Hugin — Handling Overexposure in Stitched Images

This tutorial was developed on Hugin version 2014.0.0 on a MacBook Pro.

The following two images are of the Supreme Court of Newfoundland and Labrador in St. John's, Newfoundland. The camera was set at ISO 50, f/13.0 with a 35 mm lens; I had forgotten to reset my camera after taking some waterfall shots. Unfortunately the Upper image was taken at 1/80 sec and the Lower at 1/30 sec (notice the blurred face in the bottom left of Image 2). So, two images with completely different exposure levels.

I left the EXIF information on these images so you should be able to download them from this page and follow along.

Image 1: Upper part of the Court House
Image 2: Lower part of the Court House

Using Hugin's Simple Interface

  1. On the Projection tab select Rectilinear. You may have noticed the message "Setting the panorama to rectilinear projection would keep the straight lines straight."

  2. After running "2. Align..." on the Assistant tab, I used the Move/Drag tab to pull the image down so the walls weren't completely vertical (looks a bit more natural), and then used the Crop tab to frame the building (and get rid of the head in the lower left corner).

    Notice in the Preview tab that EV is set to 14.02 (Image 3).

  3. AverageEV
    Image 3: Fast Panorama preview - Preview tab
  4. Now, back in the Assistant tab click on "3. Create panorama..." and you'll notice in the window that pops up that the only option is "Exposure corrected, low dynamic range" (the others are greyed out).

  5. Select OK and the result shows the sky overexposed with a loss of definition in the clouds (Image 4).

  6. LUOver
    Image 4: Overexposed Stitched Result
  7. To fix this the first thing to try is adjusting the EV in the Preview tab (Image 3 above). Lowering the EV (which seems logical because we want less light) only makes the problem worse!?

    Note: On my setup entering a number in the EV box will not take effect unless you press enter/return ... don't tab out of the box.

  8. Increasing the EV to 15 brings the definition in the clouds back.

    Note: you also might have to click the Photometrics check box on and off to see the effect of changing the EV value.

So, we had to increase the EV value to darken the sky! This brings the average EV up to the exposure level of the sky.

Before continuing return to the Preview tab (Image 3) and click on the little green arrow to the right of "EV:", this will reset the value back to the average (14.02). We'll see if there are other ways in Hugin to fix the overexposure problem.

Switch to Hugin's Advanced or Expert Interface


  1. On the Stitcher tab (Image 5) select only "Exposure fused from stacks" and hit the "Stitch" button (bottom right).

  2. StitcherTab
    Image 5: Advanced Interface - Stitcher tab
  3. This results in a better balanced image without the sky blown out, but the upper/lower parts of the building have different brightness levels (Image 6). If you look at the image you'll also see that a part of the sky at the left of the building is still blown out.

  4. Trying "Exposure fused from any arrangement" gives similar results.

  5. LU_fused
    Image 6: Exposure fused Result


There is a way to see the exposure of each image. The values can then be use to provide better control of the EV level.

  1. On the Photos tab (Image 7) near the bottom change the Photometric: selection to "Custom parameters"

  2. Notice that a new tab will appear near the top titled "Exposure".

  3. Photometric
    Image 7: Setting Exposure for manual
  4. Click on the Exposure tab and you'll see the actual exposure level (EV) of both images (Image 8). CourtLower = 13.3, CourtUpper = 14.7, which gives an average of (13.3+14.7)/2 = 14.

  5. ActualEV
    Image 8: EV values for each photo
  6. This explains why the clouds were blown out when the average EV was set to 14.02 earlier - the Upper image at 14.7 EV is more then 2/3 stops overexposed from that.

  7. Flip back to the Preview tab in the "Fast Panorama preview" (Image 3 above) and try setting the EV value closer to 14.7 - I tried 14.6 and got the final image shown in Image 9. No overexposure in the sky and the building intensity upper/lower is equal.

  8. LUBalanced
    Image 9: Final Result

September 2015 — Donald Johnston