Nikon's Virtual Horizon: Two Great Ways to Use It
Nikon’s Virtual Horizon (VH), a feature in many of their newest DSLRs, is a great tool that I absolutely love to incorporate in my shooting techniques.
While most of us might be familiar with how this feature works, there is a way to set it up in your camera that makes it instantly available and can seriously cut down the time it takes to frame the scene level when you are shooting. Moreover, I’ve been using a new way of shooting panoramas with Virtual Horizon that in many cases has eliminated the need for all that extra panorama equipment, the tedious exercise of finding the lens center point (nodal point), and having to precisely level the camera on your tripod. As long as your tripod is reasonably level you can incorporate this new technique and get easy stitches every time.
HOW TO USE VIRTUAL HORIZON EFFICIENTLY
This is an easy set-up, but your camera must have the Virtual Horizon tool and it must have the programmable Function (Fn) button. Here is how I set up my Nikon D810 so that I can access VH instantly and view it through the viewfinder.
Virtual Horizon Viewed in the Viewfinder
- Bring up the Camera Menu and under the CUSTOM SETTINGS MENU go to “f Controls”. Scroll down to “f4 - Assign Fn button”. Press the right arrow button once. You will now see a list of functions available. Select “Viewfinder virtual horizon”. Press the OK button.
- Your function button is now set to show the virtual horizon tool in the viewfinder. To access it simply press the function button once. In the viewfinder you should now see two scales – one running left-to-right on the bottom of the screen, and on the right side of the screen you should see the same scale running from top-to-bottom. To turn off the virtual horizon press the function button once.
Since the function button is located just under the Depth of Field (DOF) button it is really easy to call up the Virtual Horizon feature without even having to take your eye off the viewfinder. Here is an example of what you will see in the viewfinder when VH is active.
Viewfinder of Nikon D810 with Virtual Horizon Indicators
Notice the scales at the bottom and at the right. Now, in reality, it will not look like this. If the camera is not dead-level you will see the center line for each indicator and graduations in the form of those small upright rectangles in the direction which the camera is tilted on either axis. The more the rectangles the more the camera is tilted away from level. If the camera is level you will only see the center line and a small arrow point under it. Just to be clear, the scale at the bottom indicates camera roll from side to side. The scale on the right shows camera pitch up or down. One thing to remember when leveling the camera is that you always want to roll or pitch the camera in the direction of the stacked graduations. So, if you see several rectangles on the right side of the center of the scale on the bottom you must roll the camera to the right to center it. The same for the up and down pitch indicator. Rectangles above the center line - tilt the camera up.
I hope you can now see how convenient this set up is. Before I had a camera with this feature I would spend a lot of time setting up my framing, and trying, sometimes desperately in fading light, to get the camera level. It is difficult enough trying to find a shooting situation that works aesthetically, positioning yourself, dialing in critical focus, adjusting filters, evaluating exposure, and then, on top of that, making sure your camera is not askew. I am not one who is keen on throwing away valuable pixels because of framing errors, so straightening and cropping an image in post is always something I want to avoid.
USING VIRTUAL HORIZON TO SHOOT PANORAMICS
Single Row Panorama of the Battery Point Lighthouse - California
I started shooting digital panoramic images way back in 2003 using a Nikon Coolpix 5700. Over the years I’ve not only moved on to using DSLRs but I’ve acquired quite a few pieces of tripod equipment and lenses to help me get more successful series of panned images to stitch back at home on my PC. In those years I’ve also learned a few things through my mistakes. And if there is one truth in this world it is that the more complicated your processes are the more you will be prone to mistakes. Human error is the great equalizer.
While I still enjoy shooting single-row or two-row panos with wide angle lenses, my favorite being my set of 28 mm and 35 mm PC-Nikkor shift lenses, I more than likely will be using a mid-telephoto to shoot a lot of them these days. I have found that the Nikkor 70-200 mm f/4 is a great light and compact lens for this. While I rarely crank this lens up to 200 mm for this type of shooting I do get excellent results at anywhere between 70 and 150 mm. Obviously, at these focal lengths you have to make sure you aren’t too close to the main subject, but herein lies the secret to this method. When shooting panoramas at longer distances it is highly unlikely that you will have close in objects that will distort from frame to frame due to parallax or barrel distortion of the lens. This, of course, makes stitching images shot at longer distances very easy. Plus, you do not necessarily need to go to the trouble of finding the entrance pupil (nodal point) of the lens at the focal length you are shooting. This is a big convenience in my estimation. Finally, by using Virtual Horizon in the viewfinder in a clever way you won’t even have to be precise about leveling your tripod legs and panning head, and you won’t even need a camera hot shoe level. So, if you hate thinking about having to carry around a panning clamp, a separate bubble level, a rail, and having to set all this equipment up every time you see a beautiful wide panorama give this method a try.
