I don’t usually produce technique or how-to blog posts but thought I’d share my experience of using the auto-exposure bracketing (AEB) mode on the Mavic Pro. I went out this morning and shot a bunch of stills with the Mavic set to AEB mode and opted for it to take 5 frames. Nominally these are at a variance of 0.7EV from each other and indeed my software suggests between 0.6 and 0.7 EV is the norm. Bracketing is something I am very familiar with from my normal photography so I start with a good understanding of the potential benefits and pitfalls.
The first example of a 5-frame image, merged in Photoshop using HDR Pro, shows Freemans Cut and was shot into the sun, you can probably see where the sun is, just out of frame top right. In this instance the five frames have given Photoshop everything it needs to produce a nicely balanced image and the -1.3EV frame has provided the HDR engine with just enough material to work with. To be fair, the -1.3EV frame on its own has sufficient detail to produce a very acceptable image on its own and this I feel highlights the main drawback of the fixed 0.7EV step in the Mavic’s AEB settings. I have found the [-1.3 -0.7, 0, +0.7, +1,3]EV range far too limiting and often +/-1.3EV is not enough for the dynamic range of the scene. With my Fuji and Nikons I have been known to shoot +3, 0, -3 at times especially when there is sky in the frame and I’m shooting early or late in the day. It would be good at least to have a full 1EV adjustment between each frame and an option for +/-2EV would be perfect; I rarely shoot bracketed sequences at anything other than +/-1EV or +/-2EV.
Realistically, I can always revert to manually bracketing with the drone assuming the wind is light enough to give me time to manually change things between shots but it Ould be useful to have the option to vary the adjustment range via the Go4 app.
Despite this limitation I do think that it’s a worthwhile exercise to shoot in 5-frame AEB as on occasions it can really help when post-processing to have that extra +/-1.6EV available. It’s easy enough to delete files that aren’t needed later. I use a 32gb SD card and have never yet filled it in the 20 minutes or so of flight time that I am getting from each battery. I carry spare cards so in the unlikely event of filling one I can always swap it out when changing batteries.
Historically I have used Photomatix Pro for blending bracketed images preferring it to the inbuilt option with Photoshop. However, today I tried the PS version (HDR Pro) for convenience and was pleasantly surprised by the improvements. In the event I did not even bother to see what Photomatix could do as I was more than happy with the outcome from HDR Pro.
I found that using the “flat” preset in Photoshop HDR-Pro produced a good tonal range and an image that responded well to additional processing. I preferred this to any of the other more vibrant presets and it’s a good compromise between time and convenience compared to using the other presets or manually adjusting the conversion yourself.
Today’s exercise has suggested to me that it is worth keeping the drone in AEB mode for stills photography as the default, moving to single shot only occasionally when conditions are appropriate. As with all photographic bracketing it is always possible to simply use one frame out of the sequence and it costs relatively little to simply delete the other four if they are not needed. Having the option though is well worth the minor inconvenience of having additional image files to sort out back home.
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