Hi All,
Another forum member asked me for some advice about the X5 and what to expect. While I don't have one I do have extensive experience with large sensors, aperture and focus challenges so thought I'd throw in my 2¢ on the subject. Hopefully it will help prepare you for the challenges and great rewards to come.
Again, I don't have an X5 so I can't help with calibration or specific questions. This is all just foundational info on shooting with full control, which the X5 now allows.
Enjoy!
Jim
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The X5 brings the Inspire 1 further into the world of professional photography, where you can no longer point and shoot. With this additional power there are now more ways to create a terrible image than a good one so you need to know what you're working with.
This is frustrating because when you spend a lot of money you expect all your results will be superior but this isn’t the case. You will take many shots that look horrible compared to the X3, making some people feel they received defective cameras.
The most significant improvement is interchangable superior lenses. A better lens gives you much more power which does allow for much much better results, but just as it’s relatively easy to drive a car but impossible for most of us to drive a 747, you need to know how to wield the new power or you will crash and burn.
The X3 is pretty easy to use as you just point it in the right direction and as long as the image isn’t grossly over or underexposed you are going to get a decent image This is because three of the main adjustable components, focal length, focus and aperture, are fixed.
So what are focal lengths? Easiest way to understand them is how “zoomed in” or “zoomed out” the lens is. Measured in millimetres, it determines the field of view the lens sees. Wide lenses, such as the X3, show a great deal in the frame where long lenses are quite tight.
The focal length also determines the character of the image. Wide lenses create an almost bending quality where you feel like you are close to an object but can somehow see more than you would expect. Long lenses are the opposite, they feel more intimate and straight, making you feel like your subject is the only thing in the world. This goes far beyond what is physically shown in the frame, it affects how you perceive it as well.
Another thing different focal lengths affect is depth of field, which is basically how much of the image is in focus. With a shallow depth of field your subject will be in focus but everything in front or behind it will be increasingly out of focus. The longer your lens, the shallower the depth of field. Take the X3for instance. It has a very wide focal length which makes everything sharp, regardless of where it is in the frame and is so wide it completely removes the requirement to focus at all. But with the X5, longer focal lengths will require much more attention to these aspects, as focus will become a very real issue.
So choosing the right focal length for a shot and shooting conditions (single or dual control) is crucial.
While speaking of depth of field, the second aspect the X5 allows for is variable aperture. Aperture refers to the iris of the lens itself. This works the same way as your eye. If there is too much light the iris of your eye will close, and in low light it opens very wide. But light isn’t the only thing the aperture controls, it also affects depth of field. When you open the aperture by reducing the number (f/1.7) it also reduces the depth of field. When you close the aperture to f/5.6 or f/8 it expands the depth of field and makes it easier to focus to infinity. Think of squinting your eyes to make things clearer, it’s the exact same thing.
Okay, so we’re getting there. Focal length determines how tight or wide the image is, along with adding character, and aperture controls how much light comes in, and both affect depth of field, which is how much of your image is in focus. So let’s review and add it to what we already know.
Shutter speed is of course how many times per second the shutter opens and closes per second. This is another way to control light but the shutter has a big effect on the final image. Put the shutter to high and you will get a stuttered effect where every frame is ultra sharp. A high shutter will also exaggerate rolling shutter known as the jello effect. Too slow a shutter will give a lot of motion blur and aesthetically look like cheap video. In feature films, the shutter speed of choice is exactly double the frame rate. This is known as a 180° shutter as film cameras used a shutter that was literally measured in the circular degrees the shutter obstructed.
So if you are shooting 24 frames per second the shutter speed would be 48.
With the X3, since we couldn’t control aperture, it’s fixed at f/2.8, if you were already at 100IS) (lowest light sensitivity) the only other way to control light without changing the shutter was to add ND filters. The ND filters act like sunglasses and reduce the light, allowing you to get the shutter close to the correct number.
But with the X5 we can now control the aperture, so we can just raise it up to balance the shutter. So instead of f/2.8 we can raise it f/16 or even f/22 depending on the lens. But as you read above, this will also affect your depth of field so you need to be careful you are getting the right effect. It might be that you are shooting on a bright day but still want a shallow depth of field. In this case you would still put an ND filter on, set the shutter to double your frame rate, and set the aperture to a low number like f/2.8 or f/1.7.
So as you can start to see, your perfect image is a well thought out combination of all these things.
Focus. Okay, focus can be a nightmare. It’s the easiest way to ruin a beautiful shot. For this reason someone just starting out is best to use the highest aperture possible to keep the iris closed. In extreme conditions with a low (open) aperture, the depth of field can be as shallow as 1/2 inch. This means if you were filming someone’s face their eyes would be sharp in focus but the tip of their nose would out of focus. Imagine trying to determine what’s in focus using an iPhone screen while your Inspire is 1/2 mile away! The challenges are massive and expect to make some big mistakes in the early days. You will quickly learn how the lens reacts and where infinity sits. But in general, the larger the screen you are using to determine focus the better.
Finally, I just wanted to touch on the difference in sensor size. Many are surprised to hear and baffled at the concept that sensor size also affects depth of field. Crazy right? The bigger the sensor you have the shallower the depth of field. To illustrate this let’s compare sensor sizes of the X3 and X5. The X3uses a 6.17 x 4.55mm sensor and the X5 is 3x larger, 17.3x13.00mm so you will need a much longer lens to cover the same field of view. The longer the lens the shallower the depth of field and voilà!
Feel free to ask for clarification for any of this. Again, it's more general than X5 specific.
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