Photoshop Tips on Stitching Property Images
Panoramas and Stitching in Photoshop
There will be times when you just wish that you had a much wider lens than even a 16mm semi fish-eye. I have walked into some of the most beautiful rooms in large luxurious villas, and no matter where I stood; I just could not do the room justice.
Rather than miss out on the opportunity to make these properties shine, I learnt how to effectively and seamlessly stitch 2, 3 or 4 images together in a mini panorama to ensure the entire scene was recorded, whether internal or external.
There are basically 2 ways to do this and I recommend that you try both.
Stitching in Photoshop – Horizontally
Firstly, the conventional method of keeping the camera horizontal and taking 2 or 3 images fairly close together. If you move the camera too much in between shots, especially with a wide angle lens, you will have difficulty in stitching them together later.
This is because of the pin-cushion effect when using wide angle lenses, where the walls are not straight enough to be joined correctly. Try taking more images, even 4 or 5 if you have to, and the differences will be less, therefore easier to stitch.
When moving in between shots, try to move yourself and pivot the camera on the lens’ axis rather than its body. This will also help to reduce the pincushion effect.
If you are able, to use a slightly less wide angle lens such as 35mm or 50mm. This again will help to reduce any problems later.
The following three images were all taken horizontally at a focal length of about 50mm, and taken from a tripod. Make sure that you “overlap” the images well using good “anchor” points in each image for the stitching program to read. Look for things that are sharp and detailed like the bedposts and furniture in this case.
Stitching in Photoshop – Fig.1
They stitched together well but still produced slightly curved walls as in the image below. In most cases, this image is quite acceptable and does the job quite nicely.
Stitching in Photoshop – Fig.2
If you want to lessen the effect, there is a free plug-in tool for Photoshop called Panorama Tools. You can learn more and download it here;
Once installed, go to FILTER – PANORAMA TOOLS – REMAP
You will be given a few options but for now, if you just “convert” from;
QTVR Panoramic to Normal keeping the values in the two boxes at the bottom at 60. The effect is quite good as in the image below. It straightens the walls and image in general to lessen the panorama effect. Please be aware though, that it will “stretch” the image outwards slightly, losing some information from either side, so take this into account when taking the actual photographs. Try to include too much detail.
Stitching in Photoshop – Fig.3
Stitching in Photoshop – Vertically
If you wish to get more detail in the picture from top to bottom or from the floor to the ceiling, shooting horizontally will crop these areas too much. A simple solution is to flip the camera to portrait or upright and you will fill these areas nicely in the frame.
The only downside is that to get the entire room in lengthwise will mean you having to take more images. If it is a long room, you may have to take up to 10 images but the results when stitched will be simply awesome!
There are 3 main and good points to shooting property panoramas in this way;
- You are able to use a better focal length lens such as a 50mm meaning less curved walls
- Because of this, the images are much easier to stitch effectively
- You have much more detail in the image meaning you can crop it so much more effectively
This kitchen panorama was shot this way (vertically) and you can see that the wall and ceiling lines are as straight you like!
Stitching in Photoshop – Fig.4
Whereas THIS kitchen panorama was created by stitching 2 horizontal images together…notice the difference?
Stitching in Photoshop – Fig.5
If in doubt, take the panoramas using both methods and play in Photoshop to get the best results from either. In time, you will learn which method is more suitable for each type and size of room.
Stitching in Photoshop – Camera Settings and exposure
This section is extremely important if you want the images to stitch seamlessly.
First of all, take your camera off “Auto” mode in all respects;
- Shutter Speed
- White Balance
If the camera fluctuates even slightly during the exposures of each image, you will get very noticeable differences in the final image. These will show as;
- Differences in Focus
- Differences in Depth of Field
- Differences in Tones, Colours and Saturation
- Differences in Exposure
As you move the camera in Auto mode, the settings will change as you bring a window into view for example.
You need to keep the entire image range for the panorama uniform and exactly the same for each shot and to do this, the camera must be set to manual for everything.
If you have a spot meter, take a few readings from around the room, take an average, and set the camera to that. I.e. 60th/sec at F8. Then ALL images will be taken at that setting.
If you just have the cameras meter, take your reading from the part of the room that is bang in the middle of the range, not too bright, and not too dark. You can make adjustments to these areas in Photoshop later on to bring back the detail.
If you are using the studio lights, make sure that they illuminate the whole area well and evenly.
Set the cameras white balance to that which best suits the situation;
- Flash? (Studio lights)
- Natural light? (Shaded or Daylight)
- House lights? (Tungsten or Fluorescent)
If you are able, best of all, shoot in RAW. You have a much better chance of being able to pull back details later on during post-processing.
Stitching in Photoshop – Tweaking and correcting the Stitched image in Photoshop
Once your stitching program has put the images together, the chances are that you will end up with something like this;
Stitching in Photoshop – Fig.6
The exposure is off and the four corners have information missing. It is absolutely crucial that you do any post processing to the final, stitched image and not to each individual image before stitching.
That way you only have to adjust one image and not each one at a time ensuring that they are ALL processed in EXACTLY the same way, otherwise again, they will not merge correctly and uniformly.
With regard to the four corners, you can do one of two things;
Straighten the image and crop them out
Clone back in the missing detail as in the “cloning” section of this book
Each image is different and it is up to you which you do to give the best results.
For the above kitchen shot, I decided to straighten and crop out most of the missing detail as shown below;
Stitching in Photoshop – Fig.7
However, for this bathroom shot;
Stitching in Photoshop – Fig.8
I corrected the white balance/colours and simply cloned back in the missing detail meaning I lost none of the image.
Stitching in Photoshop – Fig.9
Stitching in Photoshop – Discrepancies
You may also get situations where the image doesn’t align perfectly. Rather than tirelessly re-processing in your panorama stitching software, try using the clone tool to better line up the affected areas.
I have done this on many occasions and is well worth practicing, it could save you a lot of time. Again, just take the image like below, and load in Photoshop;
Stitching in Photoshop – Fig.10
It is quite obvious where the stitching has gone a bit astray, but this really is a minor problem. You just need to find all the areas that are affected the same and do the following;
Stitching in Photoshop – Fig.11
Using the clone tool, and a suitable brush, as discussed before, place the brush over the area that you wish to clone FROM (on the outline of the beam in this case), press ALT and left click the mouse.
This will select the area to be cloned. Now place the brush over the area that you wish to clone TO, and left click and hold it down. Move the cursor and “paint” the information back in. If you go wrong, or haven’t lined up properly, just CTRL-ALT-Z to step back and try again.
Use this method for any other discrepancies that appear once the stitching is done. Then you can adjust the colour balance, levels and curves etc, to get the image looking tip top.
Stitching in Photoshop – Fig.12
This also works for Exteriors like the shot below, weddings, landscapes and so on.
Stitching in Photoshop – Fig.13
Stitching in Photoshop – SOFTWARE
The stitching software that you use/buy is entirely up to you. If you have Photoshop CS/2, you should have stitching software installed already. Go to;
FILE – AUTOMATE – PHOTOMERGE
And there you have it.
f you have purchased a Canon Digital SLR, you will have received Canon Utilities Software with your purchase that includes Photostitch.
Other makes and models of Digital SLR may have come with similar software, so check your boxes.
If you have nothing, do a bit of searching on the web to find free trials or downloads and find one that you like that gives good results. Go to forums and ask questions about what other people are using.
I won’t go into the finer details of how to use this software because I don’t know what you have. It is up to you to learn how to use it once installed.
A couple of great software packages come from Realviz who provide both a professional version and a “light” version. Follow the links below for more information.
…and for the serious pros…