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How Did I Do That - Cathedral Pictures

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In this article I have detailed the process I used to capture the photos of the Cathedrals and many of the landscape photographs. I hope that the lessons and techniques I have learnt might help you, but if you can offer me any advice that will improve this method, please email me.
My Cathedral images were created using multiple stitched images taken at three different, two stop exposures.
 

Equipment

Tripod – Manfrotto 055FM3 magfiber with a Manfrotto 338 levelling head and a Manfrotto 303SPH panoramic head.
Lens – Canon EF 24-105mm IS USM lens
Camera – Canon 5D
Cable Release – Canon TC-80N3.
 

Software

PTGui Pro www.PTGui.com
Adobe Lightroom 1.4
Adobe PhotoShop CS2
 

Visiting the Cathedrals

All three Cathedrals I have visited so far have been happy for me to use a tripod as long as you consider other visitors, not blocking doorways etc.
A contribution is expected from all visitors, usually about £5.00, which I think is very fare considering the cost for the upkeep of these buildings.
These cathedrals are very popular places to visit, so getting there early is very important if you want to avoid the crowds. Having people in you photos adds life to the shots but when you are taking multiple shots with multiple exposures, having visitors or staff moving around makes life difficult for stitching the images together. The lighting in cathedrals is usually very low so the shutter speeds will be slow which adds another problem if people are moving around within your shots.
All the cathedrals I have visited are usually open between 07:30 and 08:00 but do have the occasional closures for special services, so check on the web for availability.
 

Setting Up The Shot

When you have found the shot you want to take, level off your tripod. Having you tripod level will make the stitching process easier and will give better results.
 

ISO

Adjust the ISO setting so that the slowest shutter speed is not too slow as you could be taking 30 to 60 shots to create this picture you do not want to be spending half the day on one shot.
 

White Balance

Do not leave the white balance on Auto as the light in the picture could change from daylight to artificial light as you pan your camera around and would give different colour casts. I set the white balance to Cloudy but if you shoot in RAW you can correct the white balance in the editing software as long as the same setting is used throughout.
 

Bracketing for the HDR

Using your camera in Aperture Priority, take a light reading from the lightest and darkest areas of you picture in order to find a middle exposure you can bracket from.
For example, if the shutter speeds for the brightest area was 1/250 and the darkest area was 1/15 then the middle exposure would be 1/60. (If you half or double a shutter speed this will be equal to one stop). This example would mean bracketing your shutter speed at two stops over and under the middle exposure of 1/60 sec.
 

Camera to Manual

Set your camera to manual. You will be stitching multiple bracketed shots so would want each set of shots to have the same settings to avoid different exposures in each bracketed set of pictures.
Using the above example for bracketing, set your exposure auto bracketing to two stops over and under exposed. These setting will need experimenting with as I have found in bright conditions it is better to bracket one stop over exposed and three stops under exposed. You can often pull back a lot of detail from an under exposed image using imaging software but there in no detail to recover from a “blown out” area.
Set the aperture to the maximum f number to get the maximum depth of field if this is the effect you require.
 

Focus

Set the lens focusing to manual and check that all the required subject area is in focus.
 

Image Stabilisation

If you have image stabilisation on your lens then turn it off. If a lens with image stabilisation is placed on a tripod it can get confused and can have the opposite effect blurring some images. I had this problem with several of my images where one of two of the pictures in the collection of shots was blurred, although I had taken every precaution to avoid camera shake. Since reading an article about image stabilisation I always turn mine off if I use a tripod and have not experience any unusual blurring.
 

Shutter Release Cable

I always use a shutter release cable to avoid any camera shake. You do not want to stitch a set of 30 or 50 photos together only to find the whole picture is spoilt by a blurred photo in the centre.
 

Taking the Pictures

After fixing my camera to the panoramic head on my tripod and ensuring that the tripod is level, I point my camera at the lowest point of the area I want to capture (bottom left or right hand corner).
1) Take the first set of bracketed images.
2) Move the camera horizontally on the tripod to the next position allowing for at least a 15% overlap on the previous shot.
3) Continue panning bracketed shots horizontally until you reach the furthest point on your picture.
4) Now move you camera up vertically allowing for about a 50% overlap. (I tried allowing a 15% overlap on the vertical but found that the stitching was not as affective).
5) Continue taking your pictures on the horizontal back to your start position.
6) If required go up vertically another 50% and repeat.
 

Photo Editing

Lightroom

I load my finished RAW files into Adobe Lightroom then from the file menu, export them to a temporary folder as tiff files with no compression, 300 dpi, 16bit files. The average set of pictures would contain about 45 separate photos.
 

PTGui Pro

I would then open a new project in PTGui Pro and upload the images from my temporary folder.
Select the Align button to align the images. PTGui Pro will automatically recognise that these are bracketed shots and will ask me if I would like to create a HDR or Exposure Fusion image.
Exposure Fusion is similar to HDR but I have found that I get more control over the final image using Exposure Fusion allowing more contrast.
I am still learning using PTGui and need to experiment a bit more with HDR.
The problem with true HDR is that it can create more tones in an image than can be reproduced by a monitor or printer, so what is the point? Let me know if you have ideas on this subject.
PTGui will then display a rough final stitched image without any Exposure Fusion giving me the opportunity to edit any details.
The program has laid down “Control Points” on the images to line up the individual photos. It will display a list of the control point and number the accuracy of each point. You can visually assist the accuracy of the control points but I have found it better to set more control point than necessary then delete any point above 5.5 or 9.5 depending on the number of individual pictures in the image.
This is where using a tripod really pays off producing far less inaccurate control point.
There are then a lot of adjustments you can make within PTGui Pro if you feel it necessary, compensating for different exposures, lens variations, etc.
You can change the size of the final output image and select from 5 different output file formats. I tend to use the PhotoShop large file format of .psb. You can select the final output as individual layers that can be edited or select an individual stitched layer for each of the three different exposures used, which can also be edited. But be aware that you can create some very big files.
For example, my individual tiff files are about 74MB each. If I choose to produce a single file in PhotoShop of each photo being on its own layer, a collection of 45 images can produce a file of about 4GB which compressed in PhotoShop will be about 500MB.
My computer is only a Pentium 4 single processor with 1.75GB RAM and still handles these size file very well.
I have only touched the surface of what PTGui can do. It can be a simple or very in depth program depending on how far you want to go. (No I am not on commission).
 

