Getting used to a noisy sensor again!

Drones have tiny noisy sensors compared to your DSLR – if you’re used to brightening up shadows on an underexposed shot with your camera, you’ll be shocked how bad this is on a drone RAW file. 

So what can you do?

Bracketing and HDR is the answer. 

Bracket photos for HDR is rarely needed with modern camera sensors, but it’s back with DRONE photography. With the DJI Mavic Air I use, you have the option of taking 3 or 5 photos, each 1-stop apart, to capture a larger range. 

Yesterday I went onto Marsden Moor to test this out, having struggled with skies and dark land for the 2 months I’ve had the Mavic. 

The Mavic Air Panoramic Process and Settings

In the app, you need to know your way around the camera settings to find:-

  1. Manual exposure – so all the brackets are the same exposure – remember you’re doing a panoramic so you’ll be taking 2+ brackets.
  2. Set the exposure to 0EV if you know how – so you change the shutter speed/ISO till the little light meter says “0” 
  3. Set the camera mode to “AEB” – then select 3 or 5 – I go for 5 to be safe
  4. Get the drone into position ready to shoot. 
  5. Now rotate the camera to the upper leftmost position in the panoramic – take your bracket (it takes a few seconds to save the files to memory cards).
  6. Next, rotate the camera about 2/3 of a frame to the right to get the next shot – repeat this till you get to the top right edge. 
  7. Tilt the gimble down so you can see the bottom of the original shot at the top – this is the start of the second row of your pano (if you need rows) – now take a shot
  8. Rotate Left, taking shots as you go till you reach bottom Left of the panoramic. 

So that’s it out in the field – it takes a lot longer than the AUTO PANO modes your app may have, but you have gathered 5 times the data and you CAN get a decent sky and ground. 

Merging HDRs in Lightroom

This is where the real work happens. Whilst the latest version of Lightroom CC has “HDR Pano” blending, I’ve found this incredibly slow and you can’t queue up many panos, you have to wait for just the 1 to complete. I’ve never had the patience to let one finish it takes that long. 

So here’s the process I went through for these images:-

  1. Pull all the HDR files into a new folder – these will be the “DNG” files if you’ve shot RAW – there should be a multiple of 5 photos here (or 3 if you did brackets of 3) – so check that you’ve not missed any!
  2. Blend the first bracket of shots – so highlight a group of 5, click CTRL+H to open the HDR box. 
  3. Check the “Auto Align” box
  4. Uncheck the “Auto settings box”
  5. Check the “Create Stack” box
  6. Choose “none” for ghosting – unless you have moving objects in the scene – e.g. cars. 
  7. Click OK – the first HDR gets created! 
  8. Now choose the next bracket of 5 in your thumbnail viewer
  9. press “CTRL + SHIFT” at the same time – then hit “H”
  10. This uses the last settings you applied to a HDR to create a new blend. It does this in the background so you can do other things… 
  11. Whilst it’s blending the HDRs, you can select the next group, get them blending, then the next… I’ve had 5-6 going at the same time and it seems to work. 

 

Creating the HDR Panoramics

So now you’ll have a timeline with every raw file in a “stack” – so if you had 30 photos to begin with, these will be neatly stacked into 6. 

To get the pano, you just need to :-

  1. select the stacks which make up the panoramic in the thumbnail view, 
  2. press CTRL+M – this opens up the Pano box in Lightroom
  3. There are 3 blend mode options – you need either “Spherical” or “Cylinder” – try both to see which works. 
  4. Check Auto Crop
  5. Check Create Stack
  6. Uncheck Auto Settings
  7. Slide the Boundary Warp control to taste – 0 = a thinner wide photo, 100 is a taller photo. 
  8. Now hit “Merge” and you get a final blend of lots of photos in 1 big stack! Phew
  9. After the first Merge, you can just re-use the settings on each pano as follows
  10. Select the next group of pano stacks
  11. Press “CTRL + SHIFT + M” – this sets the panoramic blend going without the settings box popping up. 
  12. Go through all the pano groups doing this – you can queue up many whilst Lightroom is working – I’d not go past 6 in the queue though. 

At the end of all that, your folder of dozens of component shots will have reduced to a few HDR Pano photos – now you can get on to editing them as normal!