Recent content by DarkEnergy

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No continuous autofocus I believe. For most purposes you will focus at the hyperfocal distance, that for the camera parameters provided by DJI is about 10m. Focusing at 10m provides a depth of focus from 5m to infinity. To film or take a picture between 0.5m and 5m will need tap-to-focus...

Here is my 10p contribution. Below are side by side crops of the zoomed by 200% views of the pier in iPhonedo's YouTube comparison. To me, the one on the left is a bit sharper. The one on the right is from the P4. Not a big difference, but Mavic's looks better.

Exactly. Then why are you strongly concluding that Mavic is not suitable for photogrammetric purposes based in questionable simulations? Seems to me a desperate point from somebody that cannot accept being wrong.

What do you mean by 'lower"? Most of the comparisons I've seen published so far have clearly shown the the resolution/sharpness of the Mavic images are as good if not better than those of the P4.

The human eye angular resolution is about 1 arc minute for 10/10 vision and is determined by the eye effective focal length and the median distance between cones in the center of the macula where the density is higher. If we leave side the quality of the optIt is exactly the same with any...

The CoC of a given photographic camera or a video camera has nothing to do with human perception, it is a property of the camera. You can analyze the image with your naked eye or a magnifying glass or even a microscope and the result will always be the same.

You are confusing eye resolution with the photographic camera or video camera resolution. Regarding the modulation transfer function you mention, that is I believe another way of expressing the sampling theorem AKA the Nyquist-Shanon theorem mentioned above in reply 11.

Just to settle the point, I've made an estimate of the focal length of Mavic's camera based on the size of the 1/2.3" detector and the claimed FOV of 78.8º. If the FOV corresponds to the diagonal of the detector, as is commonly quoted in photography, the true focal should be about 9.4mm. For...

Yes you are correct, my mistake.

+1

I suggest you read previous discussions of this very topic in this blog. The subject has been discussed at length. Mavic's camera is not fixed focus as the P4 and Casey did not focus the camera on a distant object before flying. Mavic images are equal if not better than those of P4. Here are...

I can see now that there is a problem with your estimate of the FOV Firstly the diameter of circle of confusion seems too large. In a Nikon D4 corresponds to 4 pixels in diameter. Secondly, your computation is for a full frame camera (36x24mm) while the Mavic has a 1/2.3" detector that is about...

Simpler, tan(47º)/tan(39.4º)=1.305 = 30.5% larger. On the other hand I'm worried that the field of view provided by DJI are inconsistent with the given values of the focal length. A quick computation indicates that the Mavic FOV of about 79º should be about 74.5º if the equivalent focal length...

I don't think the reverse is correct. If you focus at 12m the focus region (depth of focus) will start at a distance below 12m and will not reach infinity.