The first thing you need to do is to assign Virtual Horizon to your camera function button as described above in the first section of this article. When you are ready to begin shooting set up your tripod so that it is reasonably level - it does not have to be perfect for this technique. I also prefer to use my 70-200 mm lens with the lens collar attached to my ball head clamp. This will make rotating (rolling) the camera and lens unit easier, which is a key element to this technique. I like to go through a dry run by looking through the viewfinder, setting the right focal length for the situation, and then panning the camera using the rotating base of my ball head counting the number of frames I want to shoot. I rarely shoot more than four frames for a standard single row panorama.
Frame 1 - Battery Lighthouse Panorama
Here is frame 1 of the panorama shown at the beginning of this section and will serve as my example. In this configuration this is the first frame of a three-frame pan going from left to right. Notice that I have leveled the camera using Virtual Horizon. You can see this as the arrow points are visible directly under the level indicators for both roll and pitch. Once this is set up I’ll adjust the zoom a final time if necessary, focus, and correct exposure. Remember when shooting panoramas use Aperture priority, turn off Auto White Balance, and do not change focus or zoom throughout the series.
Let’s now move on to the next frame. Before I pan the camera using the rotating base of the ball head, I’ll make note of where the right side gridline falls in relation to the scene and make a mental note of this position. When I pan the camera I will want to set the left side gridline exactly in the same spot. This gives me roughly about 25% overlap from frame-to-frame, more than enough space to stitch them together later. Let’s pan!
Frame 2 - Battery Lighthouse Panorama
Take a close look at the Virtual Horizon indicators now. What happened?! If you read the indicators you will notice that the camera during the panning has rolled down to the right and pitched downward. This is the natural effect of panning a camera that is not perfectly level. But that’s okay; Virtual Horizon is here to save the day. All I have to do here is reposition the camera by first loosening the lens collar and rolling the camera to the left. Remember: to correct an out of level camera using the indicators in the viewfinder you must adjust the camera in the direction of the indicators. Once you have that level again and the arrow point reappears, you can now loosen the ball head and carefully pitch the camera upward until it is level in this orientation. While you are doing this correction it is important to keep an eye on both the location of the right gridline in relation to the scene and the roll indicator. You do not want to change the position of the camera frame and you don’t want to un-level the roll position you have already corrected. Repeat this process of panning and re-acquiring your level positions using the VH tool in the viewfinder for each frame.
Frame 2 - Leveled Using Virtual Horizon
That’s all there is to it. No need for rails and special clamps, or time wasted trying to perfectly level your rig. This technique may not work in ALL situations but I’ve been using it more and more often and have yet to come home with a pano series that would not line up and stitch seamlessly with minimal effort.
So, does this mean that if you use this method you will be stuck with shooting panoramas with the camera parallel to the ground all the time? What if the framing requires that you pitch the camera up or down slightly to get the ideal perspective? Well, I thought about that one day when I was faced with just such a situation. My solution is pretty simple, and here it is. If you need to have some amount of pitch in your camera position all you need to do is count the number of upright rectangles on the right side indicator scale. Let’s take the illustration of “Frame 2 – Battery Lighthouse Panorama”. Let’s say that for this explanation the bottom indicator is level but the camera is pitched upward slightly because this makes for a better composition. Since you want to maintain this slight pitch you’ll have to account for this for each pan in the series. In this case simply use this position as the constant. Count the number of rectangles above the center line and maintain this for each panned frame. Here you’ll want to adjust the camera so that three rectangles appear above the center position each time you take a frame. If you like to shoot 2-row horizontal panoramas you can use this approach on the series of the second row of frames. In case you are wondering, you can also use Virtual Horizon in Live View. Instead of using the Function button activate Live View and then press the Info button cycling through until VH comes up in the rear LCD. You should be able to use it in the same general way.
When I first saw the Virtual Horizon debut in the D3 I was impressed, but I wondered how useful it would be. Today, I could not live without it. It has really made me a much more efficient photographer. I don’t spend much time anymore obsessing that my camera is level; and when I want to shoot a quick panorama I don’t have to dig into my camera bag trying to find all kinds of accessories. Best of all, if I set it up for use in the viewfinder, I don’t have to take my eye off the image making me lose my concentration. If you have a Nikon DSLR camera and a fixed, or zoom, mid-telephoto lens give this technique a try.