2012年12月5日星期三

Getting Started in Panoramic Photography


Getting Started in Panoramic Photography


Panoramas - Plain Sailing!

One of the most enjoyable things about photography is the scope for learning new techniques and using these creatively to take your images to the next level.  Of all the different types of photography available one of the most satisfying techniques has to be shooting panoramas.  Panoramas are impressive because they convey scale and detail in a way that standard format photos are unable to.   So if you are looking for an opportunity to learn something new and add some real punch to your portfolio then you could do worse than learning to shoot panoramas.

Basic Techniques

Panoramas are generally made by taking a number of shots and digitally 'stitching' them together to make a much bigger image.   The key to a perfect panorama is achieving an image that contains lots of detail whilst ensuring that each individual shot is perfectly meshed together without any visible seams or joins.  The big plus for panoramic photography is that despite what you may have been told, taking a good panorama requires very little in terms of gear and with a little bit of technique and processing making a good panorama is actually very easy.  To get you started here are a few basic pointers on how to make a start in panoramic photography:

Nodal Points & Expensive Brackets

Do any research into panoramic photography and you will be quickly presented with an array of specialised brackets and tripod heads.  These are designed to ensure that the camera rotates around the focal plane of the camera sensor, otherwise known as the nodal point.  Rotating the camera as close to the nodal point is a good thing as it helps to minimize distortion and improves the overall success of the stitching process.  Whilst I won't argue that these brackets do make a difference, they can be expensive and unless you are a die-hard panorama enthusiast you can achieve a more than acceptable result just by practicing good technique.

The Shots

The key to achieving a good stitch lies in how the base shots are taken.  Making sure that you have a set of clear, sharp images will provide a much better start point for the stitching software.   The best way to do this is to meter your scene in aperture priority, selecting an exposure that gives a high depth of field but also a shutter speed fast enough to give a sharp shot.  Once you have a workable exposure, lock this in using by selecting Manual mode and dialing in the metered settings.  Its also important to manage your focus carefully, assuming you are shooting with a small aperture the large depth of field should help however a good habit to get into is setting your focus and then again locking this in to avoid variation.  Ideally all of your camera settings should remain fixed throughout the entire image sequence.

Shooting Technique

The most significant factor in determining the overall success of the stitching process is the way in which the individual component images are taken, within this there are two main variables; orientation and overlap.

Image orientation is important as it can have a big effect how much perspective changes from shot to shot, the smaller the perspective difference the less distortion correction needed by the stitching software.   The best way to achieve this is to shoot in a portrait orientation as this both gives the stitching software a longer edge to work with but also keeps the perspective change between each shot to a minimum.

The second important factor in achieving a good stitch is the amount of overlap for each shot in the sequence.  The temptation here is to overlap the images by a large amount, actually this can hinder rather than help as overlapping too much can actually introduce stitching errors as the software tries to mesh the larger area.  My ideal overlap is anywhere between 20-30% and has seemed to work well for me.

Hand holding is perfectly acceptable for pano shooting so long as you can hold your camera steady and your shutter speeds are fast enough.  All this that said if you can use a tripod as a stable base will always increase the overall sharpness and reduce the potential for blur.  The image below was taken at the recent London Olympics and was created from a sequence of ten images, all of which were hand held and shot right from my seat in the stadium!

Olympic Effort - A Hand Held Panoramic Shot

Stitching & Post Processing

As with all post processing techniques it is possible to go into a great amounts of detail, however for the majority of situations and assuming you have a good set of base images, the software will pretty much take care of everything making the whole process relatively simple.  I perform all my stitching using Photoshop, although there are a number of alternatives that work in a similar way and give just as good results.   Here is my typical stitching workflow:

  1. Open Photoshop
  2. Select File > Automate > Photomerge
  3. Click 'Browse' and select the images to be stitched.
  4. Ensure that the 'Blend Images' option is selected.
  5. Click OK to start the stitching process (be warned it can take some time).

Basic Pano Workflow

In most situations it should be possible to get a decent panorama without too much manual intervention however there is always the potential for errors or other 'unusual results'.  My general approach in this situation is to experiment by trialing the various perspective modes and toggling the 'Geometric Distortion' option on and off.  In certain situations it can be the case that one or two of the images have trouble meshing, a way around this can be to try stitching the sequence in smaller batches, picking the problematic images first and then stitching these with the remaining images afterwards.  Other tactics for overcoming errors include cropping each image to achieve the optimum overlap or using cloning and patching to correct any minor glitches.

Once the final panorama has been generated, it's a simple case of cropping to remove the resulting curvature from the image edges and then applying any further post processing to achieve the desired look.

Things to Remember When Shooting Panoramic Photography

Whilst it can seem like there is a lot to remember when attempting panoramic photography, actually the basics are fairly simple:

  • Meter and focus for the scene, locking off all your camera settings to prevent changes between shots.
  • Keep your shots sharp by using a fast shutter speed and using a tripod if possible although hand holding is also fine.
  • Shoot in portrait to minimize distortion.
  • Overlap each shot by about 20-30%.

Conclusions

Taking decent panoramic images can be an extremely rewarding skill to master and one that doesn't necessarily need a lot of equipment to be successful.  Once you have gotten to grips with the set up and technique, producing impressive panoramas can be very achievable and unlocks a wide new world of creative opportunities.  As a technique for beginners or photographers wanting to try something different its a must, so if you have ever fancied panoramic photography why not expand your horizons and give it a try.

Post originally from: Digital Photography Tips.

Check out our more Photography Tips at Photography Tips for Beginners, Portrait Photography Tips and Wedding Photography Tips.

Getting Started in Panoramic Photography


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