PhotoShop

Once PTGui has done its bit, I then load the output file into PhotoShop.
All of the cathedral shots I have taken did have a lot of converging vertical (walls and pillars leaning in) but this is very easy to rectify by:
1) In PhotoShop, convert the background image to a single layer.
2) Press Ctrl + ‘ to display a grid.
3) Press Ctrl + T to select the transform tool.
4) Hold down the Ctrl key and drag the corner handles in or out to straighten any walls, pillars, etc.
5) Press the Enter key when you are finished.
6) I then Save my image as a .psd (PhotoShop) file as Lightroom will not import a .psb (large scale format) file.
 

Lightroom

The image will appear in Lightroom with a flat looking exposure and usually quite dark. I will then, in Develop mode, make a very general adjustment:
Tone Curve
  • Shadows -6
  • Darks -6
  • Lights +6
  • Highlights +6
    • Presence
    • Clarity 33
    • Vibrance 12
    • Saturation 12
      • The images generally have an orange colour cast from the tungsten lights so I set the White Balance to Auto which corrects this.
       

      Bringing the image to life

      Lightroom uses a non destructive process where you can make temporary adjustment to the “Original” photograph and produce “Edit” copies with any adjustments imbedded in the photo.
       

      Step 1. Highlights

      In Lightroom, I will deal with any over exposures on the original photo. Looking at the photo, only at the over exposed areas, I will make adjustments using the Recovery slider and under exposing using the Exposure slider. The image will be very dark but don’t worry about this as it will be adjusted later.
      In Lightroom I will then export a copy of this image with adjustments into PhotoShop. (Edit 1 Picture)
       

      Step 2 Main Image Exposures

      Going back to Lightroom and the original photo I would cancel the Recovery Slider and move the Exposure slider, together with the Fill Light slider, until I have achieved an exposure I want for the main body of the photo.
      In Lightroom I will then export a copy of this image with adjustments into PhotoShop. (Edit 2 Picture)
      PhotoShop
      1) In PhotoShop I will drag the Edit 2 Picture onto the Edit 1 Picture at the same time holding down the Ctrl key to position Edit 2 directly over Edit 1.
      2) Close Edit 2 as this picture is no longer required.
      3) In the Layers Pallet drag layer 1 (Edit 1 picture).on top of the Layer 2 (Edit 2 picture).
      4) Select the areas on the layer that you want to keep at the current exposure. This is usually just the light coming in from the windows.
      5) Feather this selection slightly then from the layers pallet, click on the Add Layer Mask button. This will retain the selected areas in layer 1 (Edit 1 picture) and show all the other areas from layer 2 (Edit 2 picture).
      6) Flatten the image and save it back to Lightroom.
      The Edit 1 and 2 photos still exist in Lightroom, by saving the Edit 1 photo in PhotoShop will update the Lightroom photo.
       

      Step 3 Dark Areas

      1) Back in Lightroom, select the original image and using mainly the Exposure and Fill Light sliders, lighten the areas of the picture that are too dark.
      2) Export a new edit copy to PhotoShop with these adjustments. (Edit 3 picture)
      PhotoShop
      3) Drag the Edit 3 photo on top of the Edit 1 photo, not forgetting to hold the Ctrl key down while dragging to ensure pixel accuracy with the layers.
      4) Close the Edit 3 photo.
      5) From the Layers pallet, turn off layer 2 (Edit 3 layer).
      6) Select layer 1 then from the menu click on Select > Color Range.
      7) Float the mouse pointer over the photo, it will become a colour picker tool, and select a sample colour from the dark areas that you want to lighten.
      8) In the Color Picker dialog you will see all the dark areas shown as white. Move the Fuzziness slider to about 90-100 then OK.
      9) The dark areas will now show as the selected areas. Feather the selection to about 5 pixels.
      10) Turn on and select layer 2 (Edit 3). The selected areas will now be the dark areas that have been lightened in Lightroom. These are the areas that we want to keep.
      11) From the Layers pallet, click on the Add Layer Mask button. The areas of the photo that we did not want to change on layer 1 (Edit 1) are now shown through and the lightened areas on layer 2 (Edit 3) remain.
      The image is slowly coming to life with you being in control of what parst of the photo gets adjusted.
      12) Flatten and Save the Edit 1 photo.
       

      Step 4 Shadows

      The process for bringing out the details in the shadows is exactly the same as Step 3:
      1) Lighten the original photo in Lightroom concentrating on the shadows but don’t over do this. If required repeat this lightening process several times bring a little detail through each time. If you over do it, it will look very flat.
      2) In PhotoShop reduce the Color Picker Fuzziness slider down to about 60-80.
      Repeat this process until you are happy that enough detail has been brought through.
       

      Conclusion

      This process might seem very long winded but the results speak for them selves, and they are getting better the more I improve this technique.
      The final picture for me is usually a 100mb to 200mb image that has so much detail.
      The next step would be composition?