can see how they would work out.

 

[Meta4]

A flight at 5m height with M2P results in 3705 images taken to cover a 100x100 m area.

What overlaps (frontlap and sidelap) is that calculation using?

 

[Keule]

What overlaps (frontlap and sidelap) is that calculation using?

frontlap 75%, sidelap 60%

 

[hiflyer201]

This is a low altitude shot of desert wild flowers taken with the lowly Spark. It's not taken vertical as I assume you are planning but even with the unfiltered high shutter speed the smaller purple flowers are hard to identify and the photo only show a small portion of what the scene really looked like..alas

 

[BobbyBob]

A flight at 5m height with M2P results in 3705 images taken to cover a 100x100 m area. You need more than 200 min. pure flight time and around 13 batteries. Your GSD would be 0.1 px/cm.

Very usful stats thanks Keule. I wont need to stitch them into a map - so getting away with a smaller overlap might be able to trim the number of shots down a bit. Looks like I need to extend the battery budget though !

 

[Keule]

so getting away with a smaller overlap might be able to trim the number of shots down a bit.

Yep, dialing it down to 50% frontlap and 25% sidelap results in 996 images taken. (~5 batteries to be used)

 

[BobbyBob]

Ah that sounds good. I'm back to trying to figure the finer points of the GSD advantage of M2Zoom, Verses the (possibly) less blur from the M2Pro (fast shutter speed that I'll get from the lower f'stop it offers) + its 20megapixels compared to the M2Zoom's 12MP

(thanks for the spark desert pic Highflyer and the GDS calculation from Keule : at least I can see it has a chance of being viable with some care and some thought. And of course the Right Drone .....

 

[Jeff A]

Mavic 2 Zoom would be best for what you are trying to accomplish like what was said above. I wouldn't worry about blur in any moderate winds. The Mavic 2 is extremely stable and you shouldn't have any problems unless it is very high winds.

My Mavic 2 Zoom is steady as a rock in gusty conditions. It never ceases to amaze